THE CRITIQUE OF PURE REASON by Immanuel Kant (1a)

                                      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 hide 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.