1781 THE CRITIQUE OF PURE REASON by Immanuel Kant

translated by J. M. D. Meiklejohn
PREFACE TO THE FIRST EDITION, 1781

Human reason, in one sphere of its cognition, is called upon to
consider questions, which it cannot decline, as they are presented
by its own nature, but which it cannot answer, as they transcend every
faculty of the mind.
It falls into this difficulty without any fault of its own. It
begins with principles, which cannot be dispensed with in the field of
experience, and the truth and sufficiency of which are, at the same
time, insured by experience. With these principles it rises, in
obedience to the laws of its own nature, to ever higher and more
remote conditions. But it quickly discovers that, in this way, its
labours must remain ever incomplete, because new questions never cease
to present themselves; and thus it finds itself compelled to have
recourse to principles which transcend the region of experience, while
they are regarded by common sense without distrust. It thus falls into
confusion and contradictions, from which it conjectures the presence
of latent errors, which, however, it is unable to discover, because
the principles it employs, transcending the limits of experience,
cannot be tested by that criterion. The arena of these endless
contests is called Metaphysic.
Time was, when she was the queen of all the sciences; and, if we
take the will for the deed, she certainly deserves, so far as
regards the high importance of her object-matter, this title of
honour. Now, it is the fashion of the time to heap contempt and
scorn upon her; and the matron mourns, forlorn and forsaken, like
Hecuba:

Modo maxima rerum,
Tot generis, natisque potens...
Nunc trahor exul, inops.*

*Ovid, Metamorphoses. [xiii, "But late on the pinnacle of fame,
strong in my many sons. now exiled, penniless."]

At first, her government, under the administration of the
dogmatists, was an absolute despotism. But, as the legislative
continued to show traces of the ancient barbaric rule, her empire
gradually broke up, and intestine wars introduced the reign of
anarchy; while the sceptics, like nomadic tribes, who hate a permanent
habitation and settled mode of living, attacked from time to time
those who had organized themselves into civil communities. But their
number was, very happily, small; and thus they could not entirely
put a stop to the exertions of those who persisted in raising new
edifices, although on no settled or uniform plan. In recent times
the hope dawned upon us of seeing those disputes settled, and the
legitimacy of her claims established by a kind of physiology of the
human understanding- that of the celebrated Locke. But it was found
that- although it was affirmed that this so-called queen could not
refer her descent to any higher source than that of common experience,
a circumstance which necessarily brought suspicion on her claims- as
this genealogy was incorrect, she persisted in the advancement of
her claims to sovereignty. Thus metaphysics necessarily fell back into
the antiquated and rotten constitution of dogmatism, and again
became obnoxious to the contempt from which efforts had been made to
save it. At present, as all methods, according to the general
persuasion, have been tried in vain, there reigns nought but weariness
and complete indifferentism- the mother of chaos and night in the
scientific world, but at the same time the source of, or at least
the prelude to, the re-creation and reinstallation of a science,
when it has fallen into confusion, obscurity, and disuse from ill
directed effort.
For it is in reality vain to profess indifference in regard to
such inquiries, the object of which cannot be indifferent to humanity.
Besides, these pretended indifferentists, however much they may try to
disguise themselves by the assumption of a popular style and by
changes on the language of the schools, unavoidably fall into
metaphysical declarations and propositions, which they profess to
regard with so much contempt. At the same time, this indifference,
which has arisen in the world of science, and which relates to that
kind of knowledge which we should wish to see destroyed the last, is a
phenomenon that well deserves our attention and reflection. It is
plainly not the effect of the levity, but of the matured judgement* of
the age, which refuses to be any longer entertained with illusory
knowledge, It is, in fact, a call to reason, again to undertake the
most laborious of all tasks- that of self-examination- and to
establish a tribunal, which may secure it in its well-grounded claims,
while it pronounces against all baseless assumptions and
pretensions, not in an arbitrary manner, but according to its own
eternal and unchangeable laws. This tribunal is nothing less than
the critical investigation of pure reason.

*We very often hear complaints of the shallowness of the present
age, and of the decay of profound science. But I do not think that
those which rest upon a secure foundation, such as mathematics,
physical science, etc., in the least deserve this reproach, but that
they rather maintain their ancient fame, and in the latter case,
indeed, far surpass it. The same would be the case with the other
kinds of cognition, if their principles were but firmly established.
In the absence of this security, indifference, doubt, and finally,
severe criticism are rather signs of a profound habit of thought.
Our age is the age of criticism, to which everything must be
subjected. The sacredness of religion, and the authority of
legislation, are by many regarded as grounds of exemption from the
examination of this tribunal. But, if they on they are exempted,
they become the subjects of just suspicion, and cannot lay claim to
sincere respect, which reason accords only to that which has stood the
test of a free and public examination.

I do not mean by this a criticism of books and systems, but a
critical inquiry into the faculty of reason, with reference to the
cognitions to which it strives to attain without the aid of
experience; in other words, the solution of the question regarding the
possibility or impossibility of metaphysics, and the determination
of the origin, as well as of the extent and limits of this science.
All this must be done on the basis of principles.
This path- the only one now remaining- has been entered upon by
me; and I flatter myself that I have, in this way, discovered the
cause of- and consequently the mode of removing- all the errors
which have hitherto set reason at variance with itself, in the
sphere of non-empirical thought. I have not returned an evasive answer
to the questions of reason, by alleging the inability and limitation
of the faculties of the mind; I have, on the contrary, examined them
completely in the light of principles, and, after having discovered
the cause of the doubts and contradictions into which reason fell,
have solved them to its perfect satisfaction. It is true, these
questions have not been solved as dogmatism, in its vain fancies and
desires, had expected; for it can only be satisfied by the exercise of
magical arts, and of these I have no knowledge. But neither do these
come within the compass of our mental powers; and it was the duty of
philosophy to destroy the illusions which had their origin in
misconceptions, whatever darling hopes and valued expectations may
be ruined by its explanations. My chief aim in this work has been
thoroughness; and I make bold to say that there is not a single
metaphysical problem that does not find its solution, or at least
the key to its solution, here. Pure reason is a perfect unity; and
therefore, if the if the principle presented by it prove to be
insufficient for the solution of even a single one of those
questions to which the very nature of reason gives birth, we must
reject it, as we could not be perfectly certain of its sufficiency
in the case of the others.
While I say this, I think I see upon the countenance of the reader
signs of dissatisfaction mingled with contempt, when he hears
declarations which sound so boastful and extravagant; and yet they are
beyond comparison more moderate than those advanced by the commonest
author of the commonest philosophical programme, in which the
dogmatist professes to demonstrate the simple nature of the soul, or
the necessity of a primal being. Such a dogmatist promises to extend
human knowledge beyond the limits of possible experience; while I
humbly confess that this is completely beyond my power. Instead of any
such attempt, I confine myself to the examination of reason alone
and its pure thought; and I do not need to seek far for the
sum-total of its cognition, because it has its seat in my own mind.
Besides, common logic presents me with a complete and systematic
catalogue of all the simple operations of reason; and it is my task to
answer the question how far reason can go, without the material
presented and the aid furnished by experience.
So much for the completeness and thoroughness necessary in the
execution of the present task. The aims set before us are not
arbitrarily proposed, but are imposed upon us by the nature of
cognition itself.
The above remarks relate to the matter of our critical inquiry. As
regards the form, there are two indispensable conditions, which any
one who undertakes so difficult a task as that of a critique of pure
reason, is bound to fulfil. These conditions are certitude and
clearness.
As regards certitude, I have fully convinced myself that, in this
sphere of thought, opinion is perfectly inadmissible, and that
everything which bears the least semblance of an hypothesis must be
excluded, as of no value in such discussions. For it is a necessary
condition of every cognition that is to be established upon a priori
grounds that it shall be held to be absolutely necessary; much more is
this the case with an attempt to determine all pure a priori
cognition, and to furnish the standard- and consequently an example-
of all apodeictic (philosophical) certitude. Whether I have
succeeded in what I professed to do, it is for the reader to
determine; it is the author's business merely to adduce grounds and
reasons, without determining what influence these ought to have on the
mind of his judges. But, lest anything he may have said may become the
innocent cause of doubt in their minds, or tend to weaken the effect
which his arguments might otherwise produce- he may be allowed to
point out those passages which may occasion mistrust or difficulty,
although these do not concern the main purpose of the present work. He
does this solely with the view of removing from the mind of the reader
any doubts which might affect his judgement of the work as a whole,
and in regard to its ultimate aim.
I know no investigations more necessary for a full insight into
the nature of the faculty which we call understanding, and at the same
time for the determination of the rules and limits of its use, than
those undertaken in the second chapter of the "Transcendental
Analytic," under the title of "Deduction of the Pure Conceptions of
the Understanding"; and they have also cost me by far the greatest
labour- labour which, I hope, will not remain uncompensated. The
view there taken, which goes somewhat deeply into the subject, has two
sides, The one relates to the objects of the pure understanding, and
is intended to demonstrate and to render comprehensible the
objective validity of its a priori conceptions; and it forms for
this reason an essential part of the Critique. The other considers the
pure understanding itself, its possibility and its powers of
cognition- that is, from a subjective point of view; and, although
this exposition is of great importance, it does not belong essentially
to the main purpose of the work, because the grand question is what
and how much can reason and understanding, apart from experience,
cognize, and not, how is the faculty of thought itself possible? As
the latter is an, inquiry into the cause of a given effect, and has
thus in it some semblance of an hypothesis (although, as I shall
show on another occasion, this is really not the fact), it would
seem that, in the present instance, I had allowed myself to enounce
a mere opinion, and that the reader must therefore be at liberty to
hold a different opinion. But I beg to remind him that, if my
subjective deduction does not produce in his mind the conviction of
its certitude at which I aimed, the objective deduction, with which
alone the present work is properly concerned, is in every respect
satisfactory.
As regards clearness, the reader has a right to demand, in the first
place, discursive or logical clearness, that is, on the basis of
conceptions, and, secondly, intuitive or aesthetic clearness, by means
of intuitions, that is, by examples or other modes of illustration
in concreto. I have done what I could for the first kind of
intelligibility. This was essential to my purpose; and it thus
became the accidental cause of my inability to do complete justice
to the second requirement. I have been almost always at a loss, during
the progress of this work, how to settle this question. Examples and
illustrations always appeared to me necessary, and, in the first
sketch of the Critique, naturally fell into their proper places. But I
very soon became aware of the magnitude of my task, and the numerous
problems with which I should be engaged; and, as I perceived that this
critical investigation would, even if delivered in the driest
scholastic manner, be far from being brief, I found it unadvisable
to enlarge it still more with examples and explanations, which are
necessary only from a popular point of view. I was induced to take
this course from the consideration also that the present work is not
intended for popular use, that those devoted to science do not require
such helps, although they are always acceptable, and that they would
have materially interfered with my present purpose. Abbe Terrasson
remarks with great justice that, if we estimate the size of a work,
not from the number of its pages, but from the time which we require
to make ourselves master of it, it may be said of many a book that
it would be much shorter, if it were not so short. On the other
hand, as regards the comprehensibility of a system of speculative
cognition, connected under a single principle, we may say with equal
justice: many a book would have been much clearer, if it had not
been intended to be so very clear. For explanations and examples,
and other helps to intelligibility, aid us in the comprehension of
parts, but they distract the attention, dissipate the mental power
of the reader, and stand in the way of his forming a clear
conception of the whole; as he cannot attain soon enough to a survey
of the system, and the colouring and embellishments bestowed upon it
prevent his observing its articulation or organization- which is the
most important consideration with him, when he comes to judge of its
unity and stability.
The reader must naturally have a strong inducement to co-operate
with the present author, if he has formed the intention of erecting
a complete and solid edifice of metaphysical science, according to the
plan now laid before him. Metaphysics, as here represented, is the
only science which admits of completion- and with little labour, if it
is united, in a short time; so that nothing will be left to future
generations except the task of illustrating and applying it
didactically. For this science is nothing more than the inventory of
all that is given us by pure reason, systematically arranged.
Nothing can escape our notice; for what reason produces from itself
cannot lie concealed, but must be brought to the light by reason
itself, so soon as we have discovered the common principle of the
ideas we seek. The perfect unity of this kind of cognitions, which are
based upon pure conceptions, and uninfluenced by any empirical
element, or any peculiar intuition leading to determinate
experience, renders this completeness not only practicable, but also
necessary.

Tecum habita, et noris quam sit tibi curta supellex.*

*Persius. [Satirae iv. 52. "Dwell with yourself, and you will know
how short your household stuff is."

Such a system of pure speculative reason I hope to be able to
publish under the title of Metaphysic of Nature. The content of this
work (which will not be half so long) will be very much richer than
that of the present Critique, which has to discover the sources of
this cognition and expose the conditions of its possibility, and at
the same time to clear and level a fit foundation for the scientific
edifice. In the present work, I look for the patient hearing and the
impartiality of a judge; in the other, for the good-will and
assistance of a co-labourer. For, however complete the list of
principles for this system may be in the Critique, the correctness
of the system requires that no deduced conceptions should be absent.
These cannot be presented a priori, but must be gradually
discovered; and, while the synthesis of conceptions has been fully
exhausted in the Critique, it is necessary that, in the proposed work,
the same should be the case with their analysis. But this will be
rather an amusement than a labour.
PREFACE TO THE SECOND EDITION, 1787

Whether the treatment of that portion of our knowledge which lies
within the province of pure reason advances with that undeviating
certainty which characterizes the progress of science, we shall be
at no loss to determine. If we find those who are engaged in
metaphysical pursuits, unable to come to an understanding as to the
method which they ought to follow; if we find them, after the most
elaborate preparations, invariably brought to a stand before the
goal is reached, and compelled to retrace their steps and strike
into fresh paths, we may then feel quite sure that they are far from
having attained to the certainty of scientific progress and may rather
be said to be merely groping about in the dark. In these circumstances
we shall render an important service to reason if we succeed in simply
indicating the path along which it must travel, in order to arrive
at any results- even if it should be found necessary to abandon many
of those aims which, without reflection, have been proposed for its
attainment.
That logic has advanced in this sure course, even from the
earliest times, is apparent from the fact that, since Aristotle, it
has been unable to advance a step and, thus, to all appearance has
reached its completion. For, if some of the moderns have thought to
enlarge its domain by introducing psychological discussions on the
mental faculties, such as imagination and wit, metaphysical,
discussions on the origin of knowledge and the different kinds of
certitude, according to the difference of the objects (idealism,
scepticism, and so on), or anthropological discussions on
prejudices, their causes and remedies: this attempt, on the part of
these authors, only shows their ignorance of the peculiar nature of
logical science. We do not enlarge but disfigure the sciences when
we lose sight of their respective limits and allow them to run into
one another. Now logic is enclosed within limits which admit of
perfectly clear definition; it is a science which has for its object
nothing but the exposition and proof of the formal laws of all
thought, whether it be a priori or empirical, whatever be its origin
or its object, and whatever the difficulties- natural or accidental-
which it encounters in the human mind.
The early success of logic must be attributed exclusively to the
narrowness of its field, in which abstraction may, or rather must,
be made of all the objects of cognition with their characteristic
distinctions, and in which the understanding has only to deal with
itself and with its own forms. It is, obviously, a much more difficult
task for reason to strike into the sure path of science, where it
has to deal not simply with itself, but with objects external to
itself. Hence, logic is properly only a propaedeutic- forms, as it
were, the vestibule of the sciences; and while it is necessary to
enable us to form a correct judgement with regard to the various
branches of knowledge, still the acquisition of real, substantive
knowledge is to be sought only in the sciences properly so called,
that is, in the objective sciences.
Now these sciences, if they can be termed rational at all, must
contain elements of a priori cognition, and this cognition may stand
in a twofold relation to its object. Either it may have to determine
the conception of the object- which must be supplied extraneously,
or it may have to establish its reality. The former is theoretical,
the latter practical, rational cognition. In both, the pure or a
priori element must be treated first, and must be carefully
distinguished from that which is supplied from other sources. Any
other method can only lead to irremediable confusion.
Mathematics and physics are the two theoretical sciences which
have to determine their objects a priori. The former is purely a
priori, the latter is partially so, but is also dependent on other
sources of cognition.
In the earliest times of which history affords us any record,
mathematics had already entered on the sure course of science, among
that wonderful nation, the Greeks. Still it is not to be supposed that
it was as easy for this science to strike into, or rather to construct
for itself, that royal road, as it was for logic, in which reason
has only to deal with itself. On the contrary, I believe that it
must have remained long- chiefly among the Egyptians- in the stage
of blind groping after its true aims and destination, and that it
was revolutionized by the happy idea of one man, who struck out and
determined for all time the path which this science must follow, and
which admits of an indefinite advancement. The history of this
intellectual revolution- much more important in its results than the
discovery of the passage round the celebrated Cape of Good Hope- and
of its author, has not been preserved. But Diogenes Laertius, in
naming the supposed discoverer of some of the simplest elements of
geometrical demonstration- elements which, according to the ordinary
opinion, do not even require to be proved- makes it apparent that
the change introduced by the first indication of this new path, must
have seemed of the utmost importance to the mathematicians of that
age, and it has thus been secured against the chance of oblivion. A
new light must have flashed on the mind of the first man (Thales, or
whatever may have been his name) who demonstrated the properties of
the isosceles triangle. For he found that it was not sufficient to
meditate on the figure, as it lay before his eyes, or the conception
of it, as it existed in his mind, and thus endeavour to get at the
knowledge of its properties, but that it was necessary to produce
these properties, as it were, by a positive a priori construction; and
that, in order to arrive with certainty at a priori cognition, he must
not attribute to the object any other properties than those which
necessarily followed from that which he had himself, in accordance
with his conception, placed in the object.
A much longer period elapsed before physics entered on the highway
of science. For it is only about a century and a half since the wise
Bacon gave a new direction to physical studies, or rather- as others
were already on the right track- imparted fresh vigour to the
pursuit of this new direction. Here, too, as in the case of
mathematics, we find evidence of a rapid intellectual revolution. In
the remarks which follow I shall confine myself to the empirical
side of natural science.
When Galilei experimented with balls of a definite weight on the
inclined plane, when Torricelli caused the air to sustain a weight
which he had calculated beforehand to be equal to that of a definite
column of water, or when Stahl, at a later period, converted metals
into lime, and reconverted lime into metal, by the addition and
subtraction of certain elements;* a light broke upon all natural
philosophers. They learned that reason only perceives that which it
produces after its own design; that it must not be content to
follow, as it were, in the leading-strings of nature, but must proceed
in advance with principles of judgement according to unvarying laws,
and compel nature to reply its questions. For accidental observations,
made according to no preconceived plan, cannot be united under a
necessary law. But it is this that reason seeks for and requires. It
is only the principles of reason which can give to concordant
phenomena the validity of laws, and it is only when experiment is
directed by these rational principles that it can have any real
utility. Reason must approach nature with the view, indeed, of
receiving information from it, not, however, in the character of a
pupil, who listens to all that his master chooses to tell him, but
in that of a judge, who compels the witnesses to reply to those
questions which he himself thinks fit to propose. To this single
idea must the revolution be ascribed, by which, after groping in the
dark for so many centuries, natural science was at length conducted
into the path of certain progress.

*I do not here follow with exactness the history of the experimental
method, of which, indeed, the first steps are involved in some
obscurity.

We come now to metaphysics, a purely speculative science, which
occupies a completely isolated position and is entirely independent of
the teachings of experience. It deals with mere conceptions- not, like
mathematics, with conceptions applied to intuition- and in it,
reason is the pupil of itself alone. It is the oldest of the sciences,
and would still survive, even if all the rest were swallowed up in the
abyss of an all-destroying barbarism. But it has not yet had the
good fortune to attain to the sure scientific method. This will be
apparent; if we apply the tests which we proposed at the outset. We
find that reason perpetually comes to a stand, when it attempts to
gain a priori the perception even of those laws which the most
common experience confirms. We find it compelled to retrace its
steps in innumerable instances, and to abandon the path on which it
had entered, because this does not lead to the desired result. We
find, too, that those who are engaged in metaphysical pursuits are far
from being able to agree among themselves, but that, on the
contrary, this science appears to furnish an arena specially adapted
for the display of skill or the exercise of strength in mock-contests-
a field in which no combatant ever yet succeeded in gaining an inch of
ground, in which, at least, no victory was ever yet crowned with
permanent possession.
This leads us to inquire why it is that, in metaphysics, the sure
path of science has not hitherto been found. Shall we suppose that
it is impossible to discover it? Why then should nature have visited
our reason with restless aspirations after it, as if it were one of
our weightiest concerns? Nay, more, how little cause should we have to
place confidence in our reason, if it abandons us in a matter about
which, most of all, we desire to know the truth- and not only so,
but even allures us to the pursuit of vain phantoms, only to betray us
in the end? Or, if the path has only hitherto been missed, what
indications do we possess to guide us in a renewed investigation,
and to enable us to hope for greater success than has fallen to the
lot of our predecessors?
It appears to me that the examples of mathematics and natural
philosophy, which, as we have seen, were brought into their present
condition by a sudden revolution, are sufficiently remarkable to fix
our attention on the essential circumstances of the change which has
proved so advantageous to them, and to induce us to make the
experiment of imitating them, so far as the analogy which, as rational
sciences, they bear to metaphysics may permit. It has hitherto been
assumed that our cognition must conform to the objects; but all
attempts to ascertain anything about these objects a priori, by
means of conceptions, and thus to extend the range of our knowledge,
have been rendered abortive by this assumption. Let us then make the
experiment whether we may not be more successful in metaphysics, if we
assume that the objects must conform to our cognition. This appears,
at all events, to accord better with the possibility of our gaining
the end we have in view, that is to say, of arriving at the
cognition of objects a priori, of determining something with respect
to these objects, before they are given to us. We here propose to do
just what Copernicus did in attempting to explain the celestial
movements. When he found that he could make no progress by assuming
that all the heavenly bodies revolved round the spectator, he reversed
the process, and tried the experiment of assuming that the spectator
revolved, while the stars remained at rest. We may make the same
experiment with regard to the intuition of objects. If the intuition
must conform to the nature of the objects, I do not see how we can
know anything of them a priori. If, on the other hand, the object
conforms to the nature of our faculty of intuition, I can then
easily conceive the possibility of such an a priori knowledge. Now
as I cannot rest in the mere intuitions, but- if they are to become
cognitions- must refer them, as representations, to something, as
object, and must determine the latter by means of the former, here
again there are two courses open to me. Either, first, I may assume
that the conceptions, by which I effect this determination, conform to
the object- and in this case I am reduced to the same perplexity as
before; or secondly, I may assume that the objects, or, which is the
same thing, that experience, in which alone as given objects they
are cognized, conform to my conceptions- and then I am at no loss
how to proceed. For experience itself is a mode of cognition which
requires understanding. Before objects, are given to me, that is, a
priori, I must presuppose in myself laws of the understanding which
are expressed in conceptions a priori. To these conceptions, then, all
the objects of experience must necessarily conform. Now there are
objects which reason thinks, and that necessarily, but which cannot be
given in experience, or, at least, cannot be given so as reason thinks
them. The attempt to think these objects will hereafter furnish an
excellent test of the new method of thought which we have adopted, and
which is based on the principle that we only cognize in things a
priori that which we ourselves place in them.*

*This method, accordingly, which we have borrowed from the natural
philosopher, consists in seeking for the elements of pure reason in
that which admits of confirmation or refutation by experiment. Now the
propositions of pure reason, especially when they transcend the limits
of possible experience, do not admit of our making any experiment with
their objects, as in natural science. Hence, with regard to those
conceptions and principles which we assume a priori, our only course
ill be to view them from two different sides. We must regard one and
the same conception, on the one hand, in relation to experience as
an object of the senses and of the understanding, on the other hand,
in relation to reason, isolated and transcending the limits of
experience, as an object of mere thought. Now if we find that, when we
regard things from this double point of view, the result is in harmony
with the principle of pure reason, but that, when we regard them
from a single point of view, reason is involved in self-contradiction,
then the experiment will establish the correctness of this
distinction.

This attempt succeeds as well as we could desire, and promises to
metaphysics, in its first part- that is, where it is occupied with
conceptions a priori, of which the corresponding objects may be
given in experience- the certain course of science. For by this new
method we are enabled perfectly to explain the possibility of a priori
cognition, and, what is more, to demonstrate satisfactorily the laws
which lie a priori at the foundation of nature, as the sum of the
objects of experience- neither of which was possible according to
the procedure hitherto followed. But from this deduction of the
faculty of a priori cognition in the first part of metaphysics, we
derive a surprising result, and one which, to all appearance,
militates against the great end of metaphysics, as treated in the
second part. For we come to the conclusion that our faculty of
cognition is unable to transcend the limits of possible experience;
and yet this is precisely the most essential object of this science.
The estimate of our rational cognition a priori at which we arrive
is that it has only to do with phenomena, and that things in
themselves, while possessing a real existence, lie beyond its
sphere. Here we are enabled to put the justice of this estimate to the
test. For that which of necessity impels us to transcend the limits of
experience and of all phenomena is the unconditioned, which reason
absolutely requires in things as they are in themselves, in order to
complete the series of conditions. Now, if it appears that when, on
the one hand, we assume that our cognition conforms to its objects
as things in themselves, the unconditioned cannot be thought without
contradiction, and that when, on the other hand, we assume that our
representation of things as they are given to us, does not conform
to these things as they are in themselves, but that these objects,
as phenomena, conform to our mode of representation, the contradiction
disappears: we shall then be convinced of the truth of that which we
began by assuming for the sake of experiment; we may look upon it as
established that the unconditioned does not lie in things as we know
them, or as they are given to us, but in things as they are in
themselves, beyond the range of our cognition.*

*This experiment of pure reason has a great similarity to that of
the chemists, which they term the experiment of reduction, or, more
usually, the synthetic process. The analysis of the metaphysician
separates pure cognition a priori into two heterogeneous elements,
viz., the cognition of things as phenomena, and of things in
themselves. Dialectic combines these again into harmony with the
necessary rational idea of the unconditioned, and finds that this
harmony never results except through the above distinction, which
is, therefore, concluded to be just.

But, after we have thus denied the power of speculative reason to
make any progress in the sphere of the supersensible, it still remains
for our consideration whether data do not exist in practical cognition
which may enable us to determine the transcendent conception of the
unconditioned, to rise beyond the limits of all possible experience
from a practical point of view, and thus to satisfy the great ends
of metaphysics. Speculative reason has thus, at least, made room for
such an extension of our knowledge: and, if it must leave this space
vacant, still it does not rob us of the liberty to fill it up, if we
can, by means of practical data- nay, it even challenges us to make
the attempt.*

*So the central laws of the movements of the heavenly bodies
established the truth of that which Copernicus, first, assumed only as
a hypothesis, and, at the same time, brought to light that invisible
force (Newtonian attraction) which holds the universe together. The
latter would have remained forever undiscovered, if Copernicus had not
ventured on the experiment- contrary to the senses but still just-
of looking for the observed movements not in the heavenly bodies,
but in the spectator. In this Preface I treat the new metaphysical
method as a hypothesis with the view of rendering apparent the first
attempts at such a change of method, which are always hypothetical.
But in the Critique itself it will be demonstrated, not
hypothetically, but apodeictically, from the nature of our
representations of space and time. and from the elementary conceptions
of the understanding.

This attempt to introduce a complete revolution in the procedure
of metaphysics, after the example of the geometricians and natural
philosophers, constitutes the aim of the Critique of Pure
Speculative Reason. It is a treatise on the method to be followed, not
a system of the science itself. But, at the same time, it marks out
and defines both the external boundaries and the internal structure of
this science. For pure speculative reason has this peculiarity,
that, in choosing the various objects of thought, it is able to define
the limits of its own faculties, and even to give a complete
enumeration of the possible modes of proposing problems to itself, and
thus to sketch out the entire system of metaphysics. For, on the one
hand, in cognition a priori, nothing must be attributed to the objects
but what the thinking subject derives from itself; and, on the other
hand, reason is, in regard to the principles of cognition, a perfectly
distinct, independent unity, in which, as in an organized body,
every member exists for the sake of the others, and all for the sake
of each, so that no principle can be viewed, with safety, in one
relationship, unless it is, at the same time, viewed in relation to
the total use of pure reason. Hence, too, metaphysics has this
singular advantage- an advantage which falls to the lot of no other
science which has to do with objects- that, if once it is conducted
into the sure path of science, by means of this criticism, it can then
take in the whole sphere of its cognitions, and can thus complete
its work, and leave it for the use of posterity, as a capital which
can never receive fresh accessions. For metaphysics has to deal only
with principles and with the limitations of its own employment as
determined by these principles. To this perfection it is, therefore,
bound, as the fundamental science, to attain, and to it the maxim
may justly be applied:

Nil actum reputans, si quid superesset agendum.*

*"He considered nothing done, so long as anything remained to be
done."

But, it will be asked, what kind of a treasure is this that we
propose to bequeath to posterity? What is the real value of this
system of metaphysics, purified by criticism, and thereby reduced to a
permanent condition? A cursory view of the present work will lead to
the supposition that its use is merely negative, that it only serves
to warn us against venturing, with speculative reason, beyond the
limits of experience. This is, in fact, its primary use. But this,
at once, assumes a positive value, when we observe that the principles
with which speculative reason endeavours to transcend its limits
lead inevitably, not to the extension, but to the contraction of the
use of reason, inasmuch as they threaten to extend the limits of
sensibility, which is their proper sphere, over the entire realm of
thought and, thus, to supplant the pure (practical) use of reason.
So far, then, as this criticism is occupied in confining speculative
reason within its proper bounds, it is only negative; but, inasmuch as
it thereby, at the same time, removes an obstacle which impedes and
even threatens to destroy the use of practical reason, it possesses
a positive and very important value. In order to admit this, we have
only to be convinced that there is an absolutely necessary use of pure
reason- the moral use- in which it inevitably transcends the limits of
sensibility, without the aid of speculation, requiring only to be
insured against the effects of a speculation which would involve it in
contradiction with itself. To deny the positive advantage of the
service which this criticism renders us would be as absurd as. to
maintain that the system of police is productive of no positive
benefit, since its main business is to prevent the violence which
citizen has to apprehend from citizen, that so each may pursue his
vocation in peace and security. That space and time are only forms
of sensible intuition, and hence are only conditions of the
existence of things as phenomena; that, moreover, we have no
conceptions of the understanding, and, consequently, no elements for
the cognition of things, except in so far as a corresponding intuition
can be given to these conceptions; that, accordingly, we can have no
cognition of an object, as a thing in itself, but only as an object of
sensible intuition, that is, as phenomenon- all this is proved in
the analytical part of the Critique; and from this the limitation of
all possible speculative cognition to the mere objects of
experience, follows as a necessary result. At the same time, it must
be carefully borne in mind that, while we surrender the power of
cognizing, we still reserve the power of thinking objects, as things
in themselves.* For, otherwise, we should require to affirm the
existence of an appearance, without something that appears- which
would be absurd. Now let us suppose, for a moment, that we had not
undertaken this criticism and, accordingly, had not drawn the
necessary distinction between things as objects of experience and
things as they are in themselves. The principle of causality, and,
by consequence, the mechanism of nature as determined by causality,
would then have absolute validity in relation to all things as
efficient causes. I should then be unable to assert, with regard to
one and the same being, e.g., the human soul, that its will is free,
and yet, at the same time, subject to natural necessity, that is,
not free, without falling into a palpable contradiction, for in both
propositions I should take the soul in the same signification, as a
thing in general, as a thing in itself- as, without previous
criticism, I could not but take it. Suppose now, on the other hand,
that we have undertaken this criticism, and have learnt that an object
may be taken in two senses, first, as a phenomenon, secondly, as a
thing in itself; and that, according to the deduction of the
conceptions of the understanding, the principle of causality has
reference only to things in the first sense. We then see how it does
not involve any contradiction to assert, on the one hand, that the
will, in the phenomenal sphere- in visible action- is necessarily
obedient to the law of nature, and, in so far, not free; and, on the
other hand, that, as belonging to a thing in itself, it is not subject
to that law, and, accordingly, is free. Now, it is true that I cannot,
by means of speculative reason, and still less by empirical
observation, cognize my soul as a thing in itself and consequently,
cannot cognize liberty as the property of a being to which I ascribe
effects in the world of sense. For, to do so, I must cognize this
being as existing, and yet not in time, which- since I cannot
support my conception by any intuition- is impossible. At the same
time, while I cannot cognize, I can quite well think freedom, that
is to say, my representation of it involves at least no contradiction,
if we bear in mind the critical distinction of the two modes of
representation (the sensible and the intellectual) and the
consequent limitation of the conceptions of the pure understanding and
of the principles which flow from them. Suppose now that morality
necessarily presupposed liberty, in the strictest sense, as a property
of our will; suppose that reason contained certain practical, original
principles a priori, which were absolutely impossible without this
presupposition; and suppose, at the same time, that speculative reason
had proved that liberty was incapable of being thought at all. It
would then follow that the moral presupposition must give way to the
speculative affirmation, the opposite of which involves an obvious
contradiction, and that liberty and, with it, morality must yield to
the mechanism of nature; for the negation of morality involves no
contradiction, except on the presupposition of liberty. Now morality
does not require the speculative cognition of liberty; it is enough
that I can think it, that its conception involves no contradiction,
that it does not interfere with the mechanism of nature. But even this
requirement we could not satisfy, if we had not learnt the twofold
sense in which things may be taken; and it is only in this way that
the doctrine of morality and the doctrine of nature are confined
within their proper limits. For this result, then, we are indebted
to a criticism which warns us of our unavoidable ignorance with regard
to things in themselves, and establishes the necessary limitation of
our theoretical cognition to mere phenomena.

*In order to cognize an object, I must be able to prove its
possibility, either from its reality as attested by experience, or a
priori, by means of reason. But I can think what I please, provided
only I do not contradict myself; that is, provided my conception is
a possible thought, though I may be unable to answer for the existence
of a corresponding object in the sum of possibilities. But something
more is required before I can attribute to such a conception objective
validity, that is real possibility- the other possibility being merely
logical. We are not, however, confined to theoretical sources of
cognition for the means of satisfying this additional requirement, but
may derive them from practical sources.

The positive value of the critical principles of pure reason in
relation to the conception of God and of the simple nature of the
soul, admits of a similar exemplification; but on this point I shall
not dwell. I cannot even make the assumption- as the practical
interests of morality require- of God, freedom, and immortality, if
I do not deprive speculative reason of its pretensions to transcendent
insight. For to arrive at these, it must make use of principles which,
in fact, extend only to the objects of possible experience, and
which cannot be applied to objects beyond this sphere without
converting them into phenomena, and thus rendering the practical
extension of pure reason impossible. I must, therefore, abolish
knowledge, to make room for belief. The dogmatism of metaphysics, that
is, the presumption that it is possible to advance in metaphysics
without previous criticism, is the true source of the unbelief (always
dogmatic) which militates against morality.
Thus, while it may be no very difficult task to bequeath a legacy to
posterity, in the shape of a system of metaphysics constructed in
accordance with the Critique of Pure Reason, still the value of such a
bequest is not to be depreciated. It will render an important
service to reason, by substituting the certainty of scientific
method for that random groping after results without the guidance of
principles, which has hitherto characterized the pursuit of
metaphysical studies. It will render an important service to the
inquiring mind of youth, by leading the student to apply his powers to
the cultivation of. genuine science, instead of wasting them, as at
present, on speculations which can never lead to any result, or on the
idle attempt to invent new ideas and opinions. But, above all, it will
confer an inestimable benefit on morality and religion, by showing
that all the objections urged against them may be silenced for ever by
the Socratic method, that is to say, by proving the ignorance of the
objector. For, as the world has never been, and, no doubt, never
will be without a system of metaphysics of one kind or another, it
is the highest and weightiest concern of philosophy to render it
powerless for harm, by closing up the sources of error.
This important change in the field of the sciences, this loss of its
fancied possessions, to which speculative reason must submit, does not
prove in any way detrimental to the general interests of humanity. The
advantages which the world has derived from the teachings of pure
reason are not at all impaired. The loss falls, in its whole extent,
on the monopoly of the schools, but does not in the slightest degree
touch the interests of mankind. I appeal to the most obstinate
dogmatist, whether the proof of the continued existence of the soul
after death, derived from the simplicity of its substance; of the
freedom of the will in opposition to the general mechanism of
nature, drawn from the subtle but impotent distinction of subjective
and objective practical necessity; or of the existence of God, deduced
from the conception of an ens realissimum- the contingency of the
changeable, and the necessity of a prime mover, has ever been able
to pass beyond the limits of the schools, to penetrate the public
mind, or to exercise the slightest influence on its convictions. It
must be admitted that this has not been the case and that, owing to
the unfitness of the common understanding for such subtle
speculations, it can never be expected to take place. On the contrary,
it is plain that the hope of a future life arises from the feeling,
which exists in the breast of every man, that the temporal is
inadequate to meet and satisfy the demands of his nature. In like
manner, it cannot be doubted that the clear exhibition of duties in
opposition to all the claims of inclination, gives rise to the
consciousness of freedom, and that the glorious order, beauty, and
providential care, everywhere displayed in nature, give rise to the
belief in a wise and great Author of the Universe. Such is the genesis
of these general convictions of mankind, so far as they depend on
rational grounds; and this public property not only remains
undisturbed, but is even raised to greater importance, by the doctrine
that the schools have no right to arrogate to themselves a more
profound insight into a matter of general human concernment than
that to which the great mass of men, ever held by us in the highest
estimation, can without difficulty attain, and that the schools
should, therefore, confine themselves to the elaboration of these
universally comprehensible and, from a moral point of view, amply
satisfactory proofs. The change, therefore, affects only the
arrogant pretensions of the schools, which would gladly retain, in
their own exclusive possession, the key to the truths which they
impart to the public.

Quod mecum nescit, solus vult scire videri.

At the same time it does not deprive the speculative philosopher of
his just title to be the sole depositor of a science which benefits
the public without its knowledge- I mean, the Critique of Pure Reason.
This can never become popular and, indeed, has no occasion to be so;
for finespun arguments in favour of useful truths make just as
little impression on the public mind as the equally subtle
objections brought against these truths. On the other hand, since both
inevitably force themselves on every man who rises to the height of
speculation, it becomes the manifest duty of the schools to enter upon
a thorough investigation of the rights of speculative reason and,
thus, to prevent the scandal which metaphysical controversies are
sure, sooner or later, to cause even to the masses. It is only by
criticism that metaphysicians (and, as such, theologians too) can be
saved from these controversies and from the consequent perversion of
their doctrines. Criticism alone can strike a blow at the root of
materialism, fatalism, atheism, free-thinking, fanaticism, and
superstition, which are universally injurious- as well as of
idealism and scepticism, which are dangerous to the schools, but can
scarcely pass over to the public. If governments think proper to
interfere with the affairs of the learned, it would be more consistent
with a wise regard for the interests of science, as well as for
those of society, to favour a criticism of this kind, by which alone
the labours of reason can be established on a firm basis, than to
support the ridiculous despotism of the schools, which raise a loud
cry of danger to the public over the destruction of cobwebs, of
which the public has never taken any notice, and the loss of which,
therefore, it can never feel.
This critical science is not opposed to the dogmatic procedure of
reason in pure cognition; for pure cognition must always be
dogmatic, that is, must rest on strict demonstration from sure
principles a priori- but to dogmatism, that is, to the presumption
that it is possible to make any progress with a pure cognition,
derived from (philosophical) conceptions, according to the
principles which reason has long been in the habit of employing-
without first inquiring in what way and by what right reason has
come into the possession of these principles. Dogmatism is thus the
dogmatic procedure of pure reason without previous criticism of its
own powers, and in opposing this procedure, we must not be supposed to
lend any countenance to that loquacious shallowness which arrogates to
itself the name of popularity, nor yet to scepticism, which makes
short work with the whole science of metaphysics. On the contrary, our
criticism is the necessary preparation for a thoroughly scientific
system of metaphysics which must perform its task entirely a priori,
to the complete satisfaction of speculative reason, and must,
therefore, be treated, not popularly, but scholastically. In
carrying out the plan which the Critique prescribes, that is, in the
future system of metaphysics, we must have recourse to the strict
method of the celebrated Wolf, the greatest of all dogmatic
philosophers. He was the first to point out the necessity of
establishing fixed principles, of clearly defining our conceptions,
and of subjecting our demonstrations to the most severe scrutiny,
instead of rashly jumping at conclusions. The example which he set
served to awaken that spirit of profound and thorough investigation
which is not yet extinct in Germany. He would have been peculiarly
well fitted to give a truly scientific character to metaphysical
studies, had it occurred to him to prepare the field by a criticism of
the organum, that is, of pure reason itself. That be failed to
perceive the necessity of such a procedure must be ascribed to the
dogmatic mode of thought which characterized his age, and on this
point the philosophers of his time, as well as of all previous
times, have nothing to reproach each other with. Those who reject at
once the method of Wolf, and of the Critique of Pure Reason, can
have no other aim but to shake off the fetters of science, to change
labour into sport, certainty into opinion, and philosophy into
philodoxy.
In this second edition, I have endeavoured, as far as possible, to
remove the difficulties and obscurity which, without fault of mine
perhaps, have given rise to many misconceptions even among acute
thinkers. In the propositions themselves, and in the demonstrations by
which they are supported, as well as in the form and the entire plan
of the work, I have found nothing to alter; which must be attributed
partly to the long examination to which I had subjected the whole
before offering it to the public and partly to the nature of the case.
For pure speculative reason is an organic structure in which there
is nothing isolated or independent, but every Single part is essential
to all the rest; and hence, the slightest imperfection, whether defect
or positive error, could not fail to betray itself in use. I
venture, further, to hope, that this system will maintain the same
unalterable character for the future. I am led to entertain this
confidence, not by vanity, but by the evidence which the equality of
the result affords, when we proceed, first, from the simplest elements
up to the complete whole of pure reason and, and then, backwards
from the whole to each part. We find that the attempt to make the
slightest alteration, in any part, leads inevitably to contradictions,
not merely in this system, but in human reason itself. At the same
time, there is still much room for improvement in the exposition of
the doctrines contained in this work. In the present edition, I have
endeavoured to remove misapprehensions of the aesthetical part,
especially with regard to the conception of time; to clear away the
obscurity which has been found in the deduction of the conceptions
of the understanding; to supply the supposed want of sufficient
evidence in the demonstration of the principles of the pure
understanding; and, lastly, to obviate the misunderstanding of the
paralogisms which immediately precede the rational psychology.
Beyond this point- the end of the second main division of the
"Transcendental Dialectic"- I have not extended my alterations,*
partly from want of time, and partly because I am not aware that any
portion of the remainder has given rise to misconceptions among
intelligent and impartial critics, whom I do not here mention with
that praise which is their due, but who will find that their
suggestions have been attended to in the work itself.

*The only addition, properly so called- and that only in the
method of proof- which I have made in the present edition, consists of
a new refutation of psychological idealism, and a strict
demonstration- the only one possible, as I believe- of the objective
reality of external intuition. However harmless idealism may be
considered- although in reality it is not so- in regard to the
essential ends of metaphysics, it must still remain a scandal to
philosophy and to the general human reason to be obliged to assume, as
an article of mere belief, the existence of things external to
ourselves (from which, yet, we derive the whole material of
cognition for the internal sense), and not to be able to oppose a
satisfactory proof to any one who may call it in question. As there is
some obscurity of expression in the demonstration as it stands in
the text, I propose to alter the passage in question as follows:
"But this permanent cannot be an intuition in me. For all the
determining grounds of my existence which can be found in me are
representations and, as such, do themselves require a permanent,
distinct from them, which may determine my existence in relation to
their changes, that is, my existence in time, wherein they change." It
may, probably, be urged in opposition to this proof that, after all, I
am only conscious immediately of that which is in me, that is, of my
representation of external things, and that, consequently, it must
always remain uncertain whether anything corresponding to this
representation does or does not exist externally to me. But I am
conscious, through internal experience, of my existence in time
(consequently, also, of the determinability of the former in the
latter), and that is more than the simple consciousness of my
representation. It is, in fact, the same as the empirical
consciousness of my existence, which can only be determined in
relation to something, which, while connected with my existence, is
external to me. This consciousness of my existence in time is,
therefore, identical with the consciousness of a relation to something
external to me, and it is, therefore, experience, not fiction,
sense, not imagination, which inseparably connects the external with
my internal sense. For the external sense is, in itself, the
relation of intuition to something real, external to me; and the
reality of this something, as opposed to the mere imagination of it,
rests solely on its inseparable connection with internal experience as
the condition of its possibility. If with the intellectual
consciousness of my existence, in the representation: I am, which
accompanies all my judgements, and all the operations of my
understanding, I could, at the same time, connect a determination of
my existence by intellectual intuition, then the consciousness of a
relation to something external to me would not be necessary. But the
internal intuition in which alone my existence can be determined,
though preceded by that purely intellectual consciousness, is itself
sensible and attached to the condition of time. Hence this
determination of my existence, and consequently my internal experience
itself, must depend on something permanent which is not in me, which
can be, therefore, only in something external to me, to which I must
look upon myself as being related. Thus the reality of the external
sense is necessarily connected with that of the internal, in order
to the possibility of experience in general; that is, I am just as
certainly conscious that there are things external to me related to my
sense as I am that I myself exist as determined in time. But in
order to ascertain to what given intuitions objects, external me,
really correspond, in other words, what intuitions belong to the
external sense and not to imagination, I must have recourse, in
every particular case, to those rules according to which experience in
general (even internal experience) is distinguished from
imagination, and which are always based on the proposition that
there really is an external experience. We may add the remark that the
representation of something permanent in existence, is not the same
thing as the permanent representation; for a representation may be
very variable and changing- as all our representations, even that of
matter, are- and yet refer to something permanent, which must,
therefore, be distinct from all my representations and external to me,
the existence of which is necessarily included in the determination of
my own existence, and with it constitutes one experience- an
experience which would not even be possible internally, if it were not
also at the same time, in part, external. To the question How? we
are no more able to reply, than we are, in general, to think the
stationary in time, the coexistence of which with the variable,
produces the conception of change.

In attempting to render the exposition of my views as intelligible
as possible, I have been compelled to leave out or abridge various
passages which were not essential to the completeness of the work, but
which many readers might consider useful in other respects, and
might be unwilling to miss. This trifling loss, which could not be
avoided without swelling the book beyond due limits, may be
supplied, at the pleasure of the reader, by a comparison with the
first edition, and will, I hope, be more than compensated for by the
greater clearness of the exposition as it now stands.
I have observed, with pleasure and thankfulness, in the pages of
various reviews and treatises, that the spirit of profound and
thorough investigation is not extinct in Germany, though it may have
been overborne and silenced for a time by the fashionable tone of a
licence in thinking, which gives itself the airs of genius, and that
the difficulties which beset the paths of criticism have not prevented
energetic and acute thinkers from making themselves masters of the
science of pure reason to which these paths conduct- a science which
is not popular, but scholastic in its character, and which alone can
hope for a lasting existence or possess an abiding value. To these
deserving men, who so happily combine profundity of view with a talent
for lucid exposition- a talent which I myself am not conscious of
possessing- I leave the task of removing any obscurity which may still
adhere to the statement of my doctrines. For, in this case, the danger
is not that of being refuted, but of being misunderstood. For my own
part, I must henceforward abstain from controversy, although I shall
carefully attend to all suggestions, whether from friends or
adversaries, which may be of use in the future elaboration of the
system of this propaedeutic. As, during these labours, I have advanced
pretty far in years this month I reach my sixty-fourth year- it will
be necessary for me to economize time, if I am to carry out my plan of
elaborating the metaphysics of nature as well as of morals, in
confirmation of the correctness of the principles established in
this Critique of Pure Reason, both speculative and practical; and I
must, therefore, leave the task of clearing up the obscurities of
the present work- inevitable, perhaps, at the outset- as well as,
the defence of the whole, to those deserving men, who have made my
system their own. A philosophical system cannot come forward armed
at all points like a mathematical treatise, and hence it may be
quite possible to take objection to particular passages, while the
organic structure of the system, considered as a unity, has no
danger to apprehend. But few possess the ability, and still fewer
the inclination, to take a comprehensive view of a new system. By
confining the view to particular passages, taking these out of their
connection and comparing them with one another, it is easy to pick out
apparent contradictions, especially in a work written with any freedom
of style. These contradictions place the work in an unfavourable light
in the eyes of those who rely on the judgement of others, but are
easily reconciled by those who have mastered the idea of the whole. If
a theory possesses stability in itself, the action and reaction
which seemed at first to threaten its existence serve only, in the
course of time, to smooth down any superficial roughness or
inequality, and- if men of insight, impartiality, and truly popular
gifts, turn their attention to it- to secure to it, in a short time,
the requisite elegance also.

Konigsberg, April 1787.
INTRODUCTION
INTRODUCTION.

I. Of the difference between Pure and Empirical Knowledge

That all our knowledge begins with experience there can be no doubt.
For how is it possible that the faculty of cognition should be
awakened into exercise otherwise than by means of objects which affect
our senses, and partly of themselves produce representations, partly
rouse our powers of understanding into activity, to compare to
connect, or to separate these, and so to convert the raw material of
our sensuous impressions into a knowledge of objects, which is
called experience? In respect of time, therefore, no knowledge of ours
is antecedent to experience, but begins with it.
But, though all our knowledge begins with experience, it by no means
follows that all arises out of experience. For, on the contrary, it is
quite possible that our empirical knowledge is a compound of that
which we receive through impressions, and that which the faculty of
cognition supplies from itself (sensuous impressions giving merely the
occasion), an addition which we cannot distinguish from the original
element given by sense, till long practice has made us attentive to,
and skilful in separating it. It is, therefore, a question which
requires close investigation, and not to be answered at first sight,
whether there exists a knowledge altogether independent of experience,
and even of all sensuous impressions? Knowledge of this kind is called
a priori, in contradistinction to empirical knowledge, which has its
sources a posteriori, that is, in experience.
But the expression, "a priori," is not as yet definite enough
adequately to indicate the whole meaning of the question above
started. For, in speaking of knowledge which has its sources in
experience, we are wont to say, that this or that may be known a
priori, because we do not derive this knowledge immediately from
experience, but from a general rule, which, however, we have itself
borrowed from experience. Thus, if a man undermined his house, we say,
"he might know a priori that it would have fallen;" that is, he needed
not to have waited for the experience that it did actually fall. But
still, a priori, he could not know even this much. For, that bodies
are heavy, and, consequently, that they fall when their supports are
taken away, must have been known to him previously, by means of
experience.
By the term "knowledge a priori," therefore, we shall in the
sequel understand, not such as is independent of this or that kind
of experience, but such as is absolutely so of all experience. Opposed
to this is empirical knowledge, or that which is possible only a
posteriori, that is, through experience. Knowledge a priori is
either pure or impure. Pure knowledge a priori is that with which no
empirical element is mixed up. For example, the proposition, "Every
change has a cause," is a proposition a priori, but impure, because
change is a conception which can only be derived from experience.

II. The Human Intellect, even in an Unphilosophical State,
is in Possession of Certain Cognitions "a priori".

The question now is as to a criterion, by which we may securely
distinguish a pure from an empirical cognition. Experience no doubt
teaches us that this or that object is constituted in such and such
a manner, but not that it could not possibly exist otherwise. Now,
in the first place, if we have a proposition which contains the idea
of necessity in its very conception, it is a if, moreover, it is not
derived from any other proposition, unless from one equally
involving the idea of necessity, it is absolutely priori. Secondly, an
empirical judgement never exhibits strict and absolute, but only
assumed and comparative universality (by induction); therefore, the
most we can say is- so far as we have hitherto observed, there is no
exception to this or that rule. If, on the other hand, a judgement
carries with it strict and absolute universality, that is, admits of
no possible exception, it is not derived from experience, but is valid
absolutely a priori.
Empirical universality is, therefore, only an arbitrary extension of
validity, from that which may be predicated of a proposition valid
in most cases, to that which is asserted of a proposition which
holds good in all; as, for example, in the affirmation, "All bodies
are heavy." When, on the contrary, strict universality characterizes a
judgement, it necessarily indicates another peculiar source of
knowledge, namely, a faculty of cognition a priori. Necessity and
strict universality, therefore, are infallible tests for
distinguishing pure from empirical knowledge, and are inseparably
connected with each other. But as in the use of these criteria the
empirical limitation is sometimes more easily detected than the
contingency of the judgement, or the unlimited universality which we
attach to a judgement is often a more convincing proof than its
necessity, it may be advisable to use the criteria separately, each
being by itself infallible.
Now, that in the sphere of human cognition we have judgements
which are necessary, and in the strictest sense universal,
consequently pure a priori, it will be an easy matter to show. If we
desire an example from the sciences, we need only take any proposition
in mathematics. If we cast our eyes upon the commonest operations of
the understanding, the proposition, "Every change must have a
cause," will amply serve our purpose. In the latter case, indeed,
the conception of a cause so plainly involves the conception of a
necessity of connection with an effect, and of a strict universality
of the law, that the very notion of a cause would entirely
disappear, were we to derive it, like Hume, from a frequent
association of what happens with that which precedes; and the habit
thence originating of connecting representations- the necessity
inherent in the judgement being therefore merely subjective.
Besides, without seeking for such examples of principles existing a
priori in cognition, we might easily show that such principles are the
indispensable basis of the possibility of experience itself, and
consequently prove their existence a priori. For whence could our
experience itself acquire certainty, if all the rules on which it
depends were themselves empirical, and consequently fortuitous? No
one, therefore, can admit the validity of the use of such rules as
first principles. But, for the present, we may content ourselves
with having established the fact, that we do possess and exercise a
faculty of pure a priori cognition; and, secondly, with having pointed
out the proper tests of such cognition, namely, universality and
necessity.
Not only in judgements, however, but even in conceptions, is an a
priori origin manifest. For example, if we take away by degrees from
our conceptions of a body all that can be referred to mere sensuous
experience- colour, hardness or softness, weight, even
impenetrability- the body will then vanish; but the space which it
occupied still remains, and this it is utterly impossible to
annihilate in thought. Again, if we take away, in like manner, from
our empirical conception of any object, corporeal or incorporeal,
all properties which mere experience has taught us to connect with it,
still we cannot think away those through which we cogitate it as
substance, or adhering to substance, although our conception of
substance is more determined than that of an object. Compelled,
therefore, by that necessity with which the conception of substance
forces itself upon us, we must confess that it has its seat in our
faculty of cognition a priori.

III. Philosophy stands in need of a Science which shall
Determine the Possibility, Principles, and Extent of
Human Knowledge "a priori"

Of far more importance than all that has been above said, is the
consideration that certain of our cognitions rise completely above the
sphere of all possible experience, and by means of conceptions, to
which there exists in the whole extent of experience no
corresponding object, seem to extend the range of our judgements
beyond its bounds. And just in this transcendental or supersensible
sphere, where experience affords us neither instruction nor
guidance, lie the investigations of reason, which, on account of their
importance, we consider far preferable to, and as having a far more
elevated aim than, all that the understanding can achieve within the
sphere of sensuous phenomena. So high a value do we set upon these
investigations, that even at the risk of error, we persist in
following them out, and permit neither doubt nor disregard nor
indifference to restrain us from the pursuit. These unavoidable
problems of mere pure reason are God, freedom (of will), and
immortality. The science which, with all its preliminaries, has for
its especial object the solution of these problems is named
metaphysics- a science which is at the very outset dogmatical, that
is, it confidently takes upon itself the execution of this task
without any previous investigation of the ability or inability of
reason for such an undertaking.
Now the safe ground of experience being thus abandoned, it seems
nevertheless natural that we should hesitate to erect a building
with the cognitions we possess, without knowing whence they come,
and on the strength of principles, the origin of which is
undiscovered. Instead of thus trying to build without a foundation, it
is rather to be expected that we should long ago have put the
question, how the understanding can arrive at these a priori
cognitions, and what is the extent, validity, and worth which they may
possess? We say, "This is natural enough," meaning by the word
natural, that which is consistent with a just and reasonable way of
thinking; but if we understand by the term, that. which usually
happens, nothing indeed could be more natural and more
comprehensible than that this investigation should be left long
unattempted. For one part of our pure knowledge, the science of
mathematics, has been long firmly established, and thus leads us to
form flattering expectations with regard to others, though these may
be of quite a different nature. Besides, when we get beyond the bounds
of experience, we are of course safe from opposition in that
quarter; and the charm of widening the range of our knowledge is so
great that, unless we are brought to a standstill by some evident
contradiction, we hurry on undoubtingly in our course. This,
however, may be avoided, if we are sufficiently cautious in the
construction of our fictions, which are not the less fictions on
that account.
Mathematical science affords us a brilliant example, how far,
independently of all experience, we may carry our a priori
knowledge. It is true that the mathematician occupies himself with
objects and cognitions only in so far as they can be represented by
means of intuition. But this circumstance is easily overlooked,
because the said intuition can itself be given a priori, and therefore
is hardly to be distinguished from a mere pure conception. Deceived by
such a proof of the power of reason, we can perceive no limits to
the extension of our knowledge. The light dove cleaving in free flight
the thin air, whose resistance it feels, might imagine that her
movements would be far more free and rapid in airless space. just in
the same way did Plato, abandoning the world of sense because of the
narrow limits it sets to the understanding, venture upon the wings
of ideas beyond it, into the void space of pure intellect. He did
not reflect that he made no real progress by all his efforts; for he
met with no resistance which might serve him for a support, as it
were, whereon to rest, and on which he might apply his powers, in
order to let the intellect acquire momentum for its progress. It is,
indeed, the common fate of human reason in speculation, to finish
the imposing edifice of thought as rapidly as possible, and then for
the first time to begin to examine whether the foundation is a solid
one or no. Arrived at this point, all sorts of excuses are sought
after, in order to console us for its want of stability, or rather,
indeed, to enable Us to dispense altogether with so late and dangerous
an investigation. But what frees us during the process of building
from all apprehension or suspicion, and flatters us into the belief of
its solidity, is this. A great part, perhaps the greatest part, of the
business of our reason consists in the analysation of the
conceptions which we already possess of objects. By this means we gain
a multitude of cognitions, which although really nothing more than
elucidations or explanations of that which (though in a confused
manner) was already thought in our conceptions, are, at least in
respect of their form, prized as new introspections; whilst, so far as
regards their matter or content, we have really made no addition to
our conceptions, but only disinvolved them. But as this process does
furnish a real priori knowledge, which has a sure progress and
useful results, reason, deceived by this, slips in, without being
itself aware of it, assertions of a quite different kind; in which, to
given conceptions it adds others, a priori indeed, but entirely
foreign to them, without our knowing how it arrives at these, and,
indeed, without such a question ever suggesting itself. I shall
therefore at once proceed to examine the difference between these
two modes of knowledge.

IV. Of the Difference Between Analytical and Synthetical Judgements.

In all judgements wherein the relation of a subject to the predicate
is cogitated (I mention affirmative judgements only here; the
application to negative will be very easy), this relation is
possible in two different ways. Either the predicate B belongs to
the subject A, as somewhat which is contained (though covertly) in the
conception A; or the predicate B lies completely out of the conception
A, although it stands in connection with it. In the first instance,
I term the judgement analytical, in the second, synthetical.
Analytical judgements (affirmative) are therefore those in which the
connection of the predicate with the subject is cogitated through
identity; those in which this connection is cogitated without
identity, are called synthetical judgements. The former may be
called explicative, the latter augmentative judgements; because the
former add in the predicate nothing to the conception of the
subject, but only analyse it into its constituent conceptions, which
were thought already in the subject, although in a confused manner;
the latter add to our conceptions of the subject a predicate which was
not contained in it, and which no analysis could ever have
discovered therein. For example, when I say, "All bodies are
extended," this is an analytical judgement. For I need not go beyond
the conception of body in order to find extension connected with it,
but merely analyse the conception, that is, become conscious of the
manifold properties which I think in that conception, in order to
discover this predicate in it: it is therefore an analytical
judgement. On the other hand, when I say, "All bodies are heavy,"
the predicate is something totally different from that which I think
in the mere conception of a body. By the addition of such a predicate,
therefore, it becomes a synthetical judgement.
Judgements of experience, as such, are always synthetical. For it
would be absurd to think of grounding an analytical judgement on
experience, because in forming such a judgement I need not go out of
the sphere of my conceptions, and therefore recourse to the
testimony of experience is quite unnecessary. That "bodies are
extended" is not an empirical judgement, but a proposition which
stands firm a priori. For before addressing myself to experience, I
already have in my conception all the requisite conditions for the
judgement, and I have only to extract the predicate from the
conception, according to the principle of contradiction, and thereby
at the same time become conscious of the necessity of the judgement, a
necessity which I could never learn from experience. On the other
hand, though at first I do not at all include the predicate of
weight in my conception of body in general, that conception still
indicates an object of experience, a part of the totality of
experience, to which I can still add other parts; and this I do when I
recognize by observation that bodies are heavy. I can cognize
beforehand by analysis the conception of body through the
characteristics of extension, impenetrability, shape, etc., all
which are cogitated in this conception. But now I extend my knowledge,
and looking back on experience from which I had derived this
conception of body, I find weight at all times connected with the
above characteristics, and therefore I synthetically add to my
conceptions this as a predicate, and say, "All bodies are heavy." Thus
it is experience upon which rests the possibility of the synthesis
of the predicate of weight with the conception of body, because both
conceptions, although the one is not contained in the other, still
belong to one another (only contingently, however), as parts of a
whole, namely, of experience, which is itself a synthesis of
intuitions.
But to synthetical judgements a priori, such aid is entirely
wanting. If I go out of and beyond the conception A, in order to
recognize another B as connected with it, what foundation have I to
rest on, whereby to render the synthesis possible? I have here no
longer the advantage of looking out in the sphere of experience for
what I want. Let us take, for example, the proposition, "Everything
that happens has a cause." In the conception of "something that
happens," I indeed think an existence which a certain time
antecedes, and from this I can derive analytical judgements. But the
conception of a cause lies quite out of the above conception, and
indicates something entirely different from "that which happens,"
and is consequently not contained in that conception. How then am I
able to assert concerning the general conception- "that which
happens"- something entirely different from that conception, and to
recognize the conception of cause although not contained in it, yet as
belonging to it, and even necessarily? what is here the unknown = X,
upon which the understanding rests when it believes it has found,
out of the conception A a foreign predicate B, which it nevertheless
considers to be connected with it? It cannot be experience, because
the principle adduced annexes the two representations, cause and
effect, to the representation existence, not only with universality,
which experience cannot give, but also with the expression of
necessity, therefore completely a priori and from pure conceptions.
Upon such synthetical, that is augmentative propositions, depends
the whole aim of our speculative knowledge a priori; for although
analytical judgements are indeed highly important and necessary,
they are so, only to arrive at that clearness of conceptions which
is requisite for a sure and extended synthesis, and this alone is a
real acquisition.

V. In all Theoretical Sciences of Reason, Synthetical Judgements
"a priori" are contained as Principles.

1. Mathematical judgements are always synthetical. Hitherto this
fact, though incontestably true and very important in its
consequences, seems to have escaped the analysts of the human mind,
nay, to be in complete opposition to all their conjectures. For as
it was found that mathematical conclusions all proceed according to
the principle of contradiction (which the nature of every apodeictic
certainty requires), people became persuaded that the fundamental
principles of the science also were recognized and admitted in the
same way. But the notion is fallacious; for although a synthetical
proposition can certainly be discerned by means of the principle of
contradiction, this is possible only when another synthetical
proposition precedes, from which the latter is deduced, but never of
itself which
Before all, be it observed, that proper mathematical propositions
are always judgements a priori, and not empirical, because they
carry along with them the conception of necessity, which cannot be
given by experience. If this be demurred to, it matters not; I will
then limit my assertion to pure mathematics, the very conception of
which implies that it consists of knowledge altogether non-empirical
and a priori.
We might, indeed at first suppose that the proposition 7 + 5 = 12 is
a merely analytical proposition, following (according to the principle
of contradiction) from the conception of a sum of seven and five.
But if we regard it more narrowly, we find that our conception of
the sum of seven and five contains nothing more than the uniting of
both sums into one, whereby it cannot at all be cogitated what this
single number is which embraces both. The conception of twelve is by
no means obtained by merely cogitating the union of seven and five;
and we may analyse our conception of such a possible sum as long as we
will, still we shall never discover in it the notion of twelve. We
must go beyond these conceptions, and have recourse to an intuition
which corresponds to one of the two- our five fingers, for example, or
like Segner in his Arithmetic five points, and so by degrees, add
the units contained in the five given in the intuition, to the
conception of seven. For I first take the number 7, and, for the
conception of 5 calling in the aid of the fingers of my hand as
objects of intuition, I add the units, which I before took together to
make up the number 5, gradually now by means of the material image
my hand, to the number 7, and by this process, I at length see the
number 12 arise. That 7 should be added to 5, I have certainly
cogitated in my conception of a sum = 7 + 5, but not that this sum was
equal to 12. Arithmetical propositions are therefore always
synthetical, of which we may become more clearly convinced by trying
large numbers. For it will thus become quite evident that, turn and
twist our conceptions as we may, it is impossible, without having
recourse to intuition, to arrive at the sum total or product by
means of the mere analysis of our conceptions. just as little is any
principle of pure geometry analytical. "A straight line between two
points is the shortest," is a synthetical proposition. For my
conception of straight contains no notion of quantity, but is merely
qualitative. The conception of the shortest is therefore fore wholly
an addition, and by no analysis can it be extracted from our
conception of a straight line. Intuition must therefore here lend
its aid, by means of which, and thus only, our synthesis is possible.
Some few principles preposited by geometricians are, indeed,
really analytical, and depend on the principle of contradiction.
They serve, however, like identical propositions, as links in the
chain of method, not as principles- for example, a = a, the whole is
equal to itself, or (a+b) > a, the whole is greater than its part. And
yet even these principles themselves, though they derive their
validity from pure conceptions, are only admitted in mathematics
because they can be presented in intuition. What causes us here
commonly to believe that the predicate of such apodeictic judgements
is already contained in our conception, and that the judgement is
therefore analytical, is merely the equivocal nature of the
expression. We must join in thought a certain predicate to a given
conception, and this necessity cleaves already to the conception.
But the question is, not what we must join in thought to the given
conception, but what we really think therein, though only obscurely,
and then it becomes manifest that the predicate pertains to these
conceptions, necessarily indeed, yet not as thought in the
conception itself, but by virtue of an intuition, which must be
added to the conception.
2. The science of natural philosophy (physics) contains in itself
synthetical judgements a priori, as principles. I shall adduce two
propositions. For instance, the proposition, "In all changes of the
material world, the quantity of matter remains unchanged"; or, that,
"In all communication of motion, action and reaction must always be
equal." In both of these, not only is the necessity, and therefore
their origin a priori clear, but also that they are synthetical
propositions. For in the conception of matter, I do not cogitate its
permanency, but merely its presence in space, which it fills. I
therefore really go out of and beyond the conception of matter, in
order to think on to it something a priori, which I did not think in
it. The proposition is therefore not analytical, but synthetical,
and nevertheless conceived a priori; and so it is with regard to the
other propositions of the pure part of natural philosophy.
3. As to metaphysics, even if we look upon it merely as an attempted
science, yet, from the nature of human reason, an indispensable one,
we find that it must contain synthetical propositions a priori. It
is not merely the duty of metaphysics to dissect, and thereby
analytically to illustrate the conceptions which we form a priori of
things; but we seek to widen the range of our a priori knowledge.
For this purpose, we must avail ourselves of such principles as add
something to the original conception- something not identical with,
nor contained in it, and by means of synthetical judgements a
priori, leave far behind us the limits of experience; for example,
in the proposition, "the world must have a beginning," and such
like. Thus metaphysics, according to the proper aim of the science,
consists merely of synthetical propositions a priori.

VI. The Universal Problem of Pure Reason.

It is extremely advantageous to be able to bring a number of
investigations under the formula of a single problem. For in this
manner, we not only facilitate our own labour, inasmuch as we define
it clearly to ourselves, but also render it more easy for others to
decide whether we have done justice to our undertaking. The proper
problem of pure reason, then, is contained in the question: "How are
synthetical judgements a priori possible?"
That metaphysical science has hitherto remained in so vacillating
a state of uncertainty and contradiction, is only to be attributed
to the fact that this great problem, and perhaps even the difference
between analytical and synthetical judgements, did not sooner
suggest itself to philosophers. Upon the solution of this problem,
or upon sufficient proof of the impossibility of synthetical knowledge
a priori, depends the existence or downfall of the science of
metaphysics. Among philosophers, David Hume came the nearest of all to
this problem; yet it never acquired in his mind sufficient
precision, nor did he regard the question in its universality. On
the contrary, he stopped short at the synthetical proposition of the
connection of an effect with its cause (principium causalitatis),
insisting that such proposition a priori was impossible. According
to his conclusions, then, all that we term metaphysical science is a
mere delusion, arising from the fancied insight of reason into that
which is in truth borrowed from experience, and to which habit has
given the appearance of necessity. Against this assertion, destructive
to all pure philosophy, he would have been guarded, had he had our
problem before his eyes in its universality. For he would then have
perceived that, according to his own argument, there likewise could
not be any pure mathematical science, which assuredly cannot exist
without synthetical propositions a priori- an absurdity from which his
good understanding must have saved him.
In the solution of the above problem is at the same time
comprehended the possibility of the use of pure reason in the
foundation and construction of all sciences which contain
theoretical knowledge a priori of objects, that is to say, the
answer to the following questions:
How is pure mathematical science possible?
How is pure natural science possible?
Respecting these sciences, as they do certainly exist, it may with
propriety be asked, how they are possible?- for that they must be
possible is shown by the fact of their really existing.* But as to
metaphysics, the miserable progress it has hitherto made, and the fact
that of no one system yet brought forward, far as regards its true
aim, can it be said that this science really exists, leaves any one at
liberty to doubt with reason the very possibility of its existence.

*As to the existence of pure natural science, or physics, perhaps
many may still express doubts. But we have only to look at the
different propositions which are commonly treated of at the
commencement of proper (empirical) physical science- those, for
example, relating to the permanence of the same quantity of matter,
the vis inertiae, the equality of action and reaction, etc.- to be
soon convinced that they form a science of pure physics (physica pura,
or rationalis), which well deserves to be separately exposed as a
special science, in its whole extent, whether that be great or
confined.

Yet, in a certain sense, this kind of knowledge must
unquestionably be looked upon as given; in other words, metaphysics
must be considered as really existing, if not as a science,
nevertheless as a natural disposition of the human mind (metaphysica
naturalis). For human reason, without any instigations imputable to
the mere vanity of great knowledge, unceasingly progresses, urged on
by its own feeling of need, towards such questions as cannot be
answered by any empirical application of reason, or principles derived
therefrom; and so there has ever really existed in every man some
system of metaphysics. It will always exist, so soon as reason
awakes to the exercise of its power of speculation. And now the
question arises: "How is metaphysics, as a natural disposition,
possible?" In other words, how, from the nature of universal human
reason, do those questions arise which pure reason proposes to itself,
and which it is impelled by its own feeling of need to answer as
well as it can?
But as in all the attempts hitherto made to answer the questions
which reason is prompted by its very nature to propose to itself,
for example, whether the world had a beginning, or has existed from
eternity, it has always met with unavoidable contradictions, we must
not rest satisfied with the mere natural disposition of the mind to
metaphysics, that is, with the existence of the faculty of pure
reason, whence, indeed, some sort of metaphysical system always
arises; but it must be possible to arrive at certainty in regard to
the question whether we know or do not know the things of which
metaphysics treats. We must be able to arrive at a decision on the
subjects of its questions, or on the ability or inability of reason to
form any judgement respecting them; and therefore either to extend
with confidence the bounds of our pure reason, or to set strictly
defined and safe limits to its action. This last question, which
arises out of the above universal problem, would properly run thus:
"How is metaphysics possible as a science?"
Thus, the critique of reason leads at last, naturally and
necessarily, to science; and, on the other hand, the dogmatical use of
reason without criticism leads to groundless assertions, against which
others equally specious can always be set, thus ending unavoidably
in scepticism.
Besides, this science cannot be of great and formidable prolixity,
because it has not to do with objects of reason, the variety of
which is inexhaustible, but merely with Reason herself and her
problems; problems which arise out of her own bosom, and are not
proposed to her by the nature of outward things, but by her own
nature. And when once Reason has previously become able completely
to understand her own power in regard to objects which she meets
with in experience, it will be easy to determine securely the extent
and limits of her attempted application to objects beyond the confines
of experience.
We may and must, therefore, regard the attempts hitherto made to
establish metaphysical science dogmatically as non-existent. For
what of analysis, that is, mere dissection of conceptions, is
contained in one or other, is not the aim of, but only a preparation
for metaphysics proper, which has for its object the extension, by
means of synthesis, of our a priori knowledge. And for this purpose,
mere analysis is of course useless, because it only shows what is
contained in these conceptions, but not how we arrive, a priori, at
them; and this it is her duty to show, in order to be able
afterwards to determine their valid use in regard to all objects of
experience, to all knowledge in general. But little self-denial,
indeed, is needed to give up these pretensions, seeing the undeniable,
and in the dogmatic mode of procedure, inevitable contradictions of
Reason with herself, have long since ruined the reputation of every
system of metaphysics that has appeared up to this time. It will
require more firmness to remain undeterred by difficulty from
within, and opposition from without, from endeavouring, by a method
quite opposed to all those hitherto followed, to further the growth
and fruitfulness of a science indispensable to human reason- a science
from which every branch it has borne may be cut away, but whose
roots remain indestructible.

VII. Idea and Division of a Particular Science, under the
Name of a Critique of Pure Reason.

From all that has been said, there results the idea of a
particular science, which may be called the Critique of Pure Reason.
For reason is the faculty which furnishes us with the principles of
knowledge a priori. Hence, pure reason is the faculty which contains
the principles of cognizing anything absolutely a priori. An organon
of pure reason would be a compendium of those principles according
to which alone all pure cognitions a priori can be obtained. The
completely extended application of such an organon would afford us a
system of pure reason. As this, however, is demanding a great deal,
and it is yet doubtful whether any extension of our knowledge be
here possible, or, if so, in what cases; we can regard a science of
the mere criticism of pure reason, its sources and limits, as the
propaedeutic to a system of pure reason. Such a science must not be
called a doctrine, but only a critique of pure reason; and its use, in
regard to speculation, would be only negative, not to enlarge the
bounds of, but to purify, our reason, and to shield it against
error- which alone is no little gain. I apply the term
transcendental to all knowledge which is not so much occupied with
objects as with the mode of our cognition of these objects, so far
as this mode of cognition is possible a priori. A system of such
conceptions would be called transcendental philosophy. But this,
again, is still beyond the bounds of our present essay. For as such
a science must contain a complete exposition not only of our
synthetical a priori, but of our analytical a priori knowledge, it
is of too wide a range for our present purpose, because we do not
require to carry our analysis any farther than is necessary to
understand, in their full extent, the principles of synthesis a
priori, with which alone we have to do. This investigation, which we
cannot properly call a doctrine, but only a transcendental critique,
because it aims not at the enlargement, but at the correction and
guidance, of our knowledge, and is to serve as a touchstone of the
worth or worthlessness of all knowledge a priori, is the sole object
of our present essay. Such a critique is consequently, as far as
possible, a preparation for an organon; and if this new organon should
be found to fail, at least for a canon of pure reason, according to
which the complete system of the philosophy of pure reason, whether it
extend or limit the bounds of that reason, might one day be set
forth both analytically and synthetically. For that this is
possible, nay, that such a system is not of so great extent as to
preclude the hope of its ever being completed, is evident. For we have
not here to do with the nature of outward objects, which is
infinite, but solely with the mind, which judges of the nature of
objects, and, again, with the mind only in respect of its cognition
a priori. And the object of our investigations, as it is not to be
sought without, but, altogether within, ourselves, cannot remain
concealed, and in all probability is limited enough to be completely
surveyed and fairly estimated, according to its worth or
worthlessness. Still less let the reader here expect a critique of
books and systems of pure reason; our present object is exclusively
a critique of the faculty of pure reason itself. Only when we make
this critique our foundation, do we possess a pure touchstone for
estimating the philosophical value of ancient and modern writings on
this subject; and without this criterion, the incompetent historian or
judge decides upon and corrects the groundless assertions of others
with his own, which have themselves just as little foundation.
Transcendental philosophy is the idea of a science, for which the
Critique of Pure Reason must sketch the whole plan
architectonically, that is, from principles, with a full guarantee for
the validity and stability of all the parts which enter into the
building. It is the system of all the principles of pure reason. If
this Critique itself does not assume the title of transcendental
philosophy, it is only because, to be a complete system, it ought to
contain a full analysis of all human knowledge a priori. Our
critique must, indeed, lay before us a complete enumeration of all the
radical conceptions which constitute the said pure knowledge. But from
the complete analysis of these conceptions themselves, as also from
a complete investigation of those derived from them, it abstains
with reason; partly because it would be deviating from the end in view
to occupy itself with this analysis, since this process is not
attended with the difficulty and insecurity to be found in the
synthesis, to which our critique is entirely devoted, and partly
because it would be inconsistent with the unity of our plan to
burden this essay with the vindication of the completeness of such
an analysis and deduction, with which, after all, we have at present
nothing to do. This completeness of the analysis of these radical
conceptions, as well as of the deduction from the conceptions a priori
which may be given by the analysis, we can, however, easily attain,
provided only that we are in possession of all these radical
conceptions, which are to serve as principles of the synthesis, and
that in respect of this main purpose nothing is wanting.
To the Critique of Pure Reason, therefore, belongs all that
constitutes transcendental philosophy; and it is the complete idea
of transcendental philosophy, but still not the science itself;
because it only proceeds so far with the analysis as is necessary to
the power of judging completely of our synthetical knowledge a priori.
The principal thing we must attend to, in the division of the
parts of a science like this, is that no conceptions must enter it
which contain aught empirical; in other words, that the knowledge a
priori must be completely pure. Hence, although the highest principles
and fundamental conceptions of morality are certainly cognitions a
priori, yet they do not belong to transcendental philosophy;
because, though they certainly do not lay the conceptions of pain,
pleasure, desires, inclinations, etc. (which are all of empirical
origin), at the foundation of its precepts, yet still into the
conception of duty- as an obstacle to be overcome, or as an incitement
which should not be made into a motive- these empirical conceptions
must necessarily enter, in the construction of a system of pure
morality. Transcendental philosophy is consequently a philosophy of
the pure and merely speculative reason. For all that is practical,
so far as it contains motives, relates to feelings, and these belong
to empirical sources of cognition.
If we wish to divide this science from the universal point of view
of a science in general, it ought to comprehend, first, a Doctrine
of the Elements, and, secondly, a Doctrine of the Method of pure
reason. Each of these main divisions will have its subdivisions, the
separate reasons for which we cannot here particularize. Only so
much seems necessary, by way of introduction of premonition, that
there are two sources of human knowledge (which probably spring from a
common, but to us unknown root), namely, sense and understanding. By
the former, objects are given to us; by the latter, thought. So far as
the faculty of sense may contain representations a priori, which
form the conditions under which objects are given, in so far it
belongs to transcendental philosophy. The transcendental doctrine of
sense must form the first part of our science of elements, because the
conditions under which alone the objects of human knowledge are
given must precede those under which they are thought.
I.

TRANSCENDENTAL DOCTRINE OF ELEMENTS.

FIRST PART. TRANSCENDENTAL AESTHETIC.

SS I. Introductory.

In whatsoever mode, or by whatsoever means, our knowledge may relate
to objects, it is at least quite clear that the only manner in which
it immediately relates to them is by means of an intuition. To this as
the indispensable groundwork, all thought points. But an intuition can
take place only in so far as the object is given to us. This, again,
is only possible, to man at least, on condition that the object affect
the mind in a certain manner. The capacity for receiving
representations (receptivity) through the mode in which we are
affected by objects, objects, is called sensibility. By means of
sensibility, therefore, objects are given to us, and it alone
furnishes us with intuitions; by the understanding they are thought,
and from it arise conceptions. But an thought must directly, or
indirectly, by means of certain signs, relate ultimately to
intuitions; consequently, with us, to sensibility, because in no other
way can an object be given to us.
The effect of an object upon the faculty of representation, so far
as we are affected by the said object, is sensation. That sort of
intuition which relates to an object by means of sensation is called
an empirical intuition. The undetermined object of an empirical
intuition is called phenomenon. That which in the phenomenon
corresponds to the sensation, I term its matter; but that which
effects that the content of the phenomenon can be arranged under
certain relations, I call its form. But that in which our sensations
are merely arranged, and by which they are susceptible of assuming a
certain form, cannot be itself sensation. It is, then, the matter of
all phenomena that is given to us a posteriori; the form must lie
ready a priori for them in the mind, and consequently can be
regarded separately from all sensation.
I call all representations pure, in the transcendental meaning of
the word, wherein nothing is met with that belongs to sensation. And
accordingly we find existing in the mind a priori, the pure form of
sensuous intuitions in general, in which all the manifold content of
the phenomenal world is arranged and viewed under certain relations.
This pure form of sensibility I shall call pure intuition. Thus, if
I take away from our representation of a body all that the
understanding thinks as belonging to it, as substance, force,
divisibility, etc., and also whatever belongs to sensation, as
impenetrability, hardness, colour, etc.; yet there is still
something left us from this empirical intuition, namely, extension and
shape. These belong to pure intuition, which exists a priori in the
mind, as a mere form of sensibility, and without any real object of
the senses or any sensation.
The science of all the principles of sensibility a priori, I call
transcendental aesthetic.* There must, then, be such a science forming
the first part of the transcendental doctrine of elements, in
contradistinction to that part which contains the principles of pure
thought, and which is called transcendental logic.

*The Germans are the only people who at present use this word to
indicate what others call the critique of taste. At the foundation
of this term lies the disappointed hope, which the eminent analyst,
Baumgarten, conceived, of subjecting the criticism of the beautiful to
principles of reason, and so of elevating its rules into a science.
But his endeavours were vain. For the said rules or criteria are, in
respect to their chief sources, merely empirical, consequently never
can serve as determinate laws a priori, by which our judgement in
matters of taste is to be directed. It is rather our judgement which
forms the proper test as to the correctness of the principles. On this
account it is advisable to give up the use of the term as
designating the critique of taste, and to apply it solely to that
doctrine, which is true science- the science of the laws of
sensibility- and thus come nearer to the language and the sense of the
ancients in their well-known division of the objects of cognition into
aiotheta kai noeta, or to share it with speculative philosophy, and
employ it partly in a transcendental, partly in a psychological
signification.

In the science of transcendental aesthetic accordingly, we shall
first isolate sensibility or the sensuous faculty, by separating
from it all that is annexed to its perceptions by the conceptions of
understanding, so that nothing be left but empirical intuition. In the
next place we shall take away from this intuition all that belongs
to sensation, so that nothing may remain but pure intuition, and the
mere form of phenomena, which is all that the sensibility can afford a
priori. From this investigation it will be found that there are two
pure forms of sensuous intuition, as principles of knowledge a priori,
namely, space and time. To the consideration of these we shall now
proceed.

SECTION I. Of Space.

SS 2. Metaphysical Exposition of this Conception.

By means of the external sense (a property of the mind), we
represent to ourselves objects as without us, and these all in
space. Herein alone are their shape, dimensions, and relations to each
other determined or determinable. The internal sense, by means of
which the mind contemplates itself or its internal state, gives,
indeed, no intuition of the soul as an object; yet there is
nevertheless a determinate form, under which alone the contemplation
of our internal state is possible, so that all which relates to the
inward determinations of the mind is represented in relations of time.
Of time we cannot have any external intuition, any more than we can
have an internal intuition of space. What then are time and space? Are
they real existences? Or, are they merely relations or
determinations of things, such, however, as would equally belong to
these things in themselves, though they should never become objects of
intuition; or, are they such as belong only to the form of
intuition, and consequently to the subjective constitution of the
mind, without which these predicates of time and space could not be
attached to any object? In order to become informed on these points,
we shall first give an exposition of the conception of space. By
exposition, I mean the clear, though not detailed, representation of
that which belongs to a conception; and an exposition is
metaphysical when it contains that which represents the conception
as given a priori.
1. Space is not a conception which has been derived from outward
experiences. For, in order that certain sensations may relate to
something without me (that is, to something which occupies a different
part of space from that in which I am); in like manner, in order
that I may represent them not merely as without, of, and near to
each other, but also in separate places, the representation of space
must already exist as a foundation. Consequently, the representation
of space cannot be borrowed from the relations of external phenomena
through experience; but, on the contrary, this external experience
is itself only possible through the said antecedent representation.
2. Space then is a necessary representation a priori, which serves
for the foundation of all external intuitions. We never can imagine or
make a representation to ourselves of the non-existence of space,
though we may easily enough think that no objects are found in it.
It must, therefore, be considered as the condition of the
possibility of phenomena, and by no means as a determination dependent
on them, and is a representation a priori, which necessarily
supplies the basis for external phenomena.
3. Space is no discursive, or as we say, general conception of the
relations of things, but a pure intuition. For, in the first place, we
can only represent to ourselves one space, and, when we talk of divers
spaces, we mean only parts of one and the same space. Moreover,
these parts cannot antecede this one all-embracing space, as the
component parts from which the aggregate can be made up, but can be
cogitated only as existing in it. Space is essentially one, and
multiplicity in it, consequently the general notion of spaces, of this
or that space, depends solely upon limitations. Hence it follows
that an a priori intuition (which is not empirical) lies at the root
of all our conceptions of space. Thus, moreover, the principles of
geometry- for example, that "in a triangle, two sides together are
greater than the third," are never deduced from general conceptions of
line and triangle, but from intuition, and this a priori, with
apodeictic certainty.
4. Space is represented as an infinite given quantity. Now every
conception must indeed be considered as a representation which is
contained in an infinite multitude of different possible
representations, which, therefore, comprises these under itself; but
no conception, as such, can be so conceived, as if it contained within
itself an infinite multitude of representations. Nevertheless, space
is so conceived of, for all parts of space are equally capable of
being produced to infinity. Consequently, the original
representation of space is an intuition a priori, and not a
conception.

SS 3. Transcendental Exposition of the Conception of Space.

By a transcendental exposition, I mean the explanation of a
conception, as a principle, whence can be discerned the possibility of
other synthetical a priori cognitions. For this purpose, it is
requisite, firstly, that such cognitions do really flow from the given
conception; and, secondly, that the said cognitions are only
possible under the presupposition of a given mode of explaining this
conception.
Geometry is a science which determines the properties of space
synthetically, and yet a priori. What, then, must be our
representation of space, in order that such a cognition of it may be
possible? It must be originally intuition, for from a mere conception,
no propositions can be deduced which go out beyond the conception, and
yet this happens in geometry. (Introd. V.) But this intuition must
be found in the mind a priori, that is, before any perception of
objects, consequently must be pure, not empirical, intuition. For
geometrical principles are always apodeictic, that is, united with the
consciousness of their necessity, as: "Space has only three
dimensions." But propositions of this kind cannot be empirical
judgements, nor conclusions from them. (Introd. II.) Now, how can an
external intuition anterior to objects themselves, and in which our
conception of objects can be determined a priori, exist in the human
mind? Obviously not otherwise than in so far as it has its seat in the
subject only, as the formal capacity of the subject's being affected
by objects, and thereby of obtaining immediate representation, that
is, intuition; consequently, only as the form of the external sense in
general.
Thus it is only by means of our explanation that the possibility
of geometry, as a synthetical science a priori, becomes
comprehensible. Every mode of explanation which does not show us
this possibility, although in appearance it may be similar to ours,
can with the utmost certainty be distinguished from it by these marks.

SS 4. Conclusions from the foregoing Conceptions.

(a) Space does Space does not represent any property of objects as
things in themselves, nor does it represent them in their relations to
each other; in other words, space does not represent to us any
determination of objects such as attaches to the objects themselves,
and would remain, even though all subjective conditions of the
intuition were abstracted. For neither absolute nor relative
determinations of objects can be intuited prior to the existence of
the things to which they belong, and therefore not a priori.
(b) Space is nothing else than the form of all phenomena of the
external sense, that is, the subjective condition of the
sensibility, under which alone external intuition is possible. Now,
because the receptivity or capacity of the subject to be affected by
objects necessarily antecedes all intuitions of these objects, it is
easily understood how the form of all phenomena can be given in the
mind previous to all actual perceptions, therefore a priori, and how
it, as a pure intuition, in which all objects must be determined,
can contain principles of the relations of these objects prior to
all experience.
It is therefore from the human point of view only that we can
speak of space, extended objects, etc. If we depart from the
subjective condition, under which alone we can obtain external
intuition, or, in other words, by means of which we are affected by
objects, the representation of space has no meaning whatsoever. This
predicate is only applicable to things in so far as they appear to us,
that is, are objects of sensibility. The constant form of this
receptivity, which we call sensibility, is a necessary condition of
all relations in which objects can be intuited as existing without us,
and when abstraction of these objects is made, is a pure intuition, to
which we give the name of space. It is clear that we cannot make the
special conditions of sensibility into conditions of the possibility
of things, but only of the possibility of their existence as far as
they are phenomena. And so we may correctly say that space contains
all which can appear to us externally, but not all things considered
as things in themselves, be they intuited or not, or by whatsoever
subject one will. As to the intuitions of other thinking beings, we
cannot judge whether they are or are not bound by the same
conditions which limit our own intuition, and which for us are
universally valid. If we join the limitation of a judgement to the
conception of the subject, then the judgement will possess
unconditioned validity. For example, the proposition, "All objects are
beside each other in space," is valid only under the limitation that
these things are taken as objects of our sensuous intuition. But if
I join the condition to the conception and say, "All things, as
external phenomena, are beside each other in space," then the rule
is valid universally, and without any limitation. Our expositions,
consequently, teach the reality (i.e., the objective validity) of
space in regard of all which can be presented to us externally as
object, and at the same time also the ideality of space in regard to
objects when they are considered by means of reason as things in
themselves, that is, without reference to the constitution of our
sensibility. We maintain, therefore, the empirical reality of space in
regard to all possible external experience, although we must admit its
transcendental ideality; in other words, that it is nothing, so soon
as we withdraw the condition upon which the possibility of all
experience depends and look upon space as something that belongs to
things in themselves.
But, with the exception of space, there is no representation,
subjective and ref erring to something external to us, which could
be called objective a priori. For there are no other subjective
representations from which we can deduce synthetical propositions a
priori, as we can from the intuition of space. (See SS 3.)
Therefore, to speak accurately, no ideality whatever belongs to these,
although they agree in this respect with the representation of
space, that they belong merely to the subjective nature of the mode of
sensuous perception; such a mode, for example, as that of sight, of
hearing, and of feeling, by means of the sensations of colour,
sound, and heat, but which, because they are only sensations and not
intuitions, do not of themselves give us the cognition of any
object, least of all, an a priori cognition. My purpose, in the
above remark, is merely this: to guard any one against illustrating
the asserted ideality of space by examples quite insufficient, for
example, by colour, taste, etc.; for these must be contemplated not as
properties of things, but only as changes in the subject, changes
which may be different in different men. For, in such a case, that
which is originally a mere phenomenon, a rose, for example, is taken
by the empirical understanding for a thing in itself, though to
every different eye, in respect of its colour, it may appear
different. On the contrary, the transcendental conception of phenomena
in space is a critical admonition, that, in general, nothing which
is intuited in space is a thing in itself, and that space is not a
form which belongs as a property to things; but that objects are quite
unknown to us in themselves, and what we call outward objects, are
nothing else but mere representations of our sensibility, whose form
is space, but whose real correlate, the thing in itself, is not
known by means of these representations, nor ever can be, but
respecting which, in experience, no inquiry is ever made.

SECTION II. Of Time.

SS 5 Metaphysical Exposition of this Conception.

1. Time is not an empirical conception. For neither coexistence
nor succession would be perceived by us, if the representation of time
did not exist as a foundation a priori. Without this presupposition we
could not represent to ourselves that things exist together at one and
the same time, or at different times, that is, contemporaneously, or
in succession.
2. Time is a necessary representation, lying at the foundation of
all our intuitions. With regard to phenomena in general, we cannot
think away time from them, and represent them to ourselves as out of
and unconnected with time, but we can quite well represent to
ourselves time void of phenomena. Time is therefore given a priori. In
it alone is all reality of phenomena possible. These may all be
annihilated in thought, but time itself, as the universal condition of
their possibility, cannot be so annulled.
3. On this necessity a priori is also founded the possibility of
apodeictic principles of the relations of time, or axioms of time in
general, such as: "Time has only one dimension," "Different times
are not coexistent but successive" (as different spaces are not
successive but coexistent). These principles cannot be derived from
experience, for it would give neither strict universality, nor
apodeictic certainty. We should only be able to say, "so common
experience teaches us," but not "it must be so." They are valid as
rules, through which, in general, experience is possible; and they
instruct us respecting experience, and not by means of it.
4. Time is not a discursive, or as it is called, general conception,
but a pure form of the sensuous intuition. Different times are
merely parts of one and the same time. But the representation which
can only be given by a single object is an intuition. Besides, the
proposition that different times cannot be coexistent could not be
derived from a general conception. For this proposition is
synthetical, and therefore cannot spring out of conceptions alone.
It is therefore contained immediately in the intuition and
representation of time.
5. The infinity of time signifies nothing more than that every
determined quantity of time is possible only through limitations of
one time lying at the foundation. Consequently, the original
representation, time, must be given as unlimited. But as the
determinate representation of the parts of time and of every
quantity of an object can only be obtained by limitation, the complete
representation of time must not be furnished by means of
conceptions, for these contain only partial representations.
Conceptions, on the contrary, must have immediate intuition for
their basis.

SS 6 Transcendental Exposition of the Conception of Time.

I may here refer to what is said above (SS 5, 3), where, for or sake
of brevity, I have placed under the head of metaphysical exposition,
that which is properly transcendental. Here I shall add that the
conception of change, and with it the conception of motion, as
change of place, is possible only through and in the representation of
time; that if this representation were not an intuition (internal) a
priori, no conception, of whatever kind, could render comprehensible
the possibility of change, in other words, of a conjunction of
contradictorily opposed predicates in one and the same object, for
example, the presence of a thing in a place and the non-presence of
the same thing in the same place. It is only in time that it is
possible to meet with two contradictorily opposed determinations in
one thing, that is, after each other. thus our conception of time
explains the possibility of so much synthetical knowledge a priori, as
is exhibited in the general doctrine of motion, which is not a
little fruitful.

SS 7 Conclusions from the above Conceptions.

(a) Time is not something which subsists of itself, or which inheres
in things as an objective determination, and therefore remains, when
abstraction is made of the subjective conditions of the intuition of
things. For in the former case, it would be something real, yet
without presenting to any power of perception any real object. In
the latter case, as an order or determination inherent in things
themselves, it could not be antecedent to things, as their
condition, nor discerned or intuited by means of synthetical
propositions a priori. But all this is quite possible when we regard
time as merely the subjective condition under which all our intuitions
take place. For in that case, this form of the inward intuition can be
represented prior to the objects, and consequently a priori.
(b) Time is nothing else than the form of the internal sense, that
is, of the intuitions of self and of our internal state. For time
cannot be any determination of outward phenomena. It has to do neither
with shape nor position; on the contrary, it determines the relation
of representations in our internal state. And precisely because this
internal intuition presents to us no shape or form, we endeavour to
supply this want by analogies, and represent the course of time by a
line progressing to infinity, the content of which constitutes a
series which is only of one dimension; and we conclude from the
properties of this line as to all the properties of time, with this
single exception, that the parts of the line are coexistent, whilst
those of time are successive. From this it is clear also that the
representation of time is itself an intuition, because all its
relations can be expressed in an external intuition.
(c) Time is the formal condition a priori of all phenomena
whatsoever. Space, as the pure form of external intuition, is
limited as a condition a priori to external phenomena alone. On the
other hand, because all representations, whether they have or have not
external things for their objects, still in themselves, as
determinations of the mind, belong to our internal state; and
because this internal state is subject to the formal condition of
the internal intuition, that is, to time- time is a condition a priori
of all phenomena whatsoever- the immediate condition of all
internal, and thereby the mediate condition of all external phenomena.
If I can say a priori, "All outward phenomena are in space, and
determined a priori according to the relations of space," I can
also, from the principle of the internal sense, affirm universally,
"All phenomena in general, that is, all objects of the senses, are
in time and stand necessarily in relations of time."
If we abstract our internal intuition of ourselves and all
external intuitions, possible only by virtue of this internal
intuition and presented to us by our faculty of representation, and
consequently take objects as they are in themselves, then time is
nothing. It is only of objective validity in regard to phenomena,
because these are things which we regard as objects of our senses.
It no longer objective we, make abstraction of the sensuousness of our
intuition, in other words, of that mode of representation which is
peculiar to us, and speak of things in general. Time is therefore
merely a subjective condition of our (human) intuition (which is
always sensuous, that is, so far as we are affected by objects), and
in itself, independently of the mind or subject, is nothing.
Nevertheless, in respect of all phenomena, consequently of all
things which come within the sphere of our experience, it is
necessarily objective. We cannot say, "All things are in time,"
because in this conception of things in general, we abstract and
make no mention of any sort of intuition of things. But this is the
proper condition under which time belongs to our representation of
objects. If we add the condition to the conception, and say, "All
things, as phenomena, that is, objects of sensuous intuition, are in
time," then the proposition has its sound objective validity and
universality a priori.
What we have now set forth teaches, therefore, the empirical reality
of time; that is, its objective validity in reference to all objects
which can ever be presented to our senses. And as our intuition is
always sensuous, no object ever can be presented to us in
experience, which does not come under the conditions of time. On the
other hand, we deny to time all claim to absolute reality; that is, we
deny that it, without having regard to the form of our sensuous
intuition, absolutely inheres in things as a condition or property.
Such properties as belong to objects as things in themselves never can
be presented to us through the medium of the senses. Herein
consists, therefore, the transcendental ideality of time, according to
which, if we abstract the subjective conditions of sensuous intuition,
it is nothing, and cannot be reckoned as subsisting or inhering in
objects as things in themselves, independently of its relation to
our intuition. this ideality, like that of space, is not to be
proved or illustrated by fallacious analogies with sensations, for
this reason- that in such arguments or illustrations, we make the
presupposition that the phenomenon, in which such and such
predicates inhere, has objective reality, while in this case we can
only find such an objective reality as is itself empirical, that is,
regards the object as a mere phenomenon. In reference to this subject,
see the remark in Section I (SS 4)

SS 8 Elucidation.

Against this theory, which grants empirical reality to time, but
denies to it absolute and transcendental reality, I have heard from
intelligent men an objection so unanimously urged that I conclude that
it must naturally present itself to every reader to whom these
considerations are novel. It runs thus: "Changes are real" (this the
continual change in our own representations demonstrates, even
though the existence of all external phenomena, together with their
changes, is denied). Now, changes are only possible in time, and
therefore time must be something real. But there is no difficulty in
answering this. I grant the whole argument. Time, no doubt, is
something real, that is, it is the real form of our internal
intuition. It therefore has subjective reality, in reference to our
internal experience, that is, I have really the representation of time
and of my determinations therein. Time, therefore, is not to be
regarded as an object, but as the mode of representation of myself
as an object. But if I could intuite myself, or be intuited by another
being, without this condition of sensibility, then those very
determinations which we now represent to ourselves as changes, would
present to us a knowledge in which the representation of time, and
consequently of change, would not appear. The empirical reality of
time, therefore, remains, as the condition of all our experience.
But absolute reality, according to what has been said above, cannot be
granted it. Time is nothing but the form of our internal intuition.*
If we take away from it the special condition of our sensibility,
the conception of time also vanishes; and it inheres not in the
objects themselves, but solely in the subject (or mind) which intuites
them.

*I can indeed say "my representations follow one another, or are
successive"; but this means only that we are conscious of them as in a
succession, that is, according to the form of the internal sense.
Time, therefore, is not a thing in itself, nor is it any objective
determination pertaining to, or inherent in things.

But the reason why this objection is so unanimously brought
against our doctrine of time, and that too by disputants who cannot
start any intelligible arguments against the doctrine of the
ideality of space, is this- they have no hope of demonstrating
apodeictically the absolute reality of space, because the doctrine
of idealism is against them, according to which the reality of
external objects is not capable of any strict proof. On the other
hand, the reality of the object of our internal sense (that is, myself
and my internal state) is clear immediately through consciousness. The
former- external objects in space- might be a mere delusion, but the
latter- the object of my internal perception- is undeniably real. They
do not, however, reflect that both, without question of their
reality as representations, belong only to the genus phenomenon, which
has always two aspects, the one, the object considered as a thing in
itself, without regard to the mode of intuiting it, and the nature
of which remains for this very reason problematical, the other, the
form of our intuition of the object, which must be sought not in the
object as a thing in itself, but in the subject to which it appears-
which form of intuition nevertheless belongs really and necessarily to
the phenomenal object.
Time and space are, therefore, two sources of knowledge, from which,
a priori, various synthetical cognitions can be drawn. Of this we find
a striking example in the cognitions of space and its relations, which
form the foundation of pure mathematics. They are the two pure forms
of all intuitions, and thereby make synthetical propositions a
priori possible. But these sources of knowledge being merely
conditions of our sensibility, do therefore, and as such, strictly
determine their own range and purpose, in that they do not and
cannot present objects as things in themselves, but are applicable
to them solely in so far as they are considered as sensuous phenomena.
The sphere of phenomena is the only sphere of their validity, and if
we venture out of this, no further objective use can be made of
them. For the rest, this formal reality of time and space leaves the
validity of our empirical knowledge unshaken; for our certainty in
that respect is equally firm, whether these forms necessarily inhere
in the things themselves, or only in our intuitions of them. On the
other hand, those who maintain the absolute reality of time and space,
whether as essentially subsisting, or only inhering, as modifications,
in things, must find themselves at utter variance with the
principles of experience itself. For, if they decide for the first
view, and make space and time into substances, this being the side
taken by mathematical natural philosophers, they must admit two
self-subsisting nonentities, infinite and eternal, which exist (yet
without there being anything real) for the purpose of containing in
themselves everything that is real. If they adopt the second view of
inherence, which is preferred by some metaphysical natural
philosophers, and regard space and time as relations (contiguity in
space or succession in time), abstracted from experience, though
represented confusedly in this state of separation, they find
themselves in that case necessitated to deny the validity of
mathematical doctrines a priori in reference to real things (for
example, in space)- at all events their apodeictic certainty. For such
certainty cannot be found in an a posteriori proposition; and the
conceptions a priori of space and time are, according to this opinion,
mere creations of the imagination, having their source really in
experience, inasmuch as, out of relations abstracted from
experience, imagination has made up something which contains,
indeed, general statements of these relations, yet of which no
application can be made without the restrictions attached thereto by
nature. The former of these parties gains this advantage, that they
keep the sphere of phenomena free for mathematical science. On the
other hand, these very conditions (space and time) embarrass them
greatly, when the understanding endeavours to pass the limits of
that sphere. The latter has, indeed, this advantage, that the
representations of space and time do not come in their way when they
wish to judge of objects, not as phenomena, but merely in their
relation to the understanding. Devoid, however, of a true and
objectively valid a priori intuition, they can neither furnish any
basis for the possibility of mathematical cognitions a priori, nor
bring the propositions of experience into necessary accordance with
those of mathematics. In our theory of the true nature of these two
original forms of the sensibility, both difficulties are surmounted.
In conclusion, that transcendental aesthetic cannot contain any more
than these two elements- space and time, is sufficiently obvious
from the fact that all other conceptions appertaining to
sensibility, even that of motion, which unites in itself both
elements, presuppose something empirical. Motion, for example,
presupposes the perception of something movable. But space
considered in itself contains nothing movable, consequently motion
must be something which is found in space only through experience-
in other words, an empirical datum. In like manner, transcendental
aesthetic cannot number the conception of change among its data a
priori; for time itself does not change, but only something which is
in time. To acquire the conception of change, therefore, the
perception of some existing object and of the succession of its
determinations, in one word, experience, is necessary.

SS 9 General Remarks on Transcendental Aesthetic.

I. In order to prevent any misunderstanding, it will be requisite,
in the first place, to recapitulate, as clearly as possible, what
our opinion is with respect to the fundamental nature of our
sensuous cognition in general. We have intended, then, to say that all
our intuition is nothing but the representation of phenomena; that the
things which we intuite, are not in themselves the same as our
representations of them in intuition, nor are their relations in
themselves so constituted as they appear to us; and that if we take
away the subject, or even only the subjective constitution of our
senses in general, then not only the nature and relations of objects
in space and time, but even space and time themselves disappear; and
that these, as phenomena, cannot exist in themselves, but only in
us. What may be the nature of objects considered as things in
themselves and without reference to the receptivity of our sensibility
is quite unknown to us. We know nothing more than our mode of
perceiving them, which is peculiar to us, and which, though not of
necessity pertaining to every animated being, is so to the whole human
race. With this alone we have to do. Space and time are the pure forms
thereof; sensation the matter. The former alone can we cognize a
priori, that is, antecedent to all actual perception; and for this
reason such cognition is called pure intuition. The latter is that
in our cognition which is called cognition a posteriori, that is,
empirical intuition. The former appertain absolutely and necessarily
to our sensibility, of whatsoever kind our sensations may be; the
latter may be of very diversified character. Supposing that we
should carry our empirical intuition even to the very highest degree
of clearness, we should not thereby advance one step nearer to a
knowledge of the constitution of objects as things in themselves.
For we could only, at best, arrive at a complete cognition of our
own mode of intuition, that is of our sensibility, and this always
under the conditions originally attaching to the subject, namely,
the conditions of space and time; while the question: "What are
objects considered as things in themselves?" remains unanswerable even
after the most thorough examination of the phenomenal world.
To say, then, that all our sensibility is nothing but the confused
representation of things containing exclusively that which belongs
to them as things in themselves, and this under an accumulation of
characteristic marks and partial representations which we cannot
distinguish in consciousness, is a falsification of the conception
of sensibility and phenomenization, which renders our whole doctrine
thereof empty and useless. The difference between a confused and a
clear representation is merely logical and has nothing to do with
content. No doubt the conception of right, as employed by a sound
understanding, contains all that the most subtle investigation could
unfold from it, although, in the ordinary practical use of the word,
we are not conscious of the manifold representations comprised in
the conception. But we cannot for this reason assert that the ordinary
conception is a sensuous one, containing a mere phenomenon, for
right cannot appear as a phenomenon; but the conception of it lies
in the understanding, and represents a property (the moral property)
of actions, which belongs to them in themselves. On the other hand,
the representation in intuition of a body contains nothing which could
belong to an object considered as a thing in itself, but merely the
phenomenon or appearance of something, and the mode in which we are
affected by that appearance; and this receptivity of our faculty of
cognition is called sensibility, and remains toto caelo different from
the cognition of an object in itself, even though we should examine
the content of the phenomenon to the very bottom.
It must be admitted that the Leibnitz-Wolfian philosophy has
assigned an entirely erroneous point of view to all investigations
into the nature and origin of our cognitions, inasmuch as it regards
the distinction between the sensuous and the intellectual as merely
logical, whereas it is plainly transcendental, and concerns not merely
the clearness or obscurity, but the content and origin of both. For
the faculty of sensibility not only does not present us with an
indistinct and confused cognition of objects as things in
themselves, but, in fact, gives us no knowledge of these at all. On
the contrary, so soon as we abstract in thought our own subjective
nature, the object represented, with the properties ascribed to it
by sensuous intuition, entirely disappears, because it was only this
subjective nature that determined the form of the object as a
phenomenon.
In phenomena, we commonly, indeed, distinguish that which
essentially belongs to the intuition of them, and is valid for the
sensuous faculty of every human being, from that which belongs to
the same intuition accidentally, as valid not for the sensuous faculty
in general, but for a particular state or organization of this or that
sense. Accordingly, we are accustomed to say that the former is a
cognition which represents the object itself, whilst the latter
presents only a particular appearance or phenomenon thereof. This
distinction, however, is only empirical. If we stop here (as is
usual), and do not regard the empirical intuition as itself a mere
phenomenon (as we ought to do), in which nothing that can appertain to
a thing in itself is to be found, our transcendental distinction is
lost, and we believe that we cognize objects as things in
themselves, although in the whole range of the sensuous world,
investigate the nature of its objects as profoundly as we may, we have
to do with nothing but phenomena. Thus, we call the rainbow a mere
appearance of phenomenon in a sunny shower, and the rain, the
reality or thing in itself; and this is right enough, if we understand
the latter conception in a merely physical sense, that is, as that
which in universal experience, and under whatever conditions of
sensuous perception, is known in intuition to be so and so determined,
and not otherwise. But if we consider this empirical datum
generally, and inquire, without reference to its accordance with all
our senses, whether there can be discovered in it aught which
represents an object as a thing in itself (the raindrops of course are
not such, for they are, as phenomena, empirical objects), the question
of the relation of the representation to the object is transcendental;
and not only are the raindrops mere phenomena, but even their circular
form, nay, the space itself through which they fall, is nothing in
itself, but both are mere modifications or fundamental dispositions of
our sensuous intuition, whilst the transcendental object remains for
us utterly unknown.
The second important concern of our aesthetic is that it does not
obtain favour merely as a plausible hypothesis, but possess as
undoubted a character of certainty as can be demanded of any theory
which is to serve for an organon. In order fully to convince the
reader of this certainty, we shall select a case which will serve to
make its validity apparent, and also to illustrate what has been
said in SS 3.
Suppose, then, that space and time are in themselves objective,
and conditions of the- possibility of objects as things in themselves.
In the first place, it is evident that both present us, with very many
apodeictic and synthetic propositions a priori, but especially
space- and for this reason we shall prefer it for investigation at
present. As the propositions of geometry are cognized synthetically
a priori, and with apodeictic certainty, I inquire: Whence do you
obtain propositions of this kind, and on what basis does the
understanding rest, in order to arrive at such absolutely necessary
and universally valid truths?
There is no other way than through intuitions or conceptions, as
such; and these are given either a priori or a posteriori. The latter,
namely, empirical conceptions, together with the empirical intuition
on which they are founded, cannot afford any synthetical
proposition, except such as is itself also empirical, that is, a
proposition of experience. But an empirical proposition cannot possess
the qualities of necessity and absolute universality, which,
nevertheless, are the characteristics of all geometrical propositions.
As to the first and only means to arrive at such cognitions, namely,
through mere conceptions or intuitions a priori, it is quite clear
that from mere conceptions no synthetical cognitions, but only
analytical ones, can be obtained. Take, for example, the
proposition: "Two straight lines cannot enclose a space, and with
these alone no figure is possible," and try to deduce it from the
conception of a straight line and the number two; or take the
proposition: "It is possible to construct a figure with three straight
lines," and endeavour, in like manner, to deduce it from the mere
conception of a straight line and the number three. All your
endeavours are in vain, and you find yourself forced to have
recourse to intuition, as, in fact, geometry always does. You
therefore give yourself an object in intuition. But of what kind is
this intuition? Is it a pure a priori, or is it an empirical
intuition? If the latter, then neither an universally valid, much less
an apodeictic proposition can arise from it, for experience never
can give us any such proposition. You must, therefore, give yourself
an object a priori in intuition, and upon that ground your synthetical
proposition. Now if there did not exist within you a faculty of
intuition a priori; if this subjective condition were not in respect
to its form also the universal condition a priori under which alone
the object of this external intuition is itself possible; if the
object (that is, the triangle) were something in itself, without
relation to you the subject; how could you affirm that that which lies
necessarily in your subjective conditions in order to construct a
triangle, must also necessarily belong to the triangle in itself?
For to your conceptions of three lines, you could not add anything new
(that is, the figure); which, therefore, must necessarily be found
in the object, because the object is given before your cognition,
and not by means of it. If, therefore, space (and time also) were
not a mere form of your intuition, which contains conditions a priori,
under which alone things can become external objects for you, and
without which subjective conditions the objects are in themselves
nothing, you could not construct any synthetical proposition
whatsoever regarding external objects. It is therefore not merely
possible or probable, but indubitably certain, that space and time, as
the necessary conditions of all our external and internal
experience, are merely subjective conditions of all our intuitions, in
relation to which all objects are therefore mere phenomena, and not
things in themselves, presented to us in this particular manner. And
for this reason, in respect to the form of phenomena, much may be said
a priori, whilst of the thing in itself, which may lie at the
foundation of these phenomena, it is impossible to say anything.
II. In confirmation of this theory of the ideality of the external
as well as internal sense, consequently of all objects of sense, as
mere phenomena, we may especially remark that all in our cognition
that belongs to intuition contains nothing more than mere relations.
(The feelings of pain and pleasure, and the will, which are not
cognitions, are excepted.) The relations, to wit, of place in an
intuition (extension), change of place (motion), and laws according to
which this change is determined (moving forces). That, however,
which is present in this or that place, or any operation going on,
or result taking place in the things themselves, with the exception of
change of place, is not given to us by intuition. Now by means of mere
relations, a thing cannot be known in itself; and it may therefore
be fairly concluded, that, as through the external sense nothing but
mere representations of relations are given us, the said external
sense in its representation can contain only the relation of the
object to the subject, but not the essential nature of the object as a
thing in itself.
The same is the case with the internal intuition, not only
because, in the internal intuition, the representation of the external
senses constitutes the material with which the mind is occupied; but
because time, in which we place, and which itself antecedes the
consciousness of, these representations in experience, and which, as
the formal condition of the mode according to which objects are placed
in the mind, lies at the foundation of them, contains relations of the
successive, the coexistent, and of that which always must be
coexistent with succession, the permanent. Now that which, as
representation, can antecede every exercise of thought (of an object),
is intuition; and when it contains nothing but relations, it is the
form of the intuition, which, as it presents us with no
representation, except in so far as something is placed in the mind,
can be nothing else than the mode in which the mind is affected by its
own activity, to wit- its presenting to itself representations,
consequently the mode in which the mind is affected by itself; that
is, it can be nothing but an internal sense in respect to its form.
Everything that is represented through the medium of sense is so far
phenomenal; consequently, we must either refuse altogether to admit an
internal sense, or the subject, which is the object of that sense,
could only be represented by it as phenomenon, and not as it would
judge of itself, if its intuition were pure spontaneous activity, that
is, were intellectual. The difficulty here lies wholly in the
question: How can the subject have an internal intuition of itself?
But this difficulty is common to every theory. The consciousness of
self (apperception) is the simple representation of the "ego"; and
if by means of that representation alone, all the manifold
representations in the subject were spontaneously given, then our
internal intuition would be intellectual. This consciousness in man
requires an internal perception of the manifold representations
which are previously given in the subject; and the manner in which
these representations are given in the mind without spontaneity, must,
on account of this difference (the want of spontaneity), be called
sensibility. If the faculty of self-consciousness is to apprehend what
lies in the mind, it must all act that and can in this way alone
produce an intuition of self. But the form of this intuition, which
lies in the original constitution of the mind, determines, in the
representation of time, the manner in which the manifold
representations are to combine themselves in the mind; since the
subject intuites itself, not as it would represent itself
immediately and spontaneously, but according to the manner in which
the mind is internally affected, consequently, as it appears, and
not as it is.
III. When we say that the intuition of external objects, and also
the self-intuition of the subject, represent both, objects and
subject, in space and time, as they affect our senses, that is, as
they appear- this is by no means equivalent to asserting that these
objects are mere illusory appearances. For when we speak of things
as phenomena, the objects, nay, even the properties which we ascribe
to them, are looked upon as really given; only that, in so far as this
or that property depends upon the mode of intuition of the subject, in
the relation of the given object to the subject, the object as
phenomenon is to be distinguished from the object as a thing in
itself. Thus I do not say that bodies seem or appear to be external to
me, or that my soul seems merely to be given in my self-consciousness,
although I maintain that the properties of space and time, in
conformity to which I set both, as the condition of their existence,
abide in my mode of intuition, and not in the objects in themselves.
It would be my own fault, if out of that which I should reckon as
phenomenon, I made mere illusory appearance.* But this will not
happen, because of our principle of the ideality of all sensuous
intuitions. On the contrary, if we ascribe objective reality to
these forms of representation, it becomes impossible to avoid changing
everything into mere appearance. For if we regard space and time as
properties, which must be found in objects as things in themselves, as
sine quibus non of the possibility of their existence, and reflect
on the absurdities in which we then find ourselves involved,
inasmuch as we are compelled to admit the existence of two infinite
things, which are nevertheless not substances, nor anything really
inhering in substances, nay, to admit that they are the necessary
conditions of the existence of all things, and moreover, that they
must continue to exist, although all existing things were annihilated-
we cannot blame the good Berkeley for degrading bodies to mere
illusory appearances. Nay, even our own existence, which would in this
case depend upon the self-existent reality of such a mere nonentity as
time, would necessarily be changed with it into mere appearance- an
absurdity which no one has as yet been guilty of.

*The predicates of the phenomenon can be affixed to the object
itself in relation to our sensuous faculty; for example, the red
colour or the perfume to the rose. But (illusory) appearance never can
be attributed as a predicate to an object, for this very reason,
that it attributes to this object in itself that which belongs to it
only in relation to our sensuous faculty, or to the subject in
general, e.g., the two handles which were formerly ascribed to Saturn.
That which is never to be found in the object itself, but always in
the relation of the object to the subject, and which moreover is
inseparable from our representation of the object, we denominate
phenomenon. Thus the predicates of space and time are rightly
attributed to objects of the senses as such, and in this there is no
illusion. On the contrary, if I ascribe redness of the rose as a thing
in itself, or to Saturn his handles, or extension to all external
objects, considered as things in themselves, without regarding the
determinate relation of these objects to the subject, and without
limiting my judgement to that relation- then, and then only, arises
illusion.

IV. In natural theology, where we think of an object- God- which
never can be an object of intuition to us, and even to himself can
never be an object of sensuous intuition, we carefully avoid
attributing to his intuition the conditions of space and time- and
intuition all his cognition must be, and not thought, which always
includes limitation. But with what right can we do this if we make
them forms of objects as things in themselves, and such, moreover,
as would continue to exist as a priori conditions of the existence
of things, even though the things themselves were annihilated? For
as conditions of all existence in general, space and time must be
conditions of the existence of the Supreme Being also. But if we do
not thus make them objective forms of all things, there is no other
way left than to make them subjective forms of our mode of
intuition- external and internal; which is called sensuous, because it
is not primitive, that is, is not such as gives in itself the
existence of the object of the intuition (a mode of intuition which,
so far as we can judge, can belong only to the Creator), but is
dependent on the existence of the object, is possible, therefore, only
on condition that the representative faculty of the subject is
affected by the object.
It is, moreover, not necessary that we should limit the mode of
intuition in space and time to the sensuous faculty of man. It may
well be that all finite thinking beings must necessarily in this
respect agree with man (though as to this we cannot decide), but
sensibility does not on account of this universality cease to be
sensibility, for this very reason, that it is a deduced (intuitus
derivativus), and not an original (intuitus originarius), consequently
not an intellectual intuition, and this intuition, as such, for
reasons above mentioned, seems to belong solely to the Supreme
Being, but never to a being dependent, quoad its existence, as well as
its intuition (which its existence determines and limits relatively to
given objects). This latter remark, however, must be taken only as
an illustration, and not as any proof of the truth of our
aesthetical theory.

SS 10 Conclusion of the Transcendental Aesthetic.

We have now completely before us one part of the solution of the
grand general problem of transcendental philosophy, namely, the
question: "How are synthetical propositions a priori possible?" That
is to say, we have shown that we are in possession of pure a priori
intuitions, namely, space and time, in which we find, when in a
judgement a priori we pass out beyond the given conception,
something which is not discoverable in that conception, but is
certainly found a priori in the intuition which corresponds to the
conception, and can be united synthetically with it. But the
judgements which these pure intuitions enable us to make, never
reach farther than to objects of the senses, and are valid only for
objects of possible experience.
INTRO
SECOND PART. TRANSCENDENTAL LOGIC.

INTRODUCTION. Idea of a Transcendental Logic.

I. Of Logic in General.

Our knowledge springs from two main sources in the mind, first of
which is the faculty or power of receiving representations
(receptivity for impressions); the second is the power of cognizing by
means of these representations (spontaneity in the production of
conceptions). Through the first an object is given to us; through
the second, it is, in relation to the representation (which is a
mere determination of the mind), thought. Intuition and conceptions
constitute, therefore, the elements of all our knowledge, so that
neither conceptions without an intuition in some way corresponding
to them, nor intuition without conceptions, can afford us a cognition.
Both are either pure or empirical. They are. empirical, when sensation
(which presupposes the actual presence of the object) is contained
in them; and pure, when no sensation is mixed with the representation.
Sensations we may call the matter of sensuous cognition. Pure
intuition consequently contains merely the form under which
something is intuited, and pure conception only the form of the
thought of an object. Only pure intuitions and pure conceptions are
possible a priori; the empirical only a posteriori.
We apply the term sensibility to the receptivity of the mind for
impressions, in so far as it is in some way affected; and, on the
other hand, we call the faculty of spontaneously producing
representations, or the spontaneity of cognition, understanding. Our
nature is so constituted that intuition with us never can be other
than sensuous, that is, it contains only the mode in which we are
affected by objects. On the other hand, the faculty of thinking the
object of sensuous intuition is the understanding. Neither of these
faculties has a preference over the other. Without the sensuous
faculty no object would be given to us, and without the
understanding no object would be thought. Thoughts without content are
void; intuitions without conceptions, blind. Hence it is as
necessary for the mind to make its conceptions sensuous (that is, to
join to them the object in intuition), as to make its intuitions
intelligible (that is, to bring them under conceptions). Neither of
these faculties can exchange its proper function. Understanding cannot
intuite, and the sensuous faculty cannot think. in no other way than
from the united operation of both, can knowledge arise. But no one
ought, on this account, to overlook the difference of the elements
contributed by each; we have rather great reason carefully to separate
and distinguish them. We therefore distinguish the science of the laws
of sensibility, that is, aesthetic, from the science of the laws of
the understanding, that is, logic.
Now, logic in its turn may be considered as twofold- namely, as
logic of the general, or of the particular use of the understanding.
The first contains the absolutely necessary laws of thought, without
which no use whatsoever of the understanding is possible, and gives
laws therefore to the understanding, without regard to the
difference of objects on which it may be employed. The logic of the
particular use of the understanding contains the laws of correct
thinking upon a particular class of objects. The former may be
called elemental logic- the latter, the organon of this or that
particular science. The latter is for the most part employed in the
schools, as a propaedeutic to the sciences, although, indeed,
according to the course of human reason, it is the last thing we
arrive at, when the science has been already matured, and needs only
the finishing touches towards its correction and completion; for our
knowledge of the objects of our attempted science must be tolerably
extensive and complete before we can indicate the laws by which a
science of these objects can be established.
General logic is again either pure or applied. In the former, we
abstract all the empirical conditions under which the understanding is
exercised; for example, the influence of the senses, the play of the
fantasy or imagination, the laws of the memory, the force of habit, of
inclination, etc., consequently also, the sources of prejudice- in a
word, we abstract all causes from which particular cognitions arise,
because these causes regard the understanding under certain
circumstances of its application, and, to the knowledge of them
experience is required. Pure general logic has to do, therefore,
merely with pure a priori principles, and is a canon of
understanding and reason, but only in respect of the formal part of
their use, be the content what it may, empirical or transcendental.
General logic is called applied, when it is directed to the laws of
the use of the understanding, under the subjective empirical
conditions which psychology teaches us. It has therefore empirical
principles, although, at the same time, it is in so far general,
that it applies to the exercise of the understanding, without regard
to the difference of objects. On this account, moreover, it is neither
a canon of the understanding in general, nor an organon of a
particular science, but merely a cathartic of the human understanding.
In general logic, therefore, that part which constitutes pure
logic must be carefully distinguished from that which constitutes
applied (though still general) logic. The former alone is properly
science, although short and dry, as the methodical exposition of an
elemental doctrine of the understanding ought to be. In this,
therefore, logicians must always bear in mind two rules:
1. As general logic, it makes abstraction of all content of the
cognition of the understanding, and of the difference of objects,
and has to do with nothing but the mere form of thought.
2. As pure logic, it has no empirical principles, and consequently
draws nothing (contrary to the common persuasion) from psychology,
which therefore has no influence on the canon of the understanding. It
is a demonstrated doctrine, and everything in it must be certain
completely a priori.
What I called applied logic (contrary to the common acceptation of
this term, according to which it should contain certain exercises
for the scholar, for which pure logic gives the rules), is a
representation of the understanding, and of the rules of its necessary
employment in concreto, that is to say, under the accidental
conditions of the subject, which may either hinder or promote this
employment, and which are all given only empirically. Thus applied
logic treats of attention, its impediments and consequences, of the
origin of error, of the state of doubt, hesitation, conviction,
etc., and to it is related pure general logic in the same way that
pure morality, which contains only the necessary moral laws of a
free will, is related to practical ethics, which considers these
laws under all the impediments of feelings, inclinations, and passions
to which men are more or less subjected, and which never can furnish
us with a true and demonstrated science, because it, as well as
applied logic, requires empirical and psychological principles.

II. Of Transcendental Logic.

General logic, as we have seen, makes abstraction of all content
of cognition, that is, of all relation of cognition to its object, and
regards only the logical form in the relation of cognitions to each
other, that is, the form of thought in general. But as we have both
pure and empirical intuitions (as transcendental aesthetic proves), in
like manner a distinction might be drawn between pure and empirical
thought (of objects). In this case, there would exist a kind of logic,
in which we should not make abstraction of all content of cognition;
for or logic which should comprise merely the laws of pure thought (of
an object), would of course exclude all those cognitions which were of
empirical content. This kind of logic would also examine the origin of
our cognitions of objects, so far as that origin cannot be ascribed to
the objects themselves; while, on the contrary, general logic has
nothing to do with the origin of our cognitions, but contemplates
our representations, be they given primitively a priori in
ourselves, or be they only of empirical origin, solely according to
the laws which the understanding observes in employing them in the
process of thought, in relation to each other. Consequently, general
logic treats of the form of the understanding only, which can be
applied to representations, from whatever source they may have arisen.
And here I shall make a remark, which the reader must bear well in
mind in the course of the following considerations, to wit, that not
every cognition a priori, but only those through which we cognize that
and how certain representations (intuitions or conceptions) are
applied or are possible only a priori; that is to say, the a priori
possibility of cognition and the a priori use of it are
transcendental. Therefore neither is space, nor any a priori
geometrical determination of space, a transcendental Representation,
but only the knowledge that such a representation is not of
empirical origin, and the possibility of its relating to objects of
experience, although itself a priori, can be called transcendental. So
also, the application of space to objects in general would be
transcendental; but if it be limited to objects of sense it is
empirical. Thus, the distinction of the transcendental and empirical
belongs only to the critique of cognitions, and does not concern the
relation of these to their object.
Accordingly, in the expectation that there may perhaps be
conceptions which relate a priori to objects, not as pure or
sensuous intuitions, but merely as acts of pure thought (which are
therefore conceptions, but neither of empirical nor aesthetical
origin)- in this expectation, I say, we form to ourselves, by
anticipation, the idea of a science of pure understanding and rational
cognition, by means of which we may cogitate objects entirely a
priori. A science of this kind, which should determine the origin, the
extent, and the objective validity of such cognitions, must be
called transcendental logic, because it has not, like general logic,
to do with the laws of understanding and reason in relation to
empirical as well as pure rational cognitions without distinction, but
concerns itself with these only in an a priori relation to objects.

III. Of the Division of General Logic into Analytic and Dialectic.

The old question with which people sought to push logicians into a
corner, so that they must either have recourse to pitiful sophisms
or confess their ignorance, and consequently the vanity of their whole
art, is this: "What is truth?" The definition of the word truth, to
wit, "the accordance of the cognition with its object," is presupposed
in the question; but we desire to be told, in the answer to it, what
is the universal and secure criterion of the truth of every cognition.
To know what questions we may reasonably propose is in itself a
strong evidence of sagacity and intelligence. For if a question be
in itself absurd and unsusceptible of a rational answer, it is
attended with the danger- not to mention the shame that falls upon the
person who proposes it- of seducing the unguarded listener into making
absurd answers, and we are presented with the ridiculous spectacle
of one (as the ancients said) "milking the he-goat, and the other
holding a sieve."
If truth consists in the accordance of a cognition with its
object, this object must be, ipso facto, distinguished from all
others; for a cognition is false if it does not accord with the object
to which it relates, although it contains something which may be
affirmed of other objects. Now an universal criterion of truth would
be that which is valid for all cognitions, without distinction of
their objects. But it is evident that since, in the case of such a
criterion, we make abstraction of all the content of a cognition (that
is, of all relation to its object), and truth relates precisely to
this content, it must be utterly absurd to ask for a mark of the truth
of this content of cognition; and that, accordingly, a sufficient, and
at the same time universal, test of truth cannot possibly be found. As
we have already termed the content of a cognition its matter, we shall
say: "Of the truth of our cognitions in respect of their matter, no
universal test can be demanded, because such a demand is
self-contradictory."
On the other hand, with regard to our cognition in respect of its
mere form (excluding all content), it is equally manifest that
logic, in so far as it exhibits the universal and necessary laws of
the understanding, must in these very laws present us with criteria of
truth. Whatever contradicts these rules is false, because thereby
the understanding is made to contradict its own universal laws of
thought; that is, to contradict itself. These criteria, however, apply
solely to the form of truth, that is, of thought in general, and in so
far they are perfectly accurate, yet not sufficient. For although a
cognition may be perfectly accurate as to logical form, that is, not
self-contradictory, it is notwithstanding quite possible that it may
not stand in agreement with its object. Consequently, the merely
logical criterion of truth, namely, the accordance of a cognition with
the universal and formal laws of understanding and reason, is
nothing more than the conditio sine qua non, or negative condition
of all truth. Farther than this logic cannot go, and the error which
depends not on the form, but on the content of the cognition, it has
no test to discover.
General logic, then, resolves the whole formal business of
understanding and reason into its elements, and exhibits them as
principles of all logical judging of our cognitions. This part of
logic may, therefore, be called analytic, and is at least the negative
test of truth, because all cognitions must first of an be estimated
and tried according to these laws before we proceed to investigate
them in respect of their content, in order to discover whether they
contain positive truth in regard to their object. Because, however,
the mere form of a cognition, accurately as it may accord with logical
laws, is insufficient to supply us with material (objective) truth, no
one, by means of logic alone, can venture to predicate anything of
or decide concerning objects, unless he has obtained, independently of
logic, well-grounded information about them, in order afterwards to
examine, according to logical laws, into the use and connection, in
a cohering whole, of that information, or, what is still better,
merely to test it by them. Notwithstanding, there lies so seductive
a charm in the possession of a specious art like this- an art which
gives to all our cognitions the form of the understanding, although
with respect to the content thereof we may be sadly deficient- that
general logic, which is merely a canon of judgement, has been employed
as an organon for the actual production, or rather for the semblance
of production, of objective assertions, and has thus been grossly
misapplied. Now general logic, in its assumed character of organon, is
called dialectic.
Different as are the significations in which the ancients used
this term for a science or an art, we may safely infer, from their
actual employment of it, that with them it was nothing else than a
logic of illusion- a sophistical art for giving ignorance, nay, even
intentional sophistries, the colouring of truth, in which the
thoroughness of procedure which logic requires was imitated, and their
topic employed to cloak the empty pretensions. Now it may be taken
as a safe and useful warning, that general logic, considered as an
organon, must always be a logic of illusion, that is, be
dialectical, for, as it teaches us nothing whatever respecting the
content of our cognitions, but merely the formal conditions of their
accordance with the understanding, which do not relate to and are
quite indifferent in respect of objects, any attempt to employ it as
an instrument (organon) in order to extend and enlarge the range of
our knowledge must end in mere prating; any one being able to maintain
or oppose, with some appearance of truth, any single assertion
whatever.
Such instruction is quite unbecoming the dignity of philosophy.
For these reasons we have chosen to denominate this part of logic
dialectic, in the sense of a critique of dialectical illusion, and
we wish the term to be so understood in this place.

IV. Of the Division of Transcendental Logic into Transcendental
Analytic and Dialectic.

In transcendental logic we isolate the understanding (as in
transcendental aesthetic the sensibility) and select from our
cognition merely that part of thought which has its origin in the
understanding alone. The exercise of this pure cognition, however,
depends upon this as its condition, that objects to which it may be
applied be given to us in intuition, for without intuition the whole
of our cognition is without objects, and is therefore quite void. That
part of transcendental logic, then, which treats of the elements of
pure cognition of the understanding, and of the principles without
which no object at all can be thought, is transcendental analytic, and
at the same time a logic of truth. For no cognition can contradict it,
without losing at the same time all content, that is, losing all
reference to an object, and therefore all truth. But because we are
very easily seduced into employing these pure cognitions and
principles of the understanding by themselves, and that even beyond
the boundaries of experience, which yet is the only source whence we
can obtain matter (objects) on which those pure conceptions may be
employed- understanding runs the risk of making, by means of empty
sophisms, a material and objective use of the mere formal principles
of the pure understanding, and of passing judgements on objects
without distinction- objects which are not given to us, nay, perhaps
cannot be given to us in any way. Now, as it ought properly to be only
a canon for judging of the empirical use of the understanding, this
kind of logic is misused when we seek to employ it as an organon of
the universal and unlimited exercise of the understanding, and attempt
with the pure understanding alone to judge synthetically, affirm,
and determine respecting objects in general. In this case the exercise
of the pure understanding becomes dialectical. The second part of
our transcendental logic must therefore be a critique of dialectical
illusion, and this critique we shall term transcendental dialectic-
not meaning it as an art of producing dogmatically such illusion (an
art which is unfortunately too current among the practitioners of
metaphysical juggling), but as a critique of understanding and
reason in regard to their hyperphysical use. This critique will expose
the groundless nature of the pretensions of these two faculties, and
invalidate their claims to the discovery and enlargement of our
cognitions merely by means of transcendental principles, and show that
the proper employment of these faculties is to test the judgements
made by the pure understanding, and to guard it from sophistical
delusion.
Transcendental Logic. FIRST DIVISION.

TRANSCENDENTAL ANALYTIC.

SS I.

Transcendental analytic is the dissection of the whole of our a
priori knowledge into the elements of the pure cognition of the
understanding. In order to effect our purpose, it is necessary: (1)
That the conceptions be pure and not empirical; (2) That they belong
not to intuition and sensibility, but to thought and understanding;
(3) That they be elementary conceptions, and as such, quite
different from deduced or compound conceptions; (4) That our table
of these elementary conceptions be complete, and fill up the whole
sphere of the pure understanding. Now this completeness of a science
cannot be accepted with confidence on the guarantee of a mere estimate
of its existence in an aggregate formed only by means of repeated
experiments and attempts. The completeness which we require is
possible only by means of an idea of the totality of the a priori
cognition of the understanding, and through the thereby determined
division of the conceptions which form the said whole; consequently,
only by means of their connection in a system. Pure understanding
distinguishes itself not merely from everything empirical, but also
completely from all sensibility. It is a unity self-subsistent,
self-sufficient, and not to be enlarged by any additions from without.
Hence the sum of its cognition constitutes a system to be determined
by and comprised under an idea; and the completeness and
articulation of this system can at the same time serve as a test of
the correctness and genuineness of all the parts of cognition that
belong to it. The whole of this part of transcendental logic
consists of two books, of which the one contains the conceptions,
and the other the principles of pure understanding.
BOOK I.

Analytic of Conceptions. SS 2

By the term Analytic of Conceptions, I do not understand the
analysis of these, or the usual process in philosophical
investigations of dissecting the conceptions which present themselves,
according to their content, and so making them clear; but I mean the
hitherto little attempted dissection of the faculty of understanding
itself, in order to investigate the possibility of conceptions a
priori, by looking for them in the understanding alone, as their
birthplace, and analysing the pure use of this faculty. For this is
the proper duty of a transcendental philosophy; what remains is the
logical treatment of the conceptions in philosophy in general. We
shall therefore follow up the pure conceptions even to their germs and
beginnings in the human understanding, in which they lie, until they
are developed on occasions presented by experience, and, freed by
the same understanding from the empirical conditions attaching to
them, are set forth in their unalloyed purity.
CHAPTER I. Of the Transcendental Clue to the Discovery of all Pure
Conceptions of the Understanding.

Introductory. SS 3

When we call into play a faculty of cognition, different conceptions
manifest themselves according to the different circumstances, and make
known this faculty, and assemble themselves into a more or less
extensive collection, according to the time or penetration that has
been applied to the consideration of them. Where this process,
conducted as it is mechanically, so to speak, will end, cannot be
determined with certainty. Besides, the conceptions which we
discover in this haphazard manner present themselves by no means in
order and systematic unity, but are at last coupled together only
according to resemblances to each other, and arranged in series,
according to the quantity of their content, from the simpler to the
more complex- series which are anything but systematic, though not
altogether without a certain kind of method in their construction.
Transcendental philosophy has the advantage, and moreover the
duty, of searching for its conceptions according to a principle;
because these conceptions spring pure and unmixed out of the
understanding as an absolute unity, and therefore must be connected
with each other according to one conception or idea. A connection of
this kind, however, furnishes us with a ready prepared rule, by
which its proper place may be assigned to every pure conception of the
understanding, and the completeness of the system of all be determined
a priori- both which would otherwise have been dependent on mere
choice or chance.

SECTION 1. Of defined above Use of understanding in General. SS 4

The understanding was defined above only negatively, as a
non-sensuous faculty of cognition. Now, independently of
sensibility, we cannot possibly have any intuition; consequently,
the understanding is no faculty of intuition. But besides intuition
there is no other mode of cognition, except through conceptions;
consequently, the cognition of every, at least of every human,
understanding is a cognition through conceptions- not intuitive, but
discursive. All intuitions, as sensuous, depend on affections;
conceptions, therefore, upon functions. By the word function I
understand the unity of the act of arranging diverse representations
under one common representation. Conceptions, then, are based on the
spontaneity of thought, as sensuous intuitions are on the
receptivity of impressions. Now, the understanding cannot make any
other use of these conceptions than to judge by means of them. As no
representation, except an intuition, relates immediately to its
object, a conception never relates immediately to an object, but
only to some other representation thereof, be that an intuition or
itself a conception. A judgement, therefore, is the mediate
cognition of an object, consequently the representation of a
representation of it. In every judgement there is a conception which
applies to, and is valid for many other conceptions, and which among
these comprehends also a given representation, this last being
immediately connected with an object. For example, in the judgement-
"All bodies are divisible," our conception of divisible applies to
various other conceptions; among these, however, it is here
particularly applied to the conception of body, and this conception of
body relates to certain phenomena which occur to us. These objects,
therefore, are mediately represented by the conception of
divisibility. All judgements, accordingly, are functions of unity in
our representations, inasmuch as, instead of an immediate, a higher
representation, which comprises this and various others, is used for
our cognition of the object, and thereby many possible cognitions
are collected into one. But we can reduce all acts of the
understanding to judgements, so that understanding may be
represented as the faculty of judging. For it is, according to what
has been said above, a faculty of thought. Now thought is cognition by
means of conceptions. But conceptions, as predicates of possible
judgements, relate to some representation of a yet undetermined
object. Thus the conception of body indicates something- for
example, metal- which can be cognized by means of that conception.
It is therefore a conception, for the reason alone that other
representations are contained under it, by means of which it can
relate to objects. It is therefore the predicate to a possible
judgement; for example: "Every metal is a body." All the functions
of the understanding therefore can be discovered, when we can
completely exhibit the functions of unity in judgements. And that this
may be effected very easily, the following section will show.

SECTION II. Of the Logical Function of the Understanding in
Judgements. SS 5

If we abstract all the content of a judgement, and consider only the
intellectual form thereof, we find that the function of thought in a
judgement can be brought under four heads, of which each contains
three momenta. These may be conveniently represented in the
following table:

1
Quantity of judgements
Universal
Particular
Singular

2 3
Quality Relation
Affirmative Categorical
Negative Hypothetical
Infinite Disjunctive

4
Modality
Problematical
Assertorical
Apodeictical

As this division appears to differ in some, though not essential
points, from the usual technique of logicians, the following
observations, for the prevention of otherwise possible
misunderstanding, will not be without their use.
1. Logicians say, with justice, that in the use of judgements in
syllogisms, singular judgements may be treated like universal ones.
For, precisely because a singular judgement has no extent at all,
its predicate cannot refer to a part of that which is contained in the
conception of the subject and be excluded from the rest. The predicate
is valid for the whole conception just as if it were a general
conception, and had extent, to the whole of which the predicate
applied. On the other hand, let us compare a singular with a general
judgement, merely as a cognition, in regard to quantity. The
singular judgement relates to the general one, as unity to infinity,
and is therefore in itself essentially different. Thus, if we estimate
a singular judgement (judicium singulare) not merely according to
its intrinsic validity as a judgement, but also as a cognition
generally, according to its quantity in comparison with that of
other cognitions, it is then entirely different from a general
judgement (judicium commune), and in a complete table of the momenta
of thought deserves a separate place- though, indeed, this would not
be necessary in a logic limited merely to the consideration of the use
of judgements in reference to each other.
2. In like manner, in transcendental logic, infinite must be
distinguished from affirmative judgements, although in general logic
they are rightly enough classed under affirmative. General logic
abstracts all content of the predicate (though it be negative), and
only considers whether the said predicate be affirmed or denied of the
subject. But transcendental logic considers also the worth or
content of this logical affirmation- an affirmation by means of a
merely negative predicate, and inquires how much the sum total of
our cognition gains by this affirmation. For example, if I say of
the soul, "It is not mortal"- by this negative judgement I should at
least ward off error. Now, by the proposition, "The soul is not
mortal," I have, in respect of the logical form, really affirmed,
inasmuch as I thereby place the soul in the unlimited sphere of
immortal beings. Now, because of the whole sphere of possible
existences, the mortal occupies one part, and the immortal the
other, neither more nor less is affirmed by the proposition than
that the soul is one among the infinite multitude of things which
remain over, when I take away the whole mortal part. But by this
proceeding we accomplish only this much, that the infinite sphere of
all possible existences is in so far limited that the mortal is
excluded from it, and the soul is placed in the remaining part of
the extent of this sphere. But this part remains, notwithstanding this
exception, infinite, and more and more parts may be taken away from
the whole sphere, without in the slightest degree thereby augmenting
or affirmatively determining our conception of the soul. These
judgements, therefore, infinite in respect of their logical extent,
are, in respect of the content of their cognition, merely
limitative; and are consequently entitled to a place in our
transcendental table of all the momenta of thought in judgements,
because the function of the understanding exercised by them may
perhaps be of importance in the field of its pure a priori cognition.
3. All relations of thought in judgements are those (a) of the
predicate to the subject; (b) of the principle to its consequence; (c)
of the divided cognition and all the members of the division to each
other. In the first of these three classes, we consider only two
conceptions; in the second, two judgements; in the third, several
judgements in relation to each other. The hypothetical proposition,
"If perfect justice exists, the obstinately wicked are punished,"
contains properly the relation to each other of two propositions,
namely, "Perfect justice exists," and "The obstinately wicked are
punished." Whether these propositions are in themselves true is a
question not here decided. Nothing is cogitated by means of this
judgement except a certain consequence. Finally, the disjunctive
judgement contains a relation of two or more propositions to each
other- a relation not of consequence, but of logical opposition, in so
far as the sphere of the one proposition excludes that of the other.
But it contains at the same time a relation of community, in so far as
all the propositions taken together fill up the sphere of the
cognition. The disjunctive judgement contains, therefore, the relation
of the parts of the whole sphere of a cognition, since the sphere of
each part is a complemental part of the sphere of the other, each
contributing to form the sum total of the divided cognition. Take, for
example, the proposition, "The world exists either through blind
chance, or through internal necessity, or through an external
cause." Each of these propositions embraces a part of the sphere of
our possible cognition as to the existence of a world; all of them
taken together, the whole sphere. To take the cognition out of one
of these spheres, is equivalent to placing it in one of the others;
and, on the other hand, to place it in one sphere is equivalent to
taking it out of the rest. There is, therefore, in a disjunctive
judgement a certain community of cognitions, which consists in this,
that they mutually exclude each other, yet thereby determine, as a
whole, the true cognition, inasmuch as, taken together, they make up
the complete content of a particular given cognition. And this is
all that I find necessary, for the sake of what follows, to remark
in this place.
4. The modality of judgements is a quite peculiar function, with
this distinguishing characteristic, that it contributes nothing to the
content of a judgement (for besides quantity, quality, and relation,
there is nothing more that constitutes the content of a judgement),
but concerns itself only with the value of the copula in relation to
thought in general. Problematical judgements are those in which the
affirmation or negation is accepted as merely possible (ad libitum).
In the assertorical, we regard the proposition as real (true); in
the apodeictical, we look on it as necessary.* Thus the two judgements
(antecedens et consequens), the relation of which constitutes a
hypothetical judgement, likewise those (the members of the division)
in whose reciprocity the disjunctive consists, are only problematical.
In the example above given the proposition, "There exists perfect
justice," is not stated assertorically, but as an ad libitum
judgement, which someone may choose to adopt, and the consequence
alone is assertorical. Hence such judgements may be obviously false,
and yet, taken problematically, be conditions of our cognition of
the truth. Thus the proposition, "The world exists only by blind
chance," is in the disjunctive judgement of problematical import only:
that is to say, one may accept it for the moment, and it helps us
(like the indication of the wrong road among all the roads that one
can take) to find out the true proposition. The problematical
proposition is, therefore, that which expresses only logical
possibility (which is not objective); that is, it expresses a free
choice to admit the validity of such a proposition- a merely arbitrary
reception of it into the understanding. The assertorical speaks of
logical reality or truth; as, for example, in a hypothetical
syllogism, the antecedens presents itself in a problematical form in
the major, in an assertorical form in the minor, and it shows that the
proposition is in harmony with the laws of the understanding. The
apodeictical proposition cogitates the assertorical as determined by
these very laws of the understanding, consequently as affirming a
priori, and in this manner it expresses logical necessity. Now because
all is here gradually incorporated with the understanding- inasmuch as
in the first place we judge problematically; then accept
assertorically our judgement as true; lastly, affirm it as inseparably
united with the understanding, that is, as necessary and apodeictical-
we may safely reckon these three functions of modality as so many
momenta of thought.

*Just as if thought were in the first instance a function of the
understanding; in the second, of judgement; in the third, of reason. A
remark which will be explained in the sequel.

SECTION III. Of the Pure Conceptions of the Understanding, or
Categories. SS 6

General logic, as has been repeatedly said, makes abstraction of all
content of cognition, and expects to receive representations from some
other quarter, in order, by means of analysis, to convert them into
conceptions. On the contrary, transcendental logic has lying before it
the manifold content of a priori sensibility, which transcendental
aesthetic presents to it in order to give matter to the pure
conceptions of the understanding, without which transcendental logic
would have no content, and be therefore utterly void. Now space and
time contain an infinite diversity of determinations of pure a
priori intuition, but are nevertheless the condition of the mind's
receptivity, under which alone it can obtain representations of
objects, and which, consequently, must always affect the conception of
these objects. But the spontaneity of thought requires that this
diversity be examined after a certain manner, received into the
mind, and connected, in order afterwards to form a cognition out of
it. This Process I call synthesis.
By the word synthesis, in its most general signification, I
understand the process of joining different representations to each
other and of comprehending their diversity in one cognition. This
synthesis is pure when the diversity is not given empirically but a
priori (as that in space and time). Our representations must be
given previously to any analysis of them; and no conceptions can
arise, quoad their content, analytically. But the synthesis of a
diversity (be it given a priori or empirically) is the first requisite
for the production of a cognition, which in its beginning, indeed, may
be crude and confused, and therefore in need of analysis- still,
synthesis is that by which alone the elements of our cognitions are
collected and united into a certain content, consequently it is the
first thing on which we must fix our attention, if we wish to
investigate the origin of our knowledge.
Synthesis, generally speaking, is, as we shall afterwards see, the
mere operation of the imagination- a blind but indispensable
function of the soul, without which we should have no cognition
whatever, but of the working of which we are seldom even conscious.
But to reduce this synthesis to conceptions is a function of the
understanding, by means of which we attain to cognition, in the proper
meaning of the term.
Pure synthesis, represented generally, gives us the pure
conception of the understanding. But by this pure synthesis, I mean
that which rests upon a basis of a priori synthetical unity. Thus, our
numeration (and this is more observable in large numbers) is a
synthesis according to conceptions, because it takes place according
to a common basis of unity (for example, the decade). By means of this
conception, therefore, the unity in the synthesis of the manifold
becomes necessary.
By means of analysis different representations are brought under one
conception- an operation of which general logic treats. On the other
hand, the duty of transcendental logic is to reduce to conceptions,
not representations, but the pure synthesis of representations. The
first thing which must be given to us for the sake of the a priori
cognition of all objects, is the diversity of the pure intuition;
the synthesis of this diversity by means of the imagination is the
second; but this gives, as yet, no cognition. The conceptions which
give unity to this pure synthesis, and which consist solely in the
representation of this necessary synthetical unity, furnish the
third requisite for the cognition of an object, and these
conceptions are given by the understanding.
The same function which gives unity to the different
representation in a judgement, gives also unity to the mere
synthesis of different representations in an intuition; and this unity
we call the pure conception of the understanding. Thus, the same
understanding, and by the same operations, whereby in conceptions,
by means of analytical unity, it produced the logical form of a
judgement, introduces, by means of the synthetical unity of the
manifold in intuition, a transcendental content into its
representations, on which account they are called pure conceptions
of the understanding, and they apply a priori to objects, a result not
within the power of general logic.
In this manner, there arise exactly so many pure conceptions of
the understanding, applying a priori to objects of intuition in
general, as there are logical functions in all possible judgements.
For there is no other function or faculty existing in the
understanding besides those enumerated in that table. These
conceptions we shall, with Aristotle, call categories, our purpose
being originally identical with his, notwithstanding the great
difference in the execution.

TABLE OF THE CATEGORIES

1 2

Of Quantity Of Quality
Unity Reality
Plurality Negation
Totality Limitation

3
Of Relation
Of Inherence and Subsistence (substantia et accidens)
Of Causality and Dependence (cause and effect)
Of Community (reciprocity between the agent and patient)

4
Of Modality
Possibility - Impossibility
Existence - Non-existence
Necessity - Contingence

This, then, is a catalogue of all the originally pure conceptions of
the synthesis which the understanding contains a priori, and these
conceptions alone entitle it to be called a pure understanding;
inasmuch as only by them it can render the manifold of intuition
conceivable, in other words, think an object of intuition. This
division is made systematically from a common principle, namely the
faculty of judgement (which is just the same as the power of thought),
and has not arisen rhapsodically from a search at haphazard after pure
conceptions, respecting the full number of which we never could be
certain, inasmuch as we employ induction alone in our search,
without considering that in this way we can never understand wherefore
precisely these conceptions, and none others, abide in the pure
understanding. It was a design worthy of an acute thinker like
Aristotle, to search for these fundamental conceptions. Destitute,
however, of any guiding principle, he picked them up just as they
occurred to him, and at first hunted out ten, which he called
categories (predicaments). Afterwards be believed that he had
discovered five others, which were added under the name of post
predicaments. But his catalogue still remained defective. Besides,
there are to be found among them some of the modes of pure sensibility
(quando, ubi, situs, also prius, simul), and likewise an empirical
conception (motus)- which can by no means belong to this
genealogical register of the pure understanding. Moreover, there are
deduced conceptions (actio, passio) enumerated among the original
conceptions, and, of the latter, some are entirely wanting.
With regard to these, it is to be remarked, that the categories,
as the true primitive conceptions of the pure understanding, have also
their pure deduced conceptions, which, in a complete system of
transcendental philosophy, must by no means be passed over; though
in a merely critical essay we must be contented with the simple
mention of the fact.
Let it be allowed me to call these pure, but deduced conceptions
of the understanding, the predicables of the pure understanding, in
contradistinction to predicaments. If we are in possession of the
original and primitive, the deduced and subsidiary conceptions can
easily be added, and the genealogical tree of the understanding
completely delineated. As my present aim is not to set forth a
complete system, but merely the principles of one, I reserve this task
for another time. It may be easily executed by any one who will
refer to the ontological manuals, and subordinate to the category of
causality, for example, the predicables of force, action, passion;
to that of community, those of presence and resistance; to the
categories of modality, those of origination, extinction, change;
and so with the rest. The categories combined with the modes of pure
sensibility, or with one another, afford a great number of deduced a
priori conceptions; a complete enumeration of which would be a
useful and not unpleasant, but in this place a perfectly
dispensable, occupation.
I purposely omit the definitions of the categories in this treatise.
I shall analyse these conceptions only so far as is necessary for
the doctrine of method, which is to form a part of this critique. In a
system of pure reason, definitions of them would be with justice
demanded of me, but to give them here would only bide from our view
the main aim of our investigation, at the same time raising doubts and
objections, the consideration of which, without injustice to our
main purpose, may be very well postponed till another opportunity.
Meanwhile, it ought to be sufficiently clear, from the little we
have already said on this subject, that the formation of a complete
vocabulary of pure conceptions, accompanied by all the requisite
explanations, is not only a possible, but an easy undertaking. The
compartments already exist; it is only necessary to fill them up;
and a systematic topic like the present, indicates with perfect
precision the proper place to which each conception belongs, while
it readily points out any that have not yet been filled up.

SS 7

Our table of the categories suggests considerations of some
importance, which may perhaps have significant results in regard to
the scientific form of all rational cognitions. For, that this table
is useful in the theoretical part of philosophy, nay, indispensable
for the sketching of the complete plan of a science, so far as that
science rests upon conceptions a priori, and for dividing it
mathematically, according to fixed principles, is most manifest from
the fact that it contains all the elementary conceptions of the
understanding, nay, even the form of a system of these in the
understanding itself, and consequently indicates all the momenta,
and also the internal arrangement of a projected speculative
science, as I have elsewhere shown.* Here follow some of these
observations.

*In the Metaphysical Principles of Natural Science.

I. This table, which contains four classes of conceptions of the
understanding, may, in the first instance, be divided into two
classes, the first of which relates to objects of intuition- pure as
well as empirical; the second, to the existence of these objects,
either in relation to one another, or to the understanding.
The former of these classes of categories I would entitle the
mathematical, and the latter the dynamical categories. The former,
as we see, has no correlates; these are only to be found in the second
class. This difference must have a ground in the nature of the human
understanding.
II. The number of the categories in each class is always the same,
namely, three- a fact which also demands some consideration, because
in all other cases division a priori through conceptions is
necessarily dichotomy. It is to be added, that the third category in
each triad always arises from the combination of the second with the
first.
Thus totality is nothing else but plurality contemplated as unity;
limitation is merely reality conjoined with negation; community is the
causality of a substance, reciprocally determining, and determined
by other substances; and finally, necessity is nothing but
existence, which is given through the possibility itself. Let it not
be supposed, however, that the third category is merely a deduced, and
not a primitive conception of the pure understanding. For the
conjunction of the first and second, in order to produce the third
conception, requires a particular function of the understanding, which
is by no means identical with those which are exercised in the first
and second. Thus, the conception of a number (which belongs to the
category of totality) is not always possible, where the conceptions of
multitude and unity exist (for example, in the representation of the
infinite). Or, if I conjoin the conception of a cause with that of a
substance, it does not follow that the conception of influence, that
is, how one substance can be the cause of something in another
substance, will be understood from that. Thus it is evident that a
particular act of the understanding is here necessary; and so in the
other instances.
III. With respect to one category, namely, that of community,
which is found in the third class, it is not so easy as with the
others to detect its accordance with the form of the disjunctive
judgement which corresponds to it in the table of the logical
functions.
In order to assure ourselves of this accordance, we must observe
that in every disjunctive judgement, the sphere of the judgement (that
is, the complex of all that is contained in it) is represented as a
whole divided into parts; and, since one part cannot be contained in
the other, they are cogitated as co-ordinated with, not subordinated
to each other, so that they do not determine each other
unilaterally, as in a linear series, but reciprocally, as in an
aggregate- (if one member of the division is posited, all the rest are
excluded; and conversely).
Now a like connection is cogitated in a whole of things; for one
thing is not subordinated, as effect, to another as cause of its
existence, but, on the contrary, is co-ordinated contemporaneously and
reciprocally, as a cause in relation to the determination of the
others (for example, in a body- the parts of which mutually attract
and repel each other). And this is an entirely different kind of
connection from that which we find in the mere relation of the cause
to the effect (the principle to the consequence), for in such a
connection the consequence does not in its turn determine the
principle, and therefore does not constitute, with the latter, a
whole- just as the Creator does not with the world make up a whole.
The process of understanding by which it represents to itself the
sphere of a divided conception, is employed also when we think of a
thing as divisible; and in the same manner as the members of the
division in the former exclude one another, and yet are connected in
one sphere, so the understanding represents to itself the parts of the
latter, as having- each of them- an existence (as substances),
independently of the others, and yet as united in one whole.

SS 8

In the transcendental philosophy of the ancients there exists one
more leading division, which contains pure conceptions of the
understanding, and which, although not numbered among the
categories, ought, according to them, as conceptions a priori, to be
valid of objects. But in this case they would augment the number of
the categories; which cannot be. These are set forth in the
proposition, so renowned among the schoolmen- "Quodlibet ens est UNUM,
VERUM, BONUM." Now, though the inferences from this principle were
mere tautological propositions, and though it is allowed only by
courtesy to retain a place in modern metaphysics, yet a thought
which maintained itself for such a length of time, however empty it
seems to be, deserves an investigation of its origin, and justifies
the conjecture that it must be grounded in some law of the
understanding, which, as is often the case, has only been
erroneously interpreted. These pretended transcendental predicates
are, in fact, nothing but logical requisites and criteria of all
cognition of objects, and they employ, as the basis for this
cognition, the categories of quantity, namely, unity, plurality, and
totality. But these, which must be taken as material conditions,
that is, as belonging to the possibility of things themselves, they
employed merely in a formal signification, as belonging to the logical
requisites of all cognition, and yet most unguardedly changed these
criteria of thought into properties of objects, as things in
themselves. Now, in every cognition of an object, there is unity of
conception, which may be called qualitative unity, so far as by this
term we understand only the unity in our connection of the manifold;
for example, unity of the theme in a play, an oration, or a story.
Secondly, there is truth in respect of the deductions from it. The
more true deductions we have from a given conception, the more
criteria of its objective reality. This we might call the
qualitative plurality of characteristic marks, which belong to a
conception as to a common foundation, but are not cogitated as a
quantity in it. Thirdly, there is perfection- which consists in
this, that the plurality falls back upon the unity of the
conception, and accords completely with that conception and with no
other. This we may denominate qualitative completeness. Hence it is
evident that these logical criteria of the possibility of cognition
are merely the three categories of quantity modified and transformed
to suit an unauthorized manner of applying them. That is to say, the
three categories, in which the unity in the production of the
quantum must be homogeneous throughout, are transformed solely with
a view to the connection of heterogeneous parts of cognition in one
act of consciousness, by means of the quality of the cognition,
which is the principle of that connection. Thus the criterion of the
possibility of a conception (not of its object) is the definition of
it, in which the unity of the conception, the truth of all that may be
immediately deduced from it, and finally, the completeness of what has
been thus deduced, constitute the requisites for the reproduction of
the whole conception. Thus also, the criterion or test of an
hypothesis is the intelligibility of the received principle of
explanation, or its unity (without help from any subsidiary
hypothesis)- the truth of our deductions from it (consistency with
each other and with experience)- and lastly, the completeness of the
principle of the explanation of these deductions, which refer to
neither more nor less than what was admitted in the hypothesis,
restoring analytically and a posteriori, what was cogitated
synthetically and a priori. By the conceptions, therefore, of unity,
truth, and perfection, we have made no addition to the
transcendental table of the categories, which is complete without
them. We have, on the contrary, merely employed the three categories
of quantity, setting aside their application to objects of experience,
as general logical laws of the consistency of cognition with itself.
CHAPTER II Of the Deduction of the Pure Conceptions of the
Understanding.

SECTION I Of the Principles of a Transcendental Deduction
in general. SS 9

Teachers of jurisprudence, when speaking of rights and claims,
distinguish in a cause the question of right (quid juris) from the
question of fact (quid facti), and while they demand proof of both,
they give to the proof of the former, which goes to establish right or
claim in law, the name of deduction. Now we make use of a great number
of empirical conceptions, without opposition from any one; and
consider ourselves, even without any attempt at deduction, justified
in attaching to them a sense, and a supposititious signification,
because we have always experience at hand to demonstrate their
objective reality. There exist also, however, usurped conceptions,
such as fortune, fate, which circulate with almost universal
indulgence, and yet are occasionally challenged by the question, "quid
juris?" In such cases, we have great difficulty in discovering any
deduction for these terms, inasmuch as we cannot produce any
manifest ground of right, either from experience or from reason, on
which the claim to employ them can be founded.
Among the many conceptions, which make up the very variegated web of
human cognition, some are destined for pure use a priori,
independent of all experience; and their title to be so employed
always requires a deduction, inasmuch as, to justify such use of them,
proofs from experience are not sufficient; but it is necessary to know
how these conceptions can apply to objects without being derived
from experience. I term, therefore, an examination of the manner in
which conceptions can apply a priori to objects, the transcendental
deduction of conceptions, and I distinguish it from the empirical
deduction, which indicates the mode in which conception is obtained
through experience and reflection thereon; consequently, does not
concern itself with the right, but only with the fact of our obtaining
conceptions in such and such a manner. We have already seen that we
are in possession of two perfectly different kinds of conceptions,
which nevertheless agree with each other in this, that they both apply
to objects completely a priori. These are the conceptions of space and
time as forms of sensibility, and the categories as pure conceptions
of the understanding. To attempt an empirical deduction of either of
these classes would be labour in vain, because the distinguishing
characteristic of their nature consists in this, that they apply to
their objects, without having borrowed anything from experience
towards the representation of them. Consequently, if a deduction of
these conceptions is necessary, it must always be transcendental.
Meanwhile, with respect to these conceptions, as with respect to all
our cognition, we certainly may discover in experience, if not the
principle of their possibility, yet the occasioning causes of their
production. It will be found that the impressions of sense give the
first occasion for bringing into action the whole faculty of
cognition, and for the production of experience, which contains two
very dissimilar elements, namely, a matter for cognition, given by the
senses, and a certain form for the arrangement of this matter, arising
out of the inner fountain of pure intuition and thought; and these, on
occasion given by sensuous impressions, are called into exercise and
produce conceptions. Such an investigation into the first efforts of
our faculty of cognition to mount from particular perceptions to
general conceptions is undoubtedly of great utility; and we have to
thank the celebrated Locke for having first opened the way for this
inquiry. But a deduction of the pure a priori conceptions of course
never can be made in this way, seeing that, in regard to their
future employment, which must be entirely independent of experience,
they must have a far different certificate of birth to show from
that of a descent from experience. This attempted physiological
derivation, which cannot properly be called deduction, because it
relates merely to a quaestio facti, I shall entitle an explanation
of the possession of a pure cognition. It is therefore manifest that
there can only be a transcendental deduction of these conceptions
and by no means an empirical one; also, that all attempts at an
empirical deduction, in regard to pure a priori conceptions, are vain,
and can only be made by one who does not understand the altogether
peculiar nature of these cognitions.
But although it is admitted that the only possible deduction of pure
a priori cognition is a transcendental deduction, it is not, for
that reason, perfectly manifest that such a deduction is absolutely
necessary. We have already traced to their sources the conceptions
of space and time, by means of a transcendental deduction, and we have
explained and determined their objective validity a priori.
Geometry, nevertheless, advances steadily and securely in the province
of pure a priori cognitions, without needing to ask from philosophy
any certificate as to the pure and legitimate origin of its
fundamental conception of space. But the use of the conception in this
science extends only to the external world of sense, the pure form
of the intuition of which is space; and in this world, therefore,
all geometrical cognition, because it is founded upon a priori
intuition, possesses immediate evidence, and the objects of this
cognition are given a priori (as regards their form) in intuition by
and through the cognition itself. With the pure conceptions of
understanding, on the contrary, commences the absolute necessity of
seeking a transcendental deduction, not only of these conceptions
themselves, but likewise of space, because, inasmuch as they make
affirmations concerning objects not by means of the predicates of
intuition and sensibility, but of pure thought a priori, they apply to
objects without any of the conditions of sensibility. Besides, not
being founded on experience, they are not presented with any object in
a priori intuition upon which, antecedently to experience, they
might base their synthesis. Hence results, not only doubt as to the
objective validity and proper limits of their use, but that even our
conception of space is rendered equivocal; inasmuch as we are very
ready with the aid of the categories, to carry the use of this
conception beyond the conditions of sensuous intuition- and, for
this reason, we have already found a transcendental deduction of it
needful. The reader, then, must be quite convinced of the absolute
necessity of a transcendental deduction, before taking a single step
in the field of pure reason; because otherwise he goes to work
blindly, and after he has wondered about in all directions, returns to
the state of utter ignorance from which he started. He ought,
moreover, clearly to recognize beforehand the unavoidable difficulties
in his undertaking, so that he may not afterwards complain of the
obscurity in which the subject itself is deeply involved, or become
too soon impatient of the obstacles in his path; because we have a
choice of only two things- either at once to give up all pretensions
to knowledge beyond the limits of possible experience, or to bring
this critical investigation to completion.
We have been able, with very little trouble, to make it
comprehensible how the conceptions of space and time, although a
priori cognitions, must necessarily apply to external objects, and
render a synthetical cognition of these possible, independently of all
experience. For inasmuch as only by means of such pure form of
sensibility an object can appear to us, that is, be an object of
empirical intuition, space and time are pure intuitions, which contain
a priori the condition of the possibility of objects as phenomena, and
an a priori synthesis in these intuitions possesses objective
validity.
On the other hand, the categories of the understanding do not
represent the conditions under which objects are given to us in
intuition; objects can consequently appear to us without necessarily
connecting themselves with these, and consequently without any
necessity binding on the understanding to contain a priori the
conditions of these objects. Thus we find ourselves involved in a
difficulty which did not present itself in the sphere of
sensibility, that is to say, we cannot discover how the subjective
conditions of thought can have objective validity, in other words, can
become conditions of the possibility of all cognition of objects;
for phenomena may certainly be given to us in intuition without any
help from the functions of the understanding. Let us take, for
example, the conception of cause, which indicates a peculiar kind of
synthesis, namely, that with something, A, something entirely
different, B, is connected according to a law. It is not a priori
manifest why phenomena should contain anything of this kind (we are of
course debarred from appealing for proof to experience, for the
objective validity of this conception must be demonstrated a
priori), and it hence remains doubtful a priori, whether such a
conception be not quite void and without any corresponding object
among phenomena. For that objects of sensuous intuition must
correspond to the formal conditions of sensibility existing a priori
in the mind is quite evident, from the fact that without these they
could not be objects for us; but that they must also correspond to the
conditions which understanding requires for the synthetical unity of
thought is an assertion, the grounds for which are not so easily to be
discovered. For phenomena might be so constituted as not to correspond
to the conditions of the unity of thought; and all things might lie in
such confusion that, for example, nothing could be met with in the
sphere of phenomena to suggest a law of synthesis, and so correspond
to the conception of cause and effect; so that this conception would
be quite void, null, and without significance. Phenomena would
nevertheless continue to present objects to our intuition; for mere
intuition does not in any respect stand in need of the functions of
thought.
If we thought to free ourselves from the labour of these
investigations by saying: "Experience is constantly offering us
examples of the relation of cause and effect in phenomena, and
presents us with abundant opportunity of abstracting the conception of
cause, and so at the same time of corroborating the objective validity
of this conception"; we should in this case be overlooking the fact,
that the conception of cause cannot arise in this way at all; that, on
the contrary, it must either have an a priori basis in the,
understanding, or be rejected as a mere chimera. For this conception
demands that something, A, should be of such a nature that something
else, B, should follow from it necessarily, and according to an
absolutely universal law. We may certainly collect from phenomena a
law, according to which this or that usually happens, but the
element of necessity is not to be found in it. Hence it is evident
that to the synthesis of cause and effect belongs a dignity, which
is utterly wanting in any empirical synthesis; for it is no mere
mechanical synthesis, by means of addition, but a dynamical one;
that is to say, the effect is not to be cogitated as merely annexed to
the cause, but as posited by and through the cause, and resulting from
it. The strict universality of this law never can be a
characteristic of empirical laws, which obtain through induction
only a comparative universality, that is, an extended range of
practical application. But the pure conceptions of the understanding
would entirely lose all their peculiar character, if we treated them
merely as the productions of experience.

Transition to the Transcendental Deduction of the
Categories. SS 10

There are only two possible ways in which synthetical representation
and its objects can coincide with and relate necessarily to each
other, and, as it were, meet together. Either the object alone makes
the representation possible, or the representation alone makes the
object possible. In the former case, the relation between them is only
empirical, and an a priori representation is impossible. And this is
the case with phenomena, as regards that in them which is referable to
mere sensation. In the latter case- although representation alone (for
of its causality, by means of the will, we do not here speak) does not
produce the object as to its existence, it must nevertheless be a
priori determinative in regard to the object, if it is only by means
of the representation that we can cognize anything as an object. Now
there are only two conditions of the possibility of a cognition of
objects; firstly, intuition, by means of which the object, though only
as phenomenon, is given; secondly, conception, by means of which the
object which corresponds to this intuition is thought. But it is
evident from what has been said on aesthetic that the first condition,
under which alone objects can be intuited, must in fact exist, as a
formal basis for them, a priori in the mind. With this formal
condition of sensibility, therefore, all phenomena necessarily
correspond, because it is only through it that they can be phenomena
at all; that is, can be empirically intuited and given. Now the
question is whether there do not exist, a priori in the mind,
conceptions of understanding also, as conditions under which alone
something, if not intuited, is yet thought as object. If this question
be answered in the affirmative, it follows that all empirical
cognition of objects is necessarily conformable to such conceptions,
since, if they are not presupposed, it is impossible that anything can
be an object of experience. Now all experience contains, besides the
intuition of the senses through which an object is given, a conception
also of an object that is given in intuition. Accordingly, conceptions
of objects in general must lie as a priori conditions at the
foundation of all empirical cognition; and consequently, the objective
validity of the categories, as a priori conceptions, will rest upon
this, that experience (as far as regards the form of thought) is
possible only by their means. For in that case they apply
necessarily and a priori to objects of experience, because only
through them can an object of experience be thought.
The whole aim of the transcendental deduction of all a priori
conceptions is to show that these conceptions are a priori
conditions of the possibility of all experience. Conceptions which
afford us the objective foundation of the possibility of experience
are for that very reason necessary. But the analysis of the
experiences in which they are met with is not deduction, but only an
illustration of them, because from experience they could never
derive the attribute of necessity. Without their original
applicability and relation to all possible experience, in which all
objects of cognition present themselves, the relation of the
categories to objects, of whatever nature, would be quite
incomprehensible.
The celebrated Locke, for want of due reflection on these points,
and because he met with pure conceptions of the understanding in
experience, sought also to deduce them from experience, and yet
proceeded so inconsequently as to attempt, with their aid, to arrive
it cognitions which lie far beyond the limits of all experience. David
Hume perceived that, to render this possible, it was necessary that
the conceptions should have an a priori origin. But as he could not
explain how it was possible that conceptions which are not connected
with each other in the understanding must nevertheless be thought as
necessarily connected in the object- and it never occurred to him that
the understanding itself might, perhaps, by means of these
conceptions, be the author of the experience in which its objects were
presented to it- he was forced to drive these conceptions from
experience, that is, from a subjective necessity arising from repeated
association of experiences erroneously considered to be objective-
in one word, from habit. But he proceeded with perfect consequence and
declared it to be impossible, with such conceptions and the principles
arising from them, to overstep the limits of experience. The empirical
derivation, however, which both of these philosophers attributed to
these conceptions, cannot possibly be reconciled with the fact that we
do possess scientific a priori cognitions, namely, those of pure
mathematics and general physics.
The former of these two celebrated men opened a wide door to
extravagance- (for if reason has once undoubted right on its side,
it will not allow itself to be confined to set limits, by vague
recommendations of moderation); the latter gave himself up entirely to
scepticism- a natural consequence, after having discovered, as he
thought, that the faculty of cognition was not trustworthy. We now
intend to make a trial whether it be not possible safely to conduct
reason between these two rocks, to assign her determinate limits,
and yet leave open for her the entire sphere of her legitimate
activity.
I shall merely premise an explanation of what the categories are.
They are conceptions of an object in general, by means of which its
intuition is contemplated as determined in relation to one of the
logical functions of judgement. The following will make this plain.
The function of the categorical judgement is that of the relation of
subject to predicate; for example, in the proposition: "All bodies are
divisible." But in regard to the merely logical use of the
understanding, it still remains undetermined to which Of these two
conceptions belongs the function Of subject and to which that of
predicate. For we could also say: "Some divisible is a body." But
the category of substance, when the conception of a body is brought
under it, determines that; and its empirical intuition in experience
must be contemplated always as subject and never as mere predicate.
And so with all the other categories.

SECTION II Transcendental Deduction of the pure Conceptions of
the Understanding. SS 11

Of the Possibility of a Conjunction of the manifold representations
given by Sense.

The manifold content in our representations can be given in an
intuition which is merely sensuous- in other words, is nothing but
susceptibility; and the form of this intuition can exist a priori in
our faculty of representation, without being anything else but the
mode in which the subject is affected. But the conjunction
(conjunctio) of a manifold in intuition never can be given us by the
senses; it cannot therefore be contained in the pure form of
sensuous intuition, for it is a spontaneous act of the faculty of
representation. And as we must, to distinguish it from sensibility,
entitle this faculty understanding; so all conjunction whether
conscious or unconscious, be it of the manifold in intuition, sensuous
or non-sensuous, or of several conceptions- is an act of the
understanding. To this act we shall give the general appellation of
synthesis, thereby to indicate, at the same time, that we cannot
represent anything as conjoined in the object without having
previously conjoined it ourselves. Of all mental notions, that of
conjunction is the only one which cannot be given through objects, but
can be originated only by the subject itself, because it is an act
of its purely spontaneous activity. The reader will easily enough
perceive that the possibility of conjunction must be grounded in the
very nature of this act, and that it must be equally valid for all
conjunction, and that analysis, which appears to be its contrary,
must, nevertheless, always presuppose it; for where the
understanding has not previously conjoined, it cannot dissect or
analyse, because only as conjoined by it, must that which is to be
analysed have been given to our faculty of representation.
But the conception of conjunction includes, besides the conception
of the manifold and of the synthesis of it, that of the unity of it
also. Conjunction is the representation of the synthetical unity of
the manifold.* This idea of unity, therefore, cannot arise out of that
of conjunction; much rather does that idea, by combining itself with
the representation of the manifold, render the conception of
conjunction possible. This unity, which a priori precedes all
conceptions of conjunction, is not the category of unity (SS 6); for
all the categories are based upon logical functions of judgement,
and in these functions we already have conjunction, and consequently
unity of given conceptions. It is therefore evident that the
category of unity presupposes conjunction. We must therefore look
still higher for this unity (as qualitative, SS 8), in that, namely,
which contains the ground of the unity of diverse conceptions in
judgements, the ground, consequently, of the possibility of the
existence of the understanding, even in regard to its logical use.

*Whether the representations are in themselves identical, and
consequently whether one can be thought analytically by means of and
through the other, is a question which we need not at present
consider. Our Consciousness of the one, when we speak of the manifold,
is always distinguishable from our consciousness of the other; and
it is only respecting the synthesis of this (possible) consciousness
that we here treat.

Of the Originally Synthetical Unity of Apperception. SS 12

The "I think" must accompany all my representations, for otherwise
something would be represented in me which could not be thought; in
other words, the representation would either be impossible, or at
least be, in relation to me, nothing. That representation which can be
given previously to all thought is called intuition. All the diversity
or manifold content of intuition, has, therefore, a necessary relation
to the 'I think," in the subject in which this diversity is found. But
this representation, "I think," is an act of spontaneity; that is to
say, it cannot be regarded as belonging to mere sensibility. I call it
pure apperception, in order to distinguish it from empirical; or
primitive apperception, because it is self-consciousness which, whilst
it gives birth to the representation" I think," must necessarily be
capable of accompanying all our representations. It is in all acts
of consciousness one and the same, and unaccompanied by it, no
representation can exist for me. The unity of this apperception I call
the transcendental unity of self-consciousness, in order to indicate
the possibility of a priori cognition arising from it. For the
manifold representations which are given in an intuition would not all
of them be my representations, if they did not all belong to one
self-consciousness, that is, as my representations (even although I am
not conscious of them as such), they must conform to the condition
under which alone they can exist together in a common
self-consciousness, because otherwise they would not all without
exception belong to me. From this primitive conjunction follow many
important results.
For example, this universal identity of the apperception of the
manifold given in intuition contains a synthesis of representations
and is possible only by means of the consciousness of this
synthesis. For the empirical consciousness which accompanies different
representations is in itself fragmentary and disunited, and without
relation to the identity of the subject. This relation, then, does not
exist because I accompany every representation with consciousness, but
because I join one representation to another, and am conscious of
the synthesis of them. Consequently, only because I can connect a
variety of given representations in one consciousness, is it
possible that I can represent to myself the identity of
consciousness in these representations; in other words, the analytical
unity of apperception is possible only under the presupposition of a
synthetical unity.* The thought, "These representations given in
intuition belong all of them to me," is accordingly just the same
as, "I unite them in one self-consciousness, or can at least so
unite them"; and although this thought is not itself the consciousness
of the synthesis of representations, it presupposes the possibility of
it; that is to say, for the reason alone that I can comprehend the
variety of my representations in one consciousness, do I call them
my representations, for otherwise I must have as many-coloured and
various a self as are the representations of which I am conscious.
Synthetical unity of the manifold in intuitions, as given a priori, is
therefore the foundation of the identity of apperception itself, which
antecedes a priori all determinate thought. But the conjunction of
representations into a conception is not to be found in objects
themselves, nor can it be, as it were, borrowed from them and taken up
into the understanding by perception, but it is on the contrary an
operation of the understanding itself, which is nothing more than
the faculty of conjoining a priori and of bringing the variety of
given representations under the unity of apperception. This
principle is the highest in all human cognition.

*All general conceptions- as such- depend, for their existence, on
the analytical unity of consciousness. For example, when I think of
red in general, I thereby think to myself a property which (as a
characteristic mark) can be discovered somewhere, or can be united
with other representations; consequently, it is only by means of a
forethought possible synthetical unity that I can think to myself
the analytical. A representation which is cogitated as common to
different representations, is regarded as belonging to such as,
besides this common representation, contain something different;
consequently it must be previously thought in synthetical unity with
other although only possible representations, before I can think in it
the analytical unity of consciousness which makes it a conceptas
communis. And thus the synthetical unity of apperception is the
highest point with which we must connect every operation of the
understanding, even the whole of logic, and after it our
transcendental philosophy; indeed, this faculty is the understanding
itself.

This fundamental principle of the necessary unity of apperception is
indeed an identical, and therefore analytical, proposition; but it
nevertheless explains the necessity for a synthesis of the manifold
given in an intuition, without which the identity of
self-consciousness would be incogitable. For the ego, as a simple
representation, presents us with no manifold content; only in
intuition, which is quite different from the representation ego, can
it be given us, and by means of conjunction it is cogitated in one
self-consciousness. An understanding, in which all the manifold should
be given by means of consciousness itself, would be intuitive; our
understanding can only think and must look for its intuition to sense.
I am, therefore, conscious of my identical self, in relation to all
the variety of representations given to me in an intuition, because
I call all of them my representations. In other words, I am
conscious myself of a necessary a priori synthesis of my
representations, which is called the original synthetical unity of
apperception, under which rank all the representations presented to
me, but that only by means of a synthesis.

The Principle of the Synthetical Unity of Apperception
is the highest Principle of all exercise of
the Understanding. SS 13

The supreme principle of the possibility of all intuition in
relation to sensibility was, according to our transcendental
aesthetic, that all the manifold in intuition be subject to the formal
conditions of space and time. The supreme principle of the possibility
of it in relation to the understanding is that all the manifold in
it be subject to conditions of the originally synthetical unity or
apperception.* To the former of these two principles are subject all
the various representations of intuition, in so far as they are
given to us; to the latter, in so far as they must be capable of
conjunction in one consciousness; for without this nothing can be
thought or cognized, because the given representations would not
have in common the act Of the apperception "I think" and therefore
could not be connected in one self-consciousness.

*Space and time, and all portions thereof, are intuitions;
consequently are, with a manifold for their content, single
representations. (See the Transcendental Aesthetic.) Consequently,
they are not pure conceptions, by means of which the same
consciousness is found in a great number of representations; but, on
the contrary, they are many representations contained in one, the
consciousness of which is, so to speak, compounded. The unity of
consciousness is nevertheless synthetical and, therefore, primitive.
From this peculiar character of consciousness follow many important
consequences. (See SS 21.)

Understanding is, to speak generally, the faculty Of cognitions.
These consist in the determined relation of given representation to an
object. But an object is that, in the conception of which the manifold
in a given intuition is united. Now all union of representations
requires unity of consciousness in the synthesis of them.
Consequently, it is the unity of consciousness alone that
constitutes the possibility of representations relating to an
object, and therefore of their objective validity, and of their
becoming cognitions, and consequently, the possibility of the
existence of the understanding itself.
The first pure cognition of understanding, then, upon which is
founded all its other exercise, and which is at the same time
perfectly independent of all conditions of mere sensuous intuition, is
the principle of the original synthetical unity of apperception.
Thus the mere form of external sensuous intuition, namely, space,
affords us, per se, no cognition; it merely contributes the manifold
in a priori intuition to a possible cognition. But, in order to
cognize something in space (for example, a line), I must draw it,
and thus produce synthetically a determined conjunction of the given
manifold, so that the unity of this act is at the same time the
unity of consciousness (in the conception of a line), and by this
means alone is an object (a determinate space) cognized. The
synthetical unity of consciousness is, therefore, an objective
condition of all cognition, which I do not merely require in order
to cognize an object, but to which every intuition must necessarily be
subject, in order to become an object for me; because in any other
way, and without this synthesis, the manifold in intuition could not
be united in one consciousness.
This proposition is, as already said, itself analytical, although it
constitutes the synthetical unity, the condition of all thought; for
it states nothing more than that all my representations in any given
intuition must be subject to the condition which alone enables me to
connect them, as my representation with the identical self, and so
to unite them synthetically in one apperception, by means of the
general expression, "I think."
But this principle is not to be regarded as a principle for every
possible understanding, but only for the understanding by means of
whose pure apperception in the thought I am, no manifold content is
given. The understanding or mind which contained the manifold in
intuition, in and through the act itself of its own
self-consciousness, in other words, an understanding by and in the
representation of which the objects of the representation should at
the same time exist, would not require a special act of synthesis of
the manifold as the condition of the unity of its consciousness, an
act of which the human understanding, which thinks only and cannot
intuite, has absolute need. But this principle is the first
principle of all the operations of our understanding, so that we
cannot form the least conception of any other possible
understanding, either of one such as should be itself intuition, or
possess a sensuous intuition, but with forms different from those of
space and time.

What Objective Unity of Self-consciousness is. SS 14

It is by means of the transcendental unity of apperception that
all the manifold, given in an intuition is united into a conception of
the object. On this account it is called objective, and must be
distinguished from the subjective unity of consciousness, which is a
determination of the internal sense, by means of which the said
manifold in intuition is given empirically to be so united. Whether
I can be empirically conscious of the manifold as coexistent or as
successive, depends upon circumstances, or empirical conditions. Hence
the empirical unity of consciousness by means of association of
representations, itself relates to a phenomenal world and is wholly
contingent. On the contrary, the pure form of intuition in time,
merely as an intuition, which contains a given manifold, is subject to
the original unity of consciousness, and that solely by means of the
necessary relation of the manifold in intuition to the "I think,"
consequently by means of the pure synthesis of the understanding,
which lies a priori at the foundation of all empirical synthesis.
The transcendental unity of apperception is alone objectively valid;
the empirical which we do not consider in this essay, and which is
merely a unity deduced from the former under given conditions in
concreto, possesses only subjective validity. One person connects
the notion conveyed in a word with one thing, another with another
thing; and the unity of consciousness in that which is empirical,
is, in relation to that which is given by experience, not
necessarily and universally valid.

The Logical Form of all Judgements consists in the Objective
Unity of Apperception of the Conceptions
contained therein. SS 15

I could never satisfy myself with the definition which logicians
give of a judgement. It is, according to them, the representation of a
relation between two conceptions. I shall not dwell here on the
faultiness of this definition, in that it suits only for categorical
and not for hypothetical or disjunctive judgements, these latter
containing a relation not of conceptions but of judgements themselves-
a blunder from which many evil results have followed.* It is more
important for our present purpose to observe, that this definition
does not determine in what the said relation consists.

*The tedious doctrine of the four syllogistic figures concerns
only categorical syllogisms; and although it is nothing more than an
artifice by surreptitiously introducing immediate conclusions
(consequentiae immediatae) among the premises of a pure syllogism,
to give ism' give rise to an appearance of more modes of drawing a
conclusion than that in the first figure, the artifice would not
have had much success, had not its authors succeeded in bringing
categorical judgements into exclusive respect, as those to which all
others must be referred- a doctrine, however, which, according to SS
5, is utterly false.

But if I investigate more closely the relation of given cognitions
in every judgement, and distinguish it, as belonging to the
understanding, from the relation which is produced according to laws
of the reproductive imagination (which has only subjective
validity), I find that judgement is nothing but the mode of bringing
given cognitions under the objective unit of apperception. This is
plain from our use of the term of relation is in judgements, in
order to distinguish the objective unity of given representations from
the subjective unity. For this term indicates the relation of these
representations to the original apperception, and also their necessary
unity, even although the judgement is empirical, therefore contingent,
as in the judgement: "All bodies are heavy." I do not mean by this,
that these representations do necessarily belong to each other in
empirical intuition, but that by means of the necessary unity of
appreciation they belong to each other in the synthesis of intuitions,
that is to say, they belong to each other according to principles of
the objective determination of all our representations, in so far as
cognition can arise from them, these principles being all deduced from
the main principle of the transcendental unity of apperception. In
this way alone can there arise from this relation a judgement, that
is, a relation which has objective validity, and is perfectly distinct
from that relation of the very same representations which has only
subjective validity- a relation, to wit, which is produced according
to laws of association. According to these laws, I could only say:
"When I hold in my hand or carry a body, I feel an impression of
weight"; but I could not say: "It, the body, is heavy"; for this is
tantamount to saying both these representations are conjoined in the
object, that is, without distinction as to the condition of the
subject, and do not merely stand together in my perception, however
frequently the perceptive act may be repeated.

All Sensuous Intuitions are subject to the Categories, as
Conditions under which alone the manifold Content of
them can be united in one Consciousness. SS 16

The manifold content given in a sensuous intuition comes necessarily
under the original synthetical unity of apperception, because
thereby alone is the unity of intuition possible (SS 13). But that act
of the understanding, by which the manifold content of given
representations (whether intuitions or conceptions) is brought under
one apperception, is the logical function of judgements (SS 15). All
the manifold, therefore, in so far as it is given in one empirical
intuition, is determined in relation to one of the logical functions
of judgement, by means of which it is brought into union in one
consciousness. Now the categories are nothing else than these
functions of judgement so far as the manifold in a given intuition
is determined in relation to them (SS 9). Consequently, the manifold
in a given intuition is necessarily subject to the categories of the
understanding.

Observation. SS 17

The manifold in an intuition, which I call mine, is represented by
means of the synthesis of the understanding, as belonging to the
necessary unity of self-consciousness, and this takes place by means
of the category.* The category indicates accordingly that the
empirical consciousness of a given manifold in an intuition is subject
to a pure self-consciousness a priori, in the same manner as an
empirical intuition is subject to a pure sensuous intuition, which
is also a priori. In the above proposition, then, lies the beginning
of a deduction of the pure conceptions of the understanding. Now, as
the categories have their origin in the understanding alone,
independently of sensibility, I must in my deduction make
abstraction of the mode in which the manifold of an empirical
intuition is given, in order to fix my attention exclusively on the
unity which is brought by the understanding into the intuition by
means of the category. In what follows (SS 22), it will be shown, from
the mode in which the empirical intuition is given in the faculty of
sensibility, that the unity which belongs to it is no other than
that which the category (according to SS 16) imposes on the manifold
in a given intuition, and thus, its a priori validity in regard to all
objects of sense being established, the purpose of our deduction
will be fully attained.

*The proof of this rests on the represented unity of intuition, by
means of which an object is given, and which always includes in itself
a synthesis of the manifold to be intuited, and also the relation of
this latter to unity of apperception.

But there is one thing in the above demonstration of which I could
not make abstraction, namely, that the manifold to be intuited must be
given previously to the synthesis of the understanding, and
independently of it. How this takes place remains here undetermined.
For if I cogitate an understanding which was itself intuitive (as, for
example, a divine understanding which should not represent given
objects, but by whose representation the objects themselves should
be given or produced), the categories would possess no significance in
relation to such a faculty of cognition. They are merely rules for
an understanding, whose whole power consists in thought, that is, in
the act of submitting the synthesis of the manifold which is presented
to it in intuition from a very different quarter, to the unity of
apperception; a faculty, therefore, which cognizes nothing per se, but
only connects and arranges the material of cognition, the intuition,
namely, which must be presented to it by means of the object. But to
show reasons for this peculiar character of our understandings, that
it produces unity of apperception a priori only by means of
categories, and a certain kind and number thereof, is as impossible as
to explain why we are endowed with precisely so many functions of
judgement and no more, or why time and space are the only forms of our
intuition.

In Cognition, its Application to Objects of Experience is
the only legitimate use of the Category. SS 18

To think an object and to cognize an object are by no means the same
thing. In cognition there are two elements: firstly, the conception,
whereby an object is cogitated (the category); and, secondly, the
intuition, whereby the object is given. For supposing that to the
conception a corresponding intuition could not be given, it would
still be a thought as regards its form, but without any object, and no
cognition of anything would be possible by means of it, inasmuch as,
so far as I knew, there existed and could exist nothing to which my
thought could be applied. Now all intuition possible to us is
sensuous; consequently, our thought of an object by means of a pure
conception of the understanding, can become cognition for us only in
so far as this conception is applied to objects of the senses.
Sensuous intuition is either pure intuition (space and time) or
empirical intuition- of that which is immediately represented in space
and time by means of sensation as real. Through the determination of
pure intuition we obtain a priori cognitions of objects, as in
mathematics, but only as regards their form as phenomena; whether
there can exist things which must be intuited in this form is not
thereby established. All mathematical conceptions, therefore, are
not per se cognition, except in so far as we presuppose that there
exist things which can only be represented conformably to the form
of our pure sensuous intuition. But things in space and time are given
only in so far as they are perceptions (representations accompanied
with sensation), therefore only by empirical representation.
Consequently the pure conceptions of the understanding, even when they
are applied to intuitions a priori (as in mathematics), produce
cognition only in so far as these (and therefore the conceptions of
the understanding by means of them) can be applied to empirical
intuitions. Consequently the categories do not, even by means of
pure intuition afford us any cognition of things; they can only do
so in so far as they can be applied to empirical intuition. That is to
say, the, categories serve only to render empirical cognition
possible. But this is what we call experience. Consequently, in
cognition, their application to objects of experience is the only
legitimate use of the categories.

SS 19

The foregoing proposition is of the utmost importance, for it
determines the limits of the exercise of the pure conceptions of the
understanding in regard to objects, just as transcendental aesthetic
determined the limits of the exercise of the pure form of our sensuous
intuition. Space and time, as conditions of the possibility of the
presentation of objects to us, are valid no further than for objects
of sense, consequently, only for experience. Beyond these limits
they represent to us nothing, for they belong only to sense, and
have no reality apart from it. The pure conceptions of the
understanding are free from this limitation, and extend to objects
of intuition in general, be the intuition like or unlike to ours,
provided only it be sensuous, and not intellectual. But this extension
of conceptions beyond the range of our intuition is of no advantage;
for they are then mere empty conceptions of objects, as to the
possibility or impossibility of the existence of which they furnish us
with no means of discovery. They are mere forms of thought, without
objective reality, because we have no intuition to which the
synthetical unity of apperception, which alone the categories contain,
could be applied, for the purpose of determining an object. Our
sensuous and empirical intuition can alone give them significance
and meaning.
If, then, we suppose an object of a non-sensuous intuition to be
given we can in that case represent it by all those predicates which
are implied in the presupposition that nothing appertaining to
sensuous intuition belongs to it; for example, that it is not
extended, or in space; that its duration is not time; that in it no
change (the effect of the determinations in time) is to be met with,
and so on. But it is no proper knowledge if I merely indicate what the
intuition of the object is not, without being able to say what is
contained in it, for I have not shown the possibility of an object
to which my pure conception of understanding could be applicable,
because I have not been able to furnish any intuition corresponding to
it, but am only able to say that our intuition is not valid for it.
But the most important point is this, that to a something of this kind
not one category can be found applicable. Take, for example, the
conception of substance, that is, something that can exist as subject,
but never as mere predicate; in regard to this conception I am quite
ignorant whether there can really be anything to correspond to such
a determination of thought, if empirical intuition did not afford me
the occasion for its application. But of this more in the sequel.

Of the Application of the Categories to Objects of the
Senses in general. SS 20

The pure conceptions of the understanding apply to objects of
intuition in general, through the understanding alone, whether the
intuition be our own or some other, provided only it be sensuous,
but are, for this very reason, mere forms of thought, by means of
which alone no determined object can be cognized. The synthesis or
conjunction of the manifold in these conceptions relates, we have
said, only to the unity of apperception, and is for this reason the
ground of the possibility of a priori cognition, in so far as this
cognition is dependent on the understanding. This synthesis is,
therefore, not merely transcendental, but also purely intellectual.
But because a certain form of sensuous intuition exists in the mind
a priori which rests on the receptivity of the representative
faculty (sensibility), the understanding, as a spontaneity, is able to
determine the internal sense by means of the diversity of given
representations, conformably to the synthetical unity of apperception,
and thus to cogitate the synthetical unity of the apperception of
the manifold of sensuous intuition a priori, as the condition to which
must necessarily be submitted all objects of human intuition. And in
this manner the categories as mere forms of thought receive
objective reality, that is, application to objects which are given
to us in intuition, but that only as phenomena, for it is only of
phenomena that we are capable of a priori intuition.
This synthesis of the manifold of sensuous intuition, which is
possible and necessary a priori, may be called figurative (synthesis
speciosa), in contradistinction to that which is cogitated in the mere
category in regard to the manifold of an intuition in general, and
is called connection or conjunction of the understanding (synthesis
intellectualis). Both are transcendental, not merely because they
themselves precede a priori all experience, but also because they form
the basis for the possibility of other cognition a priori.
But the figurative synthesis, when it has relation only to the
originally synthetical unity of apperception, that is to the
transcendental unity cogitated in the categories, must, to be
distinguished from the purely intellectual conjunction, be entitled
the transcendental synthesis of imagination. Imagination is the
faculty of representing an object even without its presence in
intuition. Now, as all our intuition is sensuous, imagination, by
reason of the subjective condition under which alone it can give a
corresponding intuition to the conceptions of the understanding,
belongs to sensibility. But in so far as the synthesis of the
imagination is an act of spontaneity, which is determinative, and not,
like sense, merely determinable, and which is consequently able to
determine sense a priori, according to its form, conformably to the
unity of apperception, in so far is the imagination a faculty of
determining sensibility a priori, and its synthesis of intuitions
according to the categories must be the transcendental synthesis of
the imagination. It is an operation of the understanding on
sensibility, and the first application of the understanding to objects
of possible intuition, and at the same time the basis for the exercise
of the other functions of that faculty. As figurative, it is
distinguished from the merely intellectual synthesis, which is
produced by the understanding alone, without the aid of imagination.
Now, in so far as imagination is spontaneity, I sometimes call it also
the productive imagination, and distinguish it from the
reproductive, the synthesis of which is subject entirely to
empirical laws, those of association, namely, and which, therefore,
contributes nothing to the explanation of the possibility of a
priori cognition, and for this reason belongs not to transcendental
philosophy, but to psychology.

We have now arrived at the proper place for explaining the paradox
which must have struck every one in our exposition of the internal
sense (SS 6), namely- how this sense represents us to our own
consciousness, only as we appear to ourselves, not as we are in
ourselves, because, to wit, we intuite ourselves only as we are
inwardly affected. Now this appears to be contradictory, inasmuch as
we thus stand in a passive relation to ourselves; and therefore in the
systems of psychology, the internal sense is commonly held to be one
with the faculty of apperception, while we, on the contrary, carefully
distinguish them.
That which determines the internal sense is the understanding, and
its original power of conjoining the manifold of intuition, that is,
of bringing this under an apperception (upon which rests the
possibility of the understanding itself). Now, as the human
understanding is not in itself a faculty of intuition, and is unable
to exercise such a power, in order to conjoin, as it were, the
manifold of its own intuition, the synthesis of understanding is,
considered per se, nothing but the unity of action, of which, as such,
it is self-conscious, even apart from sensibility, by which, moreover,
it is able to determine our internal sense in respect of the
manifold which may be presented to it according to the form of
sensuous intuition. Thus, under the name of a transcendental synthesis
of imagination, the understanding exercises an activity upon the
passive subject, whose faculty it is; and so we are right in saying
that the internal sense is affected thereby. Apperception and its
synthetical unity are by no means one and the same with the internal
sense. The former, as the source of all our synthetical conjunction,
applies, under the name of the categories, to the manifold of
intuition in general, prior to all sensuous intuition of objects.
The internal sense, on the contrary, contains merely the form of
intuition, but without any synthetical conjunction of the manifold
therein, and consequently does not contain any determined intuition,
which is possible only through consciousness of the determination of
the manifold by the transcendental act of the imagination (synthetical
influence of the understanding on the internal sense), which I have
named figurative synthesis.
This we can indeed always perceive in ourselves. We cannot
cogitate a geometrical line without drawing it in thought, nor a
circle without describing it, nor represent the three dimensions of
space without drawing three lines from the same point perpendicular to
one another. We cannot even cogitate time, unless, in drawing a
straight line (which is to serve as the external figurative
representation of time), we fix our attention on the act of the
synthesis of the manifold, whereby we determine successively the
internal sense, and thus attend also to the succession of this
determination. Motion as an act of the subject (not as a determination
of an object),* consequently the synthesis of the manifold in space,
if we make abstraction of space and attend merely to the act by
which we determine the internal sense according to its form, is that
which produces the conception of succession. The understanding,
therefore, does by no means find in the internal sense any such
synthesis of the manifold, but produces it, in that it affects this
sense. At the same time, how "I who think" is distinct from the "I"
which intuites itself (other modes of intuition being cogitable as
at least possible), and yet one and the same with this latter as the
same subject; how, therefore, I am able to say: "I, as an intelligence
and thinking subject, cognize myself as an object thought, so far as I
am, moreover, given to myself in intuition- only, like other
phenomena, not as I am in myself, and as considered by the
understanding, but merely as I appear"- is a question that has in it
neither more nor less difficulty than the question- "How can I be an
object to myself?" or this- "How I can be an object of my own
intuition and internal perceptions?" But that such must be the fact,
if we admit that space is merely a pure form of the phenomena of
external sense, can be clearly proved by the consideration that we
cannot represent time, which is not an object of external intuition,
in any other way than under the image of a line, which we draw in
thought, a mode of representation without which we could not cognize
the unity of its dimension, and also that we are necessitated to
take our determination of periods of time, or of points of time, for
all our internal perceptions from the changes which we perceive in
outward things. It follows that we must arrange the determinations
of the internal sense, as phenomena in time, exactly in the same
manner as we arrange those of the external senses in space. And
consequently, if we grant, respecting this latter, that by means of
them we know objects only in so far as we are affected externally,
we must also confess, with regard to the internal sense, that by means
of it we intuite ourselves only as we are internally affected by
ourselves; in other words, as regards internal intuition, we cognize
our own subject only as phenomenon, and not as it is in itself.*[2]

*Motion of an object in space does not belong to a pure science,
consequently not to geometry; because, that a thing is movable
cannot be known a priori, but only from experience. But motion,
considered as the description of a space, is a pure act of the
successive synthesis of the manifold in external intuition by means of
productive imagination, and belongs not only to geometry, but even
to transcendental philosophy.
*[2] I do not see why so much difficulty should be found in
admitting that our internal sense is affected by ourselves. Every
act of attention exemplifies it. In such an act the understanding
determines the internal sense by the synthetical conjunction which
it cogitates, conformably to the internal intuition which
corresponds to the manifold in the synthesis of the understanding. How
much the mind is usually affected thereby every one will be able to
perceive in himself.

SS 21

On the other hand, in the transcendental synthesis of the manifold
content of representations, consequently in the synthetical unity of
apperception, I am conscious of myself, not as I appear to myself, nor
as I am in myself, but only that "I am." This representation is a
thought, not an intuition. Now, as in order to cognize ourselves, in
addition to the act of thinking, which subjects the manifold of
every possible intuition to the unity of apperception, there is
necessary a determinate mode of intuition, whereby this manifold is
given; although my own existence is certainly not mere phenomenon
(much less mere illusion), the determination of my existence* Can only
take place conformably to the form of the internal sense, according to
the particular mode in which the manifold which I conjoin is given
in internal intuition, and I have therefore no knowledge of myself
as I am, but merely as I appear to myself. The consciousness of self
is thus very far from a knowledge of self, in which I do not use the
categories, whereby I cogitate an object, by means of the
conjunction of the manifold in one apperception. In the same way as
I require, for the sake of the cognition of an object distinct from
myself, not only the thought of an object in general (in the
category), but also an intuition by which to determine that general
conception, in the same way do I require, in order to the cognition of
myself, not only the consciousness of myself or the thought that I
think myself, but in addition an intuition of the manifold in
myself, by which to determine this thought. It is true that I exist as
an intelligence which is conscious only of its faculty of
conjunction or synthesis, but subjected in relation to the manifold
which this intelligence has to conjoin to a limitative conjunction
called the internal sense. My intelligence (that is, I) can render
that conjunction or synthesis perceptible only according to the
relations of time, which are quite beyond the proper sphere of the
conceptions of the understanding and consequently cognize itself in
respect to an intuition (which cannot possibly be intellectual, nor
given by the understanding), only as it appears to itself, and not
as it would cognize itself, if its intuition were intellectual.

*The "I think" expresses the act of determining my own existence. My
existence is thus already given by the act of consciousness; but the
mode in which I must determine my existence, that is, the mode in
which I must place the manifold belonging to my existence, is not
thereby given. For this purpose intuition of self is required, and
this intuition possesses a form given a priori, namely, time, which is
sensuous, and belongs to our receptivity of the determinable. Now,
as I do not possess another intuition of self which gives the
determining in me (of the spontaneity of which I am conscious),
prior to the act of determination, in the same manner as time gives
the determinable, it is clear that I am unable to determine my own
existence as that of a spontaneous being, but I am only able to
represent to myself the spontaneity of my thought, that is, of my
determination, and my existence remains ever determinable in a
purely sensuous manner, that is to say, like the existence of a
phenomenon. But it is because of this spontaneity that I call myself
an intelligence.

Transcendental Deduction of the universally possible
employment in experience of the Pure Conceptions
of the Understanding. SS 22

In the metaphysical deduction, the a priori origin of categories was
proved by their complete accordance with the general logical of
thought; in the transcendental deduction was exhibited the possibility
of the categories as a priori cognitions of objects of an intuition in
general (SS 16 and 17).At present we are about to explain the
possibility of cognizing, a priori, by means of the categories, all
objects which can possibly be presented to our senses, not, indeed,
according to the form of their intuition, but according to the laws of
their conjunction or synthesis, and thus, as it were, of prescribing
laws to nature and even of rendering nature possible. For if the
categories were inadequate to this task, it would not be evident to us
why everything that is presented to our senses must be subject to
those laws which have an a priori origin in the understanding itself.
I premise that by the term synthesis of apprehension I understand
the combination of the manifold in an empirical intuition, whereby
perception, that is, empirical consciousness of the intuition (as
phenomenon), is possible.
We have a priori forms of the external and internal sensuous
intuition in the representations of space and time, and to these
must the synthesis of apprehension of the manifold in a phenomenon
be always comformable, because the synthesis itself can only take
place according to these forms. But space and time are not merely
forms of sensuous intuition, but intuitions themselves (which
contain a manifold), and therefore contain a priori the
determination of the unity of this manifold.* (See the Transcendent
Aesthetic.) Therefore is unity of the synthesis of the manifold
without or within us, consequently also a conjunction to which all
that is to be represented as determined in space or time must
correspond, given a priori along with (not in) these intuitions, as
the condition of the synthesis of all apprehension of them. But this
synthetical unity can be no other than that of the conjunction of
the manifold of a given intuition in general, in a primitive act of
consciousness, according to the categories, but applied to our
sensuous intuition. Consequently all synthesis, whereby alone is
even perception possible, is subject to the categories. And, as
experience is cognition by means of conjoined perceptions, the
categories are conditions of the possibility of experience and are
therefore valid a priori for all objects of experience.

*Space represented as an object (as geometry really requires it to
be) contains more than the mere form of the intuition; namely, a
combination of the manifold given according to the form of sensibility
into a representation that can be intuited; so that the form of the
intuition gives us merely the manifold, but the formal intuition gives
unity of representation. In the aesthetic, I regarded this unity as
belonging entirely to sensibility, for the purpose of indicating
that it antecedes all conceptions, although it presupposes a synthesis
which does not belong to sense, through which alone, however, all
our conceptions of space and time are possible. For as by means of
this unity alone (the understanding determining the sensibility) space
and time are given as intuitions, it follows that the unity of this
intuition a priori belongs to space and time, and not to the
conception of the understanding (SS 20).

When, then, for example, I make the empirical intuition of a house
by apprehension of the manifold contained therein into a perception,
the necessary unity of space and of my external sensuous intuition
lies at the foundation of this act, and I, as it were, draw the form
of the house conformably to this synthetical unity of the manifold
in space. But this very synthetical unity remains, even when I
abstract the form of space, and has its seat in the understanding, and
is in fact the category of the synthesis of the homogeneous in an
intuition; that is to say, the category of quantity, to which the
aforesaid synthesis of apprehension, that is, the perception, must
be completely conformable.*

*In this manner it is proved, that the synthesis of apprehension,
which is empirical, must necessarily be conformable to the synthesis
of apperception, which is intellectual, and contained a priori in
the category. It is one and the same spontaneity which at one time,
under the name of imagination, at another under that of understanding,
produces conjunction in the manifold of intuition.

To take another example, when I perceive the freezing of water, I
apprehend two states (fluidity and solidity), which, as such, stand
toward each other mutually in a relation of time. But in the time,
which I place as an internal intuition, at the foundation of this
phenomenon, I represent to myself synthetical unity of the manifold,
without which the aforesaid relation could not be given in an
intuition as determined (in regard to the succession of time). Now
this synthetical unity, as the a priori condition under which I
conjoin the manifold of an intuition, is, if I make abstraction of the
permanent form of my internal intuition (that is to say, of time), the
category of cause, by means of which, when applied to my
sensibility, I determine everything that occurs according to relations
of time. Consequently apprehension in such an event, and the event
itself, as far as regards the possibility of its perception, stands
under the conception of the relation of cause and effect: and so in
all other cases.

Categories are conceptions which prescribe laws a priori to
phenomena, consequently to nature as the complex of all phenomena
(natura materialiter spectata). And now the question arises-
inasmuch as these categories are not derived from nature, and do not
regulate themselves according to her as their model (for in that
case they would be empirical)- how it is conceivable that nature
must regulate herself according to them, in other words, how the
categories can determine a priori the synthesis of the manifold of
nature, and yet not derive their origin from her. The following is the
solution of this enigma.
It is not in the least more difficult to conceive how the laws of
the phenomena of nature must harmonize with the understanding and with
its a priori form- that is, its faculty of conjoining the manifold-
than it is to understand how the phenomena themselves must
correspond with the a priori form of our sensuous intuition. For
laws do not exist in the phenomena any more than the phenomena exist
as things in themselves. Laws do not exist except by relation to the
subject in which the phenomena inhere, in so far as it possesses
understanding, just as phenomena have no existence except by
relation to the same existing subject in so far as it has senses. To
things as things in themselves, conformability to law must necessarily
belong independently of an understanding to cognize them. But
phenomena are only representations of things which are utterly unknown
in respect to what they are in themselves. But as mere
representations, they stand under no law of conjunction except that
which the conjoining faculty prescribes. Now that which conjoins the
manifold of sensuous intuition is imagination, a mental act to which
understanding contributes unity of intellectual synthesis, and
sensibility, manifoldness of apprehension. Now as all possible
perception depends on the synthesis of apprehension, and this
empirical synthesis itself on the transcendental, consequently on
the categories, it is evident that all possible perceptions, and
therefore everything that can attain to empirical consciousness,
that is, all phenomena of nature, must, as regards their
conjunction, be subject to the categories. And nature (considered
merely as nature in general) is dependent on them. as the original
ground of her necessary conformability to law (as natura formaliter
spectata). But the pure faculty (of the understanding) of
prescribing laws a priori to phenomena by means of mere categories, is
not competent to enounce other or more laws than those on which a
nature in general, as a conformability to law of phenomena of space
and time, depends. Particular laws, inasmuch as they concern
empirically determined phenomena, cannot be entirely deduced from pure
laws, although they all stand under them. Experience must be
superadded in order to know these particular laws; but in regard to
experience in general, and everything that can be cognized as an
object thereof, these a priori laws are our only rule and guide.

Result of this Deduction of the Conceptions of the
Understanding. SS 23

We cannot think any object except by means of the categories; we
cannot cognize any thought except by means of intuitions corresponding
to these conceptions. Now all our intuitions are sensuous, and our
cognition, in so far as the object of it is given, is empirical. But
empirical cognition is experience; consequently no a priori
cognition is possible for us, except of objects of possible
experience.*

*Lest my readers should stumble at this assertion, and the
conclusions that may be too rashly drawn from it, I must remind them
that the categories in the act of thought are by no means limited by
the conditions of our sensuous intuition, but have an unbounded sphere
of action. It is only the cognition of the object of thought, the
determining of the object, which requires intuition. In the absence of
intuition, our thought of an object may still have true and useful
consequences in regard to the exercise of reason by the subject. But
as this exercise of reason is not always directed on the determination
of the object, in other words, on cognition thereof, but also on the
determination of the subject and its volition, I do not intend to
treat of it in this place.

But this cognition, which is limited to objects of experience, is
not for that reason derived entirely, from, experience, but- and
this is asserted of the pure intuitions and the pure conceptions of
the understanding- there are, unquestionably, elements of cognition,
which exist in the mind a priori. Now there are only two ways in which
a necessary harmony of experience with the conceptions of its
objects can be cogitated. Either experience makes these conceptions
possible, or the conceptions make experience possible. The former of
these statements will not bold good with respect to the categories
(nor in regard to pure sensuous intuition), for they are a priori
conceptions, and therefore independent of experience. The assertion of
an empirical origin would attribute to them a sort of generatio
aequivoca. Consequently, nothing remains but to adopt the second
alternative (which presents us with a system, as it were, of the
epigenesis of pure reason), namely, that on the part of the
understanding the categories do contain the grounds of the possibility
of all experience. But with respect to the questions how they make
experience possible, and what are the principles of the possibility
thereof with which they present us in their application to
phenomena, the following section on the transcendental exercise of the
faculty of judgement will inform the reader.
It is quite possible that someone may propose a species of
preformation-system of pure reason- a middle way between the two- to
wit, that the categories are neither innate and first a priori
principles of cognition, nor derived from experience, but are merely
subjective aptitudes for thought implanted in us contemporaneously
with our existence, which were so ordered and disposed by our Creator,
that their exercise perfectly harmonizes with the laws of nature which
regulate experience. Now, not to mention that with such an
hypothesis it is impossible to say at what point we must stop in the
employment of predetermined aptitudes, the fact that the categories
would in this case entirely lose that character of necessity which
is essentially involved in the very conception of them, is a
conclusive objection to it. The conception of cause, for example,
which expresses the necessity of an effect under a presupposed
condition, would be false, if it rested only upon such an arbitrary
subjective necessity of uniting certain empirical representations
according to such a rule of relation. I could not then say- "The
effect is connected with its cause in the object (that is,
necessarily)," but only, "I am so constituted that I can think this
representation as so connected, and not otherwise." Now this is just
what the sceptic wants. For in this case, all our knowledge, depending
on the supposed objective validity of our judgement, is nothing but
mere illusion; nor would there be wanting people who would deny any
such subjective necessity in respect to themselves, though they must
feel it. At all events, we could not dispute with any one on that
which merely depends on the manner in which his subject is organized.

Short view of the above Deduction.

The foregoing deduction is an exposition of the pure conceptions
of the understanding (and with them of all theoretical a priori
cognition), as principles of the possibility of experience, but of
experience as the determination of all phenomena in space and time
in general- of experience, finally, from the principle of the original
synthetical unity of apperception, as the form of the understanding in
relation to time and space as original forms of sensibility.

I consider the division by paragraphs to be necessary only up to
this point, because we had to treat of the elementary conceptions.
As we now proceed to the exposition of the employment of these, I
shall not designate the chapters in this manner any further.
BOOK II.

Analytic of Principles.

General logic is constructed upon a plan which coincides exactly
with the division of the higher faculties of cognition. These are,
understanding, judgement, and reason. This science, accordingly,
treats in its analytic of conceptions, judgements, and conclusions
in exact correspondence with the functions and order of those mental
powers which we include generally under the generic denomination of
understanding.
As this merely formal logic makes abstraction of all content of
cognition, whether pure or empirical, and occupies itself with the
mere form of thought (discursive cognition), it must contain in its
analytic a canon for reason. For the form of reason has its law,
which, without taking into consideration the particular nature of
the cognition about which it is employed, can be discovered a
priori, by the simple analysis of the action of reason into its
momenta.
Transcendental logic, limited as it is to a determinate content,
that of pure a priori cognitions, to wit, cannot imitate general logic
in this division. For it is evident that the transcendental employment
of reason is not objectively valid, and therefore does not belong to
the logic of truth (that is, to analytic), but as a logic of illusion,
occupies a particular department in the scholastic system under the
name of transcendental dialectic.
Understanding and judgement accordingly possess in transcendental
logic a canon of objectively valid, and therefore true exercise, and
are comprehended in the analytical department of that logic. But
reason, in her endeavours to arrive by a priori means at some true
statement concerning objects and to extend cognition beyond the bounds
of possible experience, is altogether dialectic, and her illusory
assertions cannot be constructed into a canon such as an analytic
ought to contain.
Accordingly, the analytic of principles will be merely a canon for
the faculty of judgement, for the instruction of this faculty in its
application to phenomena of the pure conceptions of the understanding,
which contain the necessary condition for the establishment of a
priori laws. On this account, although the subject of the following
chapters is the especial principles of understanding, I shall make use
of the term Doctrine of the faculty of judgement, in order to define
more particularly my present purpose.

INTRODUCTION. Of the Transcendental Faculty of judgement in General.

If understanding in general be defined as the faculty of laws or
rules, the faculty of judgement may be termed the faculty of
subsumption under these rules; that is, of distinguishing whether this
or that does or does not stand under a given rule (casus datae legis).
General logic contains no directions or precepts for the faculty of
judgement, nor can it contain any such. For as it makes abstraction of
all content of cognition, no duty is left for it, except that of
exposing analytically the mere form of cognition in conceptions,
judgements, and conclusions, and of thereby establishing formal
rules for all exercise of the understanding. Now if this logic
wished to give some general direction how we should subsume under
these rules, that is, how we should distinguish whether this or that
did or did not stand under them, this again could not be done
otherwise than by means of a rule. But this rule, precisely because it
is a rule, requires for itself direction from the faculty of
judgement. Thus, it is evident that the understanding is capable of
being instructed by rules, but that the judgement is a peculiar
talent, which does not, and cannot require tuition, but only exercise.
This faculty is therefore the specific quality of the so-called mother
wit, the want of which no scholastic discipline can compensate.
For although education may furnish, and, as it were, engraft upon
a limited understanding rules borrowed from other minds, yet the power
of employing these rules correctly must belong to the pupil himself;
and no rule which we can prescribe to him with this purpose is, in the
absence or deficiency of this gift of nature, secure from misuse.* A
physician therefore, a judge or a statesman, may have in his head many
admirable pathological, juridical, or political rules, in a degree
that may enable him to be a profound teacher in his particular
science, and yet in the application of these rules he may very
possibly blunder- either because he is wanting in natural judgement
(though not in understanding) and, whilst he can comprehend the
general in abstracto, cannot distinguish whether a particular case
in concreto ought to rank under the former; or because his faculty
of judgement bas not been sufficiently exercised by examples and
real practice. Indeed, the grand and only use of examples, is to
sharpen the judgement. For as regards the correctness and precision of
the insight of the understanding, examples are commonly injurious
rather than otherwise, because, as casus in terminis they seldom
adequately fulfil the conditions of the rule. Besides, they often
weaken the power of our understanding to apprehend rules or laws in
their universality, independently of particular circumstances of
experience; and hence, accustom us to employ them more as formulae
than as principles. Examples are thus the go-cart of the judgement,
which he who is naturally deficient in that faculty cannot afford to
dispense with.

*Deficiency in judgement is properly that which is called stupidity;
and for such a failing we know no remedy. A dull or narrow-minded
person, to whom nothing is wanting but a proper degree of
understanding, may be improved by tuition, even so far as to deserve
the epithet of learned. But as such persons frequently labour under
a deficiency in the faculty of judgement, it is not uncommon to find
men extremely learned who in the application of their science betray a
lamentable degree this irremediable want.

But although general logic cannot give directions to the faculty
of judgement, the case is very different as regards transcendental
logic, insomuch that it appears to be the especial duty of the
latter to secure and direct, by means of determinate rules, the
faculty of judgement in the employment of the pure understanding. For,
as a doctrine, that is, as an endeavour to enlarge the sphere of the
understanding in regard to pure a priori cognitions, philosophy is
worse than useless, since from all the attempts hitherto made,
little or no ground has been gained. But, as a critique, in order to
guard against the mistakes of the faculty of judgement (lapsus
judicii) in the employment of the few pure conceptions of the
understanding which we possess, although its use is in this case
purely negative, philosophy is called upon to apply all its
acuteness and penetration.
But transcendental philosophy has this peculiarity, that besides
indicating the rule, or rather the general condition for rules,
which is given in the pure conception of the understanding, it can, at
the same time, indicate a priori the case to which the rule must be
applied. The cause of the superiority which, in this respect,
transcendental philosophy possesses above all other sciences except
mathematics, lies in this: it treats of conceptions which must
relate a priori to their objects, whose objective validity
consequently cannot be demonstrated a posteriori, and is, at the
same time, under the obligation of presenting in general but
sufficient tests, the conditions under which objects can be given in
harmony with those conceptions; otherwise they would be mere logical
forms, without content, and not pure conceptions of the understanding.
Our transcendental doctrine of the faculty of judgement will contain
two chapters. The first will treat of the sensuous condition under
which alone pure conceptions of the understanding can be employed-
that is, of the schematism of the pure understanding. The second
will treat of those synthetical judgements which are derived a
priori from pure conceptions of the understanding under those
conditions, and which lie a priori at the foundation of all other
cognitions, that is to say, it will treat of the principles of the
pure understanding.
TRANSCENDENTAL DOCTRINE OF THE FACULTY OF JUDGEMENT
OR, ANALYTIC OF PRINCIPLES.

CHAPTER I. Of the Schematism at of the Pure Conceptions
of the Understanding.

In all subsumptions of an object under a conception, the
representation of the object must be homogeneous with the
conception; in other words, the conception must contain that which
is represented in the object to be subsumed under it. For this is
the meaning of the expression: "An object is contained under a
conception." Thus the empirical conception of a plate is homogeneous
with the pure geometrical conception of a circle, inasmuch as the
roundness which is cogitated in the former is intuited in the latter.
But pure conceptions of the understanding, when compared with
empirical intuitions, or even with sensuous intuitions in general, are
quite heterogeneous, and never can be discovered in any intuition. How
then is the subsumption of the latter under the former, and
consequently the application of the categories to phenomena,
possible?- For it is impossible to say, for example: "Causality can be
intuited through the senses and is contained in the phenomenon."- This
natural and important question forms the real cause of the necessity
of a transcendental doctrine of the faculty of judgement, with the
purpose, to wit, of showing how pure conceptions of the
understanding can be applied to phenomena. In all other sciences,
where the conceptions by which the object is thought in the general
are not so different and heterogeneous from those which represent
the object in concreto- as it is given, it is quite unnecessary to
institute any special inquiries concerning the application of the
former to the latter.
Now it is quite clear that there must be some third thing, which
on the one side is homogeneous with the category, and with the
phenomenon on the other, and so makes the application of the former to
the latter possible. This mediating representation must be pure
(without any empirical content), and yet must on the one side be
intellectual, on the other sensuous. Such a representation is the
transcendental schema.
The conception of the understanding contains pure synthetical
unity of the manifold in general. Time, as the formal condition of the
manifold of the internal sense, consequently of the conjunction of all
representations, contains a priori a manifold in the pure intuition.
Now a transcendental determination of time is so far homogeneous
with the category, which constitutes the unity thereof, that it is
universal and rests upon a rule a priori. On the other hand, it is
so far homogeneous with the phenomenon, inasmuch as time is
contained in every empirical representation of the manifold. Thus an
application of the category to phenomena becomes possible, by means of
the transcendental determination of time, which, as the schema of
the conceptions of the understanding, mediates the subsumption of
the latter under the former.
After what has been proved in our deduction of the categories, no
one, it is to be hoped, can hesitate as to the proper decision of
the question, whether the employment of these pure conceptions of
the understanding ought to be merely empirical or also transcendental;
in other words, whether the categories, as conditions of a possible
experience, relate a priori solely to phenomena, or whether, as
conditions of the possibility of things in general, their
application can be extended to objects as things in themselves. For we
have there seen that conceptions are quite impossible, and utterly
without signification, unless either to them, or at least to the
elements of which they consist, an object be given; and that,
consequently, they cannot possibly apply to objects as things in
themselves without regard to the question whether and how these may be
given to us; and, further, that the only manner in which objects can
be given to us is by means of the modification of our sensibility;
and, finally, that pure a priori conceptions, in addition to the
function of the understanding in the category, must contain a priori
formal conditions of sensibility (of the internal sense, namely),
which again contain the general condition under which alone the
category can be applied to any object. This formal and pure
condition of sensibility, to which the conception of the understanding
is restricted in its employment, we shall name the schema of the
conception of the understanding, and the procedure of the
understanding with these schemata we shall call the schematism of
the pure understanding.
The schema is, in itself, always a mere product of the
imagination. But, as the synthesis of imagination has for its aim no
single intuition, but merely unity in the determination of
sensibility, the schema is clearly distinguishable from the image.
Thus, if I place five points one after another.... this is an image of
the number five. On the other hand, if I only think a number in
general, which may be either five or a hundred, this thought is rather
the representation of a method of representing in an image a sum
(e.g., a thousand) in conformity with a conception, than the image
itself, an image which I should find some little difficulty in
reviewing, and comparing with the conception. Now this
representation of a general procedure of the imagination to present
its image to a conception, I call the schema of this conception.
In truth, it is not images of objects, but schemata, which lie at
the foundation of our pure sensuous conceptions. No image could ever
be adequate to our conception of a triangle in general. For the
generalness of the conception it never could attain to, as this
includes under itself all triangles, whether right-angled,
acute-angled, etc., whilst the image would always be limited to a
single part of this sphere. The schema of the triangle can exist
nowhere else than in thought, and it indicates a rule of the synthesis
of the imagination in regard to pure figures in space. Still less is
an object of experience, or an image of the object, ever to the
empirical conception. On the contrary, the conception always relates
immediately to the schema of the imagination, as a rule for the
determination of our intuition, in conformity with a certain general
conception. The conception of a dog indicates a rule, according to
which my imagination can delineate the figure of a four-footed
animal in general, without being limited to any particular
individual form which experience presents to me, or indeed to any
possible image that I can represent to myself in concreto. This
schematism of our understanding in regard to phenomena and their
mere form, is an art, hidden in the depths of the human soul, whose
true modes of action we shall only with difficulty discover and
unveil. Thus much only can we say: "The image is a product of the
empirical faculty of the productive imagination- the schema of
sensuous conceptions (of figures in space, for example) is a
product, and, as it were, a monogram of the pure imagination a priori,
whereby and according to which images first become possible, which,
however, can be connected with the conception only mediately by
means of the schema which they indicate, and are in themselves never
fully adequate to it." On the other hand, the schema of a pure
conception of the understanding is something that cannot be reduced
into any image- it is nothing else than the pure synthesis expressed
by the category, conformably, to a rule of unity according to
conceptions. It is a transcendental product of the imagination, a
product which concerns the determination of the internal sense,
according to conditions of its form (time) in respect to all
representations, in so far as these representations must be
conjoined a priori in one conception, conformably to the unity of
apperception.
Without entering upon a dry and tedious analysis of the essential
requisites of transcendental schemata of the pure conceptions of the
understanding, we shall rather proceed at once to give an
explanation of them according to the order of the categories, and in
connection therewith.
For the external sense the pure image of all quantities
(quantorum) is space; the pure image of all objects of sense in
general, is time. But the pure schema of quantity (quantitatis) as a
conception of the understanding, is number, a representation which
comprehends the successive addition of one to one (homogeneous
quantities). Thus, number is nothing else than the unity of the
synthesis of the manifold in a homogeneous intuition, by means of my
generating time itself in my apprehension of the intuition.
Reality, in the pure conception of the understanding, is that
which corresponds to a sensation in general; that, consequently, the
conception of which indicates a being (in time). Negation is that
the conception of which represents a not-being (in time). The
opposition of these two consists therefore in the difference of one
and the same time, as a time filled or a time empty. Now as time is
only the form of intuition, consequently of objects as phenomena, that
which in objects corresponds to sensation is the transcendental matter
of all objects as things in themselves (Sachheit, reality). Now
every sensation has a degree or quantity by which it can fill time,
that is to say, the internal sense in respect of the representation of
an object, more or less, until it vanishes into nothing (= 0 =
negatio). Thus there is a relation and connection between reality
and negation, or rather a transition from the former to the latter,
which makes every reality representable to us as a quantum; and the
schema of a reality as the quantity of something in so far as it fills
time, is exactly this continuous and uniform generation of the reality
in time, as we descend in time from the sensation which has a
certain degree, down to the vanishing thereof, or gradually ascend
from negation to the quantity thereof.
The schema of substance is the permanence of the real in time;
that is, the representation of it as a substratum of the empirical
determination of time; a substratum which therefore remains, whilst
all else changes. (Time passes not, but in it passes the existence
of the changeable. To time, therefore, which is itself unchangeable
and permanent, corresponds that which in the phenomenon is
unchangeable in existence, that is, substance, and it is only by it
that the succession and coexistence of phenomena can be determined
in regard to time.)
The schema of cause and of the causality of a thing is the real
which, when posited, is always followed by something else. It
consists, therefore, in the succession of the manifold, in so far as
that succession is subjected to a rule.
The schema of community (reciprocity of action and reaction), or the
reciprocal causality of substances in respect of their accidents, is
the coexistence of the determinations of the one with those of the
other, according to a general rule.
The schema of possibility is the accordance of the synthesis of
different representations with the conditions of time in general
(as, for example, opposites cannot exist together at the same time
in the same thing, but only after each other), and is therefore the
determination of the representation of a thing at any time.
The schema of reality is existence in a determined time.
The schema of necessity is the existence of an object in all time.
It is clear, from all this, that the schema of the category of
quantity contains and represents the generation (synthesis) of time
itself, in the successive apprehension of an object; the schema of
quality the synthesis of sensation with the representation of time, or
the filling up of time; the schema of relation the relation of
perceptions to each other in all time (that is, according to a rule of
the determination of time): and finally, the schema of modality and
its categories, time itself, as the correlative of the determination
of an object- whether it does belong to time, and how. The schemata,
therefore, are nothing but a priori determinations of time according
to rules, and these, in regard to all possible objects, following
the arrangement of the categories, relate to the series in time, the
content in time, the order in time, and finally, to the complex or
totality in time.
Hence it is apparent that the schematism of the understanding, by
means of the transcendental synthesis of the imagination, amounts to
nothing else than the unity of the manifold of intuition in the
internal sense, and thus indirectly to the unity of apperception, as a
function corresponding to the internal sense (a receptivity). Thus,
the schemata of the pure conceptions of the understanding are the true
and only conditions whereby our understanding receives an
application to objects, and consequently significance. Finally,
therefore, the categories are only capable of empirical use,
inasmuch as they serve merely to subject phenomena to the universal
rules of synthesis, by means of an a priori necessary unity (on
account of the necessary union of all consciousness in one original
apperception); and so to render them susceptible of a complete
connection in one experience. But within this whole of possible
experience lie all our cognitions, and in the universal relation to
this experience consists transcendental truth, which antecedes all
empirical truth, and renders the latter possible.
It is, however, evident at first sight, that although the schemata
of sensibility are the sole agents in realizing the categories, they
do, nevertheless, also restrict them, that is, they limit the
categories by conditions which lie beyond the sphere of understanding-
namely, in sensibility. Hence the schema is properly only the
phenomenon, or the sensuous conception of an object in harmony with
the category. (Numerus est quantitas phaenomenon- sensatio realitas
phaenomenon; constans et perdurabile rerum substantia phaenomenon-
aeternitas, necessitas, phaenomena, etc.) Now, if we remove a
restrictive condition, we thereby amplify, it appears, the formerly
limited conception. In this way, the categories in their pure
signification, free from all conditions of sensibility, ought to be
valid of things as they are, and not, as the schemata represent
them, merely as they appear; and consequently the categories must have
a significance far more extended, and wholly independent of all
schemata. In truth, there does always remain to the pure conceptions
of the understanding, after abstracting every sensuous condition, a
value and significance, which is, however, merely logical. But in this
case, no object is given them, and therefore they have no meaning
sufficient to afford us a conception of an object. The notion of
substance, for example, if we leave out the sensuous determination
of permanence, would mean nothing more than a something which can be
cogitated as subject, without the possibility of becoming a
predicate to anything else. Of this representation I can make nothing,
inasmuch as it does not indicate to me what determinations the thing
possesses which must thus be valid as premier subject. Consequently,
the categories, without schemata are merely functions of the
understanding for the production of conceptions, but do not
represent any object. This significance they derive from
sensibility, which at the same time realizes the understanding and
restricts it.
CHAPTER II. System of all Principles of the Pure Understanding.

In the foregoing chapter we have merely considered the general
conditions under which alone the transcendental faculty of judgement
is justified in using the pure conceptions of the understanding for
synthetical judgements. Our duty at present is to exhibit in
systematic connection those judgements which the understanding
really produces a priori. For this purpose, our table of the
categories will certainly afford us the natural and safe guidance. For
it is precisely the categories whose application to possible
experience must constitute all pure a priori cognition of the
understanding; and the relation of which to sensibility will, on
that very account, present us with a complete and systematic catalogue
of all the transcendental principles of the use of the understanding.
Principles a priori are so called, not merely because they contain
in themselves the grounds of other judgements, but also because they
themselves are not grounded in higher and more general cognitions.
This peculiarity, however, does not raise them altogether above the
need of a proof. For although there could be found no higher
cognition, and therefore no objective proof, and although such a
principle rather serves as the foundation for all cognition of the
object, this by no means hinders us from drawing a proof from the
subjective sources of the possibility of the cognition of an object.
Such a proof is necessary, moreover, because without it the
principle might be liable to the imputation of being a mere gratuitous
assertion.
In the second place, we shall limit our investigations to those
principles which relate to the categories. For as to the principles of
transcendental aesthetic, according to which space and time are the
conditions of the possibility of things as phenomena, as also the
restriction of these principles, namely, that they cannot be applied
to objects as things in themselves- these, of course, do not fall
within the scope of our present inquiry. In like manner, the
principles of mathematical science form no part of this system,
because they are all drawn from intuition, and not from the pure
conception of the understanding. The possibility of these
principles, however, will necessarily be considered here, inasmuch
as they are synthetical judgements a priori, not indeed for the
purpose of proving their accuracy and apodeictic certainty, which is
unnecessary, but merely to render conceivable and deduce the
possibility of such evident a priori cognitions.
But we shall have also to speak of the principle of analytical
judgements, in opposition to synthetical judgements, which is the
proper subject of our inquiries, because this very opposition will
free the theory of the latter from all ambiguity, and place it clearly
before our eyes in its true nature.

SYSTEM OF THE PRINCIPLES OF THE PURE UNDERSTANDING.

SECTION I. Of the Supreme Principle of all Analytical Judgements.

Whatever may be the content of our cognition, and in whatever manner
our cognition may be related to its object, the universal, although
only negative conditions of all our judgements is that they do not
contradict themselves; otherwise these judgements are in themselves
(even without respect to the object) nothing. But although there may
exist no contradiction in our judgement, it may nevertheless connect
conceptions in such a manner that they do not correspond to the
object, or without any grounds either a priori or a posteriori for
arriving at such a judgement, and thus, without being
self-contradictory, a judgement may nevertheless be either false or
groundless.
Now, the proposition: "No subject can have a predicate that
contradicts it," is called the principle of contradiction, and is a
universal but purely negative criterion of all truth. But it belongs
to logic alone, because it is valid of cognitions, merely as
cognitions and without respect to their content, and declares that the
contradiction entirely nullifies them. We can also, however, make a
positive use of this principle, that is, not merely to banish
falsehood and error (in so far as it rests upon contradiction), but
also for the cognition of truth. For if the judgement is analytical,
be it affirmative or negative, its truth must always be recognizable
by means of the principle of contradiction. For the contrary of that
which lies and is cogitated as conception in the cognition of the
object will be always properly negatived, but the conception itself
must always be affirmed of the object, inasmuch as the contrary
thereof would be in contradiction to the object.
We must therefore hold the principle of contradiction to be the
universal and fully sufficient Principle of all analytical
cognition. But as a sufficient criterion of truth, it has no further
utility or authority. For the fact that no cognition can be at
variance with this principle without nullifying itself, constitutes
this principle the sine qua non, but not the determining ground of the
truth of our cognition. As our business at present is properly with
the synthetical part of our knowledge only, we shall always be on
our guard not to transgress this inviolable principle; but at the same
time not to expect from it any direct assistance in the
establishment of the truth of any synthetical proposition.
There exists, however, a formula of this celebrated principle- a
principle merely formal and entirely without content- which contains a
synthesis that has been inadvertently and quite unnecessarily mixed up
with it. It is this: "It is impossible for a thing to be and not to be
at the same time." Not to mention the superfluousness of the
addition of the word impossible to indicate the apodeictic
certainty, which ought to be self-evident from the proposition itself,
the proposition is affected by the condition of time, and as it were
says: "A thing = A, which is something = B, cannot at the same time be
non-B." But both, B as well as non-B, may quite well exist in
succession. For example, a man who is young cannot at the same time be
old; but the same man can very well be at one time young, and at
another not young, that is, old. Now the principle of contradiction as
a merely logical proposition must not by any means limit its
application merely to relations of time, and consequently a formula
like the preceding is quite foreign to its true purpose. The
misunderstanding arises in this way. We first of all separate a
predicate of a thing from the conception of the thing, and
afterwards connect with this predicate its opposite, and hence do
not establish any contradiction with the subject, but only with its
predicate, which has been conjoined with the subject synthetically-
a contradiction, moreover, which obtains only when the first and
second predicate are affirmed in the same time. If I say: "A man who
is ignorant is not learned," the condition "at the same time" must
be added, for he who is at one time ignorant, may at another be
learned. But if I say: "No ignorant man is a learned man," the
proposition is analytical, because the characteristic ignorance is now
a constituent part of the conception of the subject; and in this
case the negative proposition is evident immediately from the
proposition of contradiction, without the necessity of adding the
condition "the same time." This is the reason why I have altered the
formula of this principle- an alteration which shows very clearly
the nature of an analytical proposition.

SECTION II. Of the Supreme Principle of all Synthetical Judgements.

The explanation of the possibility of synthetical judgements is a
task with which general logic has nothing to do; indeed she needs
not even be acquainted with its name. But in transcendental logic it
is the most important matter to be dealt with- indeed the only one, if
the question is of the possibility of synthetical judgements a priori,
the conditions and extent of their validity. For when this question is
fully decided, it can reach its aim with perfect ease, the
determination, to wit, of the extent and limits of the pure
understanding.
In an analytical judgement I do not go beyond the given
conception, in order to arrive at some decision respecting it. If
the judgement is affirmative, I predicate of the conception only
that which was already cogitated in it; if negative, I merely
exclude from the conception its contrary. But in synthetical
judgements, I must go beyond the given conception, in order to
cogitate, in relation with it, something quite different from that
which was cogitated in it, a relation which is consequently never
one either of identity or contradiction, and by means of which the
truth or error of the judgement cannot be discerned merely from the
judgement itself.
Granted, then, that we must go out beyond a given conception, in
order to compare it synthetically with another, a third thing is
necessary, in which alone the synthesis of two conceptions can
originate. Now what is this tertium quid that is to be the medium of
all synthetical judgements? It is only a complex in which all our
representations are contained, the internal sense to wit, and its form
a priori, time.
The synthesis of our representations rests upon the imagination;
their synthetical unity (which is requisite to a judgement), upon
the unity of apperception. In this, therefore, is to be sought the
possibility of synthetical judgements, and as all three contain the
sources of a priori representations, the possibility of pure
synthetical judgements also; nay, they are necessary upon these
grounds, if we are to possess a knowledge of objects, which rests
solely upon the synthesis of representations.
If a cognition is to have objective reality, that is, to relate to
an object, and possess sense and meaning in respect to it, it is
necessary that the object be given in some way or another. Without
this, our conceptions are empty, and we may indeed have thought by
means of them, but by such thinking we have not, in fact, cognized
anything, we have merely played with representation. To give an
object, if this expression be understood in the sense of "to
present" the object, not mediately but immediately in intuition, means
nothing else than to apply the representation of it to experience,
be that experience real or only possible. Space and time themselves,
pure as these conceptions are from all that is empirical, and
certain as it is that they are represented fully a priori in the mind,
would be completely without objective validity, and without sense
and significance, if their necessary use in the objects of
experience were not shown. Nay, the representation of them is a mere
schema, that always relates to the reproductive imagination, which
calls up the objects of experience, without which they have no
meaning. And so it is with all conceptions without distinction.
The possibility of experience is, then, that which gives objective
reality to all our a priori cognitions. Now experience depends upon
the synthetical unity of phenomena, that is, upon a synthesis
according to conceptions of the object of phenomena in general, a
synthesis without which experience never could become knowledge, but
would be merely a rhapsody of perceptions, never fitting together into
any connected text, according to rules of a thoroughly united
(possible) consciousness, and therefore never subjected to the
transcendental and necessary unity of apperception. Experience has
therefore for a foundation, a priori principles of its form, that is
to say, general rules of unity in the synthesis of phenomena, the
objective reality of which rules, as necessary conditions even of
the possibility of experience can which rules, as necessary
conditions- even of the possibility of experience- can always be shown
in experience. But apart from this relation, a priori synthetical
propositions are absolutely impossible, because they have no third
term, that is, no pure object, in which the synthetical unity can
exhibit the objective reality of its conceptions.
Although, then, respecting space, or the forms which productive
imagination describes therein, we do cognize much a priori in
synthetical judgements, and are really in no need of experience for
this purpose, such knowledge would nevertheless amount to nothing
but a busy trifling with a mere chimera, were not space to be
considered as the condition of the phenomena which constitute the
material of external experience. Hence those pure synthetical
judgements do relate, though but mediately, to possible experience, or
rather to the possibility of experience, and upon that alone is
founded the objective validity of their synthesis.
While then, on the one hand, experience, as empirical synthesis,
is the only possible mode of cognition which gives reality to all
other synthesis; on the other hand, this latter synthesis, as
cognition a priori, possesses truth, that is, accordance with its
object, only in so far as it contains nothing more than what is
necessary to the synthetical unity of experience.
Accordingly, the supreme principle of all synthetical judgements is:
"Every object is subject to the necessary conditions of the
synthetical unity of the manifold of intuition in a possible
experience."
A priori synthetical judgements are possible when we apply the
formal conditions of the a priori intuition, the synthesis of the
imagination, and the necessary unity of that synthesis in a
transcendental apperception, to a possible cognition of experience,
and say: "The conditions of the possibility of experience in general
are at the same time conditions of the possibility of the objects of
experience, and have, for that reason, objective validity in an a
priori synthetical judgement."

SECTION III. Systematic Representation of all Synthetical
Principles of the Pure Understanding.

That principles exist at all is to be ascribed solely to the pure
understanding, which is not only the faculty of rules in regard to
that which happens, but is even the source of principles according
to which everything that can be presented to us as an object is
necessarily subject to rules, because without such rules we never
could attain to cognition of an object. Even the laws of nature, if
they are contemplated as principles of the empirical use of the
understanding, possess also a characteristic of necessity, and we
may therefore at least expect them to be determined upon grounds which
are valid a priori and antecedent to all experience. But all laws of
nature, without distinction, are subject to higher principles of the
understanding, inasmuch as the former are merely applications of the
latter to particular cases of experience. These higher principles
alone therefore give the conception, which contains the necessary
condition, and, as it were, the exponent of a rule; experience, on the
other hand, gives the case which comes under the rule.
There is no danger of our mistaking merely empirical principles
for principles of the pure understanding, or conversely; for the
character of necessity, according to conceptions which distinguish the
latter, and the absence of this in every empirical proposition, how
extensively valid soever it may be, is a perfect safeguard against
confounding them. There are, however, pure principles a priori,
which nevertheless I should not ascribe to the pure understanding- for
this reason, that they are not derived from pure conceptions, but
(although by the mediation of the understanding) from pure intuitions.
But understanding is the faculty of conceptions. Such principles
mathematical science possesses, but their application to experience,
consequently their objective validity, nay the possibility of such a
priori synthetical cognitions (the deduction thereof) rests entirely
upon the pure understanding.
On this account, I shall not reckon among my principles those of
mathematics; though I shall include those upon the possibility and
objective validity a priori, of principles of the mathematical
science, which, consequently, are to be looked upon as the principle
of these, and which proceed from conceptions to intuition, and not
from intuition to conceptions.
In the application of the pure conceptions of the understanding to
possible experience, the employment of their synthesis is either
mathematical or dynamical, for it is directed partly on the
intuition alone, partly on the existence of a phenomenon. But the a
priori conditions of intuition are in relation to a possible
experience absolutely necessary, those of the existence of objects
of a possible empirical intuition are in themselves contingent.
Hence the principles of the mathematical use of the categories will
possess a character of absolute necessity, that is, will be
apodeictic; those, on the other hand, of the dynamical use, the
character of an a priori necessity indeed, but only under the
condition of empirical thought in an experience, therefore only
mediately and indirectly. Consequently they will not possess that
immediate evidence which is peculiar to the former, although their
application to experience does not, for that reason, lose its truth
and certitude. But of this point we shall be better able to judge at
the conclusion of this system of principles.
The table of the categories is naturally our guide to the table of
principles, because these are nothing else than rules for the
objective employment of the former. Accordingly, all principles of the
pure understanding are:

1
Axioms
of Intuition

2 3
Anticipations Analogies
of Perception of Experience
4
Postulates of
Empirical Thought
in general

These appellations I have chosen advisedly, in order that we might
not lose sight of the distinctions in respect of the evidence and
the employment of these principles. It will, however, soon appear
that- a fact which concerns both the evidence of these principles, and
the a priori determination of phenomena- according to the categories
of quantity and quality (if we attend merely to the form of these),
the principles of these categories are distinguishable from those of
the two others, in as much as the former are possessed of an
intuitive, but the latter of a merely discursive, though in both
instances a complete, certitude. I shall therefore call the former
mathematical, and the latter dynamical principles.* It must be
observed, however, that by these terms I mean just as little in the
one case the principles of mathematics as those of general
(physical) dynamics in the other. I have here in view merely the
principles of the pure understanding, in their application to the
internal sense (without distinction of the representations given
therein), by means of which the sciences of mathematics and dynamics
become possible. Accordingly, I have named these principles rather
with reference to their application than their content; and I shall
now proceed to consider them in the order in which they stand in the
table.

*All combination (conjunctio) is either composition (compositio)
or connection (nexus). The former is the synthesis of a manifold,
the parts of which do not necessarily belong to each other. For
example, the two triangles into which a square is divided by a
diagonal, do not necessarily belong to each other, and of this kind is
the synthesis of the homogeneous in everything that can be
mathematically considered. This synthesis can be divided into those of
aggregation and coalition, the former of which is applied to
extensive, the latter to intensive quantities. The second sort of
combination (nexus) is the synthesis of a manifold, in so far as its
parts do belong necessarily to each other; for example, the accident
to a substance, or the effect to the cause. Consequently it is a
synthesis of that which though heterogeneous, is represented as
connected a priori. This combination- not an arbitrary one- I
entitle dynamical because it concerns the connection of the
existence of the manifold. This, again, may be divided into the
physical synthesis, of the phenomena divided among each other, and the
metaphysical synthesis, or the connection of phenomena a priori in the
faculty of cognition.

1. AXIOMS OF INTUITION.
The principle of these is: All Intuitions are Extensive
Quantities.

PROOF.

All phenomena contain, as regards their form, an intuition in
space and time, which lies a priori at the foundation of all without
exception. Phenomena, therefore, cannot be apprehended, that is,
received into empirical consciousness otherwise than through the
synthesis of a manifold, through which the representations of a
determinate space or time are generated; that is to say, through the
composition of the homogeneous and the consciousness of the
synthetical unity of this manifold (homogeneous). Now the
consciousness of a homogeneous manifold in intuition, in so far as
thereby the representation of an object is rendered possible, is the
conception of a quantity (quanti). Consequently, even the perception
of an object as phenomenon is possible only through the same
synthetical unity of the manifold of the given sensuous intuition,
through which the unity of the composition of the homogeneous manifold
in the conception of a quantity is cogitated; that is to say, all
phenomena are quantities, and extensive quantities, because as
intuitions in space or time they must be represented by means of the
same synthesis through which space and time themselves are determined.
An extensive quantity I call that wherein the representation of
the parts renders possible (and therefore necessarily antecedes) the
representation of the whole. I cannot represent to myself any line,
however small, without drawing it in thought, that is, without
generating from a point all its parts one after another, and in this
way alone producing this intuition. Precisely the same is the case
with every, even the smallest, portion of time. I cogitate therein
only the successive progress from one moment to another, and hence, by
means of the different portions of time and the addition of them, a
determinate quantity of time is produced. As the pure intuition in all
phenomena is either time or space, so is every phenomenon in its
character of intuition an extensive quantity, inasmuch as it can
only be cognized in our apprehension by successive synthesis (from
part to part). All phenomena are, accordingly, to be considered as
aggregates, that is, as a collection of previously given parts;
which is not the case with every sort of quantities, but only with
those which are represented and apprehended by us as extensive.
On this successive synthesis of the productive imagination, in the
generation of figures, is founded the mathematics of extension, or
geometry, with its axioms, which express the conditions of sensuous
intuition a priori, under which alone the schema of a pure
conception of external intuition can exist; for example, "be tween two
points only one straight line is possible," "two straight lines cannot
enclose a space," etc. These are the axioms which properly relate only
to quantities (quanta) as such.
But, as regards the quantity of a thing (quantitas), that is to say,
the answer to the question: "How large is this or that object?"
although, in respect to this question, we have various propositions
synthetical and immediately certain (indemonstrabilia); we have, in
the proper sense of the term, no axioms. For example, the
propositions: "If equals be added to equals, the wholes are equal";
"If equals be taken from equals, the remainders are equal"; are
analytical, because I am immediately conscious of the identity of
the production of the one quantity with the production of the other;
whereas axioms must be a priori synthetical propositions. On the other
hand, the self-evident propositions as to the relation of numbers, are
certainly synthetical but not universal, like those of geometry, and
for this reason cannot be called axioms, but numerical formulae.
That 7 + 5 = 12 is not an analytical proposition. For neither in the
representation of seven, nor of five, nor of the composition of the
two numbers, do I cogitate the number twelve. (Whether I cogitate
the number in the addition of both, is not at present the question;
for in the case of an analytical proposition, the only point is
whether I really cogitate the predicate in the representation of the
subject.) But although the proposition is synthetical, it is
nevertheless only a singular proposition. In so far as regard is
here had merely to the synthesis of the homogeneous (the units), it
cannot take place except in one manner, although our use of these
numbers is afterwards general. If I say: "A triangle can be
constructed with three lines, any two of which taken together are
greater than the third," I exercise merely the pure function of the
productive imagination, which may draw the lines longer or shorter and
construct the angles at its pleasure. On the contrary, the number
seven is possible only in one manner, and so is likewise the number
twelve, which results from the synthesis of seven and five. Such
propositions, then, cannot be termed axioms (for in that case we
should have an infinity of these), but numerical formulae.
This transcendental principle of the mathematics of phenomena
greatly enlarges our a priori cognition. For it is by this principle
alone that pure mathematics is rendered applicable in all its
precision to objects of experience, and without it the validity of
this application would not be so self-evident; on the contrary,
contradictions and confusions have often arisen on this very point.
Phenomena are not things in themselves. Empirical intuition is
possible only through pure intuition (of space and time);
consequently, what geometry affirms of the latter, is indisputably
valid of the former. All evasions, such as the statement that
objects of sense do not conform to the rules of construction in
space (for example, to the rule of the infinite divisibility of
lines or angles), must fall to the ground. For, if these objections
hold good, we deny to space, and with it to all mathematics, objective
validity, and no longer know wherefore, and how far, mathematics can
be applied to phenomena. The synthesis of spaces and times as the
essential form of all intuition, is that which renders possible the
apprehension of a phenomenon, and therefore every external experience,
consequently all cognition of the objects of experience; and
whatever mathematics in its pure use proves of the former, must
necessarily hold good of the latter. All objections are but the
chicaneries of an ill-instructed reason, which erroneously thinks to
liberate the objects of sense from the formal conditions of our
sensibility, and represents these, although mere phenomena, as
things in themselves, presented as such to our understanding. But in
this case, no a priori synthetical cognition of them could be
possible, consequently not through pure conceptions of space and the
science which determines these conceptions, that is to say,
geometry, would itself be impossible.

2. ANTICIPATIONS OF PERCEPTION.

The principle of these is: In all phenomena the Real, that
which is an object of sensation, has Intensive Quantity,
that is, has a Degree.

PROOF.

Perception is empirical consciousness, that is to say, a
consciousness which contains an element of sensation. Phenomena as
objects of perception are not pure, that is, merely formal intuitions,
like space and time, for they cannot be perceived in themselves.
They contain, then, over and above the intuition, the materials for an
object (through which is represented something existing in space or
time), that is to say, they contain the real of sensation, as a
representation merely subjective, which gives us merely the
consciousness that the subject is affected, and which we refer to some
external object. Now, a gradual transition from empirical
consciousness to pure consciousness is possible, inasmuch as the
real in this consciousness entirely vanishes, and there remains a
merely formal consciousness (a priori) of the manifold in time and
space; consequently there is possible a synthesis also of the
production of the quantity of a sensation from its commencement,
that is, from the pure intuition = 0 onwards up to a certain
quantity of the sensation. Now as sensation in itself is not an
objective representation, and in it is to be found neither the
intuition of space nor of time, it cannot possess any extensive
quantity, and yet there does belong to it a quantity (and that by
means of its apprehension, in which empirical consciousness can within
a certain time rise from nothing = 0 up to its given amount),
consequently an intensive quantity. And thus we must ascribe intensive
quantity, that is, a degree of influence on sense to all objects of
perception, in so far as this perception contains sensation.
All cognition, by means of which I am enabled to cognize and
determine a priori what belongs to empirical cognition, may be
called an anticipation; and without doubt this is the sense in which
Epicurus employed his expression prholepsis. But as there is in
phenomena something which is never cognized a priori, which on this
account constitutes the proper difference between pure and empirical
cognition, that is to say, sensation (as the matter of perception), it
follows, that sensation is just that element in cognition which cannot
be at all anticipated. On the other hand, we might very well term
the pure determinations in space and time, as well in regard to figure
as to quantity, anticipations of phenomena, because they represent a
priori that which may always be given a posteriori in experience.
But suppose that in every sensation, as sensation in general,
without any particular sensation being thought of, there existed
something which could be cognized a priori, this would deserve to be
called anticipation in a special sense- special, because it may seem
surprising to forestall experience, in that which concerns the
matter of experience, and which we can only derive from itself. Yet
such really is the case here.
Apprehension, by means of sensation alone, fills only one moment,
that is, if I do not take into consideration a succession of many
sensations. As that in the phenomenon, the apprehension of which is
not a successive synthesis advancing from parts to an entire
representation, sensation has therefore no extensive quantity; the
want of sensation in a moment of time would represent it as empty,
consequently = O. That which in the empirical intuition corresponds to
sensation is reality (realitas phaenomenon); that which corresponds to
the absence of it, negation = O. Now every sensation is capable of a
diminution, so that it can decrease, and thus gradually disappear.
Therefore, between reality in a phenomenon and negation, there
exists a continuous concatenation of many possible intermediate
sensations, the difference of which from each other is always
smaller than that between the given sensation and zero, or complete
negation. That is to say, the real in a phenomenon has always a
quantity, which however is not discoverable in apprehension,
inasmuch as apprehension take place by means of mere sensation in
one instant, and not by the successive synthesis of many sensations,
and therefore does not progress from parts to the whole. Consequently,
it has a quantity, but not an extensive quantity.
Now that quantity which is apprehended only as unity, and in which
plurality can be represented only by approximation to negation = O,
I term intensive quantity. Consequently, reality in a phenomenon has
intensive quantity, that is, a degree. if we consider this reality
as cause (be it of sensation or of another reality in the
phenomenon, for example, a change), we call the degree of reality in
its character of cause a momentum, for example, the momentum of
weight; and for this reason, that the degree only indicates that
quantity the apprehension of which is not successive, but
instantaneous. This, however, I touch upon only in passing, for with
causality I have at present nothing to do.
Accordingly, every sensation, consequently every reality in
phenomena, however small it may be, has a degree, that is, an
intensive quantity, which may always be lessened, and between
reality and negation there exists a continuous connection of
possible realities, and possible smaller perceptions. Every colour-
for example, red- has a degree, which, be it ever so small, is never
the smallest, and so is it always with heat, the momentum of weight,
etc.
This property of quantities, according to which no part of them is
the smallest possible (no part simple), is called their continuity.
Space and time are quanta continua, because no part of them can be
given, without enclosing it within boundaries (points and moments),
consequently, this given part is itself a space or a time. Space,
therefore, consists only of spaces, and time of times. Points and
moments are only boundaries, that is, the mere places or positions
of their limitation. But places always presuppose intuitions which are
to limit or determine them; and we cannot conceive either space or
time composed of constituent parts which are given before space or
time. Such quantities may also be called flowing, because synthesis
(of the productive imagination) in the production of these
quantities is a progression in time, the continuity of which we are
accustomed to indicate by the expression flowing.
All phenomena, then, are continuous quantities, in respect both to
intuition and mere perception (sensation, and with it reality). In the
former case they are extensive quantities; in the latter, intensive.
When the synthesis of the manifold of a phenomenon is interrupted,
there results merely an aggregate of several phenomena, and not
properly a phenomenon as a quantity, which is not produced by the mere
continuation of the productive synthesis of a certain kind, but by the
repetition of a synthesis always ceasing. For example, if I call
thirteen dollars a sum or quantity of money, I employ the term quite
correctly, inasmuch as I understand by thirteen dollars the value of a
mark in standard silver, which is, to be sure, a continuous
quantity, in which no part is the smallest, but every part might
constitute a piece of money, which would contain material for still
smaller pieces. If, however, by the words thirteen dollars I
understand so many coins (be their value in silver what it may), it
would be quite erroneous to use the expression a quantity of
dollars; on the contrary, I must call them aggregate, that is, a
number of coins. And as in every number we must have unity as the
foundation, so a phenomenon taken as unity is a quantity, and as
such always a continuous quantity (quantum continuum).
Now, seeing all phenomena, whether considered as extensive or
intensive, are continuous quantities, the proposition: "All change
(transition of a thing from one state into another) is continuous,"
might be proved here easily, and with mathematical evidence, were it
not that the causality of a change lies, entirely beyond the bounds of
a transcendental philosophy, and presupposes empirical principles. For
of the possibility of a cause which changes the condition of things,
that is, which determines them to the contrary to a certain given
state, the understanding gives us a priori no knowledge; not merely
because it has no insight into the possibility of it (for such insight
is absent in several a priori cognitions), but because the notion of
change concerns only certain determinations of phenomena, which
experience alone can acquaint us with, while their cause lies in the
unchangeable. But seeing that we have nothing which we could here
employ but the pure fundamental conceptions of all possible
experience, among which of course nothing empirical can be admitted,
we dare not, without injuring the unity of our system, anticipate
general physical science, which is built upon certain fundamental
experiences.
Nevertheless, we are in no want of proofs of the great influence
which the principle above developed exercises in the anticipation of
perceptions, and even in supplying the want of them, so far as to
shield us against the false conclusions which otherwise we might
rashly draw.
If all reality in perception has a degree, between which and
negation there is an endless sequence of ever smaller degrees, and if,
nevertheless, every sense must have a determinate degree of
receptivity for sensations; no perception, and consequently no
experience is possible, which can prove, either immediately or
mediately, an entire absence of all reality in a phenomenon; in
other words, it is impossible ever to draw from experience a proof
of the existence of empty space or of empty time. For in the first
place, an entire absence of reality in a sensuous intuition cannot
of course be an object of perception; secondly, such absence cannot be
deduced from the contemplation of any single phenomenon, and the
difference of the degrees in its reality; nor ought it ever to be
admitted in explanation of any phenomenon. For if even the complete
intuition of a determinate space or time is thoroughly real, that
is, if no part thereof is empty, yet because every reality has its
degree, which, with the extensive quantity of the phenomenon
unchanged, can diminish through endless gradations down to nothing
(the void), there must be infinitely graduated degrees, with which
space or time is filled, and the intensive quantity in different
phenomena may be smaller or greater, although the extensive quantity
of the intuition remains equal and unaltered.
We shall give an example of this. Almost all natural philosophers,
remarking a great difference in the quantity of the matter of
different kinds in bodies with the same volume (partly on account of
the momentum of gravity or weight, partly on account of the momentum
of resistance to other bodies in motion), conclude unanimously that
this volume (extensive quantity of the phenomenon) must be void in all
bodies, although in different proportion. But who would suspect that
these for the most part mathematical and mechanical inquirers into
nature should ground this conclusion solely on a metaphysical
hypothesis- a sort of hypothesis which they profess to disparage and
avoid? Yet this they do, in assuming that the real in space (I must
not here call it impenetrability or weight, because these are
empirical conceptions) is always identical, and can only be
distinguished according to its extensive quantity, that is,
multiplicity. Now to this presupposition, for which they can have no
ground in experience, and which consequently is merely metaphysical, I
oppose a transcendental demonstration, which it is true will not
explain the difference in the filling up of spaces, but which
nevertheless completely does away with the supposed necessity of the
above-mentioned presupposition that we cannot explain the said
difference otherwise than by the hypothesis of empty spaces. This
demonstration, moreover, has the merit of setting the understanding at
liberty to conceive this distinction in a different manner, if the
explanation of the fact requires any such hypothesis. For we
perceive that although two equal spaces may be completely filled by
matters altogether different, so that in neither of them is there left
a single point wherein matter is not present, nevertheless, every
reality has its degree (of resistance or of weight), which, without
diminution of the extensive quantity, can become less and less ad
infinitum, before it passes into nothingness and disappears. Thus an
expansion which fills a space- for example, caloric, or any other
reality in the phenomenal world- can decrease in its degrees to
infinity, yet without leaving the smallest part of the space empty; on
the contrary, filling it with those lesser degrees as completely as
another phenomenon could with greater. My intention here is by no
means to maintain that this is really the case with the difference
of matters, in regard to their specific gravity; I wish only to prove,
from a principle of the pure understanding, that the nature of our
perceptions makes such a mode of explanation possible, and that it
is erroneous to regard the real in a phenomenon as equal quoad its
degree, and different only quoad its aggregation and extensive
quantity, and this, too, on the pretended authority of an a priori
principle of the understanding.
Nevertheless, this principle of the anticipation of perception
must somewhat startle an inquirer whom initiation into
transcendental philosophy has rendered cautious. We must naturally
entertain some doubt whether or not the understanding can enounce
any such synthetical proposition as that respecting the degree of
all reality in phenomena, and consequently the possibility of the
internal difference of sensation itself- abstraction being made of its
empirical quality. Thus it is a question not unworthy of solution:
"How the understanding can pronounce synthetically and a priori
respecting phenomena, and thus anticipate these, even in that which is
peculiarly and merely empirical, that, namely, which concerns
sensation itself?"
The quality of sensation is in all cases merely empirical, and
cannot be represented a priori (for example, colours, taste, etc.).
But the real- that which corresponds to sensation- in opposition to
negation = O, only represents something the conception of which in
itself contains a being (ein seyn), and signifies nothing but the
synthesis in an empirical consciousness. That is to say, the empirical
consciousness in the internal sense can be raised from 0 to every
higher degree, so that the very same extensive quantity of
intuition, an illuminated surface, for example, excites as great a
sensation as an aggregate of many other surfaces less illuminated.
We can therefore make complete abstraction of the extensive quantity
of a phenomenon, and represent to ourselves in the mere sensation in a
certain momentum, a synthesis of homogeneous ascension from 0 up to
the given empirical consciousness, All sensations therefore as such
are given only a posteriori, but this property thereof, namely, that
they have a degree, can be known a priori. It is worthy of remark,
that in respect to quantities in general, we can cognize a priori only
a single quality, namely, continuity; but in respect to all quality
(the real in phenomena), we cannot cognize a priori anything more than
the intensive quantity thereof, namely, that they have a degree. All
else is left to experience.

3. ANALOGIES OF EXPERIENCE.

The principle of these is: Experience is possible only
through the representation of a necessary connection
of Perceptions.

PROOF.

Experience is an empirical cognition; that is to say, a cognition
which determines an object by means of perceptions. It is therefore
a synthesis of perceptions, a synthesis which is not itself
contained in perception, but which contains the synthetical unity of
the manifold of perception in a consciousness; and this unity
constitutes the essential of our cognition of objects of the senses,
that is, of experience (not merely of intuition or sensation). Now
in experience our perceptions come together contingently, so that no
character of necessity in their connection appears, or can appear from
the perceptions themselves, because apprehension is only a placing
together of the manifold of empirical intuition, and no representation
of a necessity in the connected existence of the phenomena which
apprehension brings together, is to be discovered therein. But as
experience is a cognition of objects by means of perceptions, it
follows that the relation of the existence of the existence of the
manifold must be represented in experience not as it is put together
in time, but as it is objectively in time. And as time itself cannot
be perceived, the determination of the existence of objects in time
can only take place by means of their connection in time in general,
consequently only by means of a priori connecting conceptions. Now
as these conceptions always possess the character of necessity,
experience is possible only by means of a representation of the
necessary connection of perception.
The three modi of time are permanence, succession, and
coexistence. Accordingly, there are three rules of all relations of
time in phenomena, according to which the existence of every
phenomenon is determined in respect of the unity of all time, and
these antecede all experience and render it possible.
The general principle of all three analogies rests on the
necessary unity of apperception in relation to all possible
empirical consciousness (perception) at every time, consequently, as
this unity lies a priori at the foundation of all mental operations,
the principle rests on the synthetical unity of all phenomena
according to their relation in time. For the original apperception
relates to our internal sense (the complex of all representations),
and indeed relates a priori to its form, that is to say, the
relation of the manifold empirical consciousness in time. Now this
manifold must be combined in original apperception according to
relations of time- a necessity imposed by the a priori
transcendental unity of apperception, to which is subjected all that
can belong to my (i.e., my own) cognition, and therefore all that
can become an object for me. This synthetical and a priori
determined unity in relation of perceptions in time is therefore the
rule: "All empirical determinations of time must be subject to rules
of the general determination of time"; and the analogies of
experience, of which we are now about to treat, must be rules of
this nature.
These principles have this peculiarity, that they do not concern
phenomena, and the synthesis of the empirical intuition thereof, but
merely the existence of phenomena and their relation to each other
in regard to this existence. Now the mode in which we apprehend a
thing in a phenomenon can be determined a priori in such a manner that
the rule of its synthesis can give, that is to say, can produce this a
priori intuition in every empirical example. But the existence of
phenomena cannot be known a priori, and although we could arrive by
this path at a conclusion of the fact of some existence, we could
not cognize that existence determinately, that is to say, we should be
incapable of anticipating in what respect the empirical intuition of
it would be distinguishable from that of others.
The two principles above mentioned, which I called mathematical,
in consideration of the fact of their authorizing the application of
mathematic phenomena, relate to these phenomena only in regard to
their possibility, and instruct us how phenomena, as far as regards
their intuition or the real in their perception, can be generated
according to the rules of a mathematical synthesis. Consequently,
numerical quantities, and with them the determination of a
phenomenon as a quantity, can be employed in the one case as well as
in the other. Thus, for example, out of 200,000 illuminations by the
moon, I might compose and give a priori, that is construct, the degree
of our sensations of the sunlight. We may therefore entitle these
two principles constitutive.
The case is very different with those principles whose province it
is to subject the existence of phenomena to rules a priori. For as
existence does not admit of being constructed, it is clear that they
must only concern the relations of existence and be merely
regulative principles. In this case, therefore, neither axioms nor
anticipations are to be thought of. Thus, if a perception is given us,
in a certain relation of time to other (although undetermined)
perceptions, we cannot then say a priori, what and how great (in
quantity) the other perception necessarily connected with the former
is, but only how it is connected, quoad its existence, in this given
modus of time. Analogies in philosophy mean something very different
from that which they represent in mathematics. In the latter they
are formulae, which enounce the equality of two relations of quantity,
and are always constitutive, so that if two terms of the proportion
are given, the third is also given, that is, can be constructed by the
aid of these formulae. But in philosophy, analogy is not the
equality of two quantitative but of two qualitative relations. In this
case, from three given terms, I can give a priori and cognize the
relation to a fourth member, but not this fourth term itself, although
I certainly possess a rule to guide me in the search for this fourth
term in experience, and a mark to assist me in discovering it. An
analogy of experience is therefore only a rule according to which
unity of experience must arise out of perceptions in respect to
objects (phenomena) not as a constitutive, but merely as a
regulative principle. The same holds good also of the postulates of
empirical thought in general, which relate to the synthesis of mere
intuition (which concerns the form of phenomena), the synthesis of
perception (which concerns the matter of phenomena), and the synthesis
of experience (which concerns the relation of these perceptions).
For they are only regulative principles, and clearly distinguishable
from the mathematical, which are constitutive, not indeed in regard to
the certainty which both possess a priori, but in the mode of evidence
thereof, consequently also in the manner of demonstration.
But what has been observed of all synthetical propositions, and must
be particularly remarked in this place, is this, that these
analogies possess significance and validity, not as principles of
the transcendental, but only as principles of the empirical use of the
understanding, and their truth can therefore be proved only as such,
and that consequently the phenomena must not be subjoined directly
under the categories, but only under their schemata. For if the
objects to which those principles must be applied were things in
themselves, it would be quite impossible to cognize aught concerning
them synthetically a priori. But they are nothing but phenomena; a
complete knowledge of which- a knowledge to which all principles a
priori must at last relate- is the only possible experience. It
follows that these principles can have nothing else for their aim than
the conditions of the empirical cognition in the unity of synthesis of
phenomena. But this synthesis is cogitated only in the schema of the
pure conception of the understanding, of whose unity, as that of a
synthesis in general, the category contains the function
unrestricted by any sensuous condition. These principles will
therefore authorize us to connect phenomena according to an analogy,
with the logical and universal unity of conceptions, and
consequently to employ the categories in the principles themselves;
but in the application of them to experience, we shall use only
their schemata, as the key to their proper application, instead of the
categories, or rather the latter as restricting conditions, under
the title of "formulae" of the former.

A. FIRST ANALOGY.

Principle of the Permanence of Substance.

In all changes of phenomena, substance is permanent, and the
quantum thereof in nature is neither increased nor diminished.

PROOF.

All phenomena exist in time, wherein alone as substratum, that is,
as the permanent form of the internal intuition, coexistence and
succession can be represented. Consequently time, in which all changes
of phenomena must be cogitated, remains and changes not, because it is
that in which succession and coexistence can be represented only as
determinations thereof. Now, time in itself cannot be an object of
perception. It follows that in objects of perception, that is, in
phenomena, there must be found a substratum which represents time in
general, and in which all change or coexistence can be perceived by
means of the relation of phenomena to it. But the substratum of all
reality, that is, of all that pertains to the existence of things,
is substance; all that pertains to existence can be cogitated only
as a determination of substance. Consequently, the permanent, in
relation to which alone can all relations of time in phenomena be
determined, is substance in the world of phenomena, that is, the
real in phenomena, that which, as the substratum of all change,
remains ever the same. Accordingly, as this cannot change in
existence, its quantity in nature can neither be increased nor
diminished.
Our apprehension of the manifold in a phenomenon is always
successive, is Consequently always changing. By it alone we could,
therefore, never determine whether this manifold, as an object of
experience, is coexistent or successive, unless it had for a
foundation something fixed and permanent, of the existence of which
all succession and coexistence are nothing but so many modes (modi
of time). Only in the permanent, then, are relations of time
possible (for simultaneity and succession are the only relations in
time); that is to say, the permanent is the substratum of our
empirical representation of time itself, in which alone all
determination of time is possible. Permanence is, in fact, just
another expression for time, as the abiding correlate of all existence
of phenomena, and of all change, and of all coexistence. For change
does not affect time itself, but only the phenomena in time (just as
coexistence cannot be regarded as a modus of time itself, seeing
that in time no parts are coexistent, but all successive). If we
were to attribute succession to time itself, we should be obliged to
cogitate another time, in which this succession would be possible.
It is only by means of the permanent that existence in different parts
of the successive series of time receives a quantity, which we entitle
duration. For in mere succession, existence is perpetually vanishing
and recommencing, and therefore never has even the least quantity.
Without the permanent, then, no relation in time is possible. Now,
time in itself is not an object of perception; consequently the
permanent in phenomena must be regarded as the substratum of all
determination of time, and consequently also as the condition of the
possibility of all synthetical unity of perceptions, that is, of
experience; and all existence and all change in time can only be
regarded as a mode in the existence of that which abides unchangeably.
Therefore, in all phenomena, the permanent is the object in itself,
that is, the substance (phenomenon); but all that changes or can
change belongs only to the mode of the existence of this substance
or substances, consequently to its determinations.
I find that in all ages not only the philosopher, but even the
common understanding, has preposited this permanence as a substratum
of all change in phenomena; indeed, I am compelled to believe that
they will always accept this as an indubitable fact. Only the
philosopher expresses himself in a more precise and definite manner,
when he says: "In all changes in the world, the substance remains, and
the accidents alone are changeable." But of this decidedly synthetical
proposition, I nowhere meet with even an attempt at proof; nay, it
very rarely has the good fortune to stand, as it deserves to do, at
the head of the pure and entirely a priori laws of nature. In truth,
the statement that substance is permanent, is tautological. For this
very permanence is the ground on which we apply the category of
substance to the phenomenon; and we should have been obliged to
prove that in all phenomena there is something permanent, of the
existence of which the changeable is nothing but a determination.
But because a proof of this nature cannot be dogmatical, that is,
cannot be drawn from conceptions, inasmuch as it concerns a
synthetical proposition a priori, and as philosophers never
reflected that such propositions are valid only in relation to
possible experience, and therefore cannot be proved except by means of
a deduction of the possibility of experience, it is no wonder that
while it has served as the foundation of all experience (for we feel
the need of it in empirical cognition), it has never been supported by
proof.
A philosopher was asked: "What is the weight of smoke?" He answered:
"Subtract from the weight of the burnt wood the weight of the
remaining ashes, and you will have the weight of the smoke." Thus he
presumed it to be incontrovertible that even in fire the matter
(substance) does not perish, but that only the form of it undergoes
a change. In like manner was the saying: "From nothing comes nothing,"
only another inference from the principle or permanence, or rather
of the ever-abiding existence of the true subject in phenomena. For if
that in the phenomenon which we call substance is to be the proper
substratum of all determination of time, it follows that all existence
in past as well as in future time, must be determinable by means of it
alone. Hence we are entitled to apply the term substance to a
phenomenon, only because we suppose its existence in all time, a
notion which the word permanence does not fully express, as it seems
rather to be referable to future time. However, the internal necessity
perpetually to be, is inseparably connected with the necessity
always to have been, and so the expression may stand as it is.
"Gigni de nihilo nihil; in nihilum nil posse reverti,"* are two
propositions which the ancients never parted, and which people
nowadays sometimes mistakenly disjoin, because they imagine that the
propositions apply to objects as things in themselves, and that the
former might be inimical to the dependence (even in respect of its
substance also) of the world upon a supreme cause. But this
apprehension is entirely needless, for the question in this case is
only of phenomena in the sphere of experience, the unity of which
never could be possible, if we admitted the possibility that new
things (in respect of their substance) should arise. For in that case,
we should lose altogether that which alone can represent the unity
of time, to wit, the identity of the substratum, as that through which
alone all change possesses complete and thorough unity. This
permanence is, however, nothing but the manner in which we represent
to ourselves the existence of things in the phenomenal world.

*[Persius, Satirae, iii.83-84. "Nothing can be produced from
nothing; nothing can be returned into nothing."]

The determinations of a substance, which are only particular modes
of its existence, are called accidents. They are always real,
because they concern the existence of substance (negations are only
determinations, which express the non-existence of something in the
substance). Now, if to this real in the substance we ascribe a
particular existence (for example, to motion as an accident of
matter), this existence is called inherence, in contradistinction to
the existence of substance, which we call subsistence. But hence arise
many misconceptions, and it would be a more accurate and just mode
of expression to designate the accident only as the mode in which
the existence of a substance is positively determined. Meanwhile, by
reason of the conditions of the logical exercise of our understanding,
it is impossible to avoid separating, as it were, that which in the
existence of a substance is subject to change, whilst the substance
remains, and regarding it in relation to that which is properly
permanent and radical. On this account, this category of substance
stands under the title of relation, rather because it is the condition
thereof than because it contains in itself any relation.
Now, upon this notion of permanence rests the proper notion of the
conception change. Origin and extinction are not changes of that which
originates or becomes extinct. Change is but a mode of existence,
which follows on another mode of existence of the same object; hence
all that changes is permanent, and only the condition thereof changes.
Now since this mutation affects only determinations, which can have
a beginning or an end, we may say, employing an expression which seems
somewhat paradoxical: "Only the permanent (substance) is subject to
change; the mutable suffers no change, but rather alternation, that
is, when certain determinations cease, others begin."
Change, when, cannot be perceived by us except in substances, and
origin or extinction in an absolute sense, that does not concern
merely a determination of the permanent, cannot be a possible
perception, for it is this very notion of the permanent which
renders possible the representation of a transition from one state
into another, and from non-being to being, which, consequently, can be
empirically cognized only as alternating determinations of that
which is permanent. Grant that a thing absolutely begins to be; we
must then have a point of time in which it was not. But how and by
what can we fix and determine this point of time, unless by that which
already exists? For a void time- preceding- is not an object of
perception; but if we connect this beginning with objects which
existed previously, and which continue to exist till the object in
question in question begins to be, then the latter can only be a
determination of the former as the permanent. The same holds good of
the notion of extinction, for this presupposes the empirical
representation of a time, in which a phenomenon no longer exists.
Substances (in the world of phenomena) are the substratum of all
determinations of time. The beginning of some, and the ceasing to be
of other substances, would utterly do away with the only condition
of the empirical unity of time; and in that case phenomena would
relate to two different times, in which, side by side, existence would
pass; which is absurd. For there is only one time in which all
different times must be placed, not as coexistent, but as successive.
Accordingly, permanence is a necessary condition under which alone
phenomena, as things or objects, are determinable in a possible
experience. But as regards the empirical criterion of this necessary
permanence, and with it of the substantiality of phenomena, we shall
find sufficient opportunity to speak in the sequel.

B. SECOND ANALOGY.

Principle of the Succession of Time According
to the Law of Causality.

All changes take place according to the law of the
connection of Cause and Effect.

PROOF.

(That all phenomena in the succession of time are only changes, that
is, a successive being and non-being of the determinations of
substance, which is permanent; consequently that a being of
substance itself which follows on the non-being thereof, or a
non-being of substance which follows on the being thereof, in other
words, that the origin or extinction of substance itself, is
impossible- all this has been fully established in treating of the
foregoing principle. This principle might have been expressed as
follows: "All alteration (succession) of phenomena is merely
change"; for the changes of substance are not origin or extinction,
because the conception of change presupposes the same subject as
existing with two opposite determinations, and consequently as
permanent. After this premonition, we shall proceed to the proof.)
I perceive that phenomena succeed one another, that is to say, a
state of things exists at one time, the opposite of which existed in a
former state. In this case, then, I really connect together two
perceptions in time. Now connection is not an operation of mere
sense and intuition, but is the product of a synthetical faculty of
imagination, which determines the internal sense in respect of a
relation of time. But imagination can connect these two states in
two ways, so that either the one or the other may antecede in time;
for time in itself cannot be an object of perception, and what in an
object precedes and what follows cannot be empirically determined in
relation to it. I am only conscious, then, that my imagination
places one state before and the other after; not that the one state
antecedes the other in the object. In other words, the objective
relation of the successive phenomena remains quite undetermined by
means of mere perception. Now in order that this relation may be
cognized as determined, the relation between the two states must be so
cogitated that it is thereby determined as necessary, which of them
must be placed before and which after, and not conversely. But the
conception which carries with it a necessity of synthetical unity, can
be none other than a pure conception of the understanding which does
not lie in mere perception; and in this case it is the conception of
"the relation of cause and effect," the former of which determines the
latter in time, as its necessary consequence, and not as something
which might possibly antecede (or which might in some cases not be
perceived to follow). It follows that it is only because we subject
the sequence of phenomena, and consequently all change, to the law
of causality, that experience itself, that is, empirical cognition
of phenomena, becomes possible; and consequently, that phenomena
themselves, as objects of experience, are possible only by virtue of
this law.
Our apprehension of the manifold of phenomena is always
successive. The representations of parts succeed one another.
Whether they succeed one another in the object also, is a second point
for reflection, which was not contained in the former. Now we may
certainly give the name of object to everything, even to every
representation, so far as we are conscious thereof; but what this word
may mean in the case of phenomena, not merely in so far as they (as
representations) are objects, but only in so far as they indicate an
object, is a question requiring deeper consideration. In so far as
they, regarded merely as representations, are at the same time objects
of consciousness, they are not to be distinguished from
apprehension, that is, reception into the synthesis of imagination,
and we must therefore say: "The manifold of phenomena is always
produced successively in the mind." If phenomena were things in
themselves, no man would be able to conjecture from the succession
of our representations how this manifold is connected in the object;
for we have to do only with our representations. How things may be
in themselves, without regard to the representations through which
they affect us, is utterly beyond the sphere of our cognition. Now
although phenomena are not things in themselves, and are
nevertheless the only thing given to us to be cognized, it is my
duty to show what sort of connection in time belongs to the manifold
in phenomena themselves, while the representation of this manifold
in apprehension is always successive. For example, the apprehension of
the manifold in the phenomenon of a house which stands before me, is
successive. Now comes the question whether the manifold of this
house is in itself successive- which no one will be at all willing
to grant. But, so soon as I raise my conception of an object to the
transcendental signification thereof, I find that the house is not a
thing in itself, but only a phenomenon, that is, a representation, the
transcendental object of which remains utterly unknown. What then am I
to understand by the question: "How can the manifold be connected in
the phenomenon itself- not considered as a thing in itself, but merely
as a phenomenon?" Here that which lies in my successive apprehension
is regarded as representation, whilst the phenomenon which is given
me, notwithstanding that it is nothing more than a complex of these
representations, is regarded as the object thereof, with which my
conception, drawn from the representations of apprehension, must
harmonize. It is very soon seen that, as accordance of the cognition
with its object constitutes truth, the question now before us can only
relate to the formal conditions of empirical truth; and that the
phenomenon, in opposition to the representations of apprehension,
can only be distinguished therefrom as the object of them, if it is
subject to a rule which distinguishes it from every other
apprehension, and which renders necessary a mode of connection of
the manifold. That in the phenomenon which contains the condition of
this necessary rule of apprehension, is the object.
Let us now proceed to our task. That something happens, that is to
say, that something or some state exists which before was not,
cannot be empirically perceived, unless a phenomenon precedes, which
does not contain in itself this state. For a reality which should
follow upon a void time, in other words, a beginning, which no state
of things precedes, can just as little be apprehended as the void time
itself. Every apprehension of an event is therefore a perception which
follows upon another perception. But as this is the case with all
synthesis of apprehension, as I have shown above in the example of a
house, my apprehension of an event is not yet sufficiently
distinguished from other apprehensions. But I remark also that if in a
phenomenon which contains an occurrence, I call the antecedent state
of my perception, A, and the following state, B, the perception B
can only follow A in apprehension, and the perception A cannot
follow B, but only precede it. For example, I see a ship float down
the stream of a river. My perception of its place lower down follows
upon my perception of its place higher up the course of the river, and
it is impossible that, in the apprehension of this phenomenon, the
vessel should be perceived first below and afterwards higher up the
stream. Here, therefore, the order in the sequence of perceptions in
apprehension is determined; and by this order apprehension is
regulated. In the former example, my perceptions in the apprehension
of a house might begin at the roof and end at the foundation, or
vice versa; or I might apprehend the manifold in this empirical
intuition, by going from left to right, and from right to left.
Accordingly, in the series of these perceptions, there was no
determined order, which necessitated my beginning at a certain
point, in order empirically to connect the manifold. But this rule
is always to be met with in the perception of that which happens,
and it makes the order of the successive perceptions in the
apprehension of such a phenomenon necessary.
I must, therefore, in the present case, deduce the subjective
sequence of apprehension from the objective sequence of phenomena, for
otherwise the former is quite undetermined, and one phenomenon is
not distinguishable from another. The former alone proves nothing as
to the connection of the manifold in an object, for it is quite
arbitrary. The latter must consist in the order of the manifold in a
phenomenon, according to which order the apprehension of one thing
(that which happens) follows that of another thing (which precedes),
in conformity with a rule. In this way alone can I be authorized to
say of the phenomenon itself, and not merely of my own apprehension,
that a certain order or sequence is to be found therein. That is, in
other words, I cannot arrange my apprehension otherwise than in this
order.
In conformity with this rule, then, it is necessary that in that
which antecedes an event there be found the condition of a rule,
according to which in this event follows always and necessarily; but I
cannot reverse this and go back from the event, and determine (by
apprehension) that which antecedes it. For no phenomenon goes back
from the succeeding point of time to the preceding point, although
it does certainly relate to a preceding point of time; from a given
time, on the other hand, there is always a necessary progression to
the determined succeeding time. Therefore, because there certainly
is something that follows, I must of necessity connect it with
something else, which antecedes, and upon which it follows, in
conformity with a rule, that is necessarily, so that the event, as
conditioned, affords certain indication of a condition, and this
condition determines the event.
Let us suppose that nothing precedes an event, upon which this event
must follow in conformity with a rule. All sequence of perception
would then exist only in apprehension, that is to say, would be merely
subjective, and it could not thereby be objectively determined what
thing ought to precede, and what ought to follow in perception. In
such a case, we should have nothing but a play of representations,
which would possess no application to any object. That is to say, it
would not be possible through perception to distinguish one phenomenon
from another, as regards relations of time; because the succession
in the act of apprehension would always be of the same sort, and
therefore there would be nothing in the phenomenon to determine the
succession, and to render a certain sequence objectively necessary.
And, in this case, I cannot say that two states in a phenomenon follow
one upon the other, but only that one apprehension follows upon
another. But this is merely subjective, and does not determine an
object, and consequently cannot be held to be cognition of an
object- not even in the phenomenal world.
Accordingly, when we know in experience that something happens, we
always presuppose that something precedes, whereupon it follows in
conformity with a rule. For otherwise I could not say of the object
that it follows; because the mere succession in my apprehension, if it
be not determined by a rule in relation to something preceding, does
not authorize succession in the object. Only, therefore, in
reference to a rule, according to which phenomena are determined in
their sequence, that is, as they happen, by the preceding state, can I
make my subjective synthesis (of apprehension) objective, and it is
only under this presupposition that even the experience of an event is
possible.
No doubt it appears as if this were in thorough contradiction to all
the notions which people have hitherto entertained in regard to the
procedure of the human understanding. According to these opinions,
it is by means of the perception and comparison of similar
consequences following upon certain antecedent phenomena that the
understanding is led to the discovery of a rule, according to which
certain events always follow certain phenomena, and it is only by this
process that we attain to the conception of cause. Upon such a
basis, it is clear that this conception must be merely empirical,
and the rule which it furnishes us with- "Everything that happens must
have a cause"- would be just as contingent as experience itself. The
universality and necessity of the rule or law would be perfectly
spurious attributes of it. Indeed, it could not possess universal
validity, inasmuch as it would not in this case be a priori, but
founded on deduction. But the same is the case with this law as with
other pure a priori representations (e.g., space and time), which we
can draw in perfect clearness and completeness from experience, only
because we had already placed them therein, and by that means, and
by that alone, had rendered experience possible. Indeed, the logical
clearness of this representation of a rule, determining the series
of events, is possible only when we have made use thereof in
experience. Nevertheless, the recognition of this rule, as a condition
of the synthetical unity of phenomena in time, was the ground of
experience itself and consequently preceded it a priori.
It is now our duty to show by an example that we never, even in
experience, attribute to an object the notion of succession or
effect (of an event- that is, the happening of something that did
not exist before), and distinguish it from the subjective succession
of apprehension, unless when a rule lies at the foundation, which
compels us to observe this order of perception in preference to any
other, and that, indeed, it is this necessity which first renders
possible the representation of a succession in the object.
We have representations within us, of which also we can be
conscious. But, however widely extended, however accurate and
thoroughgoing this consciousness may be, these representations are
still nothing more than representations, that is, internal
determinations of the mind in this or that relation of time. Now how
happens it that to these representations we should set an object, or
that, in addition to their subjective reality, as modifications, we
should still further attribute to them a certain unknown objective
reality? It is clear that objective significancy cannot consist in a
relation to another representation (of that which we desire to term
object), for in that case the question again arises: "How does this
other representation go out of itself, and obtain objective
significancy over and above the subjective, which is proper to it,
as a determination of a state of mind?" If we try to discover what
sort of new property the relation to an object gives to our subjective
representations, and what new importance they thereby receive, we
shall find that this relation has no other effect than that of
rendering necessary the connection of our representations in a certain
manner, and of subjecting them to a rule; and that conversely, it is
only because a certain order is necessary in the relations of time
of our representations, that objective significancy is ascribed to
them.
In the synthesis of phenomena, the manifold of our representations
is always successive. Now hereby is not represented an object, for
by means of this succession, which is common to all apprehension, no
one thing is distinguished from another. But so soon as I perceive
or assume that in this succession there is a relation to a state
antecedent, from which the representation follows in accordance with a
rule, so soon do I represent something as an event, or as a thing that
happens; in other words, I cognize an object to which I must assign
a certain determinate position in time, which cannot be altered,
because of the preceding state in the object. When, therefore, I
perceive that something happens, there is contained in this
representation, in the first place, the fact, that something
antecedes; because, it. is only in relation to this that the
phenomenon obtains its proper relation of time, in other words, exists
after an antecedent time, in which it did not exist. But it can
receive its determined place in time only by the presupposition that
something existed in the foregoing state, upon which it follows
inevitably and always, that is, in conformity with a rule. From all
this it is evident that, in the first place, I cannot reverse the
order of succession, and make that which happens precede that upon
which it follows; and that, in the second place, if the antecedent
state be posited, a certain determinate event inevitably and
necessarily follows. Hence it follows that there exists a certain
order in our representations, whereby the present gives a sure
indication of some previously existing state, as a correlate, though
still undetermined, of the existing event which is given- a
correlate which itself relates to the event as its consequence,
conditions it, and connects it necessarily with itself in the series
of time.
If then it be admitted as a necessary law of sensibility, and
consequently a formal condition of all perception, that the
preceding necessarily determines the succeeding time (inasmuch as I
cannot arrive at the succeeding except through the preceding), it must
likewise be an indispensable law of empirical representation of the
series of time that the phenomena of the past determine all
phenomena in the succeeding time, and that the latter, as events,
cannot take place, except in so far as the former determine their
existence in time, that is to say, establish it according to a rule.
For it is of course only in phenomena that we can empirically
cognize this continuity in the connection of times.
For all experience and for the possibility of experience,
understanding is indispensable, and the first step which it takes in
this sphere is not to render the representation of objects clear,
but to render the representation of an object in general, possible. It
does this by applying the order of time to phenomena, and their
existence. In other words, it assigns to each phenomenon, as a
consequence, a place in relation to preceding phenomena, determined
a priori in time, without which it could not harmonize with time
itself, which determines a place a priori to all its parts. This
determination of place cannot be derived from the relation of
phenomena to absolute time (for it is not an object of perception);
but, on the contrary, phenomena must reciprocally determine the places
in time of one another, and render these necessary in the order of
time. In other words, whatever follows or happens, must follow in
conformity with a universal rule upon that which was contained in
the foregoing state. Hence arises a series of phenomena, which, by
means of the understanding, produces and renders necessary exactly the
same order and continuous connection in the series of our possible
perceptions, as is found a priori in the form of internal intuition
(time), in which all our perceptions must have place.
That something happens, then, is a perception which belongs to a
possible experience, which becomes real only because I look upon the
phenomenon as determined in regard to its place in time,
consequently as an object, which can always be found by means of a
rule in the connected series of my perceptions. But this rule of the
determination of a thing according to succession in time is as
follows: "In what precedes may be found the condition, under which
an event always (that is, necessarily) follows." From all this it is
obvious that the principle of cause and effect is the principle of
possible experience, that is, of objective cognition of phenomena,
in regard to their relations in the succession of time.
The proof of this fundamental proposition rests entirely on the
following momenta of argument. To all empirical cognition belongs
the synthesis of the manifold by the imagination, a synthesis which is
always successive, that is, in which the representations therein
always follow one another. But the order of succession in
imagination is not determined, and the series of successive
representations may be taken retrogressively as well as progressively.
But if this synthesis is a synthesis of apprehension (of the
manifold of a given phenomenon),then the order is determined in the
object, or to speak more accurately, there is therein an order of
successive synthesis which determines an object, and according to
which something necessarily precedes, and when this is posited,
something else necessarily follows. If, then, my perception is to
contain the cognition of an event, that is, of something which
really happens, it must be an empirical judgement, wherein we think
that the succession is determined; that is, it presupposes another
phenomenon, upon which this event follows necessarily, or in
conformity with a rule. If, on the contrary, when I posited the
antecedent, the event did not necessarily follow, I should be
obliged to consider it merely as a subjective play of my
imagination, and if in this I represented to myself anything as
objective, I must look upon it as a mere dream. Thus, the relation
of phenomena (as possible perceptions), according to which that
which happens is, as to its existence, necessarily determined in
time by something which antecedes, in conformity with a rule- in other
words, the relation of cause and effect- is the condition of the
objective validity of our empirical judgements in regard to the
sequence of perceptions, consequently of their empirical truth, and
therefore of experience. The principle of the relation of causality in
the succession of phenomena is therefore valid for all objects of
experience, because it is itself the ground of the possibility of
experience.
Here, however, a difficulty arises, which must be resolved. The
principle of the connection of causality among phenomena is limited in
our formula to the succession thereof, although in practice we find
that the principle applies also when the phenomena exist together in
the same time, and that cause and effect may be simultaneous. For
example, there is heat in a room, which does not exist in the open
air. I look about for the cause, and find it to be the fire, Now the
fire as the cause is simultaneous with its effect, the heat of the
room. In this case, then, there is no succession as regards time,
between cause and effect, but they are simultaneous; and still the law
holds good. The greater part of operating causes in nature are
simultaneous with their effects, and the succession in time of the
latter is produced only because the cause cannot achieve the total
of its effect in one moment. But at the moment when the effect first
arises, it is always simultaneous with the causality of its cause,
because, if the cause had but a moment before ceased to be, the effect
could not have arisen. Here it must be specially remembered that we
must consider the order of time and not the lapse thereof. The
relation remains, even though no time has elapsed. The time between
the causality of the cause and its immediate effect may entirely
vanish, and the cause and effect be thus simultaneous, but the
relation of the one to the other remains always determinable according
to time. If, for example, I consider a leaden ball, which lies upon
a cushion and makes a hollow in it, as a cause, then it is
simultaneous with the effect. But I distinguish the two through the
relation of time of the dynamical connection of both. For if I lay the
ball upon the cushion, then the hollow follows upon the before
smooth surface; but supposing the cushion has, from some cause or
another, a hollow, there does not thereupon follow a leaden ball.
Thus, the law of succession of time is in all instances the only
empirical criterion of effect in relation to the causality of the
antecedent cause. The glass is the cause of the rising of the water
above its horizontal surface, although the two phenomena are
contemporaneous. For, as soon as I draw some water with the glass from
a larger vessel, an effect follows thereupon, namely, the change of
the horizontal state which the water had in the large vessel into a
concave, which it assumes in the glass.
This conception of causality leads us to the conception of action;
that of action, to the conception of force; and through it, to the
conception of substance. As I do not wish this critical essay, the
sole purpose of which is to treat of the sources of our synthetical
cognition a priori, to be crowded with analyses which merely
explain, but do not enlarge the sphere of our conceptions, I reserve
the detailed explanation of the above conceptions for a future
system of pure reason. Such an analysis, indeed, executed with great
particularity, may already be found in well-known works on this
subject. But I cannot at present refrain from making a few remarks
on the empirical criterion of a substance, in so far as it seems to be
more evident and more easily recognized through the conception of
action than through that of the permanence of a phenomenon.
Where action (consequently activity and force) exists, substance
also must exist, and in it alone must be sought the seat of that
fruitful source of phenomena. Very well. But if we are called upon
to explain what we mean by substance, and wish to avoid the vice of
reasoning in a circle, the answer is by no means so easy. How shall we
conclude immediately from the action to the permanence of that which
acts, this being nevertheless an essential and peculiar criterion of
substance (phenomenon)? But after what has been said above, the
solution of this question becomes easy enough, although by the
common mode of procedure- merely analysing our conceptions- it would
be quite impossible. The conception of action indicates the relation
of the subject of causality to the effect. Now because all effect
consists in that which happens, therefore in the changeable, the
last subject thereof is the permanent, as the substratum of all that
changes, that is, substance. For according to the principle of
causality, actions are always the first ground of all change in
phenomena and, consequently, cannot be a property of a subject which
itself changes, because if this were the case, other actions and
another subject would be necessary to determine this change. From
all this it results that action alone, as an empirical criterion, is a
sufficient proof of the presence of substantiality, without any
necessity on my part of endeavouring to discover the permanence of
substance by a comparison. Besides, by this mode of induction we could
not attain to the completeness which the magnitude and strict
universality of the conception requires. For that the primary
subject of the causality of all arising and passing away, all origin
and extinction, cannot itself (in the sphere of phenomena) arise and
pass away, is a sound and safe conclusion, a conclusion which leads us
to the conception of empirical necessity and permanence in
existence, and consequently to the conception of a substance as
phenomenon.
When something happens, the mere fact of the occurrence, without
regard to that which occurs, is an object requiring investigation. The
transition from the non-being of a state into the existence of it,
supposing that this state contains no quality which previously existed
in the phenomenon, is a fact of itself demanding inquiry. Such an
event, as has been shown in No. A, does not concern substance (for
substance does not thus originate), but its condition or state. It
is therefore only change, and not origin from nothing. If this
origin be regarded as the effect of a foreign cause, it is termed
creation, which cannot be admitted as an event among phenomena,
because the very possibility of it would annihilate the unity of
experience. If, however, I regard all things not as phenomena, but
as things in themselves and objects of understanding alone, they,
although substances, may be considered as dependent, in respect of
their existence, on a foreign cause. But this would require a very
different meaning in the words, a meaning which could not apply to
phenomena as objects of possible experience.
How a thing can be changed, how it is possible that upon one state
existing in one point of time, an opposite state should follow in
another point of time- of this we have not the smallest conception a
priori. There is requisite for this the knowledge of real powers,
which can only be given empirically; for example, knowledge of
moving forces, or, in other words, of certain successive phenomena (as
movements) which indicate the presence of such forces. But the form of
every change, the condition under which alone it can take place as the
coming into existence of another state (be the content of the
change, that is, the state which is changed, what it may), and
consequently the succession of the states themselves can very well
be considered a priori, in relation to the law of causality and the
conditions of time.*

*It must be remarked that I do not speak of the change of certain
relations, but of the change of the state. Thus, when a body moves
in a uniform manner, it does not change its state (of motion); but
only when all motion increases or decreases.

When a substance passes from one state, a, into another state, b,
the point of time in which the latter exists is different from, and
subsequent to that in which the former existed. In like manner, the
second state, as reality (in the phenomenon), differs from the
first, in which the reality of the second did not exist, as b from
zero. That is to say, if the state, b, differs from the state, a, only
in respect to quantity, the change is a coming into existence of b -
a, which in the former state did not exist, and in relation to which
that state is = O.
Now the question arises how a thing passes from one state = a,
into another state = b. Between two moments there is always a
certain time, and between two states existing in these moments there
is always a difference having a certain quantity (for all parts of
phenomena are in their turn quantities). Consequently, every
transition from one state into another is always effected in a time
contained between two moments, of which the first determines the state
which leaves, and the second determines the state into the thing
passes. the thing leaves, and the second determines the state into
which the thing Both moments, then, are limitations of the time of a
change, consequently of the intermediate state between both, and as
such they belong to the total of the change. Now every change has a
cause, which evidences its causality in the whole time during which
the charge takes place. The cause, therefore, does not produce the
change all at once or in one moment, but in a time, so that, as the
time gradually increases from the commencing instant, a, to its
completion at b, in like manner also, the quantity of the reality
(b - a) is generated through the lesser degrees which are contained
between the first and last. All change is therefore possible only
through a continuous action of the causality, which, in so far as it
is uniform, we call a momentum. The change does not consist of these
momenta, but is generated or produced by them as their effect.
Such is the law of the continuity of all change, the ground of which
is that neither time itself nor any phenomenon in time consists of
parts which are the smallest possible, but that, notwithstanding,
the state of a thing passes in the process of a change through all
these parts, as elements, to its second state. There is no smallest
degree of reality in a phenomenon, just as there is no smallest degree
in the quantity of time; and so the new state of reality grows up
out of the former state, through all the infinite degrees thereof, the
differences of which one from another, taken all together, are less
than the difference between o and a.
It is not our business to inquire here into the utility of this
principle in the investigation of nature. But how such a
proposition, which appears so greatly to extend our knowledge of
nature, is possible completely a priori, is indeed a question which
deserves investigation, although the first view seems to demonstrate
the truth and reality of the principle, and the question, how it is
possible, may be considered superfluous. For there are so many
groundless pretensions to the enlargement of our knowledge by pure
reason that we must take it as a general rule to be mistrustful of all
such, and without a thoroughgoing and radical deduction, to believe
nothing of the sort even on the clearest dogmatical evidence.
Every addition to our empirical knowledge, and every advance made in
the exercise of our perception, is nothing more than an extension of
the determination of the internal sense, that is to say, a progression
in time, be objects themselves what they may, phenomena, or pure
intuitions. This progression in time determines everything, and is
itself determined by nothing else. That is to say, the parts of the
progression exist only in time, and by means of the synthesis thereof,
and are not given antecedently to it. For this reason, every
transition in perception to anything which follows upon another in
time, is a determination of time by means of the production of this
perception. And as this determination of time is, always and in all
its parts, a quantity, the perception produced is to be considered
as a quantity which proceeds through all its degrees- no one of
which is the smallest possible- from zero up to its determined degree.
From this we perceive the possibility of cognizing a priori a law of
changes- a law, however, which concerns their form merely. We merely
anticipate our own apprehension, the formal condition of which,
inasmuch as it is itself to be found in the mind antecedently to all
given phenomena, must certainly be capable of being cognized a priori.
Thus, as time contains the sensuous condition a priori of the
possibility of a continuous progression of that which exists to that
which follows it, the understanding, by virtue of the unity of
apperception, contains the condition a priori of the possibility of
a continuous determination of the position in time of all phenomena,
and this by means of the series of causes and effects, the former of
which necessitate the sequence of the latter, and thereby render
universally and for all time, and by consequence, objectively, valid
the empirical cognition of the relations of time.

C. THIRD ANALOGY.

Principle of Coexistence, According to the Law
of Reciprocity or Community.

All substances, in so far as they can be perceived in space
at the same time, exist in a state of complete reciprocity
of action.

PROOF.

Things are coexistent, when in empirical intuition the perception of
the one can follow upon the perception of the other, and vice versa-
which cannot occur in the succession of phenomena, as we have shown in
the explanation of the second principle. Thus I can perceive the
moon and then the earth, or conversely, first the earth and then the
moon; and for the reason that my perceptions of these objects can
reciprocally follow each other, I say, they exist contemporaneously.
Now coexistence is the existence of the manifold in the same time. But
time itself is not an object of perception; and therefore we cannot
conclude from the fact that things are placed in the same time, the
other fact, that the perception of these things can follow each
other reciprocally. The synthesis of the imagination in apprehension
would only present to us each of these perceptions as present in the
subject when the other is not present, and contrariwise; but would not
show that the objects are coexistent, that is to say, that, if the one
exists, the other also exists in the same time, and that this is
necessarily so, in order that the perceptions may be capable of
following each other reciprocally. It follows that a conception of the
understanding or category of the reciprocal sequence of the
determinations of phenomena (existing, as they do, apart from each
other, and yet contemporaneously), is requisite to justify us in
saying that the reciprocal succession of perceptions has its
foundation in the object, and to enable us to represent coexistence as
objective. But that relation of substances in which the one contains
determinations the ground of which is in the other substance, is the
relation of influence. And, when this influence is reciprocal, it is
the relation of community or reciprocity. Consequently the coexistence
of substances in space cannot be cognized in experience otherwise than
under the precondition of their reciprocal action. This is therefore
the condition of the possibility of things themselves as objects of
experience.
Things are coexistent, in so far as they exist in one and the same
time. But how can we know that they exist in one and the same time?
Only by observing that the order in the synthesis of apprehension of
the manifold is arbitrary and a matter of indifference, that is to
say, that it can proceed from A, through B, C, D, to E, or
contrariwise from E to A. For if they were successive in time (and
in the order, let us suppose, which begins with A), it is quite
impossible for the apprehension in perception to begin with E and go
backwards to A, inasmuch as A belongs to past time and, therefore,
cannot be an object of apprehension.
Let us assume that in a number of substances considered as phenomena
each is completely isolated, that is, that no one acts upon another.
Then I say that the coexistence of these cannot be an object of
possible perception and that the existence of one cannot, by any
mode of empirical synthesis, lead us to the existence of another.
For we imagine them in this case to be separated by a completely
void space, and thus perception, which proceeds from the one to the
other in time, would indeed determine their existence by means of a
following perception, but would be quite unable to distinguish whether
the one phenomenon follows objectively upon the first, or is
coexistent with it.
Besides the mere fact of existence, then, there must be something by
means of which A determines the position of B in time and, conversely,
B the position of A; because only under this condition can
substances be empirically represented as existing contemporaneously.
Now that alone determines the position of another thing in time
which is the cause of it or of its determinations. Consequently
every substance (inasmuch as it can have succession predicated of it
only in respect of its determinations) must contain the causality of
certain determinations in another substance, and at the same time
the effects of the causality of the other in itself. That is to say,
substances must stand (mediately or immediately) in dynamical
community with each other, if coexistence is to be cognized in any
possible experience. But, in regard to objects of experience, that
is absolutely necessary without which the experience of these
objects would itself be impossible. Consequently it is absolutely
necessary that all substances in the world of phenomena, in so far
as they are coexistent, stand in a relation of complete community of
reciprocal action to each other.
The word community has in our language* two meanings, and contains
the two notions conveyed in the Latin communio and commercium. We
employ it in this place in the latter sense- that of a dynamical
community, without which even the community of place (communio spatii)
could not be empirically cognized. In our experiences it is easy to
observe that it is only the continuous influences in all parts of
space that can conduct our senses from one object to another; that the
light which plays between our eyes and the heavenly bodies produces
a mediating community between them and us, and thereby evidences their
coexistence with us; that we cannot empirically change our position
(perceive this change), unless the existence of matter throughout
the whole of space rendered possible the perception of the positions
we occupy; and that this perception can prove the contemporaneous
existence of these places only through their reciprocal influence, and
thereby also the coexistence of even the most remote objects- although
in this case the proof is only mediate. Without community, every
perception (of a phenomenon in space) is separated from every other
and isolated, and the chain of empirical representations, that is,
of experience, must, with the appearance of a new object, begin
entirely de novo, without the least connection with preceding
representations, and without standing towards these even in the
relation of time. My intention here is by no means to combat the
notion of empty space; for it may exist where our perceptions cannot
exist, inasmuch as they cannot reach thereto, and where, therefore, no
empirical perception of coexistence takes place. But in this case it
is not an object of possible experience.

*German.

The following remarks may be useful in the way of explanation. In
the mind, all phenomena, as contents of a possible experience, must
exist in community (communio) of apperception or consciousness, and in
so far as it is requisite that objects be represented as coexistent
and connected, in so far must they reciprocally determine the position
in time of each other and thereby constitute a whole. If this
subjective community is to rest upon an objective basis, or to be
applied to substances as phenomena, the perception of one substance
must render possible the perception of another, and conversely. For
otherwise succession, which is always found in perceptions as
apprehensions, would be predicated of external objects, and their
representation of their coexistence be thus impossible. But this is
a reciprocal influence, that is to say, a real community
(commercium) of substances, without which therefore the empirical
relation of coexistence would be a notion beyond the reach of our
minds. By virtue of this commercium, phenomena, in so far as they
are apart from, and nevertheless in connection with each other,
constitute a compositum reale. Such composita are possible in many
different ways. The three dynamical relations then, from which all
others spring, are those of inherence, consequence, and composition.

These, then, are the three analogies of experience. They are nothing
more than principles of the determination of the existence of
phenomena in time, according to the three modi of this
determination; to wit, the relation to time itself as a quantity
(the quantity of existence, that is, duration), the relation in time
as a series or succession, finally, the relation in time as the
complex of all existence (simultaneity). This unity of determination
in regard to time is thoroughly dynamical; that is to say, time is not
considered as that in which experience determines immediately to every
existence its position; for this is impossible, inasmuch as absolute
time is not an object of perception, by means of which phenomena can
be connected with each other. On the contrary, the rule of the
understanding, through which alone the existence of phenomena can
receive synthetical unity as regards relations of time, determines for
every phenomenon its position in time, and consequently a priori,
and with validity for all and every time.
By nature, in the empirical sense of the word, we understand the
totality of phenomena connected, in respect of their existence,
according to necessary rules, that is, laws. There are therefore
certain laws (which are moreover a priori) which make nature possible;
and all empirical laws can exist only by means of experience, and by
virtue of those primitive laws through which experience itself becomes
possible. The purpose of the analogies is therefore to represent to us
the unity of nature in the connection of all phenomena under certain
exponents, the only business of which is to express the relation of
time (in so far as it contains all existence in itself) to the unity
of apperception, which can exist in synthesis only according to rules.
The combined expression of all is this: "All phenomena exist in one
nature, and must so exist, inasmuch as without this a priori unity, no
unity of experience, and consequently no determination of objects in
experience, is possible."
As regards the mode of proof which we have employed in treating of
these transcendental laws of nature, and the peculiar character of
we must make one remark, which will at the same time be important as a
guide in every other attempt to demonstrate the truth of
intellectual and likewise synthetical propositions a priori. Had we
endeavoured to prove these analogies dogmatically, that is, from
conceptions; that is to say, had we employed this method in attempting
to show that everything which exists, exists only in that which is
permanent- that every thing or event presupposes the existence of
something in a preceding state, upon which it follows in conformity
with a rule- lastly, that in the manifold, which is coexistent, the
states coexist in connection with each other according to a rule-
all our labour would have been utterly in vain. For more conceptions
of things, analyse them as we may, cannot enable us to conclude from
the existence of one object to the existence of another. What other
course was left for us to pursue? This only, to demonstrate the
possibility of experience as a cognition in which at last all
objects must be capable of being presented to us, if the
representation of them is to possess any objective reality. Now in
this third, this mediating term, the essential form of which
consists in the synthetical unity of the apperception of all
phenomena, we found a priori conditions of the universal and necessary
determination as to time of all existences in the world of
phenomena, without which the empirical determination thereof as to
time would itself be impossible, and we also discovered rules of
synthetical unity a priori, by means of which we could anticipate
experience. For want of this method, and from the fancy that it was
possible to discover a dogmatical proof of the synthetical
propositions which are requisite in the empirical employment of the
understanding, has it happened that a proof of the principle of
sufficient reason has been so often attempted, and always in vain. The
other two analogies nobody has ever thought of, although they have
always been silently employed by the mind,* because the guiding thread
furnished by the categories was wanting, the guide which alone can
enable us to discover every hiatus, both in the system of
conceptions and of principles.

*The unity of the universe, in which all phenomena to be
connected, is evidently a mere consequence of the admitted principle
of the community of all substances which are coexistent. For were
substances isolated, they could not as parts constitute a whole, and
were their connection (reciprocal action of the manifold) not
necessary from the very fact of coexistence, we could not conclude
from the fact of the latter as a merely ideal relation to the former
as a real one. We have, however, shown in its place that community
is the proper ground of the possibility of an empirical cognition of
coexistence, and that we may therefore properly reason from the latter
to the former as its condition.

4. THE POSTULATES OF EMPIRICAL THOUGHT.

1. That which agrees with the formal conditions (intuition and
conception) of experience, is possible.
2. That which coheres with the material conditions of experience
(sensation), is real.
3. That whose coherence with the real is determined according to
universal conditions of experience is (exists) necessary.

Explanation.

The categories of modality possess this peculiarity, that they do
not in the least determine the object, or enlarge the conception to
which they are annexed as predicates, but only express its relation to
the faculty of cognition. Though my conception of a thing is in itself
complete, I am still entitled to ask whether the object of it is
merely possible, or whether it is also real, or, if the latter,
whether it is also necessary. But hereby the object itself is not more
definitely determined in thought, but the question is only in what
relation it, including all its determinations, stands to the
understanding and its employment in experience, to the empirical
faculty of judgement, and to the reason of its application to
experience.
For this very reason, too, the categories of modality are nothing
more than explanations of the conceptions of possibility, reality, and
necessity, as employed in experience, and at the same time,
restrictions of all the categories to empirical use alone, not
authorizing the transcendental employment of them. For if they are
to have something more than a merely logical significance, and to be
something more than a mere analytical expression of the form of
thought, and to have a relation to things and their possibility,
reality, or necessity, they must concern possible experience and its
synthetical unity, in which alone objects of cognition can be given.
The postulate of the possibility of things requires also, that the
conception of the things agree with the formal conditions of our
experience in general. But this, that is to say, the objective form of
experience, contains all the kinds of synthesis which are requisite
for the cognition of objects. A conception which contains a
synthesis must be regarded as empty and, without reference to an
object, if its synthesis does not belong to experience- either as
borrowed from it, and in this case it is called an empirical
conception, or such as is the ground and a priori condition of
experience (its form), and in this case it is a pure conception, a
conception which nevertheless belongs to experience, inasmuch as its
object can be found in this alone. For where shall we find the
criterion or character of the possibility of an object which is
cogitated by means of an a priori synthetical conception, if not in
the synthesis which constitutes the form of empirical cognition of
objects? That in such a conception no contradiction exists is indeed a
necessary logical condition, but very far from being sufficient to
establish the objective reality of the conception, that is, the
possibility of such an object as is thought in the conception. Thus,
in the conception of a figure which is contained within two straight
lines, there is no contradiction, for the conceptions of two
straight lines and of their junction contain no negation of a
figure. The impossibility in such a case does not rest upon the
conception in itself, but upon the construction of it in space, that
is to say, upon the conditions of space and its determinations. But
these have themselves objective reality, that is, they apply to
possible things, because they contain a priori the form of
experience in general.
And now we shall proceed to point out the extensive utility and
influence of this postulate of possibility. When I represent to myself
a thing that is permanent, so that everything in it which changes
belongs merely to its state or condition, from such a conception alone
I never can cognize that such a thing is possible. Or, if I
represent to myself something which is so constituted that, when it is
posited, something else follows always and infallibly, my thought
contains no self-contradiction; but whether such a property as
causality is to be found in any possible thing, my thought alone
affords no means of judging. Finally, I can represent to myself
different things (substances) which are so constituted that the
state or condition of one causes a change in the state of the other,
and reciprocally; but whether such a relation is a property of
things cannot be perceived from these conceptions, which contain a
merely arbitrary synthesis. Only from the fact, therefore, that
these conceptions express a priori the relations of perceptions in
every experience, do we know that they possess objective reality, that
is, transcendental truth; and that independent of experience, though
not independent of all relation to form of an experience in general
and its synthetical unity, in which alone objects can be empirically
cognized.
But when we fashion to ourselves new conceptions of substances,
forces, action, and reaction, from the material presented to us by
perception, without following the example of experience in their
connection, we create mere chimeras, of the possibility of which we
cannot discover any criterion, because we have not taken experience
for our instructress, though we have borrowed the conceptions from
her. Such fictitious conceptions derive their character of possibility
not, like the categories, a priori, as conceptions on which all
experience depends, but only, a posteriori, as conceptions given by
means of experience itself, and their possibility must either be
cognized a posteriori and empirically, or it cannot be cognized at
all. A substance which is permanently present in space, yet without
filling it (like that tertium quid between matter and the thinking
subject which some have tried to introduce into metaphysics), or a
peculiar fundamental power of the mind of intuiting the future by
anticipation (instead of merely inferring from past and present
events), or, finally, a power of the mind to place itself in community
of thought with other men, however distant they may be- these are
conceptions the possibility of which has no ground to rest upon. For
they are not based upon experience and its known laws; and, without
experience, they are a merely arbitrary conjunction of thoughts,
which, though containing no internal contradiction, has no claim to
objective reality, neither, consequently, to the possibility of such
an object as is thought in these conceptions. As far as concerns
reality, it is self-evident that we cannot cogitate such a possibility
in concreto without the aid of experience; because reality is
concerned only with sensation, as the matter of experience, and not
with the form of thought, with which we can no doubt indulge in
shaping fancies.
But I pass by everything which derives its possibility from
reality in experience, and I purpose treating here merely of the
possibility of things by means of a priori conceptions. I maintain,
then, that the possibility of things is not derived from such
conceptions per se, but only when considered as formal and objective
conditions of an experience in general.
It seems, indeed, as if the possibility of a triangle could be
cognized from the conception of it alone (which is certainly
independent of experience); for we can certainly give to the
conception a corresponding object completely a priori, that is to say,
we can construct it. But as a triangle is only the form of an
object, it must remain a mere product of the imagination, and the
possibility of the existence of an object corresponding to it must
remain doubtful, unless we can discover some other ground, unless we
know that the figure can be cogitated under the conditions upon
which all objects of experience rest. Now, the facts that space is a
formal condition a priori of external experience, that the formative
synthesis, by which we construct a triangle in imagination, is the
very same as that we employ in the apprehension of a phenomenon for
the purpose of making an empirical conception of it, are what alone
connect the notion of the possibility of such a thing, with the
conception of it. In the same manner, the possibility of continuous
quantities, indeed of quantities in general, for the conceptions of
them are without exception synthetical, is never evident from the
conceptions in themselves, but only when they are considered as the
formal conditions of the determination of objects in experience. And
where, indeed, should we look for objects to correspond to our
conceptions, if not in experience, by which alone objects are
presented to us? It is, however, true that without antecedent
experience we can cognize and characterize the possibility of
things, relatively to the formal conditions, under which something
is determined in experience as an object, consequently, completely a
priori. But still this is possible only in relation to experience
and within its limits.
The postulate concerning the cognition of the reality of things
requires perception, consequently conscious sensation, not indeed
immediately, that is, of the object itself, whose existence is to be
cognized, but still that the object have some connection with a real
perception, in accordance with the analogies of experience, which
exhibit all kinds of real connection in experience.
From the mere conception of a thing it is impossible to conclude its
existence. For, let the conception be ever so complete, and containing
a statement of all the determinations of the thing, the existence of
it has nothing to do with all this, but only with thew question
whether such a thing is given, so that the perception of it can in
every case precede the conception. For the fact that the conception of
it precedes the perception, merely indicates the possibility of its
existence; it is perception which presents matter to the conception,
that is the sole criterion of reality. Prior to the perception of
the thing, however, and therefore comparatively a priori, we are
able to cognize its existence, provided it stands in connection with
some perceptions according to the principles of the empirical
conjunction of these, that is, in conformity with the analogies of
perception. For, in this case, the existence of the supposed thing
is connected with our perception in a possible experience, and we
are able, with the guidance of these analogies, to reason in the
series of possible perceptions from a thing which we do really
perceive to the thing we do not perceive. Thus, we cognize the
existence of a magnetic matter penetrating all bodies from the
perception of the attraction of the steel-filings by the magnet,
although the constitution of our organs renders an immediate
perception of this matter impossible for us. For, according to the
laws of sensibility and the connected context of our perceptions, we
should in an experience come also on an immediate empirical
intuition of this matter, if our senses were more acute- but this
obtuseness has no influence upon and cannot alter the form of possible
experience in general. Our knowledge of the existence of things
reaches as far as our perceptions, and what may be inferred from
them according to empirical laws, extend. If we do not set out from
experience, or do not proceed according to the laws of the empirical
connection of phenomena, our pretensions to discover the existence
of a thing which we do not immediately perceive are vain. Idealism,
however, brings forward powerful objections to these rules for proving
existence mediately. This is, therefore, the proper place for its
refutation.

REFUTATION OF IDEALISM.

Idealism- I mean material idealism- is the theory which declares the
existence of objects in space without us to be either () doubtful
and indemonstrable, or (2) false and impossible. The first is the
problematical idealism of Descartes, who admits the undoubted
certainty of only one empirical assertion (assertio), to wit, "I
am." The second is the dogmatical idealism of Berkeley, who
maintains that space, together with all the objects of which it is the
inseparable condition, is a thing which is in itself impossible, and
that consequently the objects in space are mere products of the
imagination. The dogmatical theory of idealism is unavoidable, if we
regard space as a property of things in themselves; for in that case
it is, with all to which it serves as condition, a nonentity. But
the foundation for this kind of idealism we have already destroyed
in the transcendental aesthetic. Problematical idealism, which makes
no such assertion, but only alleges our incapacity to prove the
existence of anything besides ourselves by means of immediate
experience, is a theory rational and evidencing a thorough and
philosophical mode of thinking, for it observes the rule not to form a
decisive judgement before sufficient proof be shown. The desired proof
must therefore demonstrate that we have experience of external things,
and not mere fancies. For this purpose, we must prove, that our
internal and, to Descartes, indubitable experience is itself
possible only under the previous assumption of external experience.

THEOREM.

The simple but empirically determined consciousness of
my own existence proves the existence of external
objects in space.

PROOF

I am conscious of my own existence as determined in time. All
determination in regard to time presupposes the existence of something
permanent in perception. But this permanent something cannot be
something in me, for the very reason that my existence in time is
itself determined by this permanent something. It follows that the
perception of this permanent existence is possible only through a
thing without me and not through the mere representation of a thing
without me. Consequently, the determination of my existence in time is
possible only through the existence of real things external to me.
Now, consciousness in time is necessarily connected with the
consciousness of the possibility of this determination in time.
Hence it follows that consciousness in time is necessarily connected
also with the existence of things without me, inasmuch as the
existence of these things is the condition of determination in time.
That is to say, the consciousness of my own existence is at the same
time an immediate consciousness of the existence of other things
without me.
Remark I. The reader will observe, that in the foregoing proof the
game which idealism plays is retorted upon itself, and with more
justice. It assumed that the only immediate experience is internal and
that from this we can only infer the existence of external things.
But, as always happens, when we reason from given effects to
determined causes, idealism bas reasoned with too much haste and
uncertainty, for it is quite possible that the cause of our
representations may lie in ourselves, and that we ascribe it falsely
to external things. But our proof shows that external experience is
properly immediate,* that only by virtue of it- not, indeed, the
consciousness of our own existence, but certainly the determination of
our existence in time, that is, internal experience- is possible. It
is true, that the representation "I am," which is the expression of
the consciousness which can accompany all my thoughts, is that which
immediately includes the existence of a subject. But in this
representation we cannot find any knowledge of the subject, and
therefore also no empirical knowledge, that is, experience. For
experience contains, in addition to the thought of something existing,
intuition, and in this case it must be internal intuition, that is,
time, in relation to which the subject must be determined. But the
existence of external things is absolutely requisite for this purpose,
so that it follows that internal experience is itself possible only
mediately and through external experience.

*The immediate consciousness of the existence of external things is,
in the preceding theorem, not presupposed, but proved, by the
possibility of this consciousness understood by us or not. The
question as to the possibility of it would stand thus: "Have we an
internal sense, but no external sense, and is our belief in external
perception a mere delusion?" But it is evident that, in order merely
to fancy to ourselves anything as external, that is, to present it
to the sense in intuition we must already possess an external sense,
and must thereby distinguish immediately the mere receptivity of an
external intuition from the spontaneity which characterizes every
act of imagination. For merely to imagine also an external sense,
would annihilate the faculty of intuition itself which is to be
determined by the imagination.

Remark II. Now with this view all empirical use of our faculty of
cognition in the determination of time is in perfect accordance. Its
truth is supported by the fact that it is possible to perceive a
determination of time only by means of a change in external
relations (motion) to the permanent in space (for example, we become
aware of the sun's motion by observing the changes of his relation
to the objects of this earth). But this is not all. We find that we
possess nothing permanent that can correspond and be submitted to
the conception of a substance as intuition, except matter. This idea
of permanence is not itself derived from external experience, but is
an a priori necessary condition of all determination of time,
consequently also of the internal sense in reference to our own
existence, and that through the existence of external things. In the
representation "I," the consciousness of myself is not an intuition,
but a merely intellectual representation produced by the spontaneous
activity of a thinking subject. It follows, that this "I" has not
any predicate of intuition, which, in its character of permanence,
could serve as correlate to the determination of time in the
internal sense- in the same way as impenetrability is the correlate of
matter as an empirical intuition.
Remark III. From the fact that the existence of external things is a
necessary condition of the possibility of a determined consciousness
of ourselves, it does not follow that every intuitive representation
of external things involves the existence of these things, for their
representations may very well be the mere products of the
imagination (in dreams as well as in madness); though, indeed, these
are themselves created by the reproduction of previous external
perceptions, which, as has been shown, are possible only through the
reality of external objects. The sole aim of our remarks has, however,
been to prove that internal experience in general is possible only
through external experience in general. Whether this or that
supposed experience be purely imaginary must be discovered from its
particular determinations and by comparing these with the criteria
of all real experience.

Finally, as regards the third postulate, it applies to material
necessity in existence, and not to merely formal and logical necessity
in the connection of conceptions. Now as we cannot cognize
completely a priori the existence of any object of sense, though we
can do so comparatively a priori, that is, relatively to some other
previously given existence- a cognition, however, which can only be of
such an existence as must be contained in the complex of experience,
of which the previously given perception is a part- the necessity of
existence can never be cognized from conceptions, but always, on the
contrary, from its connection with that which is an object of
perception. But the only existence cognized, under the condition of
other given phenomena, as necessary, is the existence of effects
from given causes in conformity with the laws of causality. It is
consequently not the necessity of the existence of things (as
substances), but the necessity of the state of things that we cognize,
and that not immediately, but by means of the existence of other
states given in perception, according to empirical laws of
causality. Hence it follows that the criterion of necessity is to be
found only in the law of possible experience- that everything which
happens is determined a priori in the phenomenon by its cause. Thus we
cognize only the necessity of effects in nature, the causes of which
are given us. Moreover, the criterion of necessity in existence
possesses no application beyond the field of possible experience,
and even in this it is not valid of the existence of things as
substances, because these can never be considered as empirical
effects, or as something that happens and has a beginning.
Necessity, therefore, regards only the relations of phenomena
according to the dynamical law of causality, and the possibility
grounded thereon, of reasoning from some given existence (of a
cause) a priori to another existence (of an effect). "Everything
that happens is hypothetically necessary," is a principle which
subjects the changes that take place in the world to a law, that is,
to a rule of necessary existence, without which nature herself could
not possibly exist. Hence the proposition, "Nothing happens by blind
chance (in mundo non datur casus)," is an a priori law of nature.
The case is the same with the proposition, "Necessity in nature is not
blind," that is, it is conditioned, consequently intelligible
necessity (non datur fatum). Both laws subject the play of change to
"a nature of things (as phenomena)," or, which is the same thing, to
the unity of the understanding, and through the understanding alone
can changes belong to an experience, as the synthetical unity of
phenomena. Both belong to the class of dynamical principles. The
former is properly a consequence of the principle of causality- one of
the analogies of experience. The latter belongs to the principles of
modality, which to the determination of causality adds the
conception of necessity, which is itself, however, subject to a rule
of the understanding. The principle of continuity forbids any leap
in the series of phenomena regarded as changes (in mundo non datur
saltus); and likewise, in the complex of all empirical intuitions in
space, any break or hiatus between two phenomena (non datur hiatus)-
for we can so express the principle, that experience can admit nothing
which proves the existence of a vacuum, or which even admits it as a
part of an empirical synthesis. For, as regards a vacuum or void,
which we may cogitate as out and beyond the field of possible
experience (the world), such a question cannot come before the
tribunal of mere understanding, which decides only upon questions that
concern the employment of given phenomena for the construction of
empirical cognition. It is rather a problem for ideal reason, which
passes beyond the sphere of a possible experience and aims at
forming a judgement of that which surrounds and circumscribes it,
and the proper place for the consideration of it is the transcendental
dialectic. These four propositions, "In mundo non datur hiatus, non
datur saltus, non datur casus, non datur fatum," as well as all
principles of transcendental origin, we could very easily exhibit in
their proper order, that is, in conformity with the order of the
categories, and assign to each its proper place. But the already
practised reader will do this for himself, or discover the clue to
such an arrangement. But the combined result of all is simply this, to
admit into the empirical synthesis nothing which might cause a break
in or be foreign to the understanding and the continuous connection of
all phenomena, that is, the unity of the conceptions of the
understanding. For in the understanding alone is the unity of
experience, in which all perceptions must have their assigned place,
possible.
Whether the field of possibility be greater than that of reality,
and whether the field of the latter be itself greater than that of
necessity, are interesting enough questions, and quite capable of
synthetic solution, questions, however, which come under the
jurisdiction of reason alone. For they are tantamount to asking
whether all things as phenomena do without exception belong to the
complex and connected whole of a single experience, of which every
given perception is a part which therefore cannot be conjoined with
any other phenomena- or, whether my perceptions can belong to more
than one possible experience? The understanding gives to experience,
according to the subjective and formal conditions, of sensibility as
well as of apperception, the rules which alone make this experience
possible. Other forms of intuition besides those of space and time,
other forms of understanding besides the discursive forms of
thought, or of cognition by means of conceptions, we can neither
imagine nor make intelligible to ourselves; and even if we could, they
would still not belong to experience, which is the only mode of
cognition by which objects are presented to us. Whether other
perceptions besides those which belong to the total of our possible
experience, and consequently whether some other sphere of matter
exists, the understanding has no power to decide, its proper
occupation being with the synthesis of that which is given.
Moreover, the poverty of the usual arguments which go to prove the
existence of a vast sphere of possibility, of which all that is real
(every object of experience) is but a small part, is very
remarkable. "All real is possible"; from this follows naturally,
according to the logical laws of conversion, the particular
proposition: "Some possible is real." Now this seems to be
equivalent to: "Much is possible that is not real." No doubt it does
seem as if we ought to consider the sum of the possible to be
greater than that of the real, from the fact that something must be
added to the former to constitute the latter. But this notion of
adding to the possible is absurd. For that which is not in the sum
of the possible, and consequently requires to be added to it, is
manifestly impossible. In addition to accordance with the formal
conditions of experience, the understanding requires a connection with
some perception; but that which is connected with this perception is
real, even although it is not immediately perceived. But that
another series of phenomena, in complete coherence with that which
is given in perception, consequently more than one all-embracing
experience is possible, is an inference which cannot be concluded from
the data given us by experience, and still less without any data at
all. That which is possible only under conditions which are themselves
merely possible, is not possible in any respect. And yet we can find
no more certain ground on which to base the discussion of the question
whether the sphere of possibility is wider than that of experience.
I have merely mentioned these questions, that in treating of the
conception of the understanding, there might be no omission of
anything that, in the common opinion, belongs to them. In reality,
however, the notion of absolute possibility (possibility which is
valid in every respect) is not a mere conception of the understanding,
which can be employed empirically, but belongs to reason alone,
which passes the bounds of all empirical use of the understanding.
We have, therefore, contented ourselves with a merely critical remark,
leaving the subject to be explained in the sequel.
Before concluding this fourth section, and at the same time the
system of all principles of the pure understanding, it seems proper to
mention the reasons which induced me to term the principles of
modality postulates. This expression I do not here use in the sense
which some more recent philosophers, contrary to its meaning with
mathematicians, to whom the word properly belongs, attach to it-
that of a proposition, namely, immediately certain, requiring
neither deduction nor proof. For if, in the case of synthetical
propositions, however evident they may be, we accord to them without
deduction, and merely on the strength of their own pretensions,
unqualified belief, all critique of the understanding is entirely
lost; and, as there is no want of bold pretensions, which the common
belief (though for the philosopher this is no credential) does not
reject, the understanding lies exposed to every delusion and
conceit, without the power of refusing its assent to those assertions,
which, though illegitimate, demand acceptance as veritable axioms.
When, therefore, to the conception of a thing an a priori
determination is synthetically added, such a proposition must
obtain, if not a proof, at least a deduction of the legitimacy of
its assertion.
The principles of modality are, however, not objectively
synthetical, for the predicates of possibility, reality, and necessity
do not in the least augment the conception of that of which they are
affirmed, inasmuch as they contribute nothing to the representation of
the object. But as they are, nevertheless, always synthetical, they
are so merely subjectively. That is to say, they have a reflective
power, and apply to the conception of a thing, of which, in other
respects, they affirm nothing, the faculty of cognition in which the
conception originates and has its seat. So that if the conception
merely agree with the formal conditions of experience, its object is
called possible; if it is in connection with perception, and
determined thereby, the object is real; if it is determined
according to conceptions by means of the connection of perceptions,
the object is called necessary. The principles of modality therefore
predicate of a conception nothing more than the procedure of the
faculty of cognition which generated it. Now a postulate in
mathematics is a practical proposition which contains nothing but
the synthesis by which we present an object to ourselves, and
produce the conception of it, for example- "With a given line, to
describe a circle upon a plane, from a given point"; and such a
proposition does not admit of proof, because the procedure, which it
requires, is exactly that by which alone it is possible to generate
the conception of such a figure. With the same right, accordingly, can
we postulate the principles of modality, because they do not
augment* the conception of a thing but merely indicate the manner in
which it is connected with the faculty of cognition.

*When I think the reality of a thing, I do really think more than
the possibility, but not in the thing; for that can never contain more
in reality than was contained in its complete possibility. But while
the notion of possibility is merely the notion of a position of
thing in relation to the understanding (its empirical use), reality is
the conjunction of the thing with perception.

GENERAL REMARK ON THE SYSTEM OF PRINCIPLES.

It is very remarkable that we cannot perceive the possibility of a
thing from the category alone, but must always have an intuition, by
which to make evident the objective reality of the pure conception
of the understanding. Take, for example, the categories of relation.
How (1) a thing can exist only as a subject, and not as a mere
determination of other things, that is, can be substance; or how
(2), because something exists, some other thing must exist,
consequently how a thing can be a cause; or how (3), when several
things exist, from the fact that one of these things exists, some
consequence to the others follows, and reciprocally, and in this way a
community of substances can be possible- are questions whose
solution cannot be obtained from mere conceptions. The very same is
the case with the other categories; for example, how a thing can be of
the same sort with many others, that is, can be a quantity, and so on.
So long as we have not intuition we cannot know whether we do really
think an object by the categories, and where an object can anywhere be
found to cohere with them, and thus the truth is established, that the
categories are not in themselves cognitions, but mere forms of thought
for the construction of cognitions from given intuitions. For the same
reason is it true that from categories alone no synthetical
proposition can be made. For example: "In every existence there is
substance," that is, something that can exist only as a subject and
not as mere predicate; or, "Everything is a quantity"- to construct
propositions such as these, we require something to enable us to go
out beyond the given conception and connect another with it. For the
same reason the attempt to prove a synthetical proposition by means of
mere conceptions, for example: "Everything that exists contingently
has a cause," has never succeeded. We could never get further than
proving that, without this relation to conceptions, we could not
conceive the existence of the contingent, that is, could not a
priori through the understanding cognize the existence of such a
thing; but it does not hence follow that this is also the condition of
the possibility of the thing itself that is said to be contingent. If,
accordingly; we look back to our proof of the principle of
causality, we shall find that we were able to prove it as valid only
of objects of possible experience, and, indeed, only as itself the
principle of the possibility of experience, Consequently of the
cognition of an object given in empirical intuition, and not from mere
conceptions. That, however, the proposition: "Everything that is
contingent must have a cause," is evident to every one merely from
conceptions, is not to be denied. But in this case the conception of
the contingent is cogitated as involving not the category of
modality (as that the non-existence of which can be conceive but
that of relation (as that which can exist only as the consequence of
something else), and so it is really an identical proposition: "That
which can exist only as a consequence, has a cause." In fact, when
we have to give examples of contingent existence, we always refer to
changes, and not merely to the possibility of conceiving the
opposite.* But change is an event, which, as such, is possible only
through a cause, and considered per se its non-existence is
therefore possible, and we become cognizant of its contingency from
the fact that it can exist only as the effect of a cause. Hence, if
a thing is assumed to be contingent, it is an analytical proposition
to say, it has a cause.

*We can easily conceive the non-existence of matter; but the
ancients did not thence infer its contingency. But even the
alternation of the existence and non-existence of a given state in a
thing, in which all change consists, by no means proves the
contingency of that state- the ground of proof being the reality of
its opposite. For example, a body is in a state of rest after
motion, but we cannot infer the contingency of the motion from the
fact that the former is the opposite of the latter. For this
opposite is merely a logical and not a real opposite to the other.
If we wish to demonstrate the contingency of the motion, what we ought
to prove is that, instead of the motion which took place in the
preceding point of time, it was possible for the body to have been
then in rest, not, that it is afterwards in rest; for in this case,
both opposites are perfectly consistent with each other.

But it is still more remarkable that, to understand the
possibility of things according to the categories and thus to
demonstrate the objective reality of the latter, we require not merely
intuitions, but external intuitions. If, for example, we take the pure
conceptions of relation, we find that (1) for the purpose of
presenting to the conception of substance something permanent in
intuition corresponding thereto and thus of demonstrating the
objective reality of this conception, we require an intuition (of
matter) in space, because space alone is permanent and determines
things as such, while time, and with it all that is in the internal
sense, is in a state of continual flow; (2) in order to represent
change as the intuition corresponding to the conception of
causality, we require the representation of motion as change in space;
in fact, it is through it alone that changes, the possibility of which
no pure understanding can perceive, are capable of being intuited.
Change is the connection of determinations contradictorily opposed
to each other in the existence of one and the same thing. Now, how
it is possible that out of a given state one quite opposite to it in
the same thing should follow, reason without an example can not only
not conceive, but cannot even make intelligible without intuition; and
this intuition is the motion of a point in space; the existence of
which in different spaces (as a consequence of opposite
determinations) alone makes the intuition of change possible. For,
in order to make even internal change cognitable, we require to
represent time, as the form of the internal sense, figuratively by a
line, and the internal change by the drawing of that line (motion),
and consequently are obliged to employ external intuition to be able
to represent the successive existence of ourselves in different
states. The proper ground of this fact is that all change to be
perceived as change presupposes something permanent in intuition,
while in the internal sense no permanent intuition is to be found.
Lastly, the objective possibility of the category of community
cannot be conceived by mere reason, and consequently its objective
reality cannot be demonstrated without an intuition, and that external
in space. For how can we conceive the possibility of community, that
is, when several substances exist, that some effect on the existence
of the one follows from the existence of the other, and
reciprocally, and therefore that, because something exists in the
latter, something else must exist in the former, which could not be
understood from its own existence alone? For this is the very
essence of community- which is inconceivable as a property of things
which are perfectly isolated. Hence, Leibnitz, in attributing to the
substances of the world- as cogitated by the understanding alone- a
community, required the mediating aid of a divinity; for, from their
existence, such a property seemed to him with justice inconceivable.
But we can very easily conceive the possibility of community (of
substances as phenomena) if we represent them to ourselves as in
space, consequently in external intuition. For external intuition
contains in itself a priori formal external relations, as the
conditions of the possibility of the real relations of action and
reaction, and therefore of the possibility of community. With the same
ease can it be demonstrated, that the possibility of things as
quantities, and consequently the objective reality of the category
of quantity, can be grounded only in external intuition, and that by
its means alone is the notion of quantity appropriated by the internal
sense. But I must avoid prolixity, and leave the task of
illustrating this by examples to the reader's own reflection.
The above remarks are of the greatest importance, not only for the
confirmation of our previous confutation of idealism, but still more
when the subject of self-cognition by mere internal consciousness
and the determination of our own nature without the aid of external
empirical intuitions is under discussion, for the indication of the
grounds of the possibility of such a cognition.
The result of the whole of this part of the analytic of principles
is, therefore: "All principles of the pure understanding are nothing
more than a priori principles of the possibility of experience, and to
experience alone do all a priori synthetical propositions apply and
relate"; indeed, their possibility itself rests entirely on this
relation.
CHAPTER III Of the Ground of the Division of all Objects
into Phenomena and Noumena.

We have now not only traversed the region of the pure
understanding and carefully surveyed every part of it, but we have
also measured it, and assigned to everything therein its proper place.
But this land is an island, and enclosed by nature herself within
unchangeable limits. It is the land of truth (an attractive word),
surrounded by a wide and stormy ocean, the region of illusion, where
many a fog-bank, many an iceberg, seems to the mariner, on his
voyage of discovery, a new country, and, while constantly deluding him
with vain hopes, engages him in dangerous adventures, from which he
never can desist, and which yet he never can bring to a termination.
But before venturing upon this sea, in order to explore it in its
whole extent, and to arrive at a certainty whether anything is to be
discovered there, it will not be without advantage if we cast our eyes
upon the chart of the land that we are about to leave, and to ask
ourselves, firstly, whether we cannot rest perfectly contented with
what it contains, or whether we must not of necessity be contented
with it, if we can find nowhere else a solid foundation to build upon;
and, secondly, by what title we possess this land itself, and how we
hold it secure against all hostile claims? Although, in the course
of our analytic, we have already given sufficient answers to these
questions, yet a summary recapitulation of these solutions may be
useful in strengthening our conviction, by uniting in one point the
momenta of the arguments.
We have seen that everything which the understanding draws from
itself, without borrowing from experience, it nevertheless possesses
only for the behoof and use of experience. The principles of the
pure understanding, whether constitutive a priori (as the mathematical
principles), or merely regulative (as the dynamical), contain
nothing but the pure schema, as it were, of possible experience. For
experience possesses its unity from the synthetical unity which the
understanding, originally and from itself, imparts to the synthesis of
the imagination in relation to apperception, and in a priori
relation to and agreement with which phenomena, as data for a possible
cognition, must stand. But although these rules of the understanding
are not only a priori true, but the very source of all truth, that is,
of the accordance of our cognition with objects, and on this ground,
that they contain the basis of the possibility of experience, as the
ensemble of all cognition, it seems to us not enough to propound
what is true- we desire also to be told what we want to know. If,
then, we learn nothing more by this critical examination than what
we should have practised in the merely empirical use of the
understanding, without any such subtle inquiry, the presumption is
that the advantage we reap from it is not worth the labour bestowed
upon it. It may certainly be answered that no rash curiosity is more
prejudicial to the enlargement of our knowledge than that which must
know beforehand the utility of this or that piece of information which
we seek, before we have entered on the needful investigations, and
before one could form the least conception of its utility, even though
it were placed before our eyes. But there is one advantage in such
transcendental inquiries which can be made comprehensible to the
dullest and most reluctant learner- this, namely, that the
understanding which is occupied merely with empirical exercise, and
does not reflect on the sources of its own cognition, may exercise its
functions very well and very successfully, but is quite unable to do
one thing, and that of very great importance, to determine, namely,
the bounds that limit its employment, and to know what lies within
or without its own sphere. This purpose can be obtained only by such
profound investigations as we have instituted. But if it cannot
distinguish whether certain questions lie within its horizon or not,
it can never be sure either as to its claims or possessions, but
must lay its account with many humiliating corrections, when it
transgresses, as it unavoidably will, the limits of its own territory,
and loses itself in fanciful opinions and blinding illusions.
That the understanding, therefore, cannot make of its a priori
principles, or even of its conceptions, other than an empirical use,
is a proposition which leads to the most important results. A
transcendental use is made of a conception in a fundamental
proposition or principle, when it is referred to things in general and
considered as things in themselves; an empirical use, when it is
referred merely to phenomena, that is, to objects of a possible
experience. That the latter use of a conception is the only admissible
one is evident from the reasons following. For every conception are
requisite, firstly, the logical form of a conception (of thought)
general; and, secondly, the possibility of presenting to this an
object to which it may apply. Failing this latter, it has no sense,
and utterly void of content, although it may contain the logical
function for constructing a conception from certain data. Now,
object cannot be given to a conception otherwise than by intuition,
and, even if a pure intuition antecedent to the object is a priori
possible, this pure intuition can itself obtain objective validity
only from empirical intuition, of which it is itself but the form. All
conceptions, therefore, and with them all principles, however high the
degree of their a priori possibility, relate to empirical
intuitions, that is, to data towards a possible experience. Without
this they possess no objective validity, but are mere play of
imagination or of understanding with images or notions. Let us take,
for example, the conceptions of mathematics, and first in its pure
intuitions. "Space has three dimensions"- "Between two points there
can be only one straight line," etc. Although all these principles,
and the representation of the object with which this science
occupies itself, are generated in the mind entirely a priori, they
would nevertheless have no significance if we were not always able
to exhibit their significance in and by means of phenomena
(empirical objects). Hence it is requisite that an abstract conception
be made sensuous, that is, that an object corresponding to it in
intuition be forthcoming, otherwise the conception remains, as we say,
without sense, that is, without meaning. Mathematics fulfils this
requirement by the construction of the figure, which is a phenomenon
evident to the senses. The same science finds support and significance
in number; this in its turn finds it in the fingers, or in counters,
or in lines and points. The conception itself is always produced a
priori, together with the synthetical principles or formulas from such
conceptions; but the proper employment of them, and their
application to objects, can exist nowhere but in experience, the
possibility of which, as regards its form, they contain a priori.
That this is also the case with all of the categories and the
principles based upon them is evident from the fact that we cannot
render intelligible the possibility of an object corresponding to them
without having recourse to the conditions of sensibility,
consequently, to the form of phenomena, to which, as their only proper
objects, their use must therefore be confined, inasmuch as, if this
condition is removed, all significance, that is, all relation to an
object, disappears, and no example can be found to make it
comprehensible what sort of things we ought to think under such
conceptions.
The conception of quantity cannot be explained except by saying that
it is the determination of a thing whereby it can be cogitated how
many times one is placed in it. But this "how many times" is based
upon successive repetition, consequently upon time and the synthesis
of the homogeneous therein. Reality, in contradistinction to negation,
can be explained only by cogitating a time which is either filled
therewith or is void. If I leave out the notion of permanence (which
is existence in all time), there remains in the conception of
substance nothing but the logical notion of subject, a notion of which
I endeavour to realize by representing to myself something that can
exist only as a subject. But not only am I perfectly ignorant of any
conditions under which this logical prerogative can belong to a thing,
I can make nothing out of the notion, and draw no inference from it,
because no object to which to apply the conception is determined,
and we consequently do not know whether it has any meaning at all.
In like manner, if I leave out the notion of time, in which
something follows upon some other thing in conformity with a rule, I
can find nothing in the pure category, except that there is a
something of such a sort that from it a conclusion may be drawn as
to the existence of some other thing. But in this case it would not
only be impossible to distinguish between a cause and an effect,
but, as this power to draw conclusions requires conditions of which
I am quite ignorant, the conception is not determined as to the mode
in which it ought to apply to an object. The so-called principle:
"Everything that is contingent has a cause," comes with a gravity
and self-assumed authority that seems to require no support from
without. But, I ask, what is meant by contingent? The answer is that
the non-existence of which is possible. But I should like very well to
know by what means this possibility of non-existence is to be
cognized, if we do not represent to ourselves a succession in the
series of phenomena, and in this succession an existence which follows
a non-existence, or conversely, consequently, change. For to say, that
the non-existence of a thing is not self-contradictory is a lame
appeal to a logical condition, which is no doubt a necessary condition
of the existence of the conception, but is far from being sufficient
for the real objective possibility of non-existence. I can
annihilate in thought every existing substance without
self-contradiction, but I cannot infer from this their objective
contingency in existence, that is to say, the possibility of their
non-existence in itself. As regards the category of community, it
may easily be inferred that, as the pure categories of substance and
causality are incapable of a definition and explanation sufficient
to determine their object without the aid of intuition, the category
of reciprocal causality in the relation of substances to each other
(commercium) is just as little susceptible thereof. Possibility,
existence, and necessity nobody has ever yet been able to explain
without being guilty of manifest tautology, when the definition has
been drawn entirely from the pure understanding. For the
substitution of the logical possibility of the conception- the
condition of which is that it be not self-contradictory, for the
transcendental possibility of things- the condition of which is that
there be an object corresponding to the conception, is a trick which
can only deceive the inexperienced.*

*In one word, to none of these conceptions belongs a corresponding
object, and consequently their real possibility cannot be
demonstrated, if we take away sensuous intuition- the only intuition
which we possess- and there then remains nothing but the logical
possibility, that is, the fact that the conception or thought is
possible- which, however, is not the question; what we want to know
being, whether it relates to an object and thus possesses any meaning.

It follows incontestably, that the pure conceptions of the
understanding are incapable of transcendental, and must always be of
empirical use alone, and that the principles of the pure understanding
relate only to the general conditions of a possible experience, to
objects of the senses, and never to things in general, apart from
the mode in which we intuite them.
Transcendental analytic has accordingly this important result, to
wit, that the understanding is competent' effect nothing a priori,
except the anticipation of the form of a possible experience in
general, and that, as that which is not phenomenon cannot be an object
of experience, it can never overstep the limits of sensibility, within
which alone objects are presented to us. Its principles are merely
principles of the exposition of phenomena, and the proud name of an
ontology, which professes to present synthetical cognitions a priori
of things in general in a systematic doctrine, must give place to
the modest title of analytic of the pure understanding.
Thought is the act of referring a given intuition to an object. If
the mode of this intuition is unknown to us, the object is merely
transcendental, and the conception of the understanding is employed
only transcendentally, that is, to produce unity in the thought of a
manifold in general. Now a pure category, in which all conditions of
sensuous intuition- as the only intuition we possess- are
abstracted, does not determine an object, but merely expresses the
thought of an object in general, according to different modes. Now, to
employ a conception, the function of judgement is required, by which
an object is subsumed under the conception, consequently the at
least formal condition, under which something can be given in
intuition. Failing this condition of judgement (schema), subsumption
is impossible; for there is in such a case nothing given, which may be
subsumed under the conception. The merely transcendental use of the
categories is therefore, in fact, no use at all and has no determined,
or even, as regards its form, determinable object. Hence it follows
that the pure category is incompetent to establish a synthetical a
priori principle, and that the principles of the pure understanding
are only of empirical and never of transcendental use, and that beyond
the sphere of possible experience no synthetical a priori principles
are possible.
It may be advisable, therefore, to express ourselves thus. The
pure categories, apart from the formal conditions of sensibility, have
a merely transcendental meaning, but are nevertheless not of
transcendental use, because this is in itself impossible, inasmuch
as all the conditions of any employment or use of them (in judgements)
are absent, to wit, the formal conditions of the subsumption of an
object under these conceptions. As, therefore, in the character of
pure categories, they must be employed empirically, and cannot be
employed transcendentally, they are of no use at all, when separated
from sensibility, that is, they cannot be applied to an object. They
are merely the pure form of the employment of the understanding in
respect of objects in general and of thought, without its being at the
same time possible to think or to determine any object by their means.
But there lurks at the foundation of this subject an illusion
which it is very difficult to avoid. The categories are not based,
as regards their origin, upon sensibility, like the forms of
intuition, space, and time; they seem, therefore, to be capable of
an application beyond the sphere of sensuous objects. But this is
not the case. They are nothing but mere forms of thought, which
contain only the logical faculty of uniting a priori in
consciousness the manifold given in intuition. Apart, then, from the
only intuition possible for us, they have still less meaning than
the pure sensuous forms, space and time, for through them an object is
at least given, while a mode of connection of the manifold, when the
intuition which alone gives the manifold is wanting, has no meaning at
all. At the same time, when we designate certain objects as
phenomena or sensuous existences, thus distinguishing our mode of
intuiting them from their own nature as things in themselves, it is
evident that by this very distinction we as it were place the
latter, considered in this their own nature, although we do not so
intuite them, in opposition to the former, or, on the other hand, we
do so place other possible things, which are not objects of our
senses, but are cogitated by the understanding alone, and call them
intelligible existences (noumena). Now the question arises whether the
pure conceptions of our understanding do possess significance in
respect of these latter, and may possibly be a mode of cognizing them.
But we are met at the very commencement with an ambiguity, which may
easily occasion great misapprehension. The understanding, when it
terms an object in a certain relation phenomenon, at the same time
forms out of this relation a representation or notion of an object
in itself, and hence believes that it can form also conceptions of
such objects. Now as the understanding possesses no other
fundamental conceptions besides the categories, it takes for granted
that an object considered as a thing in itself must be capable of
being thought by means of these pure conceptions, and is thereby led
to hold the perfectly undetermined conception of an intelligible
existence, a something out of the sphere of our sensibility, for a
determinate conception of an existence which we can cognize in some
way or other by means of the understanding.
If, by the term noumenon, we understand a thing so far as it is
not an object of our sensuous intuition, thus making abstraction of
our mode of intuiting it, this is a noumenon in the negative sense
of the word. But if we understand by it an object of a non-sensuous
intuition, we in this case assume a peculiar mode of intuition, an
intellectual intuition, to wit, which does not, however, belong to us,
of the very possibility of which we have no notion- and this is a
noumenon in the positive sense.
The doctrine of sensibility is also the doctrine of noumena in the
negative sense, that is, of things which the understanding is
obliged to cogitate apart from any relation to our mode of
intuition, consequently not as mere phenomena, but as things in
themselves. But the understanding at the same time comprehends that it
cannot employ its categories for the consideration of things in
themselves, because these possess significance only in relation to the
unity of intuitions in space and time, and that they are competent
to determine this unity by means of general a priori connecting
conceptions only on account of the pure ideality of space and time.
Where this unity of time is not to be met with, as is the case with
noumena, the whole use, indeed the whole meaning of the categories
is entirely lost, for even the possibility of things to correspond
to the categories is in this case incomprehensible. On this point, I
need only refer the reader to what I have said at the commencement
of the General Remark appended to the foregoing chapter. Now, the
possibility of a thing can never be proved from the fact that the
conception of it is not self-contradictory, but only by means of an
intuition corresponding to the conception. If, therefore, we wish to
apply the categories to objects which cannot be regarded as phenomena,
we must have an intuition different from the sensuous, and in this
case the objects would be a noumena in the positive sense of the word.
Now, as such an intuition, that is, an intellectual intuition, is no
part of our faculty of cognition, it is absolutely impossible for
the categories to possess any application beyond the limits of
experience. It may be true that there are intelligible existences to
which our faculty of sensuous intuition has no relation, and cannot be
applied, but our conceptions of the understanding, as mere forms of
thought for our sensuous intuition, do not extend to these. What,
therefore, we call noumenon must be understood by us as such in a
negative sense.
If I take away from an empirial intuition all thought (by means of
the categories), there remains no cognition of any object; for by
means of mere intuition nothing is cogitated, and, from the
existence of such or such an affection of sensibility in me, it does
not follow that this affection or representation has any relation to
an object without me. But if I take away all intuition, there still
remains the form of thought, that is, the mode of determining an
object for the manifold of a possible intuition. Thus the categories
do in some measure really extend further than sensuous intuition,
inasmuch as they think objects in general, without regard to the
mode (of sensibility) in which these objects are given. But they do
not for this reason apply to and determine a wider sphere of
objects, because we cannot assume that such can be given, without
presupposing the possibility of another than the sensuous mode of
intuition, a supposition we are not justified in making.
I call a conception problematical which contains in itself no
contradiction, and which is connected with other cognitions as a
limitation of given conceptions, but whose objective reality cannot be
cognized in any manner. The conception of a noumenon, that is, of a
thing which must be cogitated not as an object of sense, but as a
thing in itself (solely through the pure understanding), is not
self-contradictory, for we are not entitled to maintain that
sensibility is the only possible mode of intuition. Nay, further, this
conception is necessary to restrain sensuous intuition within the
bounds of phenomena, and thus to limit the objective validity of
sensuous cognition; for things in themselves, which lie beyond its
province, are called noumena for the very purpose of indicating that
this cognition does not extend its application to all that the
understanding thinks. But, after all, the possibility of such
noumena is quite incomprehensible, and beyond the sphere of phenomena,
all is for us a mere void; that is to say, we possess an understanding
whose province does problematically extend beyond this sphere, but
we do not possess an intuition, indeed, not even the conception of a
possible intuition, by means of which objects beyond the region of
sensibility could be given us, and in reference to which the
understanding might be employed assertorically. The conception of a
noumenon is therefore merely a limitative conception and therefore
only of negative use. But it is not an arbitrary or fictitious notion,
but is connected with the limitation of sensibility, without, however,
being capable of presenting us with any positive datum beyond this
sphere.
The division of objects into phenomena and noumena, and of the world
into a mundus sensibilis and intelligibilis is therefore quite
inadmissible in a positive sense, although conceptions do certainly
admit of such a division; for the class of noumena have no determinate
object corresponding to them, and cannot therefore possess objective
validity. If we abandon the senses, how can it be made conceivable
that the categories (which are the only conceptions that could serve
as conceptions for noumena) have any sense or meaning at all, inasmuch
as something more than the mere unity of thought, namely, a possible
intuition, is requisite for their application to an object? The
conception of a noumenon, considered as merely problematical, is,
however, not only admissible, but, as a limitative conception of
sensibility, absolutely necessary. But, in this case, a noumenon is
not a particular intelligible object for our understanding; on the
contrary, the kind of understanding to which it could belong is itself
a problem, for we cannot form the most distant conception of the
possibility of an understanding which should cognize an object, not
discursively by means of categories, but intuitively in a non-sensuous
intuition. Our understanding attains in this way a sort of negative
extension. That is to say, it is not limited by, but rather limits,
sensibility, by giving the name of noumena to things, not considered
as phenomena, but as things in themselves. But it at the same time
prescribes limits to itself, for it confesses itself unable to cognize
these by means of the categories, and hence is compelled to cogitate
them merely as an unknown something.
I find, however, in the writings of modern authors, an entirely
different use of the expressions, mundus sensibilis and
intelligibilis, which quite departs from the meaning of the
ancients- an acceptation in which, indeed, there is to be found no
difficulty, but which at the same time depends on mere verbal
quibbling. According to this meaning, some have chosen to call the
complex of phenomena, in so far as it is intuited, mundus
sensibilis, but in so far as the connection thereof is cogitated
according to general laws of thought, mundus intelligibilis.
Astronomy, in so far as we mean by the word the mere observation of
the starry heaven, may represent the former; a system of astronomy,
such as the Copernican or Newtonian, the latter. But such twisting
of words is a mere sophistical subterfuge, to avoid a difficult
question, by modifying its meaning to suit our own convenience. To
be sure, understanding and reason are employed in the cognition of
phenomena; but the question is, whether these can be applied when
the object is not a phenomenon and in this sense we regard it if it is
cogitated as given to the understanding alone, and not to the
senses. The question therefore is whether, over and above the
empirical use of the understanding, a transcendental use is
possible, which applies to the noumenon as an object. This question we
have answered in the negative.
When therefore we say, the senses represent objects as they
appear, the understanding as they are, the latter statement must not
be understood in a transcendental, but only in an empirical
signification, that is, as they must be represented in the complete
connection of phenomena, and not according to what they may be,
apart from their relation to possible experience, consequently not
as objects of the pure understanding. For this must ever remain
unknown to us. Nay, it is also quite unknown to us whether any such
transcendental or extraordinary cognition is possible under any
circumstances, at least, whether it is possible by means of our
categories. Understanding and sensibility, with us, can determine
objects only in conjunction. If we separate them, we have intuitions
without conceptions, or conceptions without intuitions; in both cases,
representations, which we cannot apply to any determinate object.
If, after all our inquiries and explanations, any one still
hesitates to abandon the mere transcendental use of the categories,
let him attempt to construct with them a synthetical proposition. It
would, of course, be unnecessary for this purpose to construct an
analytical proposition, for that does not extend the sphere of the
understanding, but, being concerned only about what is cogitated in
the conception itself, it leaves it quite undecided whether the
conception has any relation to objects, or merely indicates the
unity of thought- complete abstraction being made of the modi in which
an object may be given: in such a proposition, it is sufficient for
the understanding to know what lies in the conception- to what it
applies is to it indifferent. The attempt must therefore be made
with a synthetical and so-called transcendental principle, for
example: "Everything that exists, exists as substance," or,
"Everything that is contingent exists as an effect of some other
thing, viz., of its cause." Now I ask, whence can the understanding
draw these synthetical propositions, when the conceptions contained
therein do not relate to possible experience but to things in
themselves (noumena)? Where is to be found the third term, which is
always requisite PURE site in a synthetical proposition, which may
connect in the same proposition conceptions which have no logical
(analytical) connection with each other? The proposition never will be
demonstrated, nay, more, the possibility of any such pure assertion
never can be shown, without making reference to the empirical use of
the understanding, and thus, ipso facto, completely renouncing pure
and non-sensuous judgement. Thus the conception of pure and merely
intelligible objects is completely void of all principles of its
application, because we cannot imagine any mode in which they might be
given, and the problematical thought which leaves a place open for
them serves only, like a void space, to limit the use of empirical
principles, without containing at the same time any other object of
cognition beyond their sphere.
APPENDIX
APPENDIX.

Of the Equivocal Nature or Amphiboly of the Conceptions of
Reflection from the Confusion of the Transcendental with
the Empirical use of the Understanding.

Reflection (reflexio) is not occupied about objects themselves,
for the purpose of directly obtaining conceptions of them, but is that
state of the mind in which we set ourselves to discover the subjective
conditions under which we obtain conceptions. It is the
consciousness of the relation of given representations to the
different sources or faculties of cognition, by which alone their
relation to each other can be rightly determined. The first question
which occurs in considering our representations is to what faculty
of cognition do they belong? To the understanding or to the senses?
Many judgements are admitted to be true from mere habit or
inclination; but, because reflection neither precedes nor follows,
it is held to be a judgement that has its origin in the understanding.
All judgements do not require examination, that is, investigation into
the grounds of their truth. For, when they are immediately certain
(for example: "Between two points there can be only one straight
line"), no better or less mediate test of their truth can be found
than that which they themselves contain and express. But all
judgement, nay, all comparisons require reflection, that is, a
distinction of the faculty of cognition to which the given conceptions
belong. The act whereby I compare my representations with the
faculty of cognition which originates them, and whereby I
distinguish whether they are compared with each other as belonging
to the pure understanding or to sensuous intuition, I term
transcendental reflection. Now, the relations in which conceptions can
stand to each other are those of identity and difference, agreement
and opposition, of the internal and external, finally, of the
determinable and the determining (matter and form). The proper
determination of these relations rests on the question, to what
faculty of cognition they subjectively belong, whether to
sensibility or understanding? For, on the manner in which we solve
this question depends the manner in which we must cogitate these
relations.
Before constructing any objective judgement, we compare the
conceptions that are to be placed in the judgement, and observe
whether there exists identity (of many representations in one
conception), if a general judgement is to be constructed, or
difference, if a particular; whether there is agreement when
affirmative; and opposition when negative judgements are to be
constructed, and so on. For this reason we ought to call these
conceptions, conceptions of comparison (conceptus comparationis).
But as, when the question is not as to the logical form, but as to the
content of conceptions, that is to say, whether the things
themselves are identical or different, in agreement or opposition, and
so on, the things can have a twofold relation to our faculty of
cognition, to wit, a relation either to sensibility or to the
understanding, and as on this relation depends their relation to
each other, transcendental reflection, that is, the relation of
given representations to one or the other faculty of cognition, can
alone determine this latter relation. Thus we shall not be able to
discover whether the things are identical or different, in agreement
or opposition, etc., from the mere conception of the things by means
of comparison (comparatio), but only by distinguishing the mode of
cognition to which they belong, in other words, by means of
transcendental reflection. We may, therefore, with justice say, that
logical reflection is mere comparison, for in it no account is taken
of the faculty of cognition to which the given conceptions belong, and
they are consequently, as far as regards their origin, to be treated
as homogeneous; while transcendental reflection (which applies to
the objects themselves) contains the ground of the possibility of
objective comparison of representations with each other, and is
therefore very different from the former, because the faculties of
cognition to which they belong are not even the same. Transcendental
reflection is a duty which no one can neglect who wishes to
establish an a priori judgement upon things. We shall now proceed to
fulfil this duty, and thereby throw not a little light on the question
as to the determination of the proper business of the understanding.
1. Identity and Difference. When an object is presented to us
several times, but always with the same internal determinations
(qualitas et quantitas), it, if an object of pure understanding, is
always the same, not several things, but only one thing (numerica
identitas); but if a phenomenon, we do not concern ourselves with
comparing the conception of the thing with the conception of some
other, but, although they may be in this respect perfectly the same,
the difference of place at the same time is a sufficient ground for
asserting the numerical difference of these objects (of sense).
Thus, in the case of two drops of water, we may make complete
abstraction of all internal difference (quality and quantity), and,
the fact that they are intuited at the same time in different
places, is sufficient to justify us in holding them to be
numerically different. Leibnitz regarded phenomena as things in
themselves, consequently as intelligibilia, that is, objects of pure
understanding (although, on account of the confused nature of their
representations, he gave them the name of phenomena), and in this case
his principle of the indiscernible (principium identatis
indiscernibilium) is not to be impugned. But, as phenomena are objects
of sensibility, and, as the understanding, in respect of them, must be
employed empirically and not purely or transcendentally, plurality and
numerical difference are given by space itself as the condition of
external phenomena. For one part of space, although it may be
perfectly similar and equal to another part, is still without it,
and for this reason alone is different from the latter, which is added
to it in order to make up a greater space. It follows that this must
hold good of all things that are in the different parts of space at
the same time, however similar and equal one may be to another.
2. Agreement and Opposition. When reality is represented by the pure
understanding (realitas noumenon), opposition between realities is
incogitable- such a relation, that is, that when these realities are
connected in one subject, they annihilate the effects of each other
and may be represented in the formula 3 - 3 = 0. On the other hand,
the real in a phenomenon (realitas phaenomenon) may very well be in
mutual opposition, and, when united in the same subject, the one may
completely or in part annihilate the effect or consequence of the
other; as in the case of two moving forces in the same straight line
drawing or impelling a point in opposite directions, or in the case of
a pleasure counterbalancing a certain amount of pain.
3. The Internal and External. In an object of the pure
understanding, only that is internal which has no relation (as regards
its existence) to anything different from itself. On the other hand,
the internal determinations of a substantia phaenomenon in space are
nothing but relations, and it is itself nothing more than a complex of
mere relations. Substance in space we are cognizant of only through
forces operative in it, either drawing others towards itself
(attraction), or preventing others from forcing into itself (repulsion
and impenetrability). We know no other properties that make up the
conception of substance phenomenal in space, and which we term matter.
On the other hand, as an object of the pure understanding, every
substance must have internal determination and forces. But what
other internal attributes of such an object can I think than those
which my internal sense presents to me? That, to wit, which in
either itself thought, or something analogous to it. Hence Leibnitz,
who looked upon things as noumena, after denying them everything
like external relation, and therefore also composition or combination,
declared that all substances, even the component parts of matter, were
simple substances with powers of representation, in one word, monads.
4. Matter and Form. These two conceptions lie at the foundation of
all other reflection, so inseparably are they connected with every
mode of exercising the understanding. The former denotes the
determinable in general, the second its determination, both in a
transcendental sense, abstraction being made of every difference in
that which is given, and of the mode in which it is determined.
Logicians formerly termed the universal, matter, the specific
difference of this or that part of the universal, form. In a judgement
one may call the given conceptions logical matter (for the judgement),
the relation of these to each other (by means of the copula), the form
of the judgement. In an object, the composite parts thereof
(essentialia) are the matter; the mode in which they are connected
in the object, the form. In respect to things in general, unlimited
reality was regarded as the matter of all possibility, the
limitation thereof (negation) as the form, by which one thing is
distinguished from another according to transcendental conceptions.
The understanding demands that something be given (at least in the
conception), in order to be able to determine it in a certain
manner. Hence, in a conception of the pure understanding, the matter
precedes the form, and for this reason Leibnitz first assumed the
existence of things (monads) and of an internal power of
representation in them, in order to found upon this their external
relation and the community their state (that is, of their
representations). Hence, with him, space and time were possible- the
former through the relation of substances, the latter through the
connection of their determinations with each other, as causes and
effects. And so would it really be, if the pure understanding were
capable of an immediate application to objects, and if space and
time were determinations of things in themselves. But being merely
sensuous intuitions, in which we determine all objects solely as
phenomena, the form of intuition (as a subjective property of
sensibility) must antecede all matter (sensations), consequently space
and time must antecede all phenomena and all data of experience, and
rather make experience itself possible. But the intellectual
philosopher could not endure that the form should precede the things
themselves and determine their possibility; an objection perfectly
correct, if we assume that we intuite things as they are, although
with confused representation. But as sensuous intuition is a
peculiar subjective condition, which is a priori at the foundation
of all perception, and the form of which is primitive, the form must
be given per se, and so far from matter (or the things themselves
which appear) lying at the foundation of experience (as we must
conclude, if we judge by mere conceptions), the very possibility of
itself presupposes, on the contrary, a given formal intuition (space
and time).

REMARK ON THE AMPHIBOLY OF THE CONCEPTIONS OF REFLECTION.

Let me be allowed to term the position which we assign to a
conception either in the sensibility or in the pure understanding, the
transcendental place. In this manner, the appointment of the
position which must be taken by each conception according to the
difference in its use, and the directions for determining this place
to all conceptions according to rules, would be a transcendental
topic, a doctrine which would thoroughly shield us from the
surreptitious devices of the pure understanding and the delusions
which thence arise, as it would always distinguish to what faculty
of cognition each conception properly belonged. Every conception,
every title, under which many cognitions rank together, may be
called a logical place. Upon this is based the logical topic of
Aristotle, of which teachers and rhetoricians could avail
themselves, in order, under certain titles of thought, to observe what
would best suit the matter they had to treat, and thus enable
themselves to quibble and talk with fluency and an appearance of
profundity.
Transcendental topic, on the contrary, contains nothing more than
the above-mentioned four titles of all comparison and distinction,
which differ from categories in this respect, that they do not
represent the object according to that which constitutes its
conception (quantity, reality), but set forth merely the comparison of
representations, which precedes our conceptions of things. But this
comparison requires a previous reflection, that is, a determination of
the place to which the representations of the things which are
compared belong, whether, to wit, they are cogitated by the pure
understanding, or given by sensibility.
Conceptions may be logically compared without the trouble of
inquiring to what faculty their objects belong, whether as noumena, to
the understanding, or as phenomena, to sensibility. If, however, we
wish to employ these conceptions in respect of objects, previous
transcendental reflection is necessary. Without this reflection I
should make a very unsafe use of these conceptions, and construct
pretended synthetical propositions which critical reason cannot
acknowledge and which are based solely upon a transcendental
amphiboly, that is, upon a substitution of an object of pure
understanding for a phenomenon.
For want of this doctrine of transcendental topic, and
consequently deceived by the amphiboly of the conceptions of
reflection, the celebrated Leibnitz constructed an intellectual system
of the world, or rather, believed himself competent to cognize the
internal nature of things, by comparing all objects merely with the
understanding and the abstract formal conceptions of thought. Our
table of the conceptions of reflection gives us the unexpected
advantage of being able to exhibit the distinctive peculiarities of
his system in all its parts, and at the same time of exposing the
fundamental principle of this peculiar mode of thought, which rested
upon naught but a misconception. He compared all things with each
other merely by means of conceptions, and naturally found no other
differences than those by which the understanding distinguishes its
pure conceptions one from another. The conditions of sensuous
intuition, which contain in themselves their own means of distinction,
he did not look upon as primitive, because sensibility was to him
but a confused mode of representation and not any particular source of
representations. A phenomenon was for him the representation of the
thing in itself, although distinguished from cognition by the
understanding only in respect of the logical form- the former with its
usual want of analysis containing, according to him, a certain mixture
of collateral representations in its conception of a thing, which it
is the duty of the understanding to separate and distinguish. In one
word, Leibnitz intellectualized phenomena, just as Locke, in his
system of noogony (if I may be allowed to make use of such
expressions), sensualized the conceptions of the understanding, that
is to say, declared them to be nothing more than empirical or abstract
conceptions of reflection. Instead of seeking in the understanding and
sensibility two different sources of representations, which,
however, can present us with objective judgements of things only in
conjunction, each of these great men recognized but one of these
faculties, which, in their opinion, applied immediately to things in
themselves, the other having no duty but that of confusing or
arranging the representations of the former.
Accordingly, the objects of sense were compared by Leibnitz as
things in general merely in the understanding.
1st. He compares them in regard to their identity or difference-
as judged by the understanding. As, therefore, he considered merely
the conceptions of objects, and not their position in intuition, in
which alone objects can be given, and left quite out of sight the
transcendental locale of these conceptions- whether, that is, their
object ought to be classed among phenomena, or among things in
themselves, it was to be expected that he should extend the
application of the principle of indiscernibles, which is valid
solely of conceptions of things in general, to objects of sense
(mundus phaenomenon), and that he should believe that he had thereby
contributed in no small degree to extend our knowledge of nature. In
truth, if I cognize in all its inner determinations a drop of water as
a thing in itself, I cannot look upon one drop as different from
another, if the conception of the one is completely identical with
that of the other. But if it is a phenomenon in space, it has a
place not merely in the understanding (among conceptions), but also in
sensuous external intuition (in space), and in this case, the physical
locale is a matter of indifference in regard to the internal
determinations of things, and one place, B, may contain a thing
which is perfectly similar and equal to another in a place, A, just as
well as if the two things were in every respect different from each
other. Difference of place without any other conditions, makes the
plurality and distinction of objects as phenomena, not only possible
in itself, but even necessary. Consequently, the above so-called law
is not a law of nature. It is merely an analytical rule for the
comparison of things by means of mere conceptions.
2nd. The principle: "Realities (as simple affirmations) never
logically contradict each other," is a proposition perfectly true
respecting the relation of conceptions, but, whether as regards
nature, or things in themselves (of which we have not the slightest
conception), is without any the least meaning. For real opposition, in
which A - B is = 0, exists everywhere, an opposition, that is, in
which one reality united with another in the same subject
annihilates the effects of the other- a fact which is constantly
brought before our eyes by the different antagonistic actions and
operations in nature, which, nevertheless, as depending on real
forces, must be called realitates phaenomena. General mechanics can
even present us with the empirical condition of this opposition in
an a priori rule, as it directs its attention to the opposition in the
direction of forces- a condition of which the transcendental
conception of reality can tell us nothing. Although M. Leibnitz did
not announce this proposition with precisely the pomp of a new
principle, he yet employed it for the establishment of new
propositions, and his followers introduced it into their
Leibnitzio-Wolfian system of philosophy. According to this
principle, for example, all evils are but consequences of the
limited nature of created beings, that is, negations, because these
are the only opposite of reality. (In the mere conception of a thing
in general this is really the case, but not in things as phenomena.)
In like manner, the upholders of this system deem it not only
possible, but natural also, to connect and unite all reality in one
being, because they acknowledge no other sort of opposition than
that of contradiction (by which the conception itself of a thing is
annihilated), and find themselves unable to conceive an opposition
of reciprocal destruction, so to speak, in which one real cause
destroys the effect of another, and the conditions of whose
representation we meet with only in sensibility.
3rd. The Leibnitzian monadology has really no better foundation than
on this philosopher's mode of falsely representing the difference of
the internal and external solely in relation to the understanding.
Substances, in general, must have something inward, which is therefore
free from external relations, consequently from that of composition
also. The simple- that which can be represented by a unit- is
therefore the foundation of that which is internal in things in
themselves. The internal state of substances cannot therefore
consist in place, shape, contact, or motion, determinations which
are all external relations, and we can ascribe to them no other than
that whereby we internally determine our faculty of sense itself, that
is to say, the state of representation. Thus, then, were constructed
the monads, which were to form the elements of the universe, the
active force of which consists in representation, the effects of
this force being thus entirely confined to themselves.
For the same reason, his view of the possible community of
substances could not represent it but as a predetermined harmony,
and by no means as a physical influence. For inasmuch as everything is
occupied only internally, that is, with its own representations, the
state of the representations of one substance could not stand in
active and living connection with that of another, but some third
cause operating on all without exception was necessary to make the
different states correspond with one another. And this did not
happen by means of assistance applied in each particular case (systema
assistentiae), but through the unity of the idea of a cause occupied
and connected with all substances, in which they necessarily
receive, according to the Leibnitzian school, their existence and
permanence, consequently also reciprocal correspondence, according
to universal laws.
4th. This philosopher's celebrated doctrine of space and time, in
which he intellectualized these forms of sensibility, originated in
the same delusion of transcendental reflection. If I attempt to
represent by the mere understanding, the external relations of things,
I can do so only by employing the conception of their reciprocal
action, and if I wish to connect one state of the same thing with
another state, I must avail myself of the notion of the order of cause
and effect. And thus Leibnitz regarded space as a certain order in the
community of substances, and time as the dynamical sequence of their
states. That which space and time possess proper to themselves and
independent of things, he ascribed to a necessary confusion in our
conceptions of them, whereby that which is a mere form of dynamical
relations is held to be a self-existent intuition, antecedent even
to things themselves. Thus space and time were the intelligible form
of the connection of things (substances and their states) in
themselves. But things were intelligible substances (substantiae
noumena). At the same time, he made these conceptions valid of
phenomena, because he did not allow to sensibility a peculiar mode
of intuition, but sought all, even the empirical representation of
objects, in the understanding, and left to sense naught but the
despicable task of confusing and disarranging the representations of
the former.
But even if we could frame any synthetical proposition concerning
things in themselves by means of the pure understanding (which is
impossible), it could not apply to phenomena, which do not represent
things in themselves. In such a case I should be obliged in
transcendental reflection to compare my conceptions only under the
conditions of sensibility, and so space and time would not be
determinations of things in themselves, but of phenomena. What
things may be in themselves, I know not and need not know, because a
thing is never presented to me otherwise than as a phenomenon.
I must adopt the same mode of procedure with the other conceptions
of reflection. Matter is substantia phaenomenon. That in it which is
internal I seek to discover in all parts of space which it occupies,
and in all the functions and operations it performs, and which are
indeed never anything but phenomena of the external sense. I cannot
therefore find anything that is absolutely, but only what is
comparatively internal, and which itself consists of external
relations. The absolutely internal in matter, and as it should be
according to the pure understanding, is a mere chimera, for matter
is not an object for the pure understanding. But the transcendental
object, which is the foundation of the phenomenon which we call
matter, is a mere nescio quid, the nature of which we could not
understand, even though someone were found able to tell us. For we can
understand nothing that does not bring with it something in
intuition corresponding to the expressions employed. If, by the
complaint of being unable to perceive the internal nature of things,
it is meant that we do not comprehend by the pure understanding what
the things which appear to us may be in themselves, it is a silly
and unreasonable complaint; for those who talk thus really desire that
we should be able to cognize, consequently to intuite, things
without senses, and therefore wish that we possessed a faculty of
cognition perfectly different from the human faculty, not merely in
degree, but even as regards intuition and the mode thereof, so that
thus we should not be men, but belong to a class of beings, the
possibility of whose existence, much less their nature and
constitution, we have no means of cognizing. By observation and
analysis of phenomena we penetrate into the interior of nature, and no
one can say what progress this knowledge may make in time. But those
transcendental questions which pass beyond the limits of nature, we
could never answer, even although all nature were laid open to us,
because we have not the power of observing our own mind with any other
intuition than that of our internal sense. For herein lies the mystery
of the origin and source of our faculty of sensibility. Its
application to an object, and the transcendental ground of this
unity of subjective and objective, lie too deeply concealed for us,
who cognize ourselves only through the internal sense, consequently as
phenomena, to be able to discover in our existence anything but
phenomena, the non-sensuous cause of which we at the same time
earnestly desire to penetrate to.
The great utility of this critique of conclusions arrived at by
the processes of mere reflection consists in its clear demonstration
of the nullity of all conclusions respecting objects which are
compared with each other in the understanding alone, while it at the
same time confirms what we particularly insisted on, namely, that,
although phenomena are not included as things in themselves among
the objects of the pure understanding, they are nevertheless the
only things by which our cognition can possess objective reality, that
is to say, which give us intuitions to correspond with our
conceptions.
When we reflect in a purely logical manner, we do nothing more
than compare conceptions in our understanding, to discover whether
both have the same content, whether they are self-contradictory or
not, whether anything is contained in either conception, which of
the two is given, and which is merely a mode of thinking that given.
But if I apply these conceptions to an object in general (in the
transcendental sense), without first determining whether it is an
object of sensuous or intellectual intuition, certain limitations
present themselves, which forbid us to pass beyond the conceptions and
render all empirical use of them impossible. And thus these
limitations prove that the representation of an object as a thing in
general is not only insufficient, but, without sensuous
determination and independently of empirical conditions,
self-contradictory; that we must therefore make abstraction of all
objects, as in logic, or, admitting them, must think them under
conditions of sensuous intuition; that, consequently, the intelligible
requires an altogether peculiar intuition, which we do not possess,
and in the absence of which it is for us nothing; while, on the
other hand phenomena cannot be objects in themselves. For, when I
merely think things in general, the difference in their external
relations cannot constitute a difference in the things themselves;
on the contrary, the former presupposes the latter, and if the
conception of one of two things is not internally different from
that of the other, I am merely thinking the same thing in different
relations. Further, by the addition of one affirmation (reality) to
the other, the positive therein is really augmented, and nothing is
abstracted or withdrawn from it; hence the real in things cannot be in
contradiction with or opposition to itself- and so on.

The true use of the conceptions of reflection in the employment of
the understanding has, as we have shown, been so misconceived by
Leibnitz, one of the most acute philosophers of either ancient or
modern times, that he has been misled into the construction of a
baseless system of intellectual cognition, which professes to
determine its objects without the intervention of the senses. For this
reason, the exposition of the cause of the amphiboly of these
conceptions, as the origin of these false principles, is of great
utility in determining with certainty the proper limits of the
understanding.
It is right to say whatever is affirmed or denied of the whole of
a conception can be affirmed or denied of any part of it (dictum de
omni et nullo); but it would be absurd so to alter this logical
proposition as to say whatever is not contained in a general
conception is likewise not contained in the particular conceptions
which rank under it; for the latter are particular conceptions, for
the very reason that their content is greater than that which is
cogitated in the general conception. And yet the whole intellectual
system of Leibnitz is based upon this false principle, and with it
must necessarily fall to the ground, together with all the ambiguous
principles in reference to the employment of the understanding which
have thence originated.
Leibnitz's principle of the identity of indiscernibles or
indistinguishables is really based on the presupposition that, if in
the conception of a thing a certain distinction is not to be found, it
is also not to be met with in things themselves; that, consequently,
all things are completely identical (numero eadem) which are not
distinguishable from each other (as to quality or quantity) in our
conceptions of them. But, as in the mere conception of anything
abstraction has been made of many necessary conditions of intuition,
that of which abstraction has been made is rashly held to be
non-existent, and nothing is attributed to the thing but what is
contained in its conception.
The conception of a cubic foot of space, however I may think it,
is in itself completely identical. But two cubic feet in space are
nevertheless distinct from each other from the sole fact of their
being in different places (they are numero diversa); and these
places are conditions of intuition, wherein the object of this
conception is given, and which do not belong to the conception, but to
the faculty of sensibility. In like manner, there is in the conception
of a thing no contradiction when a negative is not connected with an
affirmative; and merely affirmative conceptions cannot, in
conjunction, produce any negation. But in sensuous intuition,
wherein reality (take for example, motion) is given, we find
conditions (opposite directions)- of which abstraction has been made
in the conception of motion in general- which render possible a
contradiction or opposition (not indeed of a logical kind)- and
which from pure positives produce zero = 0. We are therefore not
justified in saying that all reality is in perfect agreement and
harmony, because no contradiction is discoverable among its
conceptions.* According to mere conceptions, that which is internal is
the substratum of all relations or external determinations. When,
therefore, I abstract all conditions of intuition, and confine
myself solely to the conception of a thing in general, I can make
abstraction of all external relations, and there must nevertheless
remain a conception of that which indicates no relation, but merely
internal determinations. Now it seems to follow that in everything
(substance) there is something which is absolutely internal and
which antecedes all external determinations, inasmuch as it renders
them possible; and that therefore this substratum is something which
does not contain any external relations and is consequently simple
(for corporeal things are never anything but relations, at least of
their parts external to each other); and, inasmuch as we know of no
other absolutely internal determinations than those of the internal
sense, this substratum is not only simple, but also, analogously
with our internal sense, determined through representations, that is
to say, all things are properly monads, or simple beings endowed
with the power of representation. Now all this would be perfectly
correct, if the conception of a thing were the only necessary
condition of the presentation of objects of external intuition. It is,
on the contrary, manifest that a permanent phenomenon in space
(impenetrable extension) can contain mere relations, and nothing
that is absolutely internal, and yet be the primary substratum of
all external perception. By mere conceptions I cannot think anything
external, without, at the same time, thinking something internal,
for the reason that conceptions of relations presuppose given
things, and without these are impossible. But, as an intuition there
is something (that is, space, which, with all it contains, consists of
purely formal, or, indeed, real relations) which is not found in the
mere conception of a thing in general, and this presents to us the
substratum which could not be cognized through conceptions alone, I
cannot say: because a thing cannot be represented by mere
conceptions without something absolutely internal, there is also, in
the things themselves which are contained under these conceptions, and
in their intuition nothing external to which something absolutely
internal does not serve as the foundation. For, when we have made
abstraction of all the conditions of intuition, there certainly
remains in the mere conception nothing but the internal in general,
through which alone the external is possible. But this necessity,
which is grounded upon abstraction alone, does not obtain in the
case of things themselves, in so far as they are given in intuition
with such determinations as express mere relations, without having
anything internal as their foundation; for they are not things of a
thing of which we can neither for they are not things in themselves,
but only phenomena. What we cognize in matter is nothing but relations
(what we call its internal determinations are but comparatively
internal). But there are some self-subsistent and permanent, through
which a determined object is given. That I, when abstraction is made
of these relations, have nothing more to think, does not destroy the
conception of a thing as phenomenon, nor the conception of an object
in abstracto, but it does away with the possibility of an object
that is determinable according to mere conceptions, that is, of a
noumenon. It is certainly startling to hear that a thing consists
solely of relations; but this thing is simply a phenomenon, and cannot
be cogitated by means of the mere categories: it does itself consist
in the mere relation of something in general to the senses. In the
same way, we cannot cogitate relations of things in abstracto, if we
commence with conceptions alone, in any other manner than that one
is the cause of determinations in the other; for that is itself the
conception of the understanding or category of relation. But, as in
this case we make abstraction of all intuition, we lose altogether the
mode in which the manifold determines to each of its parts its
place, that is, the form of sensibility (space); and yet this mode
antecedes all empirical causality.

*If any one wishes here to have recourse to the usual subterfuge,
and to say, that at least realitates noumena cannot be in opposition
to each other, it will be requisite for him to adduce an example of
this pure and non-sensuous reality, that it may be understood
whether the notion represents something or nothing. But an example
cannot be found except in experience, which never presents to us
anything more than phenomena; and thus the proposition means nothing
more than that the conception which contains only affirmatives does
not contain anything negative- a proposition nobody ever doubted.

If by intelligible objects we understand things which can be thought
by means of the pure categories, without the need of the schemata of
sensibility, such objects are impossible. For the condition of the
objective use of all our conceptions of understanding is the mode of
our sensuous intuition, whereby objects are given; and, if we make
abstraction of the latter, the former can have no relation to an
object. And even if we should suppose a different kind of intuition
from our own, still our functions of thought would have no use or
signification in respect thereof. But if we understand by the term,
objects of a non-sensuous intuition, in respect of which our
categories are not valid, and of which we can accordingly have no
knowledge (neither intuition nor conception), in this merely
negative sense noumena must be admitted. For this is no more than
saying that our mode of intuition is not applicable to all things, but
only to objects of our senses, that consequently its objective
validity is limited, and that room is therefore left for another
kind of intuition, and thus also for things that may be objects of it.
But in this sense the conception of a noumenon is problematical,
that is to say, it is the notion of that it that it is possible, nor
that it is impossible, inasmuch as we do not know of any mode of
intuition besides the sensuous, or of any other sort of conceptions
than the categories- a mode of intuition and a kind of conception
neither of which is applicable to a non-sensuous object. We are on
this account incompetent to extend the sphere of our objects of
thought beyond the conditions of our sensibility, and to assume the
existence of objects of pure thought, that is, of noumena, inasmuch as
these have no true positive signification. For it must be confessed of
the categories that they are not of themselves sufficient for the
cognition of things in themselves and, without the data of
sensibility, are mere subjective forms of the unity of the
understanding. Thought is certainly not a product of the senses, and
in so far is not limited by them, but it does not therefore follow
that it may be employed purely and without the intervention of
sensibility, for it would then be without reference to an object.
And we cannot call a noumenon an object of pure thought; for the
representation thereof is but the problematical conception of an
object for a perfectly different intuition and a perfectly different
understanding from ours, both of which are consequently themselves
problematical. The conception of a noumenon is therefore not the
conception of an object, but merely a problematical conception
inseparably connected with the limitation of our sensibility. That
is to say, this conception contains the answer to the question: "Are
there objects quite unconnected with, and independent of, our
intuition?"- a question to which only an indeterminate answer can be
given. That answer is: "Inasmuch as sensuous intuition does not
apply to all things without distinction, there remains room for
other and different objects." The existence of these problematical
objects is therefore not absolutely denied, in the absence of a
determinate conception of them, but, as no category is valid in
respect of them, neither must they be admitted as objects for our
understanding.
Understanding accordingly limits sensibility, without at the same
time enlarging its own field. While, moreover, it forbids
sensibility to apply its forms and modes to things in themselves and
restricts it to the sphere of phenomena, it cogitates an object in
itself, only, however, as a transcendental object, which is the
cause of a phenomenon (consequently not itself a phenomenon), and
which cannot be thought either as a quantity or as reality, or as
substance (because these conceptions always require sensuous forms
in which to determine an object)- an object, therefore, of which we
are quite unable to say whether it can be met with in ourselves or out
of us, whether it would be annihilated together with sensibility,
or, if this were taken away, would continue to exist. If we wish to
call this object a noumenon, because the representation of it is
non-sensuous, we are at liberty to do so. But as we can apply to it
none of the conceptions of our understanding, the representation is
for us quite void, and is available only for the indication of the
limits of our sensuous intuition, thereby leaving at the same time
an empty space, which we are competent to fill by the aid neither of
possible experience, nor of the pure understanding.
The critique of the pure understanding, accordingly, does not permit
us to create for ourselves a new field of objects beyond those which
are presented to us as phenomena, and to stray into intelligible
worlds; nay, it does not even allow us to endeavour to form so much as
a conception of them. The specious error which leads to this- and
which is a perfectly excusable one- lies in the fact that the
employment of the understanding, contrary to its proper purpose and
destination, is made transcendental, and objects, that is, possible
intuitions, are made to regulate themselves according to
conceptions, instead of the conceptions arranging themselves according
to the intuitions, on which alone their own objective validity
rests. Now the reason of this again is that apperception, and with
it thought, antecedes all possible determinate arrangement of
representations. Accordingly we think something in general and
determine it on the one hand sensuously, but, on the other,
distinguish the general and in abstracto represented object from
this particular mode of intuiting it. In this case there remains a
mode of determining the object by mere thought, which is really but
a logical form without content, which, however, seems to us to be a
mode of the existence of the object in itself (noumenon), without
regard to intuition which is limited to our senses.

Before ending this transcendental analytic, we must make an
addition, which, although in itself of no particular importance, seems
to be necessary to the completeness of the system. The highest
conception, with which a transcendental philosophy commonly begins, is
the division into possible and impossible. But as all division
presupposes a divided conception, a still higher one must exist, and
this is the conception of an object in general- problematically
understood and without its being decided whether it is something or
nothing. As the categories are the only conceptions which apply to
objects in general, the distinguishing of an object, whether it is
something or nothing, must proceed according to the order and
direction of the categories.
1. To the categories of quantity, that is, the conceptions of all,
many, and one, the conception which annihilates all, that is, the
conception of none, is opposed. And thus the object of a conception,
to which no intuition can be found to correspond, is = nothing. That
is, it is a conception without an object (ens rationis), like noumena,
which cannot be considered possible in the sphere of reality, though
they must not therefore be held to be impossible- or like certain
new fundamental forces in matter, the existence of which is
cogitable without contradiction, though, as examples from experience
are not forthcoming, they must not be regarded as possible.
2. Reality is something; negation is nothing, that is, a
conception of the absence of an object, as cold, a shadow (nihil
privativum).
3. The mere form of intuition, without substance, is in itself no
object, but the merely formal condition of an object (as
phenomenon), as pure space and pure time. These are certainly
something, as forms of intuition, but are not themselves objects which
are intuited (ens imaginarium).
4. The object of a conception which is self-contradictory, is
nothing, because the conception is nothing- is impossible, as a figure
composed of two straight lines (nihil negativum).
The table of this division of the conception of nothing (the
corresponding division of the conception of something does not require
special description) must therefore be arranged as follows:

NOTHING
AS

1
As Empty Conception
without object,
ens rationis
2 3
Empty object of Empty intuition
a conception, without object,
nihil privativum ens imaginarium
4
Empty object
without conception,
nihil negativum

We see that the ens rationis is distinguished from the nihil
negativum or pure nothing by the consideration that the former must
not be reckoned among possibilities, because it is a mere fiction-
though not self-contradictory, while the latter is completely
opposed to all possibility, inasmuch as the conception annihilates
itself. Both, however, are empty conceptions. On the other hand,
the nihil privativum and ens imaginarium are empty data for
conceptions. If light be not given to the senses, we cannot
represent to ourselves darkness, and if extended objects are not
perceived, we cannot represent space. Neither the negation, nor the
mere form of intuition can, without something real, be an object.
INTRO
TRANSCENDENTAL LOGIC. SECOND DIVISION.

TRANSCENDENTAL DIALECTIC. INTRODUCTION.

I. Of Transcendental Illusory Appearance.

We termed dialectic in general a logic of appearance. This does
not signify a doctrine of probability; for probability is truth,
only cognized upon insufficient grounds, and though the information it
gives us is imperfect, it is not therefore deceitful. Hence it must
not be separated from the analytical part of logic. Still less must
phenomenon and appearance be held to be identical. For truth or
illusory appearance does not reside in the object, in so far as it
is intuited, but in the judgement upon the object, in so far as it
is thought. It is, therefore, quite correct to say that the senses
do not err, not because they always judge correctly, but because
they do not judge at all. Hence truth and error, consequently also,
illusory appearance as the cause of error, are only to be found in a
judgement, that is, in the relation of an object to our understanding.
In a cognition which completely harmonizes with the laws of the
understanding, no error can exist. In a representation of the
senses- as not containing any judgement- there is also no error. But
no power of nature can of itself deviate from its own laws. Hence
neither the understanding per se (without the influence of another
cause), nor the senses per se, would fall into error; the former could
not, because, if it acts only according to its own laws, the effect
(the judgement) must necessarily accord with these laws. But in
accordance with the laws of the understanding consists the formal
element in all truth. In the senses there is no judgement- neither a
true nor a false one. But, as we have no source of cognition besides
these two, it follows that error is caused solely by the unobserved
influence of the sensibility upon the understanding. And thus it
happens that the subjective grounds of a judgement and are
confounded with the objective, and cause them to deviate from their
proper determination,* just as a body in motion would always of itself
proceed in a straight line, but if another impetus gives to it a
different direction, it will then start off into a curvilinear line of
motion. To distinguish the peculiar action of the understanding from
the power which mingles with it, it is necessary to consider an
erroneous judgement as the diagonal between two forces, that determine
the judgement in two different directions, which, as it were, form
an angle, and to resolve this composite operation into the simple ones
of the understanding and the sensibility. In pure a priori
judgements this must be done by means of transcendental reflection,
whereby, as has been already shown, each representation has its
place appointed in the corresponding faculty of cognition, and
consequently the influence of the one faculty upon the other is made
apparent.

*Sensibility, subjected to the understanding, as the object upon
which the understanding employs its functions, is the source of real
cognitions. But, in so far as it exercises an influence upon the
action of the understanding and determines it to judgement,
sensibility is itself the cause of error.

It is not at present our business to treat of empirical illusory
appearance (for example, optical illusion), which occurs in the
empirical application of otherwise correct rules of the understanding,
and in which the judgement is misled by the influence of
imagination. Our purpose is to speak of transcendental illusory
appearance, which influences principles- that are not even applied
to experience, for in this case we should possess a sure test of their
correctness- but which leads us, in disregard of all the warnings of
criticism, completely beyond the empirical employment of the
categories and deludes us with the chimera of an extension of the
sphere of the pure understanding. We shall term those principles the
application of which is confined entirely within the limits of
possible experience, immanent; those, on the other hand, which
transgress these limits, we shall call transcendent principles. But by
these latter I do not understand principles of the transcendental
use or misuse of the categories, which is in reality a mere fault of
the judgement when not under due restraint from criticism, and
therefore not paying sufficient attention to the limits of the
sphere in which the pure understanding is allowed to exercise its
functions; but real principles which exhort us to break down all those
barriers, and to lay claim to a perfectly new field of cognition,
which recognizes no line of demarcation. Thus transcendental and
transcendent are not identical terms. The principles of the pure
understanding, which we have already propounded, ought to be of
empirical and not of transcendental use, that is, they are not
applicable to any object beyond the sphere of experience. A
principle which removes these limits, nay, which authorizes us to
overstep them, is called transcendent. If our criticism can succeed in
exposing the illusion in these pretended principles, those which are
limited in their employment to the sphere of experience may be called,
in opposition to the others, immanent principles of the pure
understanding.
Logical illusion, which consists merely in the imitation of the form
of reason (the illusion in sophistical syllogisms), arises entirely
from a want of due attention to logical rules. So soon as the
attention is awakened to the case before us, this illusion totally
disappears. Transcendental illusion, on the contrary, does not cease
to exist, even after it has been exposed, and its nothingness
clearly perceived by means of transcendental criticism. Take, for
example, the illusion in the proposition: "The world must have a
beginning in time." The cause of this is as follows. In our reason,
subjectively considered as a faculty of human cognition, there exist
fundamental rules and maxims of its exercise, which have completely
the appearance of objective principles. Now from this cause it happens
that the subjective necessity of a certain connection of our
conceptions, is regarded as an objective necessity of the
determination of things in themselves. This illusion it is
impossible to avoid, just as we cannot avoid perceiving that the sea
appears to be higher at a distance than it is near the shore,
because we see the former by means of higher rays than the latter, or,
which is a still stronger case, as even the astronomer cannot
prevent himself from seeing the moon larger at its rising than some
time afterwards, although he is not deceived by this illusion.
Transcendental dialectic will therefore content itself with exposing
the illusory appearance in transcendental judgements, and guarding
us against it; but to make it, as in the case of logical illusion,
entirely disappear and cease to be illusion is utterly beyond its
power. For we have here to do with a natural and unavoidable illusion,
which rests upon subjective principles and imposes these upon us as
objective, while logical dialectic, in the detection of sophisms,
has to do merely with an error in the logical consequence of the
propositions, or with an artificially constructed illusion, in
imitation of the natural error. There is, therefore, a natural and
unavoidable dialectic of pure reason- not that in which the bungler,
from want of the requisite knowledge, involves himself, nor that which
the sophist devises for the purpose of misleading, but that which is
an inseparable adjunct of human reason, and which, even after its
illusions have been exposed, does not cease to deceive, and
continually to lead reason into momentary errors, which it becomes
necessary continually to remove.

II. Of Pure Reason as the Seat of Transcendental Illusory
Appearance.

A. OF REASON IN GENERAL.

All our knowledge begins with sense, proceeds thence to
understanding, and ends with reason, beyond which nothing higher can
be discovered in the human mind for elaborating the matter of
intuition and subjecting it to the highest unity of thought. At this
stage of our inquiry it is my duty to give an explanation of this, the
highest faculty of cognition, and I confess I find myself here in some
difficulty. Of reason, as of the understanding, there is a merely
formal, that is, logical use, in which it makes abstraction of all
content of cognition; but there is also a real use, inasmuch as it
contains in itself the source of certain conceptions and principles,
which it does not borrow either from the senses or the
understanding. The former faculty has been long defined by logicians
as the faculty of mediate conclusion in contradistinction to immediate
conclusions (consequentiae immediatae); but the nature of the
latter, which itself generates conceptions, is not to be understood
from this definition. Now as a division of reason into a logical and a
transcendental faculty presents itself here, it becomes necessary to
seek for a higher conception of this source of cognition which shall
comprehend both conceptions. In this we may expect, according to the
analogy of the conceptions of the understanding, that the logical
conception will give us the key to the transcendental, and that the
table of the functions of the former will present us with the clue
to the conceptions of reason.
In the former part of our transcendental logic, we defined the
understanding to be the faculty of rules; reason may be
distinguished from understanding as the faculty of principles.
The term principle is ambiguous, and commonly signifies merely a
cognition that may be employed as a principle, although it is not in
itself, and as regards its proper origin, entitled to the distinction.
Every general proposition, even if derived from experience by the
process of induction, may serve as the major in a syllogism; but it is
not for that reason a principle. Mathematical axioms (for example,
there can be only one straight line between two points) are general
a priori cognitions, and are therefore rightly denominated principles,
relatively to the cases which can be subsumed under them. But I cannot
for this reason say that I cognize this property of a straight line
from principles- I cognize it only in pure intuition.
Cognition from principles, then, is that cognition in which I
cognize the particular in the general by means of conceptions. Thus
every syllogism is a form of the deduction of a cognition from a
principle. For the major always gives a conception, through which
everything that is subsumed under the condition thereof is cognized
according to a principle. Now as every general cognition may serve
as the major in a syllogism, and the understanding presents us with
such general a priori propositions, they may be termed principles,
in respect of their possible use.
But if we consider these principles of the pure understanding in
relation to their origin, we shall find them to be anything rather
than cognitions from conceptions. For they would not even be
possible a priori, if we could not rely on the assistance of pure
intuition (in mathematics), or on that of the conditions of a possible
experience. That everything that happens has a cause, cannot be
concluded from the general conception of that which happens; on the
contrary the principle of causality instructs us as to the mode of
obtaining from that which happens a determinate empirical conception.
Synthetical cognitions from conceptions the understanding cannot
supply, and they alone are entitled to be called principles. At the
same time, all general propositions may be termed comparative
principles.
It has been a long-cherished wish- that (who knows how late), may
one day, be happily accomplished- that the principles of the endless
variety of civil laws should be investigated and exposed; for in
this way alone can we find the secret of simplifying legislation.
But in this case, laws are nothing more than limitations of our
freedom upon conditions under which it subsists in perfect harmony
with itself; they consequently have for their object that which is
completely our own work, and of which we ourselves may be the cause by
means of these conceptions. But how objects as things in themselves-
how the nature of things is subordinated to principles and is to be
determined. according to conceptions, is a question which it seems
well nigh impossible to answer. Be this, however, as it may- for on
this point our investigation is yet to be made- it is at least
manifest from what we have said that cognition from principles is
something very different from cognition by means of the understanding,
which may indeed precede other cognitions in the form of a
principle, but in itself- in so far as it is synthetical- is neither
based upon mere thought, nor contains a general proposition drawn from
conceptions alone shall comprehend
The understanding may be a faculty for the production of unity of
phenomena by virtue of rules; the reason is a faculty for the
production of unity of rules (of the understanding) under
principles. Reason, therefore, never applies directly to experience,
or to any sensuous object; its object is, on the contrary, the
understanding, to the manifold cognition of which it gives a unity a
priori by means of conceptions- a unity which may be called rational
unity, and which is of a nature very different from that of the
unity produced by the understanding.
The above is the general conception of the faculty of reason, in
so far as it has been possible to make it comprehensible in the
absence of examples. These will be given in the sequel.

B. OF THE LOGICAL USE OF REASON.

A distinction is commonly made between that which is immediately
cognized and that which is inferred or concluded. That in a figure
which is bounded by three straight lines there are three angles, is an
immediate cognition; but that these angles are together equal to two
right angles, is an inference or conclusion. Now, as we are constantly
employing this mode of thought and have thus become quite accustomed
to it, we no longer remark the above distinction, and, as in the
case of the so-called deceptions of sense, consider as immediately
perceived, what has really been inferred. In every reasoning or
syllogism, there is a fundamental proposition, afterwards a second
drawn from it, and finally the conclusion, which connects the truth in
the first with the truth in the second- and that infallibly. If the
judgement concluded is so contained in the first proposition that it
can be deduced from it without the meditation of a third notion, the
conclusion is called immediate (consequentia immediata); I prefer
the term conclusion of the understanding. But if, in addition to the
fundamental cognition, a second judgement is necessary for the
production of the conclusion, it is called a conclusion of the reason.
In the proposition: All men are mortal, are contained the
propositions: Some men are mortal, Nothing that is not mortal is a
man, and these are therefore immediate conclusions from the first.
On the other hand, the proposition: all the learned are mortal, is not
contained in the main proposition (for the conception of a learned man
does not occur in it), and it can be deduced from the main proposition
only by means of a mediating judgement.
In every syllogism I first cogitate a rule (the major) by means of
the understanding. In the next place I subsume a cognition under the
condition of the rule (and this is the minor) by means of the
judgement. And finally I determine my cognition by means of the
predicate of the rule (this is the conclusio), consequently, I
determine it a priori by means of the reason. The relations,
therefore, which the major proposition, as the rule, represents
between a cognition and its condition, constitute the different
kinds of syllogisms. These are just threefold- analogously with all
judgements, in so far as they differ in the mode of expressing the
relation of a cognition in the understanding- namely, categorical,
hypothetical, and disjunctive.
When as often happens, the conclusion is a judgement which may
follow from other given judgements, through which a perfectly
different object is cogitated, I endeavour to discover in the
understanding whether the assertion in this conclusion does not
stand under certain conditions according to a general rule. If I
find such a condition, and if the object mentioned in the conclusion
can be subsumed under the given condition, then this conclusion
follows from a rule which is also valid for other objects of
cognition. From this we see that reason endeavours to subject the
great variety of the cognitions of the understanding to the smallest
possible number of principles (general conditions), and thus to
produce in it the highest unity.

C. OF THE PURE USE OF REASON.

Can we isolate reason, and, if so, is it in this case a peculiar
source of conceptions and judgements which spring from it alone, and
through which it can be applied to objects; or is it merely a
subordinate faculty, whose duty it is to give a certain form to
given cognitions- a form which is called logical, and through which
the cognitions of the understanding are subordinated to each other,
and lower rules to higher (those, to wit, whose condition comprises in
its sphere the condition of the others), in so far as this can be done
by comparison? This is the question which we have at present to
answer. Manifold variety of rules and unity of principles is a
requirement of reason, for the purpose of bringing the understanding
into complete accordance with itself, just as understanding subjects
the manifold content of intuition to conceptions, and thereby
introduces connection into it. But this principle prescribes no law to
objects, and does not contain any ground of the possibility of
cognizing or of determining them as such, but is merely a subjective
law for the proper arrangement of the content of the understanding.
The purpose of this law is, by a comparison of the conceptions of
the understanding, to reduce them to the smallest possible number,
although, at the same time, it does not justify us in demanding from
objects themselves such a uniformity as might contribute to the
convenience and the enlargement of the sphere of the understanding, or
in expecting that it will itself thus receive from them objective
validity. In one word, the question is: "does reason in itself, that
is, does pure reason contain a priori synthetical principles and
rules, and what are those principles?"
The formal and logical procedure of reason in syllogisms gives us
sufficient information in regard to the ground on which the
transcendental principle of reason in its pure synthetical cognition
will rest.
1. Reason, as observed in the syllogistic process, is not applicable
to intuitions, for the purpose of subjecting them to rules- for this
is the province of the understanding with its categories- but to
conceptions and judgements. If pure reason does apply to objects and
the intuition of them, it does so not immediately, but mediately-
through the understanding and its judgements, which have a direct
relation to the senses and their intuition, for the purpose of
determining their objects. The unity of reason is therefore not the
unity of a possible experience, but is essentially different from this
unity, which is that of the understanding. That everything which
happens has a cause, is not a principle cognized and prescribed by
reason. This principle makes the unity of experience possible and
borrows nothing from reason, which, without a reference to possible
experience, could never have produced by means of mere conceptions any
such synthetical unity.
2. Reason, in its logical use, endeavours to discover the general
condition of its judgement (the conclusion), and a syllogism is itself
nothing but a judgement by means of the subsumption of its condition
under a general rule (the major). Now as this rule may itself be
subjected to the same process of reason, and thus the condition of the
condition be sought (by means of a prosyllogism) as long as the
process can be continued, it is very manifest that the peculiar
principle of reason in its logical use is to find for the
conditioned cognition of the understanding the unconditioned whereby
the unity of the former is completed.
But this logical maxim cannot be a principle of pure reason,
unless we admit that, if the conditioned is given, the whole series of
conditions subordinated to one another- a series which is consequently
itself unconditioned- is also given, that is, contained in the
object and its connection.
But this principle of pure reason is evidently synthetical; for,
analytically, the conditioned certainly relates to some condition, but
not to the unconditioned. From this principle also there must
originate different synthetical propositions, of which the pure
understanding is perfectly ignorant, for it has to do only with
objects of a possible experience, the cognition and synthesis of which
is always conditioned. The unconditioned, if it does really exist,
must be especially considered in regard to the determinations which
distinguish it from whatever is conditioned, and will thus afford us
material for many a priori synthetical propositions.
The principles resulting from this highest principle of pure
reason will, however, be transcendent in relation to phenomena, that
is to say, it will be impossible to make any adequate empirical use of
this principle. It is therefore completely different from all
principles of the understanding, the use made of which is entirely
immanent, their object and purpose being merely the possibility of
experience. Now our duty in the transcendental dialectic is as
follows. To discover whether the principle that the series of
conditions (in the synthesis of phenomena, or of thought in general)
extends to the unconditioned is objectively true, or not; what
consequences result therefrom affecting the empirical use of the
understanding, or rather whether there exists any such objectively
valid proposition of reason, and whether it is not, on the contrary, a
merely logical precept which directs us to ascend perpetually to still
higher conditions, to approach completeness in the series of them, and
thus to introduce into our cognition the highest possible unity of
reason. We must ascertain, I say, whether this requirement of reason
has not been regarded, by a misunderstanding, as a transcendental
principle of pure reason, which postulates a thorough completeness
in the series of conditions in objects themselves. We must show,
moreover, the misconceptions and illusions that intrude into
syllogisms, the major proposition of which pure reason has supplied- a
proposition which has perhaps more of the character of a petitio
than of a postulatum- and that proceed from experience upwards to
its conditions. The solution of these problems is our task in
transcendental dialectic, which we are about to expose even at its
source, that lies deep in human reason. We shall divide it into two
parts, the first of which will treat of the transcendent conceptions
of pure reason, the second of transcendent and dialectical syllogisms.
BOOK I.

OF THE CONCEPTIONS OF PURE REASON.

The conceptions of pure reason- we do not here speak of the
possibility of them- are not obtained by reflection, but by
inference or conclusion. The conceptions of understanding are also
cogitated a priori antecedently to experience, and render it possible;
but they contain nothing but the unity of reflection upon phenomena,
in so far as these must necessarily belong to a possible empirical
consciousness. Through them alone are cognition and the
determination of an object possible. It is from them, accordingly,
that we receive material for reasoning, and antecedently to them we
possess no a priori conceptions of objects from which they might be
deduced, On the other hand, the sole basis of their objective
reality consists in the necessity imposed on them, as containing the
intellectual form of all experience, of restricting their
application and influence to the sphere of experience.
But the term, conception of reason, or rational conception, itself
indicates that it does not confine itself within the limits of
experience, because its object-matter is a cognition, of which every
empirical cognition is but a part- nay, the whole of possible
experience may be itself but a part of it- a cognition to which no
actual experience ever fully attains, although it does always
pertain to it. The aim of rational conceptions is the comprehension,
as that of the conceptions of understanding is the understanding of
perceptions. If they contain the unconditioned, they relate to that to
which all experience is subordinate, but which is never itself an
object of experience- that towards which reason tends in all its
conclusions from experience, and by the standard of which it estimates
the degree of their empirical use, but which is never itself an
element in an empirical synthesis. If, notwithstanding, such
conceptions possess objective validity, they may be called conceptus
ratiocinati (conceptions legitimately concluded); in cases where
they do not, they have been admitted on account of having the
appearance of being correctly concluded, and may be called conceptus
ratiocinantes (sophistical conceptions). But as this can only be
sufficiently demonstrated in that part of our treatise which relates
to the dialectical conclusions of reason, we shall omit any
consideration of it in this place. As we called the pure conceptions
of the understanding categories, we shall also distinguish those of
pure reason by a new name and call them transcendental ideas. These
terms, however, we must in the first place explain and justify.

SECTION I - Of Ideas in General.

Despite the great wealth of words which European languages
possess, the thinker finds himself often at a loss for an expression
exactly suited to his conception, for want of which he is unable to
make himself intelligible either to others or to himself. To coin
new words is a pretension to legislation in language which is seldom
successful; and, before recourse is taken to so desperate an
expedient, it is advisable to examine the dead and learned
languages, with the hope and the probability that we may there meet
with some adequate expression of the notion we have in our minds. In
this case, even if the original meaning of the word has become
somewhat uncertain, from carelessness or want of caution on the part
of the authors of it, it is always better to adhere to and confirm its
proper meaning- even although it may be doubtful whether it was
formerly used in exactly this sense- than to make our labour vain by
want of sufficient care to render ourselves intelligible.
For this reason, when it happens that there exists only a single
word to express a certain conception, and this word, in its usual
acceptation, is thoroughly adequate to the conception, the accurate
distinction of which from related conceptions is of great
importance, we ought not to employ the expression improvidently, or,
for the sake of variety and elegance of style, use it as a synonym for
other cognate words. It is our duty, on the contrary, carefully to
preserve its peculiar signification, as otherwise it easily happens
that when the attention of the reader is no longer particularly
attracted to the expression, and it is lost amid the multitude of
other words of very different import, the thought which it conveyed,
and which it alone conveyed, is lost with it.
Plato employed the expression idea in a way that plainly showed he
meant by it something which is never derived from the senses, but
which far transcends even the conceptions of the understanding (with
which Aristotle occupied himself), inasmuch as in experience nothing
perfectly corresponding to them could be found. Ideas are, according
to him, archetypes of things themselves, and not merely keys to
possible experiences, like the categories. In his view they flow
from the highest reason, by which they have been imparted to human
reason, which, however, exists no longer in its original state, but is
obliged with great labour to recall by reminiscence- which is called
philosophy- the old but now sadly obscured ideas. I will not here
enter upon any literary investigation of the sense which this
sublime philosopher attached to this expression. I shall content
myself with remarking that it is nothing unusual, in common
conversation as well as in written works, by comparing the thoughts
which an author has delivered upon a subject, to understand him better
than he understood himself inasmuch as he may not have sufficiently
determined his conception, and thus have sometimes spoken, nay even
thought, in opposition to his own opinions.
Plato perceived very clearly that our faculty of cognition has the
feeling of a much higher vocation than that of merely spelling out
phenomena according to synthetical unity, for the purpose of being
able to read them as experience, and that our reason naturally
raises itself to cognitions far too elevated to admit of the
possibility of an object given by experience corresponding to them-
cognitions which are nevertheless real, and are not mere phantoms of
the brain.
This philosopher found his ideas especially in all that is
practical,* that is, which rests upon freedom, which in its turn ranks
under cognitions that are the peculiar product of reason. He who would
derive from experience the conceptions of virtue, who would make (as
many have really done) that, which at best can but serve as an
imperfectly illustrative example, a model for or the formation of a
perfectly adequate idea on the subject, would in fact transform virtue
into a nonentity changeable according to time and circumstance and
utterly incapable of being employed as a rule. On the contrary,
every one is conscious that, when any one is held up to him as a model
of virtue, he compares this so-called model with the true original
which he possesses in his own mind and values him according to this
standard. But this standard is the idea of virtue, in relation to
which all possible objects of experience are indeed serviceable as
examples- proofs of the practicability in a certain degree of that
which the conception of virtue demands- but certainly not as
archetypes. That the actions of man will never be in perfect
accordance with all the requirements of the pure ideas of reason, does
not prove the thought to be chimerical. For only through this idea are
all judgements as to moral merit or demerit possible; it
consequently lies at the foundation of every approach to moral
perfection, however far removed from it the obstacles in human nature-
indeterminable as to degree- may keep us.

*He certainly extended the application of his conception to
speculative cognitions also, provided they were given pure and
completely a priori, nay, even to mathematics, although this science
cannot possess an object otherwhere than in Possible experience. I
cannot follow him in this, and as little can I follow him in his
mystical deduction of these ideas, or in his hypostatization of
them; although, in truth, the elevated and exaggerated language
which he employed in describing them is quite capable of an
interpretation more subdued and more in accordance with fact and the
nature of things.

The Platonic Republic has become proverbial as an example- and a
striking one- of imaginary perfection, such as can exist only in the
brain of the idle thinker; and Brucker ridicules the philosopher for
maintaining that a prince can never govern well, unless he is
participant in the ideas. But we should do better to follow up this
thought and, where this admirable thinker leaves us without
assistance, employ new efforts to place it in clearer light, rather
than carelessly fling it aside as useless, under the very miserable
and pernicious pretext of impracticability. A constitution of the
greatest possible human freedom according to laws, by which the
liberty of every individual can consist with the liberty of every
other (not of the greatest possible happiness, for this follows
necessarily from the former), is, to say the least, a necessary
idea, which must be placed at the foundation not only of the first
plan of the constitution of a state, but of all its laws. And, in
this, it not necessary at the outset to take account of the
obstacles which lie in our way- obstacles which perhaps do not
necessarily arise from the character of human nature, but rather
from the previous neglect of true ideas in legislation. For there is
nothing more pernicious and more unworthy of a philosopher, than the
vulgar appeal to a so-called adverse experience, which indeed would
not have existed, if those institutions had been established at the
proper time and in accordance with ideas; while, instead of this,
conceptions, crude for the very reason that they have been drawn
from experience, have marred and frustrated all our better views and
intentions. The more legislation and government are in harmony with
this idea, the more rare do punishments become and thus it is quite
reasonable to maintain, as Plato did, that in a perfect state no
punishments at all would be necessary. Now although a perfect state
may never exist, the idea is not on that account the less just,
which holds up this maximum as the archetype or standard of a
constitution, in order to bring legislative government always nearer
and nearer to the greatest possible perfection. For at what precise
degree human nature must stop in its progress, and how wide must be
the chasm which must necessarily exist between the idea and its
realization, are problems which no one can or ought to determine-
and for this reason, that it is the destination of freedom to overstep
all assigned limits between itself and the idea.
But not only in that wherein human reason is a real causal agent and
where ideas are operative causes (of actions and their objects),
that is to say, in the region of ethics, but also in regard to
nature herself, Plato saw clear proofs of an origin from ideas. A
plant, and animal, the regular order of nature- probably also the
disposition of the whole universe- give manifest evidence that they
are possible only by means of and according to ideas; that, indeed, no
one creature, under the individual conditions of its existence,
perfectly harmonizes with the idea of the most perfect of its kind-
just as little as man with the idea of humanity, which nevertheless he
bears in his soul as the archetypal standard of his actions; that,
notwithstanding, these ideas are in the highest sense individually,
unchangeably, and completely determined, and are the original causes
of things; and that the totality of connected objects in the
universe is alone fully adequate to that idea. Setting aside the
exaggerations of expression in the writings of this philosopher, the
mental power exhibited in this ascent from the ectypal mode of
regarding the physical world to the architectonic connection thereof
according to ends, that is, ideas, is an effort which deserves
imitation and claims respect. But as regards the principles of ethics,
of legislation, and of religion, spheres in which ideas alone render
experience possible, although they never attain to full expression
therein, he has vindicated for himself a position of peculiar merit,
which is not appreciated only because it is judged by the very
empirical rules, the validity of which as principles is destroyed by
ideas. For as regards nature, experience presents us with rules and is
the source of truth, but in relation to ethical laws experience is the
parent of illusion, and it is in the highest degree reprehensible to
limit or to deduce the laws which dictate what I ought to do, from
what is done.
We must, however, omit the consideration of these important
subjects, the development of which is in reality the peculiar duty and
dignity of philosophy, and confine ourselves for the present to the
more humble but not less useful task of preparing a firm foundation
for those majestic edifices of moral science. For this foundation
has been hitherto insecure from the many subterranean passages which
reason in its confident but vain search for treasures has made in
all directions. Our present duty is to make ourselves perfectly
acquainted with the transcendental use made of pure reason, its
principles and ideas, that we may be able properly to determine and
value its influence and real worth. But before bringing these
introductory remarks to a close, I beg those who really have
philosophy at heart- and their number is but small- if they shall find
themselves convinced by the considerations following as well as by
those above, to exert themselves to preserve to the expression idea
its original signification, and to take care that it be not lost among
those other expressions by which all sorts of representations are
loosely designated- that the interests of science may not thereby
suffer. We are in no want of words to denominate adequately every mode
of representation, without the necessity of encroaching upon terms
which are proper to others. The following is a graduated list of them.
The genus is representation in general (representation. Under it
stands representation with consciousness (perceptio). A perception
which relates solely to the subject as a modification of its state, is
a sensation (sensatio), an objective perception is a cognition
(cognitio). A cognition is either an intuition or a conception
(intuitus vel conceptus). The former has an immediate relation to
the object and is singular and individual; the latter has but a
mediate relation, by means of a characteristic mark which may be
common to several things. A conception is either empirical or pure.
A pure conception, in so far as it has its origin in the understanding
alone, and is not the conception of a pure sensuous image, is called
notio. A conception formed from notions, which transcends the
possibility of experience, is an idea, or a conception of reason. To
one who has accustomed himself to these distinctions, it must be quite
intolerable to hear the representation of the colour red called an
idea. It ought not even to be called a notion or conception of
understanding.

SECTION II. Of Transcendental Ideas.

Transcendental analytic showed us how the mere logical form of our
cognition can contain the origin of pure conceptions a priori,
conceptions which represent objects antecedently to all experience, or
rather, indicate the synthetical unity which alone renders possible an
empirical cognition of objects. The form of judgements- converted into
a conception of the synthesis of intuitions- produced the categories
which direct the employment of the understanding in experience. This
consideration warrants us to expect that the form of syllogisms,
when applied to synthetical unity of intuitions, following the rule of
the categories, will contain the origin of particular a priori
conceptions, which we may call pure conceptions of reason or
transcendental ideas, and which will determine the use of the
understanding in the totality of experience according to principles.
The function of reason in arguments consists in the universality
of a cognition according to conceptions, and the syllogism itself is a
judgement which is determined a priori in the whole extent of its
condition. The proposition: "Caius is mortal," is one which may be
obtained from experience by the aid of the understanding alone; but my
wish is to find a conception which contains the condition under
which the predicate of this judgement is given- in this case, the
conception of man- and after subsuming under this condition, taken
in its whole extent (all men are mortal), I determine according to
it the cognition of the object thought, and say: "Caius is mortal."
Hence, in the conclusion of a syllogism we restrict a predicate to a
certain object, after having thought it in the major in its whole
extent under a certain condition. This complete quantity of the extent
in relation to such a condition is called universality
(universalitas). To this corresponds totality (universitas) of
conditions in the synthesis of intuitions. The transcendental
conception of reason is therefore nothing else than the conception
of the totality of the conditions of a given conditioned. Now as the
unconditioned alone renders possible totality of conditions, and,
conversely, the totality of conditions is itself always unconditioned;
a pure rational conception in general can be defined and explained
by means of the conception of the unconditioned, in so far as it
contains a basis for the synthesis of the conditioned.
To the number of modes of relation which the understanding cogitates
by means of the categories, the number of pure rational conceptions
will correspond. We must therefore seek for, first, an unconditioned
of the categorical synthesis in a subject; secondly, of the
hypothetical synthesis of the members of a series; thirdly, of the
disjunctive synthesis of parts in a system.
There are exactly the same number of modes of syllogisms, each of
which proceeds through prosyllogisms to the unconditioned- one to
the subject which cannot be employed as predicate, another to the
presupposition which supposes nothing higher than itself, and the
third to an aggregate of the members of the complete division of a
conception. Hence the pure rational conceptions of totality in the
synthesis of conditions have a necessary foundation in the nature of
human reason- at least as modes of elevating the unity of the
understanding to the unconditioned. They may have no valid
application, corresponding to their transcendental employment, in
concreto, and be thus of no greater utility than to direct the
understanding how, while extending them as widely as possible, to
maintain its exercise and application in perfect consistence and
harmony.
But, while speaking here of the totality of conditions and of the
unconditioned as the common title of all conceptions of reason, we
again light upon an expression which we find it impossible to dispense
with, and which nevertheless, owing to the ambiguity attaching to it
from long abuse, we cannot employ with safety. The word absolute is
one of the few words which, in its original signification, was
perfectly adequate to the conception it was intended to convey- a
conception which no other word in the same language exactly suits, and
the loss- or, which is the same thing, the incautious and loose
employment- of which must be followed by the loss of the conception
itself. And, as it is a conception which occupies much of the
attention of reason, its loss would be greatly to the detriment of all
transcendental philosophy. The word absolute is at present
frequently used to denote that something can be predicated of a
thing considered in itself and intrinsically. In this sense absolutely
possible would signify that which is possible in itself (interne)-
which is, in fact, the least that one can predicate of an object. On
the other hand, it is sometimes employed to indicate that a thing is
valid in all respects- for example, absolute sovereignty. Absolutely
possible would in this sense signify that which is possible in all
relations and in every respect; and this is the most that can be
predicated of the possibility of a thing. Now these significations
do in truth frequently coincide. Thus, for example, that which is
intrinsically impossible, is also impossible in all relations, that
is, absolutely impossible. But in most cases they differ from each
other toto caelo, and I can by no means conclude that, because a thing
is in itself possible, it is also possible in all relations, and
therefore absolutely. Nay, more, I shall in the sequel show that
absolute necessity does not by any means depend on internal necessity,
and that, therefore, it must not be considered as synonymous with
it. Of an opposite which is intrinsically impossible, we may affirm
that it is in all respects impossible, and that, consequently, the
thing itself, of which this is the opposite, is absolutely
necessary; but I cannot reason conversely and say, the opposite of
that which is absolutely necessary is intrinsically impossible, that
is, that the absolute necessity of things is an internal necessity.
For this internal necessity is in certain cases a mere empty word with
which the least conception cannot be connected, while the conception
of the necessity of a thing in all relations possesses very peculiar
determinations. Now as the loss of a conception of great utility in
speculative science cannot be a matter of indifference to the
philosopher, I trust that the proper determination and careful
preservation of the expression on which the conception depends will
likewise be not indifferent to him.
In this enlarged signification, then, shall I employ the word
absolute, in opposition to that which is valid only in some particular
respect; for the latter is restricted by conditions, the former is
valid without any restriction whatever.
Now the transcendental conception of reason has for its object
nothing else than absolute totality in the synthesis of conditions and
does not rest satisfied till it has attained to the absolutely, that
is, in all respects and relations, unconditioned. For pure reason
leaves to the understanding everything that immediately relates to the
object of intuition or rather to their synthesis in imagination. The
former restricts itself to the absolute totality in the employment
of the conceptions of the understanding and aims at carrying out the
synthetical unity which is cogitated in the category, even to the
unconditioned. This unity may hence be called the rational unity of
phenomena, as the other, which the category expresses, may be termed
the unity of the understanding. Reason, therefore, has an immediate
relation to the use of the understanding, not indeed in so far as
the latter contains the ground of possible experience (for the
conception of the absolute totality of conditions is not a
conception that can be employed in experience, because no experience
is unconditioned), but solely for the purpose of directing it to a
certain unity, of which the understanding has no conception, and the
aim of which is to collect into an absolute whole all acts of the
understanding. Hence the objective employment of the pure
conceptions of reason is always transcendent, while that of the pure
conceptions of the understanding must, according to their nature, be
always immanent, inasmuch as they are limited to possible experience.
I understand by idea a necessary conception of reason, to which no
corresponding object can be discovered in the world of sense.
Accordingly, the pure conceptions of reason at present under
consideration are transcendental ideas. They are conceptions of pure
reason, for they regard all empirical cognition as determined by means
of an absolute totality of conditions. They are not mere fictions, but
natural and necessary products of reason, and have hence a necessary
relation to the whole sphere of the exercise of the understanding.
And, finally, they are transcendent, and overstep the limits of all
experiences, in which, consequently, no object can ever be presented
that would be perfectly adequate to a transcendental idea. When we use
the word idea, we say, as regards its object (an object of the pure
understanding), a great deal, but as regards its subject (that is,
in respect of its reality under conditions of experience), exceedingly
little, because the idea, as the conception of a maximum, can never be
completely and adequately presented in concreto. Now, as in the merely
speculative employment of reason the latter is properly the sole
aim, and as in this case the approximation to a conception, which is
never attained in practice, is the same thing as if the conception
were non-existent- it is commonly said of the conception of this kind,
"it is only an idea." So we might very well say, "the absolute
totality of all phenomena is only an idea," for, as we never can
present an adequate representation of it, it remains for us a
problem incapable of solution. On the other hand, as in the
practical use of the understanding we have only to do with action
and practice according to rules, an idea of pure reason can always
be given really in concreto, although only partially, nay, it is the
indispensable condition of all practical employment of reason. The
practice or execution of the idea is always limited and defective, but
nevertheless within indeterminable boundaries, consequently always
under the influence of the conception of an absolute perfection. And
thus the practical idea is always in the highest degree fruitful,
and in relation to real actions indispensably necessary. In the
idea, pure reason possesses even causality and the power of
producing that which its conception contains. Hence we cannot say of
wisdom, in a disparaging way, "it is only an idea." For, for the
very reason that it is the idea of the necessary unity of all possible
aims, it must be for all practical exertions and endeavours the
primitive condition and rule- a rule which, if not constitutive, is at
least limitative.
Now, although we must say of the transcendental conceptions of
reason, "they are only ideas," we must not, on this account, look upon
them as superfluous and nugatory. For, although no object can be
determined by them, they can be of great utility, unobserved and at
the basis of the edifice of the understanding, as the canon for its
extended and self-consistent exercise- a canon which, indeed, does not
enable it to cognize more in an object than it would cognize by the
help of its own conceptions, but which guides it more securely in
its cognition. Not to mention that they perhaps render possible a
transition from our conceptions of nature and the non-ego to the
practical conceptions, and thus produce for even ethical ideas
keeping, so to speak, and connection with the speculative cognitions
of reason. The explication of all this must be looked for in the
sequel.
But setting aside, in conformity with our original purpose, the
consideration of the practical ideas, we proceed to contemplate reason
in its speculative use alone, nay, in a still more restricted
sphere, to wit, in the transcendental use; and here must strike into
the same path which we followed in our deduction of the categories.
That is to say, we shall consider the logical form of the cognition of
reason, that we may see whether reason may not be thereby a source
of conceptions which enables us to regard objects in themselves as
determined synthetically a priori, in relation to one or other of
the functions of reason.
Reason, considered as the faculty of a certain logical form of
cognition, is the faculty of conclusion, that is, of mediate
judgement- by means of the subsumption of the condition of a
possible judgement under the condition of a given judgement. The given
judgement is the general rule (major). The subsumption of the
condition of another possible judgement under the condition of the
rule is the minor. The actual judgement, which enounces the
assertion of the rule in the subsumed case, is the conclusion
(conclusio). The rule predicates something generally under a certain
condition. The condition of the rule is satisfied in some particular
case. It follows that what was valid in general under that condition
must also be considered as valid in the particular case which
satisfies this condition. It is very plain that reason attains to a
cognition, by means of acts of the understanding which constitute a
series of conditions. When I arrive at the proposition, "All bodies
are changeable," by beginning with the more remote cognition (in which
the conception of body does not appear, but which nevertheless
contains the condition of that conception), "All compound is
changeable," by proceeding from this to a less remote cognition, which
stands under the condition of the former, "Bodies are compound," and
hence to a third, which at length connects for me the remote cognition
(changeable) with the one before me, "Consequently, bodies are
changeable"- I have arrived at a cognition (conclusion) through a
series of conditions (premisses). Now every series, whose exponent (of
the categorical or hypothetical judgement) is given, can be continued;
consequently the same procedure of reason conducts us to the
ratiocinatio polysyllogistica, which is a series of syllogisms, that
can be continued either on the side of the conditions (per
prosyllogismos) or of the conditioned (per episyllogismos) to an
indefinite extent.
But we very soon perceive that the chain or series of prosyllogisms,
that is, of deduced cognitions on the side of the grounds or
conditions of a given cognition, in other words, the ascending
series of syllogisms must have a very different relation to the
faculty of reason from that of the descending series, that is, the
progressive procedure of reason on the side of the conditioned by
means of episyllogisms. For, as in the former case the cognition
(conclusio) is given only as conditioned, reason can attain to this
cognition only under the presupposition that all the members of the
series on the side of the conditions are given (totality in the series
of premisses), because only under this supposition is the judgement we
may be considering possible a priori; while on the side of the
conditioned or the inferences, only an incomplete and becoming, and
not a presupposed or given series, consequently only a potential
progression, is cogitated. Hence, when a cognition is contemplated
as conditioned, reason is compelled to consider the series of
conditions in an ascending line as completed and given in their
totality. But if the very same condition is considered at the same
time as the condition of other cognitions, which together constitute a
series of inferences or consequences in a descending line, reason
may preserve a perfect indifference, as to how far this progression
may extend a parte posteriori, and whether the totality of this series
is possible, because it stands in no need of such a series for the
purpose of arriving at the conclusion before it, inasmuch as this
conclusion is sufficiently guaranteed and determined on grounds a
parte priori. It may be the case, that upon the side of the conditions
the series of premisses has a first or highest condition, or it may
not possess this, and so be a parte priori unlimited; but it must,
nevertheless, contain totality of conditions, even admitting that we
never could succeed in completely apprehending it; and the whole
series must be unconditionally true, if the conditioned, which is
considered as an inference resulting from it, is to be held as true.
This is a requirement of reason, which announces its cognition as
determined a priori and as necessary, either in itself- and in this
case it needs no grounds to rest upon- or, if it is deduced, as a
member of a series of grounds, which is itself unconditionally true.

SECTION III. System of Transcendental Ideas.

We are not at present engaged with a logical dialectic, which
makes complete abstraction of the content of cognition and aims only
at unveiling the illusory appearance in the form of syllogisms. Our
subject is transcendental dialectic, which must contain, completely
a priori, the origin of certain cognitions drawn from pure reason, and
the origin of certain deduced conceptions, the object of which
cannot be given empirically and which therefore lie beyond the
sphere of the faculty of understanding. We have observed, from the
natural relation which the transcendental use of our cognition, in
syllogisms as well as in judgements, must have to the logical, that
there are three kinds of dialectical arguments, corresponding to the
three modes of conclusion, by which reason attains to cognitions on
principles; and that in all it is the business of reason to ascend
from the conditioned synthesis, beyond which the understanding never
proceeds, to the unconditioned which the understanding never can
reach.
Now the most general relations which can exist in our
representations are: 1st, the relation to the subject; 2nd, the
relation to objects, either as phenomena, or as objects of thought
in general. If we connect this subdivision with the main division, all
the relations of our representations, of which we can form either a
conception or an idea, are threefold: 1. The relation to the
subject; 2. The relation to the manifold of the object as a
phenomenon; 3. The relation to all things in general.
Now all pure conceptions have to do in general with the
synthetical unity of representations; conceptions of pure reason
(transcendental ideas), on the other hand, with the unconditional
synthetical unity of all conditions. It follows that all
transcendental ideas arrange themselves in three classes, the first of
which contains the absolute (unconditioned) unity of the thinking
subject, the second the absolute unity of the series of the conditions
of a phenomenon, the third the absolute unity of the condition of
all objects of thought in general.
The thinking subject is the object-matter of Psychology; the sum
total of all phenomena (the world) is the object-matter of
Cosmology; and the thing which contains the highest condition of the
possibility of all that is cogitable (the being of all beings) is
the object-matter of all Theology. Thus pure reason presents us with
the idea of a transcendental doctrine of the soul (psychologia
rationalis), of a transcendental science of the world (cosmologia
rationalis), and finally of a transcendental doctrine of God
(theologia transcendentalis). Understanding cannot originate even
the outline of any of these sciences, even when connected with the
highest logical use of reason, that is, all cogitable syllogisms-
for the purpose of proceeding from one object (phenomenon) to all
others, even to the utmost limits of the empirical synthesis. They
are, on the contrary, pure and genuine products, or problems, of
pure reason.
What modi of the pure conceptions of reason these transcendental
ideas are will be fully exposed in the following chapter. They
follow the guiding thread of the categories. For pure reason never
relates immediately to objects, but to the conceptions of these
contained in the understanding. In like manner, it will be made
manifest in the detailed explanation of these ideas- how reason,
merely through the synthetical use of the same function which it
employs in a categorical syllogism, necessarily attains to the
conception of the absolute unity of the thinking subject- how the
logical procedure in hypothetical ideas necessarily produces the
idea of the absolutely unconditioned in a series of given
conditions, and finally- how the mere form of the disjunctive
syllogism involves the highest conception of a being of all beings:
a thought which at first sight seems in the highest degree
paradoxical.
An objective deduction, such as we were able to present in the
case of the categories, is impossible as regards these
transcendental ideas. For they have, in truth, no relation to any
object, in experience, for the very reason that they are only ideas.
But a subjective deduction of them from the nature of our reason is
possible, and has been given in the present chapter.
It is easy to perceive that the sole aim of pure reason is the
absolute totality of the synthesis on the side of the conditions,
and that it does not concern itself with the absolute completeness
on the Part of the conditioned. For of the former alone does she stand
in need, in order to preposit the whole series of conditions, and thus
present them to the understanding a priori. But if we once have a
completely (and unconditionally) given condition, there is no
further necessity, in proceeding with the series, for a conception
of reason; for the understanding takes of itself every step
downward, from the condition to the conditioned. Thus the
transcendental ideas are available only for ascending in the series of
conditions, till we reach the unconditioned, that is, principles. As
regards descending to the conditioned, on the other hand, we find that
there is a widely extensive logical use which reason makes of the laws
of the understanding, but that a transcendental use thereof is
impossible; and that when we form an idea of the absolute totality
of such a synthesis, for example, of the whole series of all future
changes in the world, this idea is a mere ens rationis, an arbitrary
fiction of thought, and not a necessary presupposition of reason.
For the possibility of the conditioned presupposes the totality of its
conditions, but not of its consequences. Consequently, this conception
is not a transcendental idea- and it is with these alone that we are
at present occupied.
Finally, it is obvious that there exists among the transcendental
ideas a certain connection and unity, and that pure reason, by means
of them, collects all its cognitions into one system. From the
cognition of self to the cognition of the world, and through these
to the supreme being, the progression is so natural, that it seems
to resemble the logical march of reason from the premisses to the
conclusion.* Now whether there lies unobserved at the foundation of
these ideas an analogy of the same kind as exists between the
logical and transcendental procedure of reason, is another of those
questions, the answer to which we must not expect till we arrive at
a more advanced stage in our inquiries. In this cursory and
preliminary view, we have, meanwhile, reached our aim. For we have
dispelled the ambiguity which attached to the transcendental
conceptions of reason, from their being commonly mixed up with other
conceptions in the systems of philosophers, and not properly
distinguished from the conceptions of the understanding; we have
exposed their origin and, thereby, at the same time their
determinate number, and presented them in a systematic connection, and
have thus marked out and enclosed a definite sphere for pure reason.

*The science of Metaphysics has for the proper object of its
inquiries only three grand ideas: GOD, FREEDOM, and IMMORTALITY, and
it aims at showing, that the second conception, conjoined with the
first, must lead to the third, as a necessary conclusion. All the
other subjects with which it occupies itself, are merely means for the
attainment and realization of these ideas. It does not require these
ideas for the construction of a science of nature, but, on the
contrary, for the purpose of passing beyond the sphere of nature. A
complete insight into and comprehension of them would render Theology,
Ethics, and, through the conjunction of both, Religion, solely
dependent on the speculative faculty of reason. In a systematic
representation of these ideas the above-mentioned arrangement- the
synthetical one- would be the most suitable; but in the
investigation which must necessarily precede it, the analytical, which
reverses this arrangement, would be better adapted to our purpose,
as in it we should proceed from that which experience immediately
presents to us- psychology, to cosmology, and thence to theology.
BOOK II.

OF THE DIALECTICAL PROCEDURE OF PURE REASON.

It may be said that the object of a merely transcendental idea is
something of which we have no conception, although the idea may be a
necessary product of reason according to its original laws. For, in
fact, a conception of an object that is adequate to the idea given
by reason, is impossible. For such an object must be capable of
being presented and intuited in a Possible experience. But we should
express our meaning better, and with less risk of being misunderstood,
if we said that we can have no knowledge of an object, which perfectly
corresponds to an idea, although we may possess a problematical
conception thereof.
Now the transcendental (subjective) reality at least of the pure
conceptions of reason rests upon the fact that we are led to such
ideas by a necessary procedure of reason. There must therefore be
syllogisms which contain no empirical premisses, and by means of which
we conclude from something that we do know, to something of which we
do not even possess a conception, to which we, nevertheless, by an
unavoidable illusion, ascribe objective reality. Such arguments are,
as regards their result, rather to be termed sophisms than syllogisms,
although indeed, as regards their origin, they are very well
entitled to the latter name, inasmuch as they are not fictions or
accidental products of reason, but are necessitated by its very
nature. They are sophisms, not of men, but of pure reason herself,
from which the Wisest cannot free himself. After long labour he may be
able to guard against the error, but he can never be thoroughly rid of
the illusion which continually mocks and misleads him.
Of these dialectical arguments there are three kinds,
corresponding to the number of the ideas which their conclusions
present. In the argument or syllogism of the first class, I
conclude, from the transcendental conception of the subject contains
no manifold, the absolute unity of the subject itself, of which I
cannot in this manner attain to a conception. This dialectical
argument I shall call the transcendental paralogism. The second
class of sophistical arguments is occupied with the transcendental
conception of the absolute totality of the series of conditions for
a given phenomenon, and I conclude, from the fact that I have always a
self-contradictory conception of the unconditioned synthetical unity
of the series upon one side, the truth of the opposite unity, of which
I have nevertheless no conception. The condition of reason in these
dialectical arguments, I shall term the antinomy of pure reason.
Finally, according to the third kind of sophistical argument, I
conclude, from the totality of the conditions of thinking objects in
general, in so far as they can be given, the absolute synthetical
unity of all conditions of the possibility of things in general;
that is, from things which I do not know in their mere
transcendental conception, I conclude a being of all beings which I
know still less by means of a transcendental conception, and of
whose unconditioned necessity I can form no conception whatever.
This dialectical argument I shall call the ideal of pure reason.
CHAPTER I. Of the Paralogisms of Pure Reason.

The logical paralogism consists in the falsity of an argument in
respect of its form, be the content what it may. But a
transcendental paralogism has a transcendental foundation, and
concludes falsely, while the form is correct and unexceptionable. In
this manner the paralogism has its foundation in the nature of human
reason, and is the parent of an unavoidable, though not insoluble,
mental illusion.
We now come to a conception which was not inserted in the general
list of transcendental conceptions. and yet must be reckoned with
them, but at the same time without in the least altering, or
indicating a deficiency in that table. This is the conception, or,
if the term is preferred, the judgement, "I think." But it is
readily perceived that this thought is as it were the vehicle of all
conceptions in general, and consequently of transcendental conceptions
also, and that it is therefore regarded as a transcendental
conception, although it can have no peculiar claim to be so ranked,
inasmuch as its only use is to indicate that all thought is
accompanied by consciousness. At the same time, pure as this
conception is from empirical content (impressions of the senses), it
enables us to distinguish two different kinds of objects. "I," as
thinking, am an object of the internal sense, and am called soul. That
which is an object of the external senses is called body. Thus the
expression, "I," as a thinking being, designates the object-matter
of psychology, which may be called "the rational doctrine of the
soul," inasmuch as in this science I desire to know nothing of the
soul but what, independently of all experience (which determines me in
concreto), may be concluded from this conception "I," in so far as
it appears in all thought.
Now, the rational doctrine of the soul is really an undertaking of
this kind. For if the smallest empirical element of thought, if any
particular perception of my internal state, were to be introduced
among the grounds of cognition of this science, it would not be a
rational, but an empirical doctrine of the soul. We have thus before
us a pretended science, raised upon the single proposition, "I think,"
whose foundation or want of foundation we may very properly, and
agreeably with the nature of a transcendental philosophy, here
examine. It ought not to be objected that in this proposition, which
expresses the perception of one's self, an internal experience is
asserted, and that consequently the rational doctrine of the soul
which is founded upon it, is not pure, but partly founded upon an
empirical principle. For this internal perception is nothing more than
the mere apperception, "I think," which in fact renders all
transcendental conceptions possible, in which we say, "I think
substance, cause, etc." For internal experience in general and its
possibility, or perception in general, and its relation to other
perceptions, unless some particular distinction or determination
thereof is empirically given, cannot be regarded as empirical
cognition, but as cognition of the empirical, and belongs to the
investigation of the possibility of every experience, which is
certainly transcendental. The smallest object of experience (for
example, only pleasure or pain), that should be included in the
general representation of self-consciousness, would immediately change
the rational into an empirical psychology.
"I think" is therefore the only text of rational psychology, from
which it must develop its whole system. It is manifest that this
thought, when applied to an object (myself), can contain nothing but
transcendental predicates thereof; because the least empirical
predicate would destroy the purity of the science and its independence
of all experience.
But we shall have to follow here the guidance of the categories-
only, as in the present case a thing, "I," as thinking being, is at
first given, we shall- not indeed change the order of the categories
as it stands in the table- but begin at the category of substance,
by which at the a thing a thing is represented and proceeds
backwards through the series. The topic of the rational doctrine of
the soul, from which everything else it may contain must be deduced,
is accordingly as follows:

1 2
The Soul is SUBSTANCE As regards its quality
it is SIMPLE

3
As regards the different
times in which it exists,
it is numerically identical,
that is UNITY, not Plurality.

4
It is in relation to possible objects in space*

*The reader, who may not so easily perceive the psychological
sense of these expressions, taken here in their transcendental
abstraction, and cannot guess why the latter attribute of the soul
belongs to the category of existence, will find the expressions
sufficiently explained and justified in the sequel. I have,
moreover, to apologize for the Latin terms which have been
employed,instead of their German synonyms, contrary to the rules of
correct writing. But I judged it better to sacrifice elegance to
perspicuity.

From these elements originate all the conceptions of pure
psychology, by combination alone, without the aid of any other
principle. This substance, merely as an object of the internal
sense, gives the conception of Immateriality; as simple substance,
that of Incorruptibility; its identity, as intellectual substance,
gives the conception of Personality; all these three together,
Spirituality. Its relation to objects in space gives us the conception
of connection (commercium) with bodies. Thus it represents thinking
substance as the principle of life in matter, that is, as a soul
(anima), and as the ground of Animality; and this, limited and
determined by the conception of spirituality, gives us that of
Immortality.
Now to these conceptions relate four paralogisms of a transcendental
psychology, which is falsely held to be a science of pure reason.
touching the nature of our thinking being. We can, however, lay at the
foundation of this science nothing but the simple and in itself
perfectly contentless representation "I which cannot even be called
a conception, but merely a consciousness which accompanies all
conceptions. By this "I," or "He," or "It," who or which thinks,
nothing more is represented than a transcendental subject of thought =
x, which is cognized only by means of the thoughts that are its
predicates, and of which, apart from these, we cannot form the least
conception. Hence in a perpetual circle, inasmuch as we must always
employ it, in order to frame any judgement respecting it. And this
inconvenience we find it impossible to rid ourselves of, because
consciousness in itself is not so much a representation distinguishing
a particular object, as a form of representation in general, in so far
as it may be termed cognition; for in and by cognition alone do I
think anything.
It must, however, appear extraordinary at first sight that the
condition under which I think, and which is consequently a property of
my subject, should be held to be likewise valid for every existence
which thinks, and that we can presume to base upon a seemingly
empirical proposition a judgement which is apodeictic and universal,
to wit, that everything which thinks is constituted as the voice of my
consciousness declares it to be, that is, as a self-conscious being.
The cause of this belief is to be found in the fact that we
necessarily attribute to things a priori all the properties which
constitute conditions under which alone we can cogitate them. Now I
cannot obtain the least representation of a thinking being by means of
external experience, but solely through self-consciousness. Such
objects are consequently nothing more than the transference of this
consciousness of mine to other things which can only thus be
represented as thinking beings. The proposition, "I think," is, in the
present case, understood in a problematical sense, not in so far as it
contains a perception of an existence (like the Cartesian "Cogito,
ergo sum"),* but in regard to its mere possibility- for the purpose of
discovering what properties may be inferred from so simple a
proposition and predicated of the subject of it.

*["I think, therefore I am."]

If at the foundation of our pure rational cognition of thinking
beings there lay more than the mere Cogito- if we could likewise
call in aid observations on the play of our thoughts, and the thence
derived natural laws of the thinking self, there would arise an
empirical psychology which would be a kind of physiology of the
internal sense and might possibly be capable of explaining the
phenomena of that sense. But it could never be available for
discovering those properties which do not belong to possible
experience (such as the quality of simplicity), nor could it make
any apodeictic enunciation on the nature of thinking beings: it
would therefore not be a rational psychology.
Now, as the proposition "I think" (in the problematical sense)
contains the form of every judgement in general and is the constant
accompaniment of all the categories, it is manifest that conclusions
are drawn from it only by a transcendental employment of the
understanding. This use of the understanding excludes all empirical
elements; and we cannot, as has been shown above, have any
favourable conception beforehand of its procedure. We shall
therefore follow with a critical eye this proposition through all
the predicaments of pure psychology; but we shall, for brevity's sake,
allow this examination to proceed in an uninterrupted connection.
Before entering on this task, however, the following general
remark may help to quicken our attention to this mode of argument.
It is not merely through my thinking that I cognize an object, but
only through my determining a given intuition in relation to the unity
of consciousness in which all thinking consists. It follows that I
cognize myself, not through my being conscious of myself as
thinking, but only when I am conscious of the intuition of myself as
determined in relation to the function of thought. All the modi of
self-consciousness in thought are hence not conceptions of objects
(conceptions of the understanding- categories); they are mere
logical functions, which do not present to thought an object to be
cognized, and cannot therefore present my Self as an object. Not the
consciousness of the determining, but only that of the determinable
self, that is, of my internal intuition (in so far as the manifold
contained in it can be connected conformably with the general
condition of the unity of apperception in thought), is the object.
1. In all judgements I am the determining subject of that relation
which constitutes a judgement. But that the I which thinks, must be
considered as in thought always a subject, and as a thing which cannot
be a predicate to thought, is an apodeictic and identical proposition.
But this proposition does not signify that I, as an object, am, for
myself, a self-subsistent being or substance. This latter statement-
an ambitious one- requires to be supported by data which are not to be
discovered in thought; and are perhaps (in so far as I consider the
thinking self merely as such) not to be discovered in the thinking
self at all.
2. That the I or Ego of apperception, and consequently in all
thought, is singular or simple, an;3 cannot be resolved into a
plurality of subjects, and therefore indicates a logically simple
subject- this is self-evident from the very conception of an Ego,
and is consequently an analytical proposition. But this is not
tantamount to declaring that the thinking Ego is a simple substance-
for this would be a synthetical proposition. The conception of
substance always relates to intuitions, which with me cannot be
other than sensuous, and which consequently lie completely out of
the sphere of the understanding and its thought: but to this sphere
belongs the affirmation that the Ego is simple in thought. It would
indeed be surprising, if the conception of "substance," which in other
cases requires so much labour to distinguish from the other elements
presented by intuition- so much trouble, too, to discover whether it
can be simple (as in the case of the parts of matter)- should be
presented immediately to me, as if by revelation, in the poorest
mental representation of all.
3. The proposition of the identity of my Self amidst all the
manifold representations of which I am conscious, is likewise a
proposition lying in the conceptions themselves, and is consequently
analytical. But this identity of the subject, of which I am
conscious in all its representations, does not relate to or concern
the intuition of the subject, by which it is given as an object.
This proposition cannot therefore enounce the identity of the
person, by which is understood the consciousness of the identity of
its own substance as a thinking being in all change and variation of
circumstances. To prove this, we should require not a mere analysis of
the proposition, but synthetical judgements based upon a given
intuition.
4. I distinguish my own existence, as that of a thinking being, from
that of other things external to me- among which my body also is
reckoned. This is also an analytical proposition, for other things are
exactly those which I think as different or distinguished from myself.
But whether this consciousness of myself is possible without things
external to me; and whether therefore I can exist merely as a thinking
being (without being man)- cannot be known or inferred from this
proposition.
Thus we have gained nothing as regards the cognition of myself as
object, by the analysis of the consciousness of my Self in thought.
The logical exposition of thought in general is mistaken for a
metaphysical determination of the object.
Our Critique would be an investigation utterly superfluous, if there
existed a possibility of proving a priori, that all thinking beings
are in themselves simple substances, as such, therefore, possess the
inseparable attribute of personality, and are conscious of their
existence apart from and unconnected with matter. For we should thus
have taken a step beyond the world of sense, and have penetrated
into the sphere of noumena; and in this case the right could not be
denied us of extending our knowledge in this sphere, of establishing
ourselves, and, under a favouring star, appropriating to ourselves
possessions in it. For the proposition: "Every thinking being, as
such, is simple substance," is an a priori synthetical proposition;
because in the first place it goes beyond the conception which is
the subject of it, and adds to the mere notion of a thinking being the
mode of its existence, and in the second place annexes a predicate
(that of simplicity) to the latter conception- a predicate which it
could not have discovered in the sphere of experience. It would follow
that a priori synthetical propositions are possible and legitimate,
not only, as we have maintained, in relation to objects of possible
experience, and as principles of the possibility of this experience
itself, but are applicable to things in themselves- an inference which
makes an end of the whole of this Critique, and obliges us to fall
back on the old mode of metaphysical procedure. But indeed the
danger is not so great, if we look a little closer into the question.
There lurks in the procedure of rational Psychology a paralogism,
which is represented in the following syllogism:
That which cannot be cogitated otherwise than as subject, does not
exist otherwise than as subject, and is therefore substance.
A thinking being, considered merely as such, cannot be cogitated
otherwise than as subject.
Therefore it exists also as such, that is, as substance.
In the major we speak of a being that can be cogitated generally and
in every relation, consequently as it may be given in intuition. But
in the minor we speak of the same being only in so far as it regards
itself as subject, relatively to thought and the unity of
consciousness, but not in relation to intuition, by which it is
presented as an object to thought. Thus the conclusion is here arrived
at by a Sophisma figurae dictionis.*

*Thought is taken in the two premisses in two totally different
senses. In the major it is considered as relating and applying to
objects in general, consequently to objects of intuition also. In
the minor, we understand it as relating merely to
self-consciousness. In this sense, we do not cogitate an object, but
merely the relation to the self-consciousness of the subject, as the
form of thought. In the former premiss we speak of things which cannot
be cogitated otherwise than as subjects. In the second, we do not
speak of things, but of thought all objects being abstracted), in
which the Ego is always the subject of consciousness. Hence the
conclusion cannot be, "I cannot exist otherwise than as subject";
but only "I can, in cogitating my existence, employ my Ego only as the
subject of the judgement." But this is an identical proposition, and
throws no light on the mode of my existence.

That this famous argument is a mere paralogism, will be plain to any
one who will consider the general remark which precedes our exposition
of the principles of the pure understanding, and the section on
noumena. For it was there proved that the conception of a thing, which
can exist per se- only as a subject and never as a predicate,
possesses no objective reality; that is to say, we can never know
whether there exists any object to correspond to the conception;
consequently, the conception is nothing more than a conception, and
from it we derive no proper knowledge. If this conception is to
indicate by the term substance, an object that can be given, if it
is to become a cognition, we must have at the foundation of the
cognition a permanent intuition, as the indispensable condition of its
objective reality. For through intuition alone can an object be given.
But in internal intuition there is nothing permanent, for the Ego is
but the consciousness of my thought. If then, we appeal merely to
thought, we cannot discover the necessary condition of the application
of the conception of substance- that is, of a subject existing per se-
to the subject as a thinking being. And thus the conception of the
simple nature of substance, which is connected with the objective
reality of this conception, is shown to be also invalid, and to be, in
fact, nothing more than the logical qualitative unity of
self-consciousness in thought; whilst we remain perfectly ignorant
whether the subject is composite or not.

Refutation of the Argument of Mendelssohn for the
Substantiality or Permanence of the Soul.

This acute philosopher easily perceived the insufficiency of the
common argument which attempts to prove that the soul- it being
granted that it is a simple being- cannot perish by dissolution or
decomposition; he saw it is not impossible for it to cease to be by
extinction, or disappearance. He endeavoured to prove in his Phaedo,
that the soul cannot be annihilated, by showing that a simple being
cannot cease to exist. Inasmuch as, be said, a simple existence cannot
diminish, nor gradually lose portions of its being, and thus be by
degrees reduced to nothing (for it possesses no parts, and therefore
no multiplicity), between the moment in which it is, and the moment in
which it is not, no time can be discovered- which is impossible. But
this philosopher did not consider that, granting the soul to possess
this simple nature, which contains no parts external to each other and
consequently no extensive quantity, we cannot refuse to it any less
than to any other being, intensive quantity, that is, a degree of
reality in regard to all its faculties, nay, to all that constitutes
its existence. But this degree of reality can become less and less
through an infinite series of smaller degrees. It follows,
therefore, that this supposed substance- this thing, the permanence of
which is not assured in any other way, may, if not by decomposition,
by gradual loss (remissio) of its powers (consequently by
elanguescence, if I may employ this expression), be changed into
nothing. For consciousness itself has always a degree, which may be
lessened.* Consequently the faculty of being conscious may be
diminished; and so with all other faculties. The permanence of the
soul, therefore, as an object of the internal sense, remains
undemonstrated, nay, even indemonstrable. Its permanence in life is
evident, per se, inasmuch as the thinking being (as man) is to itself,
at the same time, an object of the external senses. But this does
not authorize the rational psychologist to affirm, from mere
conceptions, its permanence beyond life.*[2]

*Clearness is not, as logicians maintain, the consciousness of a
representation. For a certain degree of consciousness, which may
not, however, be sufficient for recollection, is to be met with in
many dim representations. For without any consciousness at all, we
should not be able to recognize any difference in the obscure
representations we connect; as we really can do with many conceptions,
such as those of right and justice, and those of the musician, who
strikes at once several notes in improvising a piece of music. But a
representation is clear, in which our consciousness is sufficient
for the consciousness of the difference of this representation from
others. If we are only conscious that there is a difference, but are
not conscious of the difference- that is, what the difference is-
the representation must be termed obscure. There is, consequently,
an infinite series of degrees of consciousness down to its entire
disappearance.
*[2] There are some who think they have done enough to establish a
new possibility in the mode of the existence of souls, when they
have shown that there is no contradiction in their hypotheses on
this subject. Such are those who affirm the possibility of thought- of
which they have no other knowledge than what they derive from its
use in connecting empirical intuitions presented in this our human
life- after this life bas ceased. But it is very easy to embarrass
them by the introduction of counter-possibilities, which rest upon
quite as good a foundation. Such, for example, is the possibility of
the division of a simple substance into several substances; and
conversely, of the coalition of several into one simple substance.
For, although divisibility presupposes composition, it does not
necessarily require a composition of substances, but only of the
degrees (of the several faculties) of one and the same substance.
Now we can cogitate all the powers and faculties of the soul- even
that of consciousness- as diminished by one half, the substance
still remaining. In the same way we can represent to ourselves without
contradiction, this obliterated half as preserved, not in the soul,
but without it; and we can believe that, as in this case every.
thing that is real in the soul, and has a degree- consequently its
entire existence- has been halved, a particular substance would
arise out of the soul. For the multiplicity, which has been divided,
formerly existed, but not as a multiplicity of substances, but of
every reality as the quantum of existence in it; and the unity of
substance was merely a mode of existence, which by this division alone
has been transformed into a plurality of subsistence. In the same
manner several simple substances might coalesce into one, without
anything being lost except the plurality of subsistence, inasmuch as
the one substance would contain the degree of reality of all the
former substances. Perhaps, indeed, the simple substances, which
appear under the form of matter, might (not indeed by a mechanical
or chemical influence upon each other, but by an unknown influence, of
which the former would be but the phenomenal appearance), by means
of such a dynamical division of the parent-souls, as intensive
quantities, produce other souls, while the former repaired the loss
thus sustained with new matter of the same sort. I am far from
allowing any value to such chimeras; and the principles of our
analytic have clearly proved that no other than an empirical use of
the categories- that of substance, for example- is possible. But if
the rationalist is bold enough to construct, on the mere authority
of the faculty of thought- without any intuition, whereby an object is
given- a self-subsistent being, merely because the unity of
apperception in thought cannot allow him to believe it a composite
being, instead of declaring, as he ought to do, that he is unable to
explain the possibility of a thinking nature; what ought to hinder the
materialist, with as complete an independence of experience, to employ
the principle of the rationalist in a directly opposite manner-
still preserving the formal unity required by his opponent?

If, now, we take the above propositions- as they must be accepted as
valid for all thinking beings in the system of rational psychology- in
synthetical connection, and proceed, from the category of relation,
with the proposition: "All thinking beings are, as such,
substances," backwards through the series, till the circle is
completed; we come at last to their existence, of which, in this
system of rational psychology, substances are held to be conscious,
independently of external things; nay, it is asserted that, in
relation to the permanence which is a necessary characteristic of
substance, they can of themselves determine external things. It
follows that idealism- at least problematical idealism, is perfectly
unavoidable in this rationalistic system. And, if the existence of
outward things is not held to be requisite to the determination of the
existence of a substance in time, the existence of these outward
things at all, is a gratuitous assumption which remains without the
possibility of a proof.
But if we proceed analytically- the "I think" as a proposition
containing in itself an existence as given, consequently modality
being the principle- and dissect this proposition, in order to
ascertain its content, and discover whether and how this Ego
determines its existence in time and space without the aid of anything
external; the propositions of rationalistic psychology would not begin
with the conception of a thinking being, but with a reality, and the
properties of a thinking being in general would be deduced from the
mode in which this reality is cogitated, after everything empirical
had been abstracted; as is shown in the following table:

1
I think,

2 3
as Subject, as simple Subject,

4
as identical Subject,
in every state of my thought.

Now, inasmuch as it is not determined in this second proposition,
whether I can exist and be cogitated only as subject, and not also
as a predicate of another being, the conception of a subject is here
taken in a merely logical sense; and it remains undetermined,
whether substance is to be cogitated under the conception or not.
But in the third proposition, the absolute unity of apperception-
the simple Ego in the representation to which all connection and
separation, which constitute thought, relate, is of itself
important; even although it presents us with no information about
the constitution or subsistence of the subject. Apperception is
something real, and the simplicity of its nature is given in the
very fact of its possibility. Now in space there is nothing real
that is at the same time simple; for points, which are the only simple
things in space, are merely limits, but not constituent parts of
space. From this follows the impossibility of a definition on the
basis of materialism of the constitution of my Ego as a merely
thinking subject. But, because my existence is considered in the first
proposition as given, for it does not mean, "Every thinking being
exists" (for this would be predicating of them absolute necessity),
but only, "I exist thinking"; the proposition is quite empirical,
and contains the determinability of my existence merely in relation to
my representations in time. But as I require for this purpose
something that is permanent, such as is not given in internal
intuition; the mode of my existence, whether as substance or as
accident, cannot be determined by means of this simple
self-consciousness. Thus, if materialism is inadequate to explain
the mode in which I exist, spiritualism is likewise as insufficient;
and the conclusion is that we are utterly unable to attain to any
knowledge of the constitution of the soul, in so far as relates to the
possibility of its existence apart from external objects.
And, indeed, how should it be possible, merely by the aid of the
unity of consciousness- which we cognize only for the reason that it
is indispensable to the possibility of experience- to pass the
bounds of experience (our existence in this life); and to extend our
cognition to the nature of all thinking beings by means of the
empirical- but in relation to every sort of intuition, perfectly
undetermined- proposition, "I think"?
There does not then exist any rational psychology as a doctrine
furnishing any addition to our knowledge of ourselves. It is nothing
more than a discipline, which sets impassable limits to speculative
reason in this region of thought, to prevent it, on the one hand, from
throwing itself into the arms of a soulless materialism, and, on the
other, from losing itself in the mazes of a baseless spiritualism.
It teaches us to consider this refusal of our reason to give any
satisfactory answer to questions which reach beyond the limits of this
our human life, as a hint to abandon fruitless speculation; and to
direct, to a practical use, our knowledge of ourselves- which,
although applicable only to objects of experience, receives its
principles from a higher source, and regulates its procedure as if our
destiny reached far beyond the boundaries of experience and life.
From all this it is evident that rational psychology has its
origin in a mere misunderstanding. The unity of consciousness, which
lies at the basis of the categories, is considered to be an
intuition of the subject as an object; and the category of substance
is applied to the intuition. But this unity is nothing more than the
unity in thought, by which no object is given; to which therefore
the category of substance- which always presupposes a given intuition-
cannot be applied. Consequently, the subject cannot be cognized. The
subject of the categories cannot, therefore, for the very reason
that it cogitates these, frame any conception of itself as an object
of the categories; for, to cogitate these, it must lay at the
foundation its own pure self-consciousness- the very thing that it
wishes to explain and describe. In like manner, the subject, in
which the representation of time has its basis, cannot determine,
for this very reason, its own existence in time. Now, if the latter is
impossible, the former, as an attempt to determine itself by means
of the categories as a thinking being in general, is no less so.*

*The "I think" is, as has been already stated, an empirical
proposition, and contains the proposition, "I exist." But I cannot
say, "Everything, which thinks, exists"; for in this case the property
of thought would constitute all beings possessing it, necessary
being Hence my existence cannot be considered as an inference from the
proposition, "I think," as Descartes maintained- because in this
case the major premiss, "Everything, which thinks, exists," must
precede- but the two propositions are identical. The proposition, "I
think," expresses an undetermined empirical intuition, that perception
(proving consequently that sensation, which must belong to
sensibility, lies at the foundation of this proposition); but it
precedes experience, whose province it is to determine an object of
perception by means of the categories in relation to time; and
existence in this proposition is not a category, as it does not
apply to an undetermined given object, but only to one of which we
have a conception, and about which we wish to know whether it does
or does not exist, out of, and apart from this conception. An
undetermined perception signifies here merely something real that
has been given, only, however, to thought in general- but not as a
phenomenon, nor as a thing in itself (noumenon), but only as something
that really exists, and is designated as such in the proposition, "I
think." For it must be remarked that, when I call the proposition,
"I think," an empirical proposition, I do not thereby mean that the
Ego in the proposition is an empirical representation; on the
contrary, it is purely intellectual, because it belongs to thought
in general. But without some empirical representation, which
presents to the mind material for thought, the mental act, "I
think," would not take place; and the empirical is only the
condition of the application or employment of the pure intellectual
faculty.

Thus, then, appears the vanity of the hope of establishing a
cognition which is to extend its rule beyond the limits of experience-
a cognition which is one of the highest interests of humanity; and
thus is proved the futility of the attempt of speculative philosophy
in this region of thought. But, in this interest of thought, the
severity of criticism has rendered to reason a not unimportant
service, by the demonstration of the impossibility of making any
dogmatical affirmation concerning an object of experience beyond the
boundaries of experience. She has thus fortified reason against all
affirmations of the contrary. Now, this can be accomplished in only
two ways. Either our proposition must be proved apodeictically; or, if
this is unsuccessful, the sources of this inability must be sought
for, and, if these are discovered to exist in the natural and
necessary limitation of our reason, our opponents must submit to the
same law of renunciation and refrain from advancing claims to dogmatic
assertion.
But the right, say rather the necessity to admit a future life, upon
principles of the practical conjoined with the speculative use of
reason, has lost nothing by this renunciation; for the merely
speculative proof has never had any influence upon the common reason
of men. It stands upon the point of a hair, so that even the schools
have been able to preserve it from falling only by incessantly
discussing it and spinning it like a top; and even in their eyes it
has never been able to present any safe foundation for the erection of
a theory. The proofs which have been current among men, preserve their
value undiminished; nay, rather gain in clearness and
unsophisticated power, by the rejection of the dogmatical
assumptions of speculative reason. For reason is thus confined
within her own peculiar province- the arrangement of ends or aims,
which is at the same time the arrangement of nature; and, as a
practical faculty, without limiting itself to the latter, it is
justified in extending the former, and with it our own existence,
beyond the boundaries of experience and life. If we turn our attention
to the analogy of the nature of living beings in this world, in the
consideration of which reason is obliged to accept as a principle that
no organ, no faculty, no appetite is useless, and that nothing is
superfluous, nothing disproportionate to its use, nothing unsuited
to its end; but that, on the contrary, everything is perfectly
conformed to its destination in life- we shall find that man, who
alone is the final end and aim of this order, is still the only animal
that seems to be excepted from it. For his natural gifts- not merely
as regards the talents and motives that may incite him to employ them,
but especially the moral law in him- stretch so far beyond all mere
earthly utility and advantage, that he feels himself bound to prize
the mere consciousness of probity, apart from all advantageous
consequences- even the shadowy gift of posthumous fame- above
everything; and he is conscious of an inward call to constitute
himself, by his conduct in this world- without regard to mere
sublunary interests- the citizen of a better. This mighty,
irresistible proof- accompanied by an ever-increasing knowledge of the
conformability to a purpose in everything we see around us, by the
conviction of the boundless immensity of creation, by the
consciousness of a certain illimitableness in the possible extension
of our knowledge, and by a desire commensurate therewith- remains to
humanity, even after the theoretical cognition of ourselves bas failed
to establish the necessity of an existence after death.

Conclusion of the Solution of the
Psychological Paralogism.

The dialectical illusion in rational psychology arises from our
confounding an idea of reason (of a pure intelligence) with the
conception- in every respect undetermined- of a thinking being in
general. I cogitate myself in behalf of a possible experience, at
the same time making abstraction of all actual experience; and infer
therefrom that I can be conscious of myself apart from experience
and its empirical conditions. I consequently confound the possible
abstraction of my empirically determined existence with the supposed
consciousness of a possible separate existence of my thinking self;
and I believe that I cognize what is substantial in myself as a
transcendental subject, when I have nothing more in thought than the
unity of consciousness, which lies at the basis of all determination
of cognition.
The task of explaining the community of the soul with the body
does not properly belong to the psychology of which we are here
speaking; because it proposes to prove the personality of the soul
apart from this communion (after death), and is therefore transcendent
in the proper sense of the word, although occupying itself with an
object of experience- only in so far, however, as it ceases to be an
object of experience. But a sufficient answer may be found to the
question in our system. The difficulty which lies in the execution
of this task consists, as is well known, in the presupposed
heterogeneity of the object of the internal sense (the soul) and the
objects of the external senses; inasmuch as the formal condition of
the intuition of the one is time, and of that of the other space also.
But if we consider that both kinds of objects do not differ
internally, but only in so far as the one appears externally to the
other- consequently, that what lies at the basis of phenomena, as a
thing in itself, may not be heterogeneous; this difficulty disappears.
There then remains no other difficulty than is to be found in the
question- how a community of substances is possible; a question
which lies out of the region of psychology, and which the reader,
after what in our analytic has been said of primitive forces and
faculties, will easily judge to be also beyond the region of human
cognition.

GENERAL REMARK

On the Transition from Rational Psychology to Cosmology.

The proposition, "I think," or, "I exist thinking," is an
empirical proposition. But such a proposition must be based on
empirical intuition, and the object cogitated as a phenomenon; and
thus our theory appears to maintain that the soul, even in thought, is
merely a phenomenon; and in this way our consciousness itself, in
fact, abuts upon nothing.
Thought, per se, is merely the purely spontaneous logical function
which operates to connect the manifold of a possible intuition; and it
does not represent the subject of consciousness as a phenomenon- for
this reason alone, that it pays no attention to the question whether
the mode of intuiting it is sensuous or intellectual. I therefore do
not represent myself in thought either as I am, or as I appear to
myself; I merely cogitate myself as an object in general, of the
mode of intuiting which I make abstraction. When I represent myself as
the subject of thought, or as the ground of thought, these modes of
representation are not related to the categories of substance or of
cause; for these are functions of thought applicable only to our
sensuous intuition. The application of these categories to the Ego
would, however, be necessary, if I wished to make myself an object
of knowledge. But I wish to be conscious of myself only as thinking;
in what mode my Self is given in intuition, I do not consider, and
it may be that I, who think, am a phenomenon- although not in so far
as I am a thinking being; but in the consciousness of myself in mere
thought I am a being, though this consciousness does not present to me
any property of this being as material for thought.
But the proposition, "I think," in so far as it declares, "I exist
thinking," is not the mere representation of a logical function. It
determines the subject (which is in this case an object also) in
relation to existence; and it cannot be given without the aid of the
internal sense, whose intuition presents to us an object, not as a
thing in itself, but always as a phenomenon. In this proposition there
is therefore something more to be found than the mere spontaneity of
thought; there is also the receptivity of intuition, that is, my
thought of myself applied to the empirical intuition of myself. Now,
in this intuition the thinking self must seek the conditions of the
employment of its logical functions as categories of substance, cause,
and so forth; not merely for the purpose of distinguishing itself as
an object in itself by means of the representation "I," but also for
the purpose of determining the mode of its existence, that is, of
cognizing itself as noumenon. But this is impossible, for the internal
empirical intuition is sensuous, and presents us with nothing but
phenomenal data, which do not assist the object of pure
consciousness in its attempt to cognize itself as a separate
existence, but are useful only as contributions to experience.
But, let it be granted that we could discover, not in experience,
but in certain firmly-established a priori laws of the use of pure
reason- laws relating to our existence, authority to consider
ourselves as legislating a priori in relation to our own existence and
as determining this existence; we should, on this supposition, find
ourselves possessed of a spontaneity, by which our actual existence
would be determinable, without the aid of the conditions of
empirical intuition. We should also become aware that in the
consciousness of our existence there was an a priori content, which
would serve to determine our own existence- an existence only
sensuously determinable- relatively, however, to a certain internal
faculty in relation to an intelligible world.
But this would not give the least help to the attempts of rational
psychology. For this wonderful faculty, which the consciousness of the
moral law in me reveals, would present me with a principle of the
determination of my own existence which is purely intellectual- but by
what predicates? By none other than those which are given in
sensuous intuition. Thus I should find myself in the same position
in rational psychology which I formerly occupied, that is to say, I
should find myself still in need of sensuous intuitions, in order to
give significance to my conceptions of substance and cause, by means
of which alone I can possess a knowledge of myself: but these
intuitions can never raise me above the sphere of experience. I should
be justified, however, in applying these conceptions, in regard to
their practical use, which is always directed to objects of
experience- in conformity with their analogical significance when
employed theoretically- to freedom and its subject. At the same
time, I should understand by them merely the logical functions of
subject and predicate, of principle and consequence, in conformity
with which all actions are so determined, that they are capable of
being explained along with the laws of nature, conformably to the
categories of substance and cause, although they originate from a very
different principle. We have made these observations for the purpose
of guarding against misunderstanding, to which the doctrine of our
intuition of self as a phenomenon is exposed. We shall have occasion
to perceive their utility in the sequel.
CHAPTER II. The Antinomy of Pure Reason.

We showed in the introduction to this part of our work, that all
transcendental illusion of pure reason arose from dialectical
arguments, the schema of which logic gives us in its three formal
species of syllogisms- just as the categories find their logical
schema in the four functions of all judgements. The first kind of
these sophistical arguments related to the unconditioned unity of
the subjective conditions of all representations in general (of the
subject or soul), in correspondence with the categorical syllogisms,
the major of which, as the principle, enounces the relation of a
predicate to a subject. The second kind of dialectical argument will
therefore be concerned, following the analogy with hypothetical
syllogisms, with the unconditioned unity of the objective conditions
in the phenomenon; and, in this way, the theme of the third kind to be
treated of in the following chapter will be the unconditioned unity of
the objective conditions of the possibility of objects in general.
But it is worthy of remark that the transcendental paralogism
produced in the mind only a one-third illusion, in regard to the
idea of the subject of our thought; and the conceptions of reason gave
no ground to maintain the contrary proposition. The advantage is
completely on the side of Pneumatism; although this theory itself
passes into naught, in the crucible of pure reason.
Very different is the case when we apply reason to the objective
synthesis of phenomena. Here, certainly, reason establishes, with much
plausibility, its principle of unconditioned unity; but it very soon
falls into such contradictions that it is compelled, in relation to
cosmology, to renounce its pretensions.
For here a new phenomenon of human reason meets us- a perfectly
natural antithetic, which does not require to be sought for by
subtle sophistry, but into which reason of itself unavoidably falls.
It is thereby preserved, to be sure, from the slumber of a fancied
conviction- which a merely one-sided illusion produces; but it is at
the same time compelled, either, on the one hand, to abandon itself to
a despairing scepticism, or, on the other, to assume a dogmatical
confidence and obstinate persistence in certain assertions, without
granting a fair hearing to the other side of the question. Either is
the death of a sound philosophy, although the former might perhaps
deserve the title of the euthanasia of pure reason.
Before entering this region of discord and confusion, which the
conflict of the laws of pure reason (antinomy) produces, we shall
present the reader with some considerations, in explanation and
justification of the method we intend to follow in our treatment of
this subject. I term all transcendental ideas, in so far as they
relate to the absolute totality in the synthesis of phenomena,
cosmical conceptions; partly on account of this unconditioned
totality, on which the conception of the world-whole is based- a
conception, which is itself an idea- partly because they relate solely
to the synthesis of phenomena- the empirical synthesis; while, on
the other hand, the absolute totality in the synthesis of the
conditions of all possible things gives rise to an ideal of pure
reason, which is quite distinct from the cosmical conception, although
it stands in relation with it. Hence, as the paralogisms of pure
reason laid the foundation for a dialectical psychology, the
antinomy of pure reason will present us with the transcendental
principles of a pretended pure (rational) cosmology- not, however,
to declare it valid and to appropriate it, but- as the very term of
a conflict of reason sufficiently indicates, to present it as an
idea which cannot be reconciled with phenomena and experience.

SECTION I. System of Cosmological Ideas.

That We may be able to enumerate with systematic precision these
ideas according to a principle, we must remark, in the first place,
that it is from the understanding alone that pure and transcendental
conceptions take their origin; that the reason does not properly
give birth to any conception, but only frees the conception of the
understanding from the unavoidable limitation of a possible
experience, and thus endeavours to raise it above the empirical,
though it must still be in connection with it. This happens from the
fact that, for a given conditioned, reason demands absolute totality
on the side of the conditions (to which the understanding submits
all phenomena), and thus makes of the category a transcendental
idea. This it does that it may be able to give absolute completeness
to the empirical synthesis, by continuing it to the unconditioned
(which is not to be found in experience, but only in the idea). Reason
requires this according to the principle: If the conditioned is
given the whole of the conditions, and consequently the absolutely
unconditioned, is also given, whereby alone the former was possible.
First, then, the transcendental ideas are properly nothing but
categories elevated to the unconditioned; and they may be arranged
in a table according to the titles of the latter. But, secondly, all
the categories are not available for this purpose, but only those in
which the synthesis constitutes a series- of conditions subordinated
to, not co-ordinated with, each other. Absolute totality is required
of reason only in so far as concerns the ascending series of the
conditions of a conditioned; not, consequently, when the question
relates to the descending series of consequences, or to the
aggregate of the co-ordinated conditions of these consequences. For,
in relation to a given conditioned, conditions are presupposed and
considered to be given along with it. On the other hand, as the
consequences do not render possible their conditions, but rather
presuppose them- in the consideration of the procession of
consequences (or in the descent from the given condition to the
conditioned), we may be quite unconcerned whether the series ceases or
not; and their totality is not a necessary demand of reason.
Thus we cogitate- and necessarily- a given time completely elapsed
up to a given moment, although that time is not determinable by us.
But as regards time future, which is not the condition of arriving
at the present, in order to conceive it; it is quite indifferent
whether we consider future time as ceasing at some point, or as
prolonging itself to infinity. Take, for example, the series m, n,
o, in which n is given as conditioned in relation to m, but at the
same time as the condition of o, and let the series proceed upwards
from the conditioned n to m (l, k, i, etc.), and also downwards from
the condition n to the conditioned o (p, q, r, etc.)- I must
presuppose the former series, to be able to consider n as given, and n
is according to reason (the totality of conditions) possible only by
means of that series. But its possibility does not rest on the
following series o, p, q, r, which for this reason cannot be
regarded as given, but only as capable of being given (dabilis).
I shall term the synthesis of the series on the side of the
conditions- from that nearest to the given phenomenon up to the more
remote- regressive; that which proceeds on the side of the
conditioned, from the immediate consequence to the more remote, I
shall call the progressive synthesis. The former proceeds in
antecedentia, the latter in consequentia. The cosmological ideas are
therefore occupied with the totality of the regressive synthesis,
and proceed in antecedentia, not in consequentia. When the latter
takes place, it is an arbitrary and not a necessary problem of pure
reason; for we require, for the complete understanding of what is
given in a phenomenon, not the consequences which succeed, but the
grounds or principles which precede.