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Showing posts with label Philosophy of Science. Show all posts
Showing posts with label Philosophy of Science. Show all posts

Tuesday, January 19, 2010

"Against Method" by Paul Karl Feyerabend,1975



Paul Karl Feyerabend (January 13, 1924 – February 11, 1994) was an Austrian-born philosopher of science best known for his work as a professor of philosophy at the University of California, Berkeley, where he worked for three decades (1958–1989).

His life was a peripatetic one, as he lived at various times in England, the United States, New Zealand, Italy, Germany, and finally Switzerland. His major works include :
Against Method (published in 1975),
Science in a Free Society (published in 1978) and
Farewell to Reason (a collection of papers published in 1987).

Feyerabend became famous for his purportedly anarchistic view of science and his rejection of the existence of universal methodological rules. He is an influential figure in the philosophy of science, and also in the sociology of scientific knowledge.

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Source: Analytical Index (being a sketch of the main argument) and the concluding chapter from Against Method (1975) publ. Humanities Press. Just the Analytical Table of Contents and Concluding Chapter reproduced here.
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Outline of an anarchistic theory of knowledge :


Science is an essentially anarchistic enterprise:

theoretical anarchism is more humanitarian and more likely to encourage progress than its law-and-order alternatives.

This is shown both by an examination of historical episodes and by an abstract analysis of the relation between idea and action. The only principle that does not inhibit progress is: anything goes.

For example, we may use hypotheses that contradict well-confirmed theories and/or well-established experimental results. We may advance science by proceeding counter-inductively.

The consistency condition which demands that new hypotheses agree with accepted theories is unreasonable because it preserves the older theory, and not the better theory. Hypotheses contradicting well-confirmed theories give us evidence that cannot be obtained in any other way. Proliferation of theories is beneficial for science, while uniformity impairs its critical power. Uniformity also endangers the free development of the individual.

There is no idea, however ancient and absurd, that is not capable of improving our knowledge. The whole history of thought is absorbed into science and is used for improving every single theory. Nor is political interference rejected. It may be needed to overcome the chauvinism of science that resists alternatives to the status quo.

No theory ever agrees with all the facts in its domain, yet it is not always the theory that is to blame. Facts are constituted by older ideologies, and a clash between facts and theories may be proof of progress. It is also a first step in our attempts to find the principles implicit in familiar observational notions.

As an example of such an attempt I examine the tower argument which the Aristotelians used to refute the motion of the earth. The argument involves natural interpretations - ideas so closely connected with observations that it needs a special effort to realise their existence and to determine their content. Galileo identifies the natural interpretations which are inconsistent with Copernicus and replaces them by others.

The new natural interpretations constitute a new and highly abstract observation language. They are introduced and concealed so that one falls to notice the change that has taken place (method of anamnesis). They contain the idea of the relativity of all motion and the law of circular inertia.

Initial difficulties caused by the change are defused by ad hoc hypotheses, which thus turn out occasionally to have a positive function; they give new theories a breathing space, and they indicate the direction of future research.
In addition to natural interpretations, Galileo also changes sensations that seem to endanger Copernicus. He admits that there are such sensations, he praises Copernicus for having disregarded them, he claims to have removed them with the help of the telescope. However, he offers no theoretical reasons why the telescope should be expected to give a true picture of the sky.

Nor does the initial experience with the telescope provide such reasons. The first telescopic observations of the sky are indistinct, indeterminate, contradictory and in conflict with what everyone can see with his unaided eyes. And, the only theory that could have helped to separate telescopic illusions from veridical phenomena was refuted by simple tests.

On the other hand, there are some telescopic phenomena which are plainly Copernican. Galileo introduces these phenomena as independent evidence for Copernicus while the situation is rather that one refuted view - Copernicanism - has a certain similarity with phenomena emerging from another refuted view - the idea that telescopic phenomena are faithful images of the sky. Galileo prevails because of his style and his clever techniques of persuasion, because he writes in Italian rather than in Latin, and because he appeals to people who are temperamentally opposed to the old ideas and the standards of learning connected with them.

Such 'irrational' methods of support are needed because of the 'uneven development' (Marx, Lenin) of different parts of science. Copernicanism and other essential ingredients of modern science survived only because reason was frequently overruled in their past.

Galileo's method works in other fields as well. For example, it can be used to eliminate the existing arguments against materialism, and to put an end to the philosophical mind/body problem (the corresponding scientific problems remain untouched, however).

The results obtained so far suggest abolishing the distinction between a context of discovery and a context of justification and disregarding the related distinction between observational terms and theoretical terms. Neither distinction plays a role in scientific practice. Attempts to enforce them would have disastrous consequences.

Finally, the discussion in Chapters 6-13 shows that Popper's version of Mill's pluralism is not in agreement with scientific practice and would destroy science as we know it. Given science, reason cannot be universal and unreason cannot be excluded. This feature of science calls for an anarchistic epistemology. The realisation that science is not sacrosanct, and that the debate between science and myth has ceased without having been won by either side, further strengthens the case for anarchism.

Even the ingenious attempt of Lakatos to construct a methodology that (a) does not issue orders and yet (b) puts restrictions upon our knowledge-increasing activities, does not escape this conclusion. For Lakatos' philosophy appears liberal only because it is an anarchism in disguise. And his standards which are abstracted from modern science cannot be regarded as neutral arbiters in the issue between modern science and Aristotelian science, myth, magic, religion, etc.

Moreover, these standards, which involve a comparison of content classes, are not always applicable. The content classes of certain theories are incomparable in the sense that none of the usual logical relations (inclusion, exclusion, overlap) can be said to hold between them. This occurs when we compare myths with science. It also occurs in the most advanced, most general and therefore most mythological parts of science itself.

Thus science is much closer to myth than a scientific philosophy is prepared to admit. It is one of the many forms of thought that have been developed by man, and not necessarily the best. It is conspicuous, noisy, and impudent, but it is inherently superior only for those who have already decided in favour of a certain ideology, or who have accepted it without having ever examined its advantages and its limits. And as the accepting and rejecting of ideologies should be left to the individual it follows that the separation of state and church must be supplemented by the separation of state and science, that most recent, most aggressive, and most dogmatic religious institution. Such a separation may be our only chance to achieve a humanity we are capable of, but have never fully realised.

Thursday, December 17, 2009

"Complex systems, trade-offs, and theoretical population biology" by Richard Levin,

His theoretical interests have been applied to problems of community development as part of the Board of Directors of OXFAM-America and chair of their subcommittee on Latin America and the Caribbean from 1989 to 1995. Working from a critique of the industrial-commercial pathway of development, he promoted alternative development pathways that emphasize economic viability with equity, ecological and social sustainability and empowerment of the dispossessed. As part of the New World Agriculture and Ecology Group, he has helped to develop modern agroecology, concentrating on the whole-system approaches to gentle pest management. The "Dialectical Biologist," co-authored with Richard Lewontin, presented the authors' approach to the study of the philosophy, sociology and history of science.
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Evolution in changing environments :
Prior to Levins' work, population genetics assumed the environment to be constant, while mathematical ecology assumed the genetic makeup of the species involved to be constant. Levins modelled the situation in which evolution is taking place while the environment changes. One of the surprising consequences of his model is that selection need not maximize adaptation, and that species can select themselves to extinction. He encapsulated his major early results in Evolution in Changing Environments, a book based on lectures he delivered in Cuba in the early 1960s. Levins made extensive use of mathematics, some of which he invented himself, although it had been previously developed in other areas of pure mathematics or economics without his awareness of it. For instance Levins makes extensive use of convex set theory for fitness sets, (resembling the economic formulations of J. R. Hicks) and extends Sewall Wright's path analysis to the analysis of causal feedback loops.
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Ecologist Richard Levins argues population biologists must trade-off the generality, realism, and precision of their models since biological systems are complex and our limitations are severe. Steven Orzack and Elliott Sober argue that there are cases where these model properties cannot be varied independently of one another. If this is correct, then Levins's thesis that there is a necessary trade-off between generality, precision, and realism in mathematical models in biology is false. I argue that Orzack and Sober's arguments fail since Levins's thesis concerns the pragmatic features of model building not just the formal properties of models.

Monday, December 14, 2009

"1965, delivers John Locke Lectures for 1965–66 at Oxford University"by Wilfrid Sellars,1965

Wilfrid Sellars

Wilfrid Stalker Sellars (b. 1912, d. 1989) was a profoundly creative and synthetic thinker whose work both as a systematic philosopher and as an influential editor helped set and shape the Anglo-American philosophical agenda for over four decades. Sellars is perhaps best known for his classic 1956 essay “Empiricism and the Philosophy of Mind”, a comprehensive and sophisticated critique of “the myth of the given” which played a major role in the postwar deconstruction of Cartesianism, but his published corpus of three books and more than one hundred essays includes numerous original contributions to ontology, epistemology, and the philosophies of science, language, and mind, as well as sensitive historical and exegetical studies.

1. Sellars' Life and Career
2. Sellars' Metaphilosophy
3. Sellars' Philosophy of Science and Epistemology
4. Sellars' Philosophy of Language and Mind
5. A Final Remark
6. Principal Works by Wilfrid Sellars
Bibliography
Other Internet Resources
Related Entries
1. Sellars' Life and Career

1912, born May 20 in Ann Arbor, MI
1933, receives A.B. at the University of Michigan
1934, receives A.M. at the University of Buffalo, NY, enters Oriel College, Oxford, as a Rhodes Scholar
1936, receives B.A. with First Class Honours in Philosophy, Politics, and Economics (M.A. 1940)
1938, becomes Assistant Professor of Philosophy, University of Iowa
1943, enters U.S. Naval Reserve, assigned to Air Combat Intelligence
1946, becomes Assistant Professor of Philosophy, University of Minnesota
1950, founds Philosophical Studies with Herbert Feigl, the first scholarly forum explicitly created for the new hybrid “analytic philosophy”
1951, becomes Professor of Philosophy, University of Minnesota
1956, serves as Special Lecturer in Philosophy at the University of London, published as “Empiricism and the Philosophy of Mind”
1958, moves to Yale University, CN, first as a visitor, subsequently as Professor of Philosophy
1963, assumes the position of University Professor of Philosophy and Research Professor of Philosophy at the University of Pittsburgh, PA, publishes Science, Perception and Reality
1965, delivers John Locke Lectures for 1965–66 at Oxford University, subsequently published as Science and Metaphysics
1970, serves as president of the Eastern Division of the American Philosophical Association
1971, delivers Matchette Foundation Lectures, University of Texas, subsequently published as “The Structure of Knowledge”
1973, delivers John Dewey Lectures for 1973–74, University of Chicago, IL, subsequently published as Naturalism and Ontology
1977, delivers Paul Carus Lectures for 1977–78 at the Eastern Division meetings of the American Philosophical Association, later published as “Foundations for a Metaphysics of Pure Process”
1987, Colloquium in Sellarsian Philosophy held at University of Pittsburgh in honor of Sellars' 75th birthday
1989, dies at home in Pittsburgh, PA, on July 2
2. Sellars' Metaphilosophy

Although Wilfrid Sellars is best known for his his ground-breaking essay “Empiricism and the Philosophy of Mind” [EPM] and his critique of what he there called “the myth of the given”, he was in fact a systematic philosopher par excellence. “The aim of philosophy,” he wrote, “is to understand how things in the broadest possible sense of the term hang together in the broadest possible sense of the term” (PSIM, 37). This image of the philosopher as a reflective generalist recurs frequently in Sellars' metaphilosophical reflections. His most explicit account of the central task confronting contemporary philosophy aligns it firmly with the modernist project of achieving a rapprochement between our humanistic understanding of ourselves as free and rational agents, at home among meanings and values, and the thoroughly “disenchanted” picture of the world being painted by an increasingly comprehensive natural science. Sellars thematized this contrast as a confrontation of two “images”: the “manifest image” whose primary objects are persons, beings who can and do conceive of themselves as sentient perceivers, cognitive knowers, and deliberative agents, and the “scientific image”, whose primary entities are some sophisticated version of “atoms in the void”. “The scientific image,” Sellars wrote, “presents itself as a rival image. From its point of view the manifest image on which it [methodologically] rests is an ‘inadequate’ but pragmatically useful likeness of a reality which first finds its adequate (in principle) likeness in the scientific image” (PSIM, 57). As Sellars saw it, the goal of philosophy was to transform this tension between our lived self-conception and our hard won explanatory understanding of the world into a single “stereoscopic” image, a synoptic vision of persons-in-the-world. Much of his philosophical work is addressed to three central moments of this complex undertaking: accommodating the intentional contents of thought and language, the sensuous contents of perception and imagination, and the normative dimensions of knowledge and conduct within such a stereoscopic image — all the while resolutely maintaining a robust scientific realism, for “in the dimension of describing and explaining the world, science is the measure of all things, of what is that it is, and of what is not that it is not” (EPM, 173).

3. Sellars' Philosophy of Science and Epistemology

Sellars' interpretation of the epistemology of natural science departed decisively from the received view according to which explanation was identified with derivation — singular matters of empirical fact being explained by deriving descriptions of them from (“inductively” established) empirical generalizations (along with appropriate statements of initial conditions), and these “empirical laws” in turn being explained by deriving them from theoretical postulates and correspondence rules. On this received Positivist view, theories (e.g., microtheories) explain empirical matters of fact only indirectly, by implying generalizations framed in an observation-language that explain them directly. In consequence, as Hempel pointed out in “The Theoretician's Dilemma”, such theories, although perhaps convenient aids to calculation and compact representation, are in principle utterly dispensable.

Sellars regarded this “layer-cake model” or “levels picture” of theories as fundamentally misguided. He argued that there is no autonomous stratum of empirical counterparts to theoretical laws. The empirical generalizations corresponding to theoretical laws become salient only from the theoretical perspective. Generalizations arrived at autonomously at the observational level, however reliable, are not laws of nature, and theories consequently cannot be in the business of explaining such lower-level generalizations by entailing them. Rather, “theories explain laws by explaining why the objects of the domain in question obey the laws that they do to the extent that they do” (LT, 123).

[That is,] they explain why individual objects of various kinds and in various circumstances in the observation framework behave in those ways in which it has been inductively established that they do behave. Roughly, it is because a gas is ... a cloud of molecules which are behaving in certain theoretically defined ways, that it obeys the empirical Boyle-Charles Law. (LT, 121)
On Sellars' view stories that postulate “theoretical entities” are not merely manageable second-class surrogates for more complicated and unwieldy stories about entities that we have good, i.e., observational, reasons to believe actually exist. Theoretical entities, rather, are those entities we warrantedly believe to exist for good and sufficient theoretical reasons. On this understanding, scientific theories explanatorily “save the appearances” precisely by characterizing the reality of which the appearances are appearances.

Like Quine, Sellars was deeply influenced by the work of Rudolf Carnap. Sellars' sophisticated account of the nature and import of theoretical reasoning in natural science, however, enabled him to develop a systematic naturalistic alternative to Quine's influential critique of Carnapian logical empiricism. In particular, the epistemological contrast between two sorts of empirical generalizations — those adopted on narrowly inductive grounds and those expressing constitutive principles of postulational theories adopted on broadly empirical, i.e., explanatory grounds — enabled Sellars to distinguish among three different grades of “observational involvement”: observations and general claims individually validated “inductively” by way of direct appeals to observational backing, the constitutive posits of postulational theories holistically validated by way of indirect, explanatory appeals to observational backing, and purely formal claims expressing necessary conditions for the formulation of scientific hypotheses in general. Consequently, where Quine rejected the classical Kantian analytic-synthetic dichotomy out of hand, Sellars argued that there were two quite different distinctions tangled up in the single dichotomy that Carnap had inherited from the Kantian tradition: the distinction between logical and empirical (matter-of-factual) claims (analytic2-synthetic2), and the distinction between claims whose revision requires abandonment or modification of the system of (theoretical) concepts in terms of which they are framed and claims revisable on the basis of observations formulated in terms of a system of (theoretical) concepts which remained fixed throughout (analytic1-synthetic1). Like Quine, then, Sellars moved decisively away from classical Kantian rationalism, but in the direction of a Kantian empiricism which preserved logical space for a theory of semantic meaning and the correlative distinctions between individual matter-of-factual truths and truths which, although belonging to theoretical systems themselves adopted on broadly empirical (synthetic2) grounds, were, relative to such a system, true ex vi terminorum (analytic1):

Kant's Rationalism

Grounded in experience
(“a posteriori”, simple induction)
Not so grounded
(“a priori”)
Synthetic
Analytic
Empirical Laws
(regularities)
Arithmetic, Geometry, Mechanics
(“synthetic a priori”)
Logic
“Our conceptual framework” (innate principles)
Kantian Empiricism

Grounded in experience (Empirical)
Not so grounded
Synthetic2
Analytic2 (L-true)
Synthetic1
Analytic1
Observation, Simple Induction
(Operational geometry, mechanics)
Postulation
(Physical geometry, idealizing scientific theories, mechanics, micro-physics)
Logic, arithmetic, mathematical analysis
(Pure geometry qua calculus)
“Our conceptual framework”:
Material (empirical) categories
Formal (ontological) categories
4. Sellars' Philosophy of Language and Mind

Essential to Sellars' thoroughgoing naturalism is an account of semantic meaning that requires no recourse to irreducibly platonistic or mentalistic idioms. Sellars consequently resolutely locates the normative conceptual order within the causal order and advances a naturalistic interpretation of the modes of causality exercised by linguistic rules centered on the notion of pattern-governed behavior, i.e.:

behavior which exhibits a pattern, not because it is brought about by the intention that it exhibit this pattern, but because the propensity to emit behavior of the pattern has been selectively reinforced, and the propensity to emit behavior which does not conform to this pattern selectively extinguished. (MFC, 423)
Pattern-governed behavior characteristic of a species — e.g., the dance of the bees — can arise from processes of natural selection on an evolutionary time scale, but, crucially, pattern-governed behavior can also be developed in individual “trainees” by deliberate selective reinforcement on the part of other individuals, the trainers, acting under the guidance of linguistic rules of criticism. In contrast to linguistic rules of action, e.g., “Ceteris paribus, one ought to (or: may) say such and such if in circumstances C”, which can be efficacious in guiding linguistic activity only to the extent that their subjects already possess the concepts of “saying such-and-such”, “being in circumstances C”, and, indeed, obeying a rule (i.e., doing something because it is enjoined or permitted by a rule), rules of criticism are ought-to-be's — e.g., “Westminster clock chimes ought to strike on the quarter hour” (LTC, 95) — whose subjects, although their performances may be assessed according to such rules, need not themselves have the concept of a rule nor, indeed, any concepts at all. Thus a trainer can be construed as reasoning

Patterned-behavior of such and such a kind ought to be exhibited by trainees, hence we, the trainers, ought to do this and that, as likely to bring it about that it is exhibited. (MFC, 423)
And, in consequence of the conducts of trainers under the guidance of such rules of action, the behavior of a language-learner can come to conform to the relevant rules of criticism without his “grasping” them himself in any other sense. “Trainees conform to ought-to-be's because trainers obey corresponding ought-to-do's” (MFC, 423).

Against this background, then, Sellars advanced an account of meaning as functional classification according to which semantic idioms in the first instance mark contexts within which structurally distinct “natural-linguistic objects” (e.g., utterings or inscribings) are classified in terms of their roles or functions in language entry transitions (linguistic responses to perceptual stimuli), language exit transitions (causal-linguistic antecedents of non-linguistic conduct), and intra-linguistic moves (inferential transitions from one linguistic representing to another). In particular, ‘means’ is interpreted as a specialized form of the copula, tailored to metalinguistic contexts, according to which the right side of the superficially relational form “___ means …” is properly understood as mentioning or exhibiting a linguistic item.

On Sellars' view, such special copulae and metalinguistic indicators initially arise in response to the need to abstract from our domestic sign designs in order to classify items of different languages on the basis of such functional criteria. In this project, ordinary quotation suffers from a systematic ambiguity regarding the criteria — structural (e.g., geometric, acoustic) or functional — according to which linguistic tokens are classifiable as belonging to this or that linguistic type. Accordingly, Sellars introduced a more straightforward device of two separate styles of quotation marks, star-quotes and dot-quotes, tied respectively to the structural and functional modes of sorting and individuating lexical items. Both star- and dot-quotes are illustrating, and thus indexical, devices, but dot-quotes are, in a sense, doubly so. For, whereas star-quotes form a common noun that is true of inscriptions (empirical structures) appropriately design-isomorphic to the token exhibited between them, dot-quotes form a common noun true of items in any language that play the role or do the job performed in our language by the tokens exhibited between them. In terms of this notational apparatus, then, such semantic claims as, for example,

(1s) (In German) ‘rot’ means red.
(2s) (In German) ‘Schnee ist weiss’ means snow is white.
can be more perspicuously expressed by

(1*) (In the German linguistic community) *rot*s are .red.s.
(2*) (In the German linguistic community) *Schnee ist weiss*s are .snow is white.s.
Once such a distinction between functional and structural classification of linguistic representing items is in hand, it is a straightforward matter to extend it to an account of mental representations, i.e., thoughts, as well. Unlike Quine, Sellars never abandoned the classical notion of thoughts as intentional inner episodes that play a causal-explanatory role vis-à-vis overt, paradigmatically linguistic, behavior. Consistent with his thoroughgoing naturalism, however, correlative to his ontological “linguistic nominalism”, Sellars embraced a form of “psychological nominalism”, whose leitmotif was

… the denial of the claim, characteristic of the realist tradition, that a “perception” or “awareness” of abstract entities is the root mental ingredient of mental acts and dispositions. (EAE, 445)
Instead, Sellars argued, the proper account of the distinctive intentionality of thought is also to be drawn in terms of the forms and functions of natural linguistic items. The positive thesis correlative to psychological nominalism, consequently, is modeled by what Sellars came to call “verbal behaviorism”.

According to VB [verbal behaviorism], thinking ‘that-p,’ where this means ‘having the thought occur to one that-p,’ has as its primary sense [an event of] saying ‘p’; and a secondary sense in which it stands for a short term proximate propensity [dispositional] to say ‘p’. (MFC, 419)
The origins of Sellars' mature forms of verbal behaviorism lie in the revolutionary theses of his classic essay “Empiricism and the Philosophy of Mind”, and, in particular, in his mythical story of our Rylean ancestors and the genius Jones. The story begins in medias res with people who have mastered a “Rylean language”, a sophisticated expressive system, including logical operators and subjunctive conditionals, whose fundamental descriptive vocabulary pertains to public spatio-temporal objects. Consonant with the Sellarsian account of linguistic meaning as functional classification, this hypothetical Rylean language, although lacking any resources for speaking of inner episodes, thoughts or experiences has been enriched by the fundamental resources of semantical discourse — enabling our ancestors to say of the their peers' utterances that they mean this or that, that they stand in various logical relations to one another, that they are true or false, and so on. In this milieu now appears the genius Jones.

[In] the attempt to account for the fact that his fellow men behave intelligently not only when their conduct is threaded on a string of overt verbal episodes … but also when no detectable verbal output is present, Jones develops a theory according to which overt utterances are but the culmination of a process which begins with certain inner episodes… . [His] model for these episodes which initiate the events which culminate in overt verbal behavior is that of overt verbal behavior itself. (EPM, 186)
Although the primary use of semantical terms remains the semantical characterization of overt verbal episodes, this Jonesean theory thus carries over the applicability of those semantical categories to its postulated inner episodes. i.e., to (occurrent) thoughts. The point of the Jonesean myth is to suggest that the epistemological status of thoughts (qua inner episodes) vis-à-vis candid public verbal performances is most usefully understood as analogous to the epistemological status of, e.g., molecules vis-à-vis the public observable behavior of gases.

[Thought] episodes are ‘in’ language-using animals as molecular impacts are ‘in’ gases, not as ‘ghosts’ are in ‘machines’. (EPM, 187)
Unlike molecules, however, which are introduced into kinetic gas theory as having a specific empirical character (represented by the posited essentially Newtonian lawfulness of their dynamic interactions), the thought episodes postulated by that theory as covert states of persons are introduced by a purely functional analogy. The concept of an occurrent thought is that of a causally-mediating logico-semantic role player, whose determinate empirical/ontological character, and thereby logical space for some form of “identity theory” is so far left open.

[The] fact that [thoughts] are not introduced as physiological entities does not preclude the possibility that at a later methodological stage they may, so to speak, ‘turn out’ to be such. Thus, there are many who would say that it is already reasonable to suppose that these thoughts are to be ‘identified’ with complex events in the cerebral cortex … (EPM, 187–8)
Since, on Sellars' account, the concept of a thought is fundamentally the concept of a functional kind, no ontological tensions would be generated by the identification within the scientific image of items belonging to that functional kind with, for instance, states and episodes of an organism's central nervous system. The manifest image's conception of person as thinkers, Sellars concludes, can fuse smoothly with the scientific image's conception of persons as complex material organisms having a determinate physiological and neurological structure.

The idea that the intentionality of the mental is to be understood in terms of epistemologically theoretical transpositions of the semantic categories of public language, themselves interpreted as modes of functional classification earn Sellars a definitive place in contemporary analytic philosophy of mind. As Dennett puts it,

Thus was contemporary functionalism in the philosophy of mind born, and the varieties of functionalism we have subsequently seen are in one way or another enabled, and directly or indirectly inspired, by what was left open in Sellars' initial proposal … (Dennett 1987, 341)
Sellars' proposal that we can illuminate the epistemic status of mental concepts by an appeal to the contrast between theoretical and non-theoretical discourse makes sense only against the background of another central element of his philosophical thought, his comprehensive critique of the “myth of the given”. The philosophical framework of givenness historically takes on many guises, including not only the idea that empirical knowledge rests on a foundation, but also, crucially, the assumption that the “privacy” of the mental and one's “privileged access” to one's own mental states are fundamental features of experience, both logically and epistemologically prior to all intersubjective concepts pertaining to inner episodes.

Sellars argues, on the contrary, that what begins in the case of inner episodes as a language with a purely theoretical use can acquire a first-person reporting role. It can turn out to be possible to train people, in essence by a process of operant conditioning, to have “privileged access” to some of their inner episodes, that is, to respond directly and non-inferentially to the occurrence of one thought with another (meta-) thought to the effect that one is thinking it. It is a special virtue of this aspect of Sellars' Jonesean story that it shows how the essential intersubjectivity of language can be reconciled with the “privacy” of inner episodes, i.e.,

… that it helps us understand that concepts pertaining to such inner episodes as thoughts are primarily and essentially inter-subjective, as inter-subjective as the concept of a positron, and that the [first-person] reporting role of these concepts … constitutes a dimension of [their] use … which is built on and presupposes this inter-subjective status. (EPM, 189)
At the heart of Sellars' general case against the Myth of the Given is his articulate recognition of the irreducibly normative character of epistemic discourse.

The essential point is that in characterizing an episode or a state as that of knowing, we are not giving an empirical description of that episode or state, we are placing it in the logical space of reasons, of justifying and being able to justify what one says. (EPM, 169)
Once it is acknowledged that the senses per se grasp no facts, that all knowledge that something is such-and-so (all “subsumption of particulars under universals”) presupposes learning, concept formation, and even symbolic representation, it follows that “… instead of coming to have a concept of something because we have noticed that sort of thing, to have the ability to notice a sort of thing is already to have the concept of that sort of thing, and cannot account for it.” (EPM, 176)

Sellars follows Kant in rejecting the Cartesian picture of a sensory-cognitive continuum. The “of-ness” of sensations — e.g., a sensation's being of a red triangle or of a sharp shooting pain — he insists, is not the intentional “of-ness” (“aboutness”) of thoughts. The “rawness” of “raw feels” is rather their non-conceptual character (cf. IAMBP, 376). Consequently, while his epistemological views regarding sensory episodes parallel his treatment of the epistemology of occurrent thoughts, Sellars' account of the ontology of sensations diverges dramatically from his functionalist account of thoughts.

In a final episode of the Jonesean myth, sensations are introduced as elements of an explanatory account of the occurrence in various circumstances of perceptual cognitions, having determinate semantic contents:

… the hero … postulates a class of inner — theoretical — episodes which he calls, say, impressions, and which are the end results of the impingement of physical objects and processes on various parts of the body… (EPM,191)
This time, however, the model for Jones' theory is not that of functionally-individuated families of sentences, but rather “a domain of ‘inner replicas’ which, when brought about in standard conditions share the perceptible characteristics of their physical sources” (EPM, 191). The leading idea of this model is the occurrence, ‘in’ perceivers of “replicas” per se, not of perceivings of “replicas” (which would mistakenly inject into the account of impressions the intentionality of thought), and, although the entities of this model are particulars, the entities introduced by the theory are not particulars but rather states of a perceiving subject. Thus, although talk of the “of-ness” of sensations, like that of the “of-ness” of thoughts is, on Sellars' view, fundamentally classificatory, the classification at issue is based not on a functional (logical, semantic) analogy but rather on analogies that, although in the first instance extrinsic and causal, ultimately attribute to sensations a determinate intrinsic content. The specific point of the model is to insist that states of, e.g., sensing [red triangle]ly (to highlight the status of ‘sensation’ as a “verbal noun”), characteristically brought about in normal perceivers in standard conditions by the action of red triangular objects on the eyes, can discharge their explanatory jobs in relation to cognitive perceptual takings (especially non-veridical perceptual judgments) only if they are conceived as resembling and differing from other sensory states — e.g., sensing [green triangular]ly, sensing [red square]ly, etc. — in a manner formally analogous to the way in which objects of the “replica” model — e.g., red and triangular, green and triangular, and red and square “wafers” — are conceived to resemble and differ from one another.

If that were the end of Sellars' ontological story regarding sensations, matters would be complicated enough. But Sellars proceeds to develop this core account in a variety of different directions, in consequence of which his full theory of sensations has emerged as being one of the most difficult and controversial aspects of his philosophy.

The first complication of Sellars' theory of sensation results from his conviction that, in the case of sensations, Jones' theory is interpretive. It does not introduce new domains of entities, but rather reinterprets the categorial/ontological status of sensory contents as states of perceivers. The crux of the original Jonesean theory that the very color quanta of which we are perceptually aware as existing in space are instead actually states of persons-qua-perceivers. Already within the manifest image, then, the ontological status ultimately accorded to sensory “content qualia” is incompatible with their being instantiated in physical space.

The second complication of Sellars' theory of sensations arises from the further conclusion that it is this manifest image conception of sensory contents as states of perceivers which must ultimately be synoptically “fused” with the scientific image, and that the latter's commitment to the idea that those perceivers themselves are complex systems of micro-physical particles constitutes a barrier to doing so in any straightforward way. Sellars notoriously concludes that sensory contents can be synoptically integrated into the scientific image only after both they and the currently-fundamental micro-physical particulars of that image as well undergo yet another categorial transposition into a categorially monistic ontology whose fundamental entities are all “absolute processes”. Sensings qua absolute processes would then be physical, he writes,

… not only in the weak sense of not being mental (i.e., conceptual), for they lack intentionality, but in the richer sense of playing a genuine causal role in the behavior of sentient organisms. They would, as I have used the terms, be physical-l but not physical-2. Not being epiphenomenal, they would conform to a basic metaphysical intuition: to be is to make a difference. (CL, III, 126)
5. A Final Remark

Lengthy as this discussion has been, it only begins to capture the scope, depth, and systematic character of Sellars' philosophical accomplishments. Many themes from his work have simply gone unmentioned — his anticipation of epistemological externalism and defense of a strong internalist alternative, his insightful analysis of predication and correlative nominalistic alternative to classical Platonistic categorial ontology, his sophisticated account of induction as a form of vindicatory practical reasoning, his significant contributions to ethical theory and the theory of action, and his masterful interpretations of the work of many of the discipline's great historical figures, not as scholarly museum exhibits, but always as active participants in a continuing philosophical conversation. The bibliographies and Internet resources listed below will point the way to both more comprehensive and more detailed accounts of the work of this towering philosophical figure of the postwar era.

6. Principal Works by Wilfrid Sellars

Books

Pure Pragmatics and Possible Worlds-The Early Essays of Wilfrid Sellars, [PPPW], ed. by Jeffrey F. Sicha, (Ridgeview Publishing Co; Atascadero, CA; 1980). [Contains a long introductory essay by Sicha and an extensive bibliography of Sellars' work through 1979.]
Science, Perception and Reality, [SPR], (Routledge & Kegan Paul Ltd; London, and The Humanities Press: New York; 1963) [Reissued in 1991 by Ridgeview Publishing Co., Atascadero, CA. This edition contains a complete bibliography of Sellars' published work through 1989.]
Philosophical Perspectives, [PP], (Charles C. Thomas: Springfield, IL; 1967). Reprinted in two volumes, Philosophical Perspectives: History of Philosophy and Philosophical Perspective: Metaphysics and Epistemology, (Ridgeview Publishing Co.; Atascadero, CA; 1977).
Science and Metaphysics: Variations on Kantian Themes. [S&M], (Routledge & Kegan Paul Ltd; London, and The Humanities Press; New York; 1968). The 1966 John Locke Lectures. [Reissued in 1992 by Ridgeview Publishing Co., Atascadero, CA. This edition contains a complete bibliography of Sellars' published work through 1989, a register of Sellars' philosophical correspondence, and a listing of circulated but unpublished papers and lectures.]
Essays in Philosophy and Its History, [EPH], (D. Reidel Publishing Co.; Dordrecht, Holland; 1975).
Naturalism and Ontology, [N&O], (Ridgeview Publishing Co.; Atascadero, CA: 1979). [An expanded version of the 1974 John Dewey Lectures]
The Metaphysics of Epistemology, Lectures by Wilfrid Sellars, edited by Pedro Amaral, (Ridgeview Publishing Co.; Atascadero, CA; 1989). [Contains a complete bibliography of Sellars' published work through 1989.]
Empiricism and the Philosophy of Mind [EPM*], edited by Robert Brandom, (Harvard University Press.; Cambridge, MA; 1997). [The original, 1956, version of [EPM] (see below), lacking footnotes added in [SPR], with an Introduction by Richard Rorty and Study Guide by Brandom.]
Kant and Pre-Kantian Themes: Lectures by Wilfrid Sellars, edited by Pedro Amaral, (Ridgeview Publishing Co.; Atascadero, CA: 2002). [A transcription of Sellars' Kant lectures, plus essays on Descartes, Locke, Spinoza, and Leibniz.]
Kant's Transcendental Metaphysics: Sellars' Cassirer Lecture Notes and Other Essays, edited by Jeffrey F. Sicha, (Ridgeview Publishing Co.; Atascadero, CA: 2002). [Contains a complete bibliography of Sellars' published work, philosophical correspondence, and circulated manuscripts through 2002.]
Selected Essays

[AAE] “Actions and Events”, Noûs 7, 1973, pp. 179–202.
[AE] “Abstract Entities”, Review of Metaphysics 16, 1983; reprinted in [PP], pp. 229–69.
[CDCM] “Counterfactuals, Dispositions, and the Causal Modalities”, in Minnesota Studies in the Philosophy of Science, Vol. II, ed. by H. Feigl, M. Scriven, and G. Maxwell, (University of Minnesota Press; Minneapolis, MN: 1957), pp. 225–308.
[CL] “Foundations for a Metaphysics of Pure Process”, The Carus Lectures for 1977–78, published in The Monist 64, No. 1, 1981.
[EAE] “Empiricism and Abstract Entities”, in The Philosophy of Rudolph Carnap, ed. by P.A. Schilpp (Open Court; LaSalle, IL; 1963); reprinted in [EPH], pp. 245–86.
[EPM] “Empiricism and the Philosophy of Mind”, in The Foundations of Science and the Concepts of Psychoanalysis, Minnesota Studies in the Philosophy of Science, Vol. I, ed. by H. Feigl and M. Scriven (University of Minnesota Press; Minneapolis, MN; 1956); reprinted in [SPR], pp. 127–96).
[FD] “Fatalism and Determinism”, in Keith Lehrer, ed., Freedom and Determinism, (Random House; New York, NY: 1966), pp. 141–74.
[GEC] “Givenness and Explanatory Coherence”, Journal of Philosophy 70, 1973, pp. 612–24.
[I] “…this I or he or it (the thing) which thinks”, the 1970 Presidential Address, American Philosophical Association (Eastern Division), reprinted in [EPH].
[IAMBP] “The Identity Approach to the Mind-Body Problem”, Review of Metaphysics 18, 1965; reprinted in [PP], pp. 370–88.
[IKTE] “The Role of Imagination in Kant's Theory of Experience”, The 1977 Dotterer Lecture, in H.W. Johnstone, Jr., ed., Categories: A Colloquium, (Pennsylvania State University Press: 1977), pp. 231–45.
[IV] “Induction as Vindication”, Philosophy of Science 31, 1964; reprinted in [EPH], pp. 367–416.
[ISRT] “Is Scientific Realism Tenable”, Proceedings of the PSA, Volume 2, 1976, pp. 307–34.
[KTE] “Some Remarks on Kant's Theory of Experience”, Journal of Philosophy 64, 1967, pp. 633–47.
[LT] “The Language of Theories”, in Current Issues in the Philosophy Science, ed. by H. Feigl and G. Maxwell (Henry Holt, Rhinehart and Winston; New York, NY; 1961): reprinted in [SPR], pp. 106–26.
[LTC] Language as Thought and Communication“, Philosophy and Phenomenological Research 29. 1969; reprinted in [EPH], pp. 93–117.
[MFC] ”Meaning as Functional Classification“, Synthese 27, 1974; pp. 417–37. (Issue also contains comments by Daniel Dennett and Hilary Putnam and Sellars' replies.)
[MEV] ”Mental Events“, Philosophical Studies 81, 1981; pp. 325–45.
[MGEC] ”More on Givenness and Explanatory Coherence“, in George S. Pappas, ed., Justification and Knowledge, (D. Reidel Publishing Co.; Dordrecht, Holland: 1979), pp. 169–82.
[NDL] ”Are There Non-Deductive Logics?“, in N. Rescher et al, eds., Essays in Honor of Carl G. Hempel, Synthese Library, (D. Reidel Publishing Co.; Dordrecht, Holland: 1970), pp. 83–103.
[OAFP] ”On Accepting First Principles“, in J. Tomberlin, ed., Philosophical Perspectives 2: Epistemology, 1988, (Ridgeview Publishing Co.; Atascadero, CA: 1988), pp. 301–14.
[P] ”Phenomenalism“, in [SPR], pp. 60–105.
[PSIM] ”Philosophy and the Scientific Image of Man“, in Frontiers of Science and Philosophy, ed. by Robert Colodny (University of Pittsburgh Press; Pittsburgh, PA; 1962); reprinted in [SPR], pp. 1–40.
[SK] ”The Structure of Knowledge“, The Matchette Foundation Lectures for 1971, published in Castañeda, ed., Action, Knowledge, and Reality (see below).
[SSMB] ”A Semantical Solution of the Mind-Body Problem“, Methodos 5, 1953, pp. 45–82. Reprinted in [PPPW].
[TA] ”Thought and Action“, in Keith Lehrer, ed., Freedom and Determinism, (Random House; New York, NY: 1966), pp. 105–39.
[TWO] ”Time and the World Order“, in Minnesota Studies in the Philosophy of Science, Vol. III, ed. by H. Feigl and G. Maxwell, (University of Minnesota Press; Minneapolis, MN: 1962), pp. 527–616.
Bibliography

Major Critical Studies

By Author

Castañeda, H-N., ed. Action, Knowledge, and Reality [AK&R] (Bobbs-Merrill; Indianapolis, IN; 1975). [Also contains an extensive bibliography of Sellars' work through 1974, Sellars' intellectual autobiography, and ‘The Structure of Knowledge’ (see above).]
deVries, Willem A., Wilfrid Sellars, (Acumen Publishing Ltd.; Chesham, UK; 2005). [A clearly written and accessible survey of Sellars' systematic philosophy as a whole.]
deVries, Willem A., and Timm Triplett, Knowledge, Mind, and the Given: Reading Wilfrid Sellars' ”Empiricism and the Philosophy of Mind“, (Hackett Publishing Co.; Indianapolis, IN & Cambridge, MA; 2000). [A detailed commentary on [EPM] (see above), including the complete text as published with additional footnotes in [SPR], 1963. The best general introduction to Sellars' classic essay.]
Delaney, C.F., Michael J. Loux, Gary Gutting, and W. David Solomon, The Synoptic Vision: Essays on the Philosophy of Wilfrid Sellars (University of Notre Dame Press; Notre Dame. IN; 1977). [Also contains an extensive bibliography.]
Pitt, Joseph C., ed., The Philosophy of Wilfrid Sellars: Queries and Extensions [PSQE] (D. Reidel Publishing Co; Dordrecht, Holland; 1978). [Revised proceedings of a workshop on the Philosophy of Wilfrid Sellars held at Virginia Polytechnic Institute and State University in Blacksburg, VA, in November 1976.]
Pitt, Joseph C., Pictures, Images, and Conceptual Change: An Analysis of Wilfrid Sellars' Philosophy of Science (D. Reidel Publishing Co.; Dordrecht, Holland; 1981).
Seibt, Johanna, Properties as Processes, A Synoptic Study of Wilfrid Sellars' Nominalism”, (Ridgeview Publishing Co.; Atascadero, CA; 1990.
By Journal

Noûs, Vol. 7, No. 2, 1973. [Special issue devoted to the philosophy of Wilfrid Sellars.]
The Monist, Vol. 65, No. 3, 1982. [Issue devoted to the philosophy of Wilfrid Sellars.]
Philosophical Studies, Vol. 54, No. 2, 1988. [Revised proceedings of the colloquium on Sellars' philosophy held in October 1987 at the University of Pittburgh's Center for Philosophy of Science.]
Philosophical Studies, Vol. 101, Nos. 2–3, 2000. [Special issue devoted to the philosophy of Wilfrid Sellars.]
Supplementary Bibliography

Alanen, L., 1992, “Thought-Talk: Descartes and Sellars on Intentionality,” American Philosophical Quarterly, 29: 19–34.
Alston, William P., 2002, “Sellars and the ‘Myth of the Given’,” Philosophy and Phenomenological Research, 65: 69–86.
Aune, Bruce, 1990, “Sellars' Two Images of the World,” Journal of Philosophy, 87: 537–45.
Bernstein, Richard J., 1965–66, “Sellars' Vision of Man-in-the-Universe,” Review of Metaphysics, 20: 290–316.
Bonevac, Daniel, 2002, “Sellars vs. the Given,” Philosophy and Phenomenological Research, 64: 1–30.
Brandom, Robert, 1995, Making It Explicit, Cambridge, MA: Harvard University Press.
–––, 1997, “Study Guide,” in EPM* (see above).
–––, 2000, Articulating Reasons: An Introduction to Inferentialism, Cambridge, MA: Harvard University Press.
Clark, Romane, 1982, “Sensibility and Understanding: The Given of Wilfrid Sellars,” The Monist, 65: 350–64.
Cornman, James, 1969–70, “Sellars, Scientific Realism, and Sensa,” Review of Metaphysics, 23: 417–51.
–––, 1976, “Sellars on Scientific Realism and Perceiving”, in F. Suppe and P.D. Asquith (eds.), Proceedings of the PSA, 2: 344–58.
Dennett, Daniel C., 1987, “Mid-Term Examination: Compare and Contrast,” in The Intentional Stance, Cambridge, MA: Bradford Books, The MIT Press, pp. 339–50.
Echelbarger, Charles, 1974, “Sellars on Thinking and the Myth of the Given,” Philosophical Studies, 25: 231–46.
–––, 1981, “An Alleged Legend,” Philosophical Studies, 39: 227–46.
Garfield, Jay, 1989, “The Myth of Jones and the Mirror of Nature: Reflections on Introspection,” Philosophy and Phenomenological Research, 50: 1–23.
Geiger, L., 1969, Die Logik der seelischen Ereignisse. Zu Theorien von L. Wittgenstein und W. Sellars, Frankfurt/M: Suhrkamp Verlag.
Gordon, Robert, 2000, “Sellars's Ryleans Revisited,” Proto Sociology, 14: 102–14.
Habermas, Juergen, 1975, “Sprachspiel, Intention und Bedeutung. Zu Motiven bei Sellars und Wittgenstein,”, in R. Wiggerhaus, (ed.), Sprachanalyse und Soziologie. Die sozialwissenschalfliche Relevanz von Wittgensteins Sprachphilosophie, Frankfurt/M: Suhrkamp Verlag, pp. 319–40.
Harman, Gilbert H., 1970, “Sellars' Semantics,” The Philosophical Review, 79: 404–19.
Hooker, C.A., 1977, “Sellars' Argument for the Inevitability of the Secondary Qualities,” Philosophical Studies, 32: 335–48.
Koch, Anton F., 1980, Vernunft und Sinnlichkeit im praktischen Denken. Eine sprachbehavioristische Rekonstruktion Kantisher Theoreme gegen Sellars, Würzburg: Verlag Königshausen + Neumann.
Kurthen, M., 1990, “Qualia, Sensa und Absolute Prozesse. Zu W. Sellars' Kritik des psychocerebalen Reduktionismus,” Journal for General Philosophy of Science (Zeitschrift für Allgemeine Wissenschaftstheorie), 21: 25–41.
Marras, Antonio, 1973, “Sellars on Thought and Language,” Noûs, 7: 152–63.
–––, 1973, “On Sellars' Linguistic Theory of Conceptual Activity,” Canadian Journal of Philosophy, 2: 471–83.
–––, 1973, “Reply to Sellars,” Canadian Journal of Philosophy, 2: 495–501.
–––, 1976, “Sellars' Behaviourism: A Reply to Fred Wilson,” Philosophical Studies, 30: 413–18.
McDowell, John, 1994, Mind and World, Cambridge, MA: Harvard University Press.
–––, 1998, “Having the World in View: Sellars, Kant, and Intentionality,” Journal of Philosophy, 95: 431–91.
McGilvray, J.A., 1983, “Pure Process(es)?,” Philosophical Studies, 43: 243–51.
Meyers, R.G., 1981, “Sellars' Rejection of Foundations,” Philosophical Studies, 39: 61–78.
Pohlenz, G., 1990, “Phänomenale Realität und naturalistische Philosophie. Eine systematische Widerlegung der Feigl'schen und Sellars'schen Theorien phänomenaler Qualitäten und Skizze einer alternativen Theorie,” Zeitschrift für philosophische Forschung, 44: 106–42.
Richardson, R.C. and Muilenburg, G., 1982, “Sellars and Sense Impressions,” Erkenntnis, 17: 171–211.
Rosenberg, Jay F., 1975, “The Elusiveness of Categories, the Archimedean Dilemma, and the Nature of Man,” in Castañeda (ed.) 1975, [AK&R] (see above), pp. 147–84.
–––, 1978, “Linguistic Roles and Proper Names,” in Pitt 1978, [PSQE] (see above), pp. 189–216.
–––, 1982, “The Place of Color in the Scheme of Things: A Roadmap to Sellars' Carus Lectures,” The Monist, 65(3): 315–35.
–––, 1983, “Wilfrid Sellars' Philosophy of Mind” in Contemporary Philosophy, 4: Philosophy of Mind, Guttorm Floistad (ed.), The Hague: Martinus Nijhoff Publishers, pp. 417–39.
–––, 1990a, “Fusing the Images: Nachruf for Wilfrid Sellars,” Journal for General Philosophy of Science (Zeitschrift für allgemeine Wissenschaftstheorie), 21(1): 3–25.
–––, 1990b, “Response to Aune, ‘Sellars' Two Images of the World’,” (Abstract), The Journal of Philosophy, 87(10): 546–7.
–––, 2000, “Wilfrid Sellars und die Theorie-Theorie,” Deutsche Zeitschrift für Philosophie, 48: 639–655.
–––, 2001, “Wilfrid Stalker Sellars”, in A. Martinich & D. Sosa (eds.), A Companion to Analytic Philosophy, Oxford: Blackwell Publishing Ltd, pp. 239–53.
–––, 2003, “Sellarsian Seeing: In Search of Perceptual Authority,” in Ralph Schumacher (ed.), Perception and Reality, Paderborn, Germany: mentis Verlag GmbH, pp. 262–85.
–––, 2005, “Ryleans and Outlookers: Wilfrid Sellars on ‘Mental States’,” Midwest Studies in Philosophy, 28(1), 239–265.
Rottschaefer, W.A., 1983, “Verbal Behaviorism and Theoretical Mentalism: An Assessment of the Marras-Sellars Dialogue,” Philosophical Research Archives, 9: 511–33.
Seibt, Johanna, 1990, “Analysis without synopsis must be blind. Obituary for W. Sellars,” Erkenntnis, 33: 5–8.
–––, 1995, “Wilfrid Sellars' systematischer Nominalismus,” Information Philosophie, 3: 22–6.
Sicha, Jeffrey, 1974, The Metaphysics of Elementary Mathematics, Amherst, MA: University of Massachusetts Press.
Smart, J.J.C., 1982, “Sellars on Process,” The Monist, 65: 302–14.
Sosa, Ernest, 1997, “Mythology of the Given,” History of Philosophy Quarterly, 14: 275–87.
–––, 2003, “Knowledge, Animal and Reflective: A Reply to Michael Williams,” (Part II of “Are There Two Grades of Knowledge?”), Proceedings of the Aristotelian Society, 77 (Supplement): 113–30.
Tye, Michael, 1975, “The Adverbial Theory: A Defense of Sellars against Jackson,” Metaphilosophy, 6: 136–43.
van Fraassen, Bas C., 1975, “Wilfrid Sellars on Scientific Realism,” Dialogue, 14: 606–16.
–––, 1976, “On the Radical Incompleteness of the Manifest Image,” in F. Suppe and P.D. Asquith (eds.), Proceedings of the PSA, 2: 335–43.
Vinci, T., 1981, “Sellars and the Adverbial Theory of Sensation,” Canadian Journal of Philosophy, 11: 199–217.
Williams, Michael, 2003, “Mythology of the Given: Sosa, Sellars and the Task of Epistemology,” (Part I of “Are There Two Grades of Knowledge?”), Proceedings of the Aristotelian Society, 77 (Supplement): 91–112.
Wilson, Fred, 1975, “Marras on Sellars on Thought and Language,” Philosophical Studies, 28: 91–102.
Woods, M., 1984, “Sellars on Kantian Intuitions,” Philosophy and Phenomenological Research, 44: 413–18.
Wright, E.L., 1985, “A Defense of Sellars,” Philosophy and Phenomenological Research, 46: 73–90.

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Carnap, Rudolf | functionalism | intentionality | Kant, Immanuel | meaning, theories of | mind: philosophy of | Quine, Willard van Orman | science, philosophy of

"Jaspers on the Intersection of Philosophy and Psychiatry" by Leonard H. Ehrlich,1963

Nassir Ghaemi has been involved in mastering the substance and import of Jaspers's work in psychopathology and psychology for many years. His book Concepts of Psychiatry (2003), from which Ghaemi's article to this issue of Philosophy, Psychiatry, & Psychology is excerpted, attests to his insight into the intersection of psychiatry and philosophy, and Jaspers's signal contribution in this regard. Roughly, Jaspers's work can be said to have two aspects to this intersection: first, a critical methodology of psychopathological and psychological research, and, second, philosophical reflections on the question "what is man?"1 Both aspects inform the last edition of General Psychopathology (1963), Jaspers's main work in the relevant field, and the only one fully translated into English. Although Ghaemi discusses both aspects in his book and in the article, he concentrates on the former, on the question of Jaspers's 'philosophy of science'. Working with Jaspers on the intersection of psychiatry and philosophy presents the researcher with considerable problems. Ghaemi is to be credited with achieving success despite the problems. Let me discuss some of these problems.

First, we are dealing with two languages, both of which, but each in its own way, demand precision of thought and of thought elements (e.g., terms). The task of the translator, whether from German to English or vice versa, is unenviable. Thus, the reader who is dependent on the English translation of General Psychopathology by Hoenig and Hamilton faces a handicap, which the translators acknowledge. Writing their "Translators' Preface" in the early 1960s, they not only observe that "modern clinical psychiatry is still largely based on the achievements of continental psychiatrists," but report that they "were not able to get much help from translations of Jaspers's philosophical works" nor from colleagues with orientations that, at that time, predominated in British philosophy departments (Jaspers 1963, vii, viii). Hoenig and Hamilton often inform the reader of these difficulties by means of adding the German original to their translated section titles.

Is Verstehen a Science?
One of the main problems Ghaemi faces in his article is the question of whether verstehende psychology is a science. The insuperable difficulty [End Page 75] lies in that 'Wissenschaft' can only be translated as 'science', but the way these terms are used in their respective languages differs. In recent usage, especially on the part of philosophers of science, 'science' refers to methodical research into inanimate or animate nature. Moreover, philosophers of science of the last century, whether German or English, have tended to regard measurable and mathematizable reality as the standard object of true 'science', as practiced especially in physics. Significantly, they have had little to say about biological fields. And by and large they have discounted thought that is a matter of Verstehen, whether history or verstehende psychology, as cognitively significant areas of science (e.g., see Popper, Hempel).

In German, 'Wissenschaft' refers to any area of critical, methodical inquiry, whether into realms of nature or not. To the English speaker, it may sound strange that in German Wissenschaft includes theology and musicology no less than astronomy and microbiology. (Perhaps it would be more useful to translate the word as 'disciplined inquiry'.) Because of that inclusiveness, Jaspers characterizes Wissenschaft by means of three marks that underlie both the natural sciences and the human studies. Jaspers mention those marks very briefly in General Psychopathology, and Ghaemi refers to them; Jaspers elaborates on them in other works. Ghaemi correctly stresses that the mark of "universal validity" is not to be taken as a pattern to which scientific cognition must conform. Instead, it is an aim of scientific work for it to be accepted as sound and true by anyone capable of following its procedure, and thus functions as a standard against which results of research are measured. To phrase it more concretely: A psychiatric finding has to be capable of being recognized as 'valid' by qualified peers.

Cogency
The mark of "cogency" (German: zwingende Gewissheit, literally "compelling certainty") is also an aim rather than an attribute of scientific cognition. In the natural sciences, what is 'certain' is the explanatory causal rule, nexus, or theory, and the degree of certainty is expressed in terms of probability. In cognition that is or involves interpretive Verstehen, the attainment of certainty is quite problematic. The reason is that what is 'understood' is not there as something that can be observed through a perceptive apparatus, much less measured, experimentally connected, and so on. The 'object' of 'understanding' can be 'understood' in several ways, even in opposite ways, and its interpretation is never at and end.2 Because various interpretations are possible, Verstehen is not a matter of determining degrees of probability. Because conflicting interpretations are equally possible, or more a propos, equally plausible, the determination of certainty with respect to pertinent factual, medical, and behavioral contexts of the case at hand is a matter of demonstrating the plausibility of one, and disproving that of the other. Here is where discussion among, and consultation with peers comes in.

This also points to another aspect of Jaspers's characterization of Verstehen raised to the level of a critically clarified method, namely that it proceeds along a 'hermeneutic circle' (1963, 356f). What is meant is that we never direct our attention to something with a blank mind, but always within a horizon of general dispositions, be they curiosity, prior knowledge, prejudice, or theoretical convictions. As we consider a specific case, we may recognize it as an instance or even a confirmation of a general type, in which case we complete the circle in a simple manner. Although the presence of the horizon of general meaning contexts is as indispensable as it is inevitable, it must not obtrude in the consideration of a case or in the process of research. Hence, the researcher has to suspend any interpretive predispositions much in line with the practice of 'bracketing out' (epochē) practiced by phenomenologists.

Methodological Consciousness
The key to aiming at universal validity and compelling certainty lies in that science is at heart research; that is, cognition is a doing. This is what is contained in what Jaspers calls 'methodological consciousness': 'method-' indicates a structured procedure; '-logical' means the structure is defined [End Page 76] in relation to specific presuppositions, to the pertinence to the 'object' at hand, and to the limits within which the procedure is operable, such that overstepping these limits would constitute an uncritical shift of perspective on one's 'object', or even a shift of focus on a different 'object'. And 'consciousness' means not simply that that the methodical doing is undertaken deliberately, but that the very doing is a thinking (Jaspers defines surgery as thinking with one's hands), informing the doing with attention to the defined parameters of the method deliberately undertaken.

Pluralism
Ghaemi maintains that "[methodological] pluralism and science are synonymous for Jaspers" (2007, 62), and in particular with reference to the equal pertinence to psychiatry of the methods of causal explanation and Verstehen of meaningful connections. Perhaps 'synonymity' does not quite capture what is meant by Jaspers. The reason is that even if the idea of 'science' were, for example, to be restricted only to 'causal explanation', it would still be a matter of pluralism. The conception of the category of 'cause' is labile and has a checkered history. Just one example: To arrive at the theory of gravitation, natural philosophers had to find a way of departing from the time-honored 'naturally' intuitable contiguity of cause and effect to imagining causation at a distance. And what the physicist means by cause is removed from, say, what the medical diagnostician means by etiology. And something equivalent pertains to the methodology of Verstehen: It will differ among the historian, the literary critic, the police investigator, the psychopathologist, and the psychotherapist. They all 'understand', but each in a different mode.

Thus, pluralism is at one with the methodological nature of the scientific enterprise. What is at play is the implication that Jaspers draws from the circumstance that different 'objects' require different mindsets on the part of the researcher, namely that thought must be critically sovereign.

Phenomena and Factualities
At no place does this sense of methodological pluralism come more clearly into play in General Psychopathology than in Part One, the largest and most elaborate part of the work. Here also the positive and negative interplay is displayed of what, in the respective later parts, are the topics of explanation and Verstehen. To clarify this, one has to point out that in Part One the English reader is confronted with terminological confusion, due in large part to the translators' vain search for knowledgeable consultants.

The heading for Part One is followed by the heading of Chapter I, which in turn is followed by Section One. In the English translation the three titles read as follows:

Part One: Individual Psychic Phenomena Chapter
I: Subjective Phenomena of Morbid Psychic Life (Phenomenology)
Section One: Abnormal Psychic Phenomena

Each of the three titles contains the word 'phenomena', but this same word is used to translate three different terms in the original.

Like all sciences, psychopathological research and diagnosis begins with data. Although the 'object' of the science is the 'psyche'—man's 'soul' and 'spirit'—not all data are strictly 'psychic', but are inferable—by means of Verstehen—through somatic and other material data. This is reflected in the division of this part into four chapters. Whereas the first chapter deals with the various kinds of subjective manifestations of "morbid psychic life," the other three chapters bring in 'objective' data: Chapter II, in dealing with the objective manifestation of psychic life ('performance psychology'), brings in the interplay of 'understandable' subjectivity (psyche) and observable objectivity (soma). At the very beginning of this chapter, Jaspers defines the antagonism between the 'psychological schema of task plus performance' and the 'neurological schema of the reflex arc'. Somatic manifestations as effects and symptoms of psychic life are the subject of Chapter III. And finally, Chapter IV classifies the display and testimony of meaning in expression, behavior, in productions and in works. [End Page 77]

If Part One consisted solely of the subject matter of Chapter I, then "Individual Psychic Phenomena" would be a correct title. But because the other three chapters deal with data that are not simply 'psychic phenomena', Jaspers entitles this part as

Die Einzeltatbestände des Seelenlebens, meaning "Individual Factualities of Psychic Life."

Jaspers speaks here of Tatbestand rather than Tatsache (fact) because the scientist reserves 'fact' for a material occurrence, not for what is indicated by a psychic datum. To accommodate both, Jaspers speaks of Tatbestand, which in the present context is best translated as kind of fact, or factuality. It does not mean 'phenomenon'.

Jaspers refers only to the methodology of Chapter I as 'phenomenology', which in his usage as he explains in the book, is really an aspect of Verstehen, namely "static" Verstehen, i.e., Verstehen of data rather than the connection among data. His title of Chapter I is:

Die subjektiven Erscheinungen des kranken Seelenlebens (Phänomenologie), meaning "Subjective Appearances of Morbid Psychic Life (Phenomenology)."

Accordingly the use of 'phenomena' makes sense and is correct only in the title of the Section One:

Einzelphänomene des abnormen Seelenlebens ("Individual Phenomena of Abnormal Psychic Life")

Philosophy and Psychiatry
A concentration on Part One of General Psychopathology could better illustrate the methodological need for both causal explanation and Verstehen in psychiatric research and practice, than on the juxtaposed Parts Two and Three. The question of methodology is not the only relevance of philosophy to psychiatry. It is of great interest to read Ghaemi's reference to the Parts of General Psychopathology that deal with the intersection of philosophy and psychiatry. These parts take up questions concerning the whole of the human being, mainly from a psychiatric viewpoint in Part Four, and mainly from a philosophical perspective in Part Six. It is fascinating that in Jaspers's elaborate treatise on nosology in Part Four, Ghaemi found his diagnostic psychopathologic schema as remarkably coinciding with a classification now in use in the field. And no study of Jaspers the philosopher-plus-psychopathologist would be complete without regard to Part Six, which was completely new in his last revision of General Psychopathology, the edition that is translated into English. It contains the sententious sentence that has become famous out of its context: "The human being is always more than he knows, or he or anyone else can know about himself.

Friday, December 11, 2009

"Later Semantic Incommensurability Thesis" byThomas Samuel Kuhn,

Thomas Samuel Kuhn (1922-1996) became one of the most influential philosophers of science of the twentieth century, perhaps the most influential—his The Structure of Scientific Revolutions is one of the most cited academic books of all time. His contribution to the philosophy science marked not only a break with several key positivist doctrines but also inaugurated a new style of philosophy of science that brought it much closer to the history of science. His account of the development of science held that science enjoys periods of stable growth punctuated by revisionary revolutions, to which he added the controversial ‘incommensurability thesis’, that theories from differing periods suffer from certain deep kinds of failure of comparability.
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Although Kuhn asserted a semantic incommensurability thesis in The Structure of Scientific Revolutions he did not there articulate or argue for the thesis in detail. This he attempted in subsequent work, with the result that the nature of the thesis changed over time. The heart of the incommensurability thesis after The Structure of Scientific Revolutions is the idea that certain kinds of translation are impossible. Early on Kuhn drew a parallel with Quine's thesis of the indeterminacy of translation (1970a, 202; 1970c, 268). According to the latter, if we are translating one language into another, there are inevitably a multitude of ways of providing a translation that is adequate to the behaviour of the speakers. None of the translations is the uniquely correct one, and in Quine's view there is no such thing as the meaning of the words to be translated. It was nonetheless clear that Quine's thesis was rather far from Kuhn's thesis, indeed that they are incompatible. First, Kuhn thought that incommensurability was a matter of there being no fully adequate translation whereas Quine's thesis involved the availability of multiple translations. Secondly, Kuhn does believe that the translated expressions do have a meaning, whereas Quine denies this. Thirdly, Kuhn later went on to say that unlike Quine he does not think that reference is inscrutable—it is just very difficult to recover (1976, 191).

Subsequently, Kuhn developed the view that incommensurability arises from differences in classificatory schemes—taxonomic incommensurability. A field of science is governed by a taxonomy, which divides its subject matter into kinds. Associated with a taxonomy is a lexical network—a network of related terms. A significant scientific change will bring with it an alteration in the lexical network which in turn will lead to a re-alignment of the taxonomy of the field. The terms of the new and old taxonomies will not be inter-translatable.

The problematic nature of translation arises from two assumptions. First, as we have seen, Kuhn assumes that meaning is (locally) holistic. A change in the meaning of one part of the lexical structure will result in a change to all its parts. This would rule out preservation of the translatability of taxonomies by redefining the changed part in terms of the unchanged part. Secondly, Kuhn adopts the ‘no-overlap’ principle which states that categories in a taxonomy must either be disjoint or one be a subset of the other. They cannot simply overlap. This rules out the possibility of an all-encompassing taxonomy that incorporates both the original and the changed taxonomies.

Kuhn continued to develop his conceptual approach to incommensurability. At the time of his death he had made considerable progress on a book in which he related incommensurability to issues in developmental psychology and concept acquisition.

"The Analysis of Sensations and the Relation of the Physical to the Psychical" by Ernst Mach,1905

I. INTRODUCTORY REMARKS:
ANTI METAPHYSICAL.

1.

THE great results achieved by physical science in modern times - results not restricted to its own sphere but embracing that of other sciences which employ its help - have brought it about that physical ways of thinking and physical modes of procedure enjoy on all hands unwonted prominence, and that the greatest expectations are associated with their application. In keeping with this drift of modern inquiry, the physiology of the senses, gradually abandoning the method of investigating sensations in themselves followed by men like Goethe, Schopenhauer, and others, but with greatest success by Johannes Muller, has also assumed an almost exclusively physical character. This tendency must appear to us as not altogether appropriate, when we reflect that physics, despite its considerable development, nevertheless constitutes but a portion of a larger collective body of knowledge, and that it is unable, with its limited intellectual implements, created for limited and special purposes, to exhaust all the subject-matter in question. Without renouncing the support of physics, it is possible for the physiology of the senses, not only to pursue its own course of development, but also to afford to physical science itself powerful assistance. The following simple considerations will serve to illustrate this relation between the two.

2.

Colours, sounds, temperatures, pressures, spaces, times, and so forth, are connected with one another in manifold ways; and with them are associated dispositions of mind, feelings, and volitions. Out of this fabric, that which is relatively more fixed and permanent stands prominently forth, engraves itself on the memory, and expresses itself in language. Relatively greater permanency is exhibited, first, by certain complexes of colours, sounds, pressures, and so forth, functionally connected in time and space, which therefore receive special names, and are called bodies. Absolutely permanent such complexes are not.

My table is now brightly, now dimly lighted. Its temperature varies. It may receive an ink stain. One of its legs may be broken. It may be repaired, polished, and replaced part by part. But, for me, it remains the table at which I daily write.

My friend may put on a different coat. His countenance may assume a serious or a cheerful expression. His complexion, under the effects of light or emotion, may change. His shape may be altered by motion, or be definitely changed. Yet the number of the permanent features presented, compared with the number of the gradual alterations, is always so great, that the latter may be overlooked. It is the same friend with whom I take my daily walk.

My coat may receive a stain, a tear. My very manner of expressing this shows that we are concerned here with a sum-total of permanency, to which the new element is added and from which that which is lacking is subsequently taken away.

Our greater intimacy with this sum-total of permanency, and the preponderance of its importance for me as contrasted with the changeable element, impel us to the partly instinctive, partly voluntary and conscious economy of mental presentation and designation, as expressed in ordinary thought and speech. That which is presented in a single image receives a single designation, a single name.

Further, that complex of memories, moods, and feelings, joined to a particular body (the human body), which is called the "I" or "Ego," manifests itself as relatively permanent. I may be engaged upon this or that subject, I may be quiet and cheerful, excited and ill-humoured. Yet, pathological cases apart, enough durable features remain to identify the ego. Of course, the ego also is only of relative permanency.

The apparent permanency of the ego consists chiefly in the single fact of its continuity, in the slowness of its changes. The many thoughts and plans of yesterday that are continued today, and of which our environment in waking hours incessantly reminds us (whence in dreams the ego can be very indistinct, doubled, or entirely wanting), and the little habits that are unconsciously and involuntarily kept up for long periods of time, constitute the groundwork of the ego. There can hardly be greater differences in the egos of different people, than occur in the course of years in one person. When I recall today my early youth, I should take the boy that I then was, with the exception of a few individual features, for a different person, were it not for the existence of the chain of memories. Many an article that I myself penned twenty years ago impresses me now as something quite foreign to myself. The very gradual character of the changes of the body also contributes to the stability of the ego, but in a much less degree than people imagine. Such things are much less analysed and noticed than the intellectual and the moral ego. Personally, people know themselves very poorly. When I wrote these lines in 1886, Ribot's admirable little book, The Diseases of Personality (second edition, Paris, 1888, Chicago, 1895), was unknown to me. Ribot ascribes the principal role in preserving the continuity of the ego to the general sensibility. Generally, I am in perfect accord with his views.

The ego is as little absolutely permanent as are bodies. That which we so much dread in death, the annihilation of our permanency, actually occurs in life in abundant measure. That which is most valued by us, remains preserved in countless copies, or, in cases of exceptional excellence, is even preserved of itself. In the best human being, however, there are individual traits, the loss of which neither he himself nor others need regret. Indeed, at times, death, viewed as a liberation from individuality, may even become a pleasant thought. Such reflections of course do not make physiological death any the easier to bear.

After a first survey has been obtained, by the formation of the substance-concepts " body " and " ego " (matter and soul), the will is impelled to a more exact examination of the changes that take place in these relatively permanent existences. The element of change in bodies and the ego, is in fact, exactly what moves the will I to this examination. Here the component parts of the complex are first exhibited as its properties. A fruit is sweet; but it can also be bitter. Also, other fruits may be sweet. The red colour we are seeking is found in many bodies. The neighbourhood of some bodies is pleasant; that of others, unpleasant. Thus, gradually, different complexes are found to be made up of common elements. The visible, the audible, the tangible, are separated from bodies. The visible is analysed into colours and into form. In the manifoldness of the colours, again, though here fewer in number, other component parts are discerned - such as the primary colours, and so forth. The complexes are disintegrated into elements, that is to say, into their ultimate component parts, which hitherto we have been unable to subdivide any further. The nature of these elements need not be discussed at present; it is possible that future investigations may throw light on it. We need not here be disturbed by the fact that it is easier for the scientist to study relations of relations of these elements than the direct relations between them.

3.

The useful habit of designating such relatively permanent compounds by single names, and of apprehending them by single thoughts, without going to the trouble each time of an analysis of their component parts, is apt to come into strange conflict with the tendency to isolate the component parts. The vague image which we have of a given permanent complex, being an image which does not perceptibly change when one or another of the component parts is taken away, seems to be something which exists in itself. Inasmuch as it is possible to take away singly every constituent part without destroying the capacity of the image to stand for the totality and to be recognised again, it is imagined that it is possible to subtract all the parts and to have something still remaining. Thus naturally arises the philosophical notion, at first impressive, but subsequently recognised as monstrous, of a " thing-in-itself," different from its "appearance," and unknowable.

Thing, body, matter, are nothing apart from the combinations of the elements, - the colours, sounds, and so forth - nothing apart from their so-called attributes. That protean pseudo-philosophical problem of the single thing with its many attributes, arises wholly from a misinterpretation of the fact, that summary comprehension and precise analysis, although both are provisionally justifiable and for many purposes profitable, cannot be carried on simultaneously. A body is one and unchangeable only so long as it is unnecessary to consider its details. Thus both the earth and a billiard-ball are spheres, if we are willing to neglect all deviations from the spherical form, and if greater precision is not necessary. But when we are obliged to carry on investigations in orography or microscopy, both bodies cease to be spheres.

4.

Man is pre-eminently endowed with the power of voluntarily and consciously determining his own point of view. He can at one time disregard the most salient features of an object, and immediately thereafter give attention to its smallest details; now consider a stationary current, without a thought of its contents (whether heat, electricity or fluidity), and then measure the width of a Fraunhofer line in the spectrum; he can rise at will to the most general abstractions or bury himself in the minutest particulars. Animals possess this capacity in a far less degree. They do not assume a point of view, but are usually forced to it by their sense-impressions. The baby that does not know its father with his hat on, the dog that is perplexed at the new coat of its master, have both succumbed in this conflict of points of view. Who has not been worsted in similar plights ? Even the man of philosophy at times succumbs, as the grotesque problem, above referred to, shows.

In this last case, the circumstances appear to furnish a real ground of justification. Colours, sounds, and the odours of bodies are evanescent. But their tangibility, as a sort of constant nucleus, not readily susceptible of annihilation, remains behind; appearing as the vehicle of the more fugitive properties attached to it. Habit, thus, keeps our thought firmly attached to this central nucleus, even when we have begun to recognise that seeing hearing, smelling, and touching are intimately akin in character. A further consideration is, that owing to the singularly extensive development of mechanical physics a kind of higher reality is ascribed to the spatial and to the temporal than to colours, sounds, and odours; agreeably to which, the temporal and spatial links of colours, sounds, and odours appear to be more real than the colours, sounds and odours themselves. The physiology of the senses, however, demonstrates, that spaces and times may just as appropriately be called sensations as colours and sounds. But of this later.

5.

Not only the relation of bodies to the ego, but the ego itself also, gives rise to similar pseudo - problems, the character of which may be briefly indicated as follows:

Let us denote the above-mentioned elements by the letters A B C . . ., X L M . . ., a, b, c . . . Let those complexes of colours, sounds, and so forth, commonly called bodies, be denoted, for the sake of clearness, by A B C . .; the complex, known as our own body, which is a part of the former complexes distinguished by certain peculiarities, may be called K L M . . .; the complex composed of volitions, memory-images, and the rest, we shall represent by a b c . . . Usually, now, the complex a , c . . . K L M. . ., as making up the ego, is opposed to the complex A B C . . ., as making up the world of physical objects; sometimes also, a b c . . . is viewed as ego, and K L M . . . A B C . . . as world of physical objects. Now, at first blush, A B C . . . appears independent of the ego, and opposed to it as a separate existence. But this independence is only relative, and gives way upon closer inspection. Much, it is true, may change in the complex a b c . . . without much perceptible change being induced in A B C . . .; and vice versa. But many changes in a b c . . . do pass, by way of changes in K L M . . ., to A B C . . .; and vice versa. (As, for example, when powerful ideas burst forth into acts, or when our environment induces noticeable changes in our body.) At the same time the group K L M . . . appears to be more intimately connected with a b c . . . and with A B C . . ., than the latter with one another; and their relations find their expression in common thought and speech.

Precisely viewed, however, it appears that the group A B C . . . is always codetermined by K L M. A cube when seen close at hand, looks large; when seen at a distance, small; its appearance to the right eye differs from its appearance to the left; sometimes it appears double; with closed eyes it is invisible. The properties of one and the same body, therefore, appear modified by our own body; they appear conditioned by it. But where, now, is that same body, which appears so different? All that can be said is, that with different K L M different A B C . . . are associated.

A common and popular way of thinking and speaking is to contrast " appearance " with " reality." A pencil held in front of us in the air is seen by us as straight; dip it into the water, and we see it crooked. In the latter case we say that the pencil appears crooked, but is in reality straight. But what justifies us in declaring one fact rather than another to be the reality, and degrading the other to the level of appearance ? In both cases we have to do with facts which present us with different combinations of the elements, combinations which in the two cases are differently conditioned. Precisely because of its environment the pencil dipped in water is optically crooked; but it is tactually and metrically straight. An image in a concave or flat mirror is only visible, whereas under other and ordinary circumstances a tangible body as well corresponds to the visible image. A bright surface is brighter beside a dark surface than beside one brighter than itself. To be sure, our expectation is deceived when, not paying sufficient attention to the conditions, and substituting for one another different cases of the combination, we fall into the natural error of expecting what we are accustomed to, although the case may be an unusual one. The facts are not to blame for that. In these cases, to speak of " appearance " may have a practical meaning, but cannot have a scientific meaning. Similarly, the question which is often asked, whether the world is real or whether we merely dream it, is devoid of all scientific meaning. Even the wildest dream is a fact as much as any other. If our dreams were more regular, more connected, more stable, they would also have more practical importance for us. In our waking hours the relations of the elements to one another are immensely amplified in comparison with what they were in our dreams. We recognise the dream for what it is. When the process is reversed, the field of psychic vision is narrowed; the contrast is almost entirely lacking. Where there is no contrast, the distinction between dream and waking, between appearance and reality, is quite otiose and worthless.

The popular notion of an antithesis between appearance and reality has exercised a very powerful influence on scientific and philosophical thought. We see this, for example, in Plato's pregnant and poetical fiction of the Cave, in which, with our backs turned towards the fire, we observe merely the shadows of what passes (Republic, vii. 1). But this conception was not thought out to its final consequences, with the result that it has had an unfortunate influence on our ideas about the universe. The universe, of which nevertheless we are a part, became completely separated from us, and was removed an infinite distance away. Similarly, many a young man, hearing for the first time of the refraction of stellar light, has thought that doubt was cast on the whole of astronomy, whereas nothing is required but an easily effected and unimportant correction to put everything right again.

6.

We see an object having a point S. If we touch S, that is, bring it into connexion with our body, we receive a prick. We can see S, without feeling the prick. But as soon as we feel the prick we find S on the skin. The visible point, therefore, is a permanent nucleus, to which the prick is annexed, according to circumstances, as something accidental. From the frequency of analogous occurrences we ultimately accustom ourselves to regard all properties of bodies as " effects " proceeding from permanent nuclei and conveyed to the ego through the medium of the body; which effects we call sensations. By this operation, however, these nuclei are deprived of their entire sensory content, and converted into mere mental symbols. The assertion, then, is correct that the world consists only of our sensations. In which case we have knowledge only of sensations, and the assumption of the nuclei referred to, or of a reciprocal action between them, from which sensations proceed, turns out to be quite idle and superfluous. Such a view can only suit with a half-hearted realism or a half-hearted philosophical criticism.

7.

Ordinarily the complex a b c . . . K L M . . . is contrasted as ego with the complex A B C . . . At first only those elements of A B C ... that more strongly alter a b c .... as a prick, a pain, are wont to be thought of as comprised in the ego. Afterwards, however, through observations of the kind just referred to, it appears that the right to annex A B C . . . to the ego nowhere ceases. In conformity with this view the ego can be so extended as ultimately to embrace the entire world. The ego is not sharply marked off, its limits are very indefinite and arbitrarily displaceable Only by failing to observe this fact, and by unconsciously narrowing those limits, while at the same time we enlarge them, arise, in the conflict of points of view, the metaphysical difficulties met with in this connexion.

As soon as we have perceived that the supposed unities " body " and " ego " are only makeshifts, designed for provisional orientation and for definite practical ends (so that we may take hold of bodies, protect ourselves against pain, and so forth), we find ourselves obliged, in many more advanced scientific investigations, to abandon them as insufficient and inappropriate. The antithesis between ego and world, between sensation (appearance) and thing, then vanishes, and we have simply to deal with the connexion of the elements a b c . . . A B C . . . K L M . . ., of which this antithesis was only a partially appropriate and imperfect expression. This connexion is nothing more or less than the combination of the above-mentioned elements with other similar elements (time and space). Science has simply to accept this connexion, and to get its bearings in it, without at once wanting to explain its existence.

On a superficial examination the complex a b c . . . appears to be made up of much more evanescent elements than A B C . . . and K L M . . ., in which last the elements seem to be connected with greater stability and in a more permanent manner (being joined to solid nuclei as it were). Although on closer inspection the elements of all complexes prove to be homogeneous, yet even when this has been recognised, the earlier notion of an antithesis of body and spirit easily slips in again. The philosophical spiritualist is often sensible of the difficulty of imparting the needed solidity to his mind-created world of bodies; the materialist is at a loss when required to endow the world of matter with sensation. The monistic point of view, which reflexion has evolved, is easily clouded by our older and more powerful instinctive notions.

8.

The difficulty referred to is particularly felt when we consider the following case. In the complex A B C . . .. which we have called the world of matter, we find as parts, not only our own body K L M . . ., but also the bodies of other persons (or animals) K' L' M' . . , K" L" M" . . .. to which, by analogy, we imagine other a' b' c'..., a" b" c", annexed, similar to a b c . . . So long as we deal with K' L' M' . . ., we find ourselves in a thoroughly familiar province which is at every point accessible to our senses. When, however, we inquire after the sensations or feelings belonging to the body K' L' M' . . ., we no longer find these in the province of sense: we add them in thought. Not only is the domain which we now enter far less familiar to us, but the transition into it is also relatively unsafe. We have the feeling as if we were plunging into an abyss. Persons who adopt this way of thinking only, will never thoroughly rid themselves of that sense of insecurity, which is a very fertile source of illusory problems.

But we are not restricted to this course. Let us consider, first, the reciprocal relations of the elements of the complex A B C . . ., without regarding K L M . . . (our body). All physical investigations are of this sort. A white ball falls upon a bell; a sound is heard. The ball turns yellow before a sodium lamp, red before a lithium lamp. Here the elements (A B C . . . ) appear to be connected only with one another and to be independent of our body (K L M . . . ). But if we take santonin, the ball again turns yellow. If we press one eye to the side, we see two balls. If we close our eyes entirely, there is no ball there at all. If we sever the auditory nerve, no sound is heard. The elements =4 B C . . ., therefore, are not only connected with one another, but also with K L M; To this extent, and to this extent only, do we call A B C . . . sensations, and regard A B C as belonging to the ego. In what follows, wherever the reader finds the terms " Sensation," " Sensation-complex," used alongside of or instead of the expressions " element," " complex of elements," it must be borne in mind that it is only in the connexion and relation in question, only in their functional dependence, that the elements are sensations. In another functional relation they are at the same time physical objects. We only use the additional term " sensations" to describe the elements, because most people are much more familiar with the elements in question as sensations (colours, sounds, pressures, spaces, times, etc.), while according to the popular conception it is particles of mass that are considered as physical elements, to which the elements, in the sense here used, are attached as " properties " or " effects.".

In this way, accordingly, we do not find the gap between bodies and sensations above described, between what is without and what is within, between the material world and the spiritual world. All elements A B C . . ., K L M. . .. constitute a single coherent mass only, in which, when any one element is disturbed, all is put in motion; except that a disturbance in K, L M, . . . has a more extensive and profound action than one in A B C . . . A magnet in our neighbourhood disturbs the particles of iron near it; a falling boulder shakes the earth; but the severing of a nerve sets in motion the whole system of elements. Quite involuntarily does this relation of things suggest the picture of a viscous mass, at certain places (as in the ego) more firmly coherent than in others. I have often made use of this image in lectures.

9.

Thus the great gulf between physical and psychological research persists only when we acquiesce in our habitual stereotyped conceptions. A colour is a physical object as soon as we consider its dependence, for instance, upon its luminous source, upon other colours, upon temperatures, upon spaces, and so forth. When we consider, however, its dependence upon the retina (the elements K L M. . .), it is a psychological object, a sensation. Not the subject matter, but the direction of our investigation, is different in the two domains. (Cp. also Chapter II., pp. 43, 44.)

Both in reasoning from the observation of the bodies of other men or animals, to the sensations which they possess, as well as in investigating the influence of our own body upon our own sensations, we have to complete observed facts by analogy. This is accomplished with much greater ease and certainty, when it relates, say, only to nervous processes, which cannot be fully observed in our own bodies - that is, when it is carried out in the more familiar physical domain - than when it is extended to the psychical domain, to the sensations and thoughts of other people. Otherwise there is no essential difference.

10.

The considerations just advanced, expressed as they have been in an abstract form, will gain in strength and vividness if we consider the concrete facts from which they flow. Thus, I lie upon my sofa. If I close my right eye, the picture represented in the accompanying cut is presented to my left eye In a frame formed by the ridge of my eyebrow, by my nose, and by my moustache, appears a part of my body, so far as visible, with its environment. My body differs from other human bodies - beyond the fact that every intense motor idea is immediately expressed by a movement of it, and that, if it is touched, more striking changes are determined than if other bodies are touched - by the circumstance, that it is only seen piecemeal, and, especially, is seen without a head. If I observe an element A within my field of vision, and investigate its connexion with another element B within the same field, I step out of the domain of physics into that of physiology or psychology, provided B, to use the apposite expression of a friend of mine made upon seeing this drawing, passes through my skin. Reflexions like that for the field of vision may be made with regard to the province of touch and the perceptual domains of the other senses.

11.

Reference has already been made to the different character of the groups of elements denoted by A B C . . . and a b c . . . As a matter of fact, when we see a green tree before us, or remember a green tree, that is, represent a green tree to ourselves, we are perfectly aware of the difference of the two cases. The represented tree has a much less determinate, a much more changeable form; its green is much paler and more evanescent; and, what is of especial note, it plainly appears in a different domain. A movement that we will to execute is never more than a represented movement, and appears in a different domain from that of the executed movement, which always takes place when the image is vivid enough. Now the statement that the elements A and a appear in different domains, means, if we go to the bottom of it, simply this, that these elements are united with different other elements. Thus far, therefore, the fundamental constituents of A B C . . .. a b c . . . would seem to be the same (colours, sounds, spaces, times, motor sensations . . .), and only the character of their connexion different.

Ordinarily pleasure and pain are regarded as different from sensations. Yet not only tactual sensations, but all other kinds of sensations, may pass gradually into pleasure and pain. Pleasure and pain also may be justly termed sensations. Only they are not so well analysed and so familiar, nor, perhaps, limited to so few organs as the common sensations. In fact, sensations of pleasure and pain, however faint they may be, really constitute an essential part of the content of all so-called emotions. Any additional element that emerges into consciousness when we are under the- influence of emotions may be described as more or less diffused and not sharply localised sensations. William James, and after him Theodule Ribot, have investigated the physiological mechanism of the emotions: they hold that what is essential is purposive tendencies of the body to action - tendencies which correspond to circumstances and are expressed in the organism. Only a part of these emerges into consciousness. We are sad because we shed tears, and not vice versa, says James. And Ribot justly observes that a cause of the backward state of our knowledge of the emotions is that we have always confined our observation to so much of these physiological processes as emerges into consciousness. At the same time he goes too far when he maintains that everything psychical is merely "surajoute" to the physical, and that it is only the physical that produces effects. For us this distinction is non-existent.

Thus, perceptions, presentations, volitions, and emotions, in short the whole inner and outer world, are put together, in combinations of varying evanescence and permanence, out of a small number of homogeneous elements. Usually, these elements are called sensations. But as vestiges of a one-sided theory inhere in that term, we prefer to speak simply of elements, as we have already done. The aim of all research is to ascertain the mode of connexion of these elements. If it proves impossible to solve the problem by assuming one set of such elements, then more than one will have to be assumed. But for the questions under discussion it would be improper to begin by making complicated assumptions in advance.

12.

That in this complex of elements, which fundamentally is only one, the boundaries of bodies and of the ego do not admit of being established in a manner definite and sufficient for all cases, has already been remarked. To bring together elements that are most intimately connected with pleasure and pain into one ideal mental-economical unity, the ego; this is a task of the highest importance for the intellect working in the service of the pain-avoiding, pleasure-seeking will. The delimitation of the ego, therefore, is instinctively effected, is rendered familiar, and possibly becomes fixed through heredity. Owing to their high practical importance, not only for the individual, but for the entire species, the composites " ego " and " body " instinctively make good their claims, and assert themselves with elementary force. In special cases, however, in which practical ends are not concerned, but where knowledge is an end in itself, the delimitation in question may prove to be insufficient, obstructive, and untenable.

Similarly, class-consciousness, class-prejudice, the feeling of nationality, and even the narrowest-minded local patriotism may have a high importance, for certain purposes. But such attitudes will not be shared by the broad-minded investigator, at least not in moments of research. All such egoistic views are adequate only for practical purposes. Of course, even the investigator may succumb to habit. Trifling pedantries and nonsensical discussions; the cunning appropriation of others' thoughts, with perfidious silence as to the sources; when the word of recognition must be given, the difficulty of swallowing one's defeat, and the too common eagerness at the same time to set the opponent's achievement in a false light: all this abundantly shows that the scientist and scholar have also the battle of existence to fight, that the ways even of science still lead to the mouth, and that the pure impulse towards knowledge is still an ideal in our present social conditions.

The primary fact is not the ego, but the elements (sensations). What was said on p. 21 as to the term " sensation " must be borne in mind. The elements constitute the I. s have the sensation green, signifies that the element green occurs in a given complex of other elements (sensations, memories). When I cease to have the sensation green, when I die, then the elements no longer occur in the ordinary, familiar association. That is all. Only an ideal mental-economical unity, not a real unity, has ceased to exist. The ego is not a definite, unalterable, sharply bounded unity. None of these attributes are important; for all vary even within the sphere of individual life; in fact their alteration is even sought after by the individual. Continuity alone is important. This view accords admirably with the position which Weismann has reached by biological investigations. ("Zur Frage der Unsterblichkeit der Einzelligen," Biolog Centralbl., Vol. IV., Nos. 21, 22; compare especially pages 654 and 655, where the scission of the individual into two equal halves is spoken of.) But continuity is only a means of preparing and conserving what is contained in the ego. This content, and not the ego, is the principal thing. This content, however, is not confined to the individual. With the exception of some insignificant and valueless personal memories, it remains presented in others even after the death of the individual. The elements that make up the consciousness of a given individual are firmly connected with one another, but with those of another individual they are only feebly connected, and the connexion is only casually apparent. Contents of consciousness, however, that are of universal significance, break through these limits of the individual, and, attached of course to individuals again, can enjoy a continued existence of an impersonal, superpersonal kind, independently of the personality by means of which they were developed. To contribute to this is the greatest happiness of the artist, the scientist, the inventor, the social reformer, etc.

The ego must be given up. It is partly the perception of this fact, partly the fear of it, that has given rise to the many extravagances of pessimism and optimism, and to numerous religious, ascetic, and philosophical absurdities. In the long run we shall not be able to close our eyes to this simple truth, which is the immediate outcome of psychological analysis. We shall then no longer place so high a value upon the ego, which even during the individual life greatly changes, and which, in sleep or during absorption in some idea, just in our very happiest moments, may be partially or wholly absent. We shall then be willing to renounce individual immortality,' and not place more value upon the subsidiary elements than upon the principal ones. In this way we shall arrive at a freer and more enlightened view of life, which will preclude the disregard of other egos and the overestimation of our own. The ethical ideal founded on this view of life will be equally far removed from the ideal of the ascetic, which is not biologically tenable for whoever practises it, and vanishes at once with his disappearance, and from the ideal of an overweening Nietzschean "superman," who cannot, and I hope will not be tolerated by his fellow-men.

If a knowledge of the connexion of the elements (sensations) does not suffice us, and we ask, Who possesses this connexion of sensations, Who experiences it ? then we have succumbed to the old habit of subsuming every element (every sensation) under some unanalysed complex, and we are falling back imperceptibly upon an older, lower, and more limited point of view. It is often pointed out, that a psychical experience which is not the experience of a determinate subject is unthinkable, and it is held that in this way the essential part played by the unity of consciousness has been demonstrated. But the Ego-consciousness can be of many different degrees and composed of a multiplicity of chance memories. One might just as well say that a physical process which does not take place in some environment or other, or at least somewhere in the universe, is unthinkable. In both cases, in order to make a beginning with our investigation, we must be allowed to abstract from the environment, which, as regards its influence, may be very different in different cases, and in special cases may shrink to a minimum. Consider the sensations of the lower animals, to which a subject with definite features can hardly be ascribed. It is out of sensations that the subject is built up, and, once built up, no doubt the subject reacts in turn on the sensations.

The habit of treating the unanalysed ego complex as an indiscerptible unity frequently assumes in science remarkable forms. First, the nervous system is separated from the body as the seat of the sensations. In the nervous system again, the brain is selected as the organ best fitted for this end, and finally, to save the supposed psychical unity, a point is sought in the brain as the seat of the soul. But such crude conceptions are hardly fit even to foreshadow the roughest outlines of what future research will do for the connexion of the physical and the psychical. The fact that the different organs and parts of the nervous system are physically connected with, and can be readily excited by, one another, is probably at the bottom of the notion of "psychical unity."

I once heard the question seriously discussed, "How the perception of a large tree could find room in the little head of a man?)' Now, although this "problem " is no problem, yet it renders us vividly sensible of the absurdity that can be committed by thinking sensations spatially into the brain. When I speak of the sensations of another person, those sensations are, of course, not exhibited in my optical or physical space; they are mentally added, and I conceive them causally, not spatially, attached to the brain observed, or rather, functionally presented. When I speak of my own sensations, these sensations do not exist spatially in my head, but rather my "head" shares with them the same spatial field, as was explained above. (Compare the remarks on Fig. I on pp. I7-I9 above.).

The unity of consciousness is not an argument in point. Since the apparent antithesis between the real world and the world given through the senses lies entirely in our mode of view, and no actual gulf exists between them, a complicated and variously interconnected content of consciousness is no more difficult to understand than is the complicated interconnection of the world.

If we regard the ego as a real unity, we become involved in the following dilemma: either we must set over against the ego a world of unknowable entities (which would be quite idle and purposeless), or we must regard the whole world, the egos of other people included, as comprised in our own ego (a proposition to which it is difficult to yield serious assent).

But if we take the ego simply as a practical unity, put together for purposes of provisional survey, or as a more strongly cohering group of elements, less strongly connected with other groups of this kind, questions like those above discussed will not arise, and research will have an unobstructed future.

In his philosophical notes Lichtenberg says: " We become conscious of certain presentations that are not dependent upon us; of others that we at least think are dependent upon us. Where is the border-line? We know only the existence of our sensations, presentations, and thoughts. We should say, It thinks, just as we say, It lightens. It is going too far to say cogito, if we translate cogito by I think. The assumption, or postulation, of the ego is a mere practical necessity." Though the method by which Lichtenberg arrived at this result is somewhat different from ours, we must nevertheless give our full assent to his conclusion.

13.

Bodies do not produce sensations, but complexes of elements (complexes of sensations) make up bodies. If, to the physicist, bodies appear the real, abiding existences, whilst the " elements " are regarded merely as their evanescent, transitory appearance, the physicist forgets, in the assumption of such a view, that all bodies are but thought-symbols for complexes of elements (complexes of sensations). Here, too, the elements in question form the real, immediate, and ultimate foundation, which it is the task of physiologico-physical research to investigate. By the recognition of this fact, many points of physiology and physics assume more distinct and more economical forms, and many spurious problems are disposed of.

For us, therefore, the world does not consist of mysterious entities, which by their interaction with another, equally mysterious entity, the ego, produce sensations, which alone are accessible. For us, colours, sounds, spaces, times, . . . are provisionally the ultimate elements, whose given connexion it is our business to investigate.

[I have always felt it as a stroke of special good fortune, that early in life, at about the age of fifteen, I lighted, in the library of my father, on a copy of Kant's Prolegomena to any Future Metaphysics. The book made at the time a powerful and ineffaceable impression upon me, the like of which I never afterwards experienced in any of my philosophical reading. Some two or three years later the superfluity of the role played by "the thing in itself" abruptly dawned upon me. On a bright summer day in the open air, the world with my ego suddenly appeared to me as one coherent mass of sensations, only more strongly coherent in the ego. Although the actual working out of this thought did not occur until a later period, yet this moment was decisive for my whole view. I had still to struggle long and hard before I was able to retain the new conception in my special subject. With the valuable parts of physical theories we necessarily absorb a good dose of false metaphysics, which it is very difficult to sift out from what deserves to be preserved, especially when those theories have become very familiar to us. At times, too, the traditional, instinctive views would arise with great power and place impediments in my way. Only by alternate studies in physics and in the physiology of the senses, and by historico-physical investigations (since about 1863), and after having endeavoured in vain to settle the conflict by a physico-psychological monadology (in my lectures on psycho-physics, in the Zeitschrift fur praktische Heilkunde, Vienna, 1863, p. 364), have I attained to any considerable stability in my views. I make no pretensions to the title of philosopher. I only seek to adopt in physics a point of view that need not be changed the moment our glance is carried over into the domain of another science; for, ultimately, all must form one whole. The molecular physics of today certainly does not meet this requirement. What I say I have probably not been the first to say. I also do not wish to offer this exposition of mine as a special achievement. It is rather my belief that every one will be led to a similar view, who makes a careful survey of any extensive body of knowledge. Avenarius, with whose works I became acquainted in 1883, approaches my point of view (Philosophie als Denken des Welt nach dem Princip des kleinsten Kraftmasses, 1876). Also Hering, in his paper on Memory (Almanach der Wiener Akademie, 1870, p. 258; English translation, O. C. Pub. Co., Chicago, 4th edition, enlarged, 1913), and J. Popper in his beautiful book, Das Rechte zu leben und die Pflicht zu sterben (Leipzig, 1878, p. 62), have advanced allied thoughts. Compare also my paper Ueber die okonomische Natur der physikalis der Forschung (Almanach der WienerAkadernie, 1882, p. 179, note; English translation in my Popular Scientific Lectures, Chicago, 1894). Finally let me also refer here to the introduction to W. Preyer's Reine Empfindungslehres to Riehl's Freibrurger Antrittsrede, p. 40, and to R. Wahle's Gehirn und Bewusstsein, 1884. My views were indicated briefly in 1872 and 1875, and not expounded at length until 1882 and 1883. I should probably have much additional matter to cite as more or less allied to this line of thought, if my knowledge of the literature were more extensive.]

It is precisely in this that the exploration of reality consists. In this investigation we must not allow ourselves to be impeded by such abridgments and delimitations as body, ego, matter, spirit, etc., which have been formed for special, practical purposes and with wholly provisional and limited ends in view. On the contrary, the fittest forms of thought must be created in and by that research itself, just as is done in every special science. In place of the traditional, instinctive ways of thought, a freer, fresher view, conforming to developed experience, and reaching out beyond the requirements of practical life, must be substituted throughout.

14.

Science always has its origin in the adaptation of thought to some definite field of experience. The results of the adaptation are thought-elements, which are able to represent the whole field. The outcome, of course, is different, according to the character and extent of the field. If the field of experience is enlarged, or if several fields heretofore disconnected are united, the traditional, familiar thought-elements no longer suffice for the extended field. In the struggle of acquired habit with the effort after adaptation, problems arise, which disappear when the adaptation is perfected, to make room for others which have arisen meanwhile.

To the physicist, qua physicist, the idea of "body" is productive of a real facilitation of view, and is not the cause of disturbance. So, also, the person with purely practical aims, is materially supported by the idea of the I or ego. For, unquestionably, every form of thought that has been designedly or undesignedly constructed for a given purpose, possesses for that purpose a permanent value. When, however, physics and psychology meet, the ideas held in the one domain prove to be untenable in the other. From the attempt at mutual adaptation arise the various atomic and monadistic theories - which, however, never attain their end. If we regard sensations, in the sense above defined (p. 13), as the elements of the world, the problems referred to appear to be disposed of in all essentials, and the first and most important adaptation to be consequently effected. This fundamental view (without any pretension to being a philosophy for all eternity) can at present be adhered to in all fields of experience; it is consequently the one that accommodates itself with the least expenditure of energy, that is, more economically than any other, to the present temporary collective state of knowledge Furthermore, in the consciousness of its purely economical function, this fundamental view is eminently tolerant. It does not obtrude itself into fields in which the current conceptions are still adequate. It is also ever ready, upon subsequent extensions of the field of experience, to give way before a better conception.

The presentations and conceptions of the average man of the world are formed and dominated, not by the full and pure desire for knowledge as an end in itself, but by the struggle to adapt himself favourably to the conditions of life. Consequently they are less exact, but at the same time also they are preserved from the monstrosities which easily result from a one-sided and impassioned pursuit of a scientific or philosophical point of view. The unprejudiced man of normal psychological development takes the elements which we have called A B C . . . to be spatially contiguous and external to the elements K L M. . .. and he holds this view immediately, and not by any process of psychological projection or logical inference or construction; even were such a process to exist, he would certainly not be conscious of it. He sees, then, an " external world " A B C . . . different from his body K L M . and existing outside it. As he does not observe at first the dependence of the A B C's . . . on the K L M's . . . (which are always repeating themselves in the same way and consequently receive little attention), but is always dwelling upon the fixed connexion of the A B C's . . . with one another, there appears to him a world of things independent of his Ego. This Ego is formed by the observation of the special properties of the particular thing K L M . . . with which pain, pleasure, feeling, will, etc., are intimately connected. Further, he notices things K' L' M', K" L" M", which behave in a manner perfectly analogous to K L M, and whose behaviour he thoroughly understands as soon as he has thought of analogous feelings, sensations, etc., as attached to them in the same way as he observed these feelings, sensations, etc., to be attached to himself. The analogy impelling him to this result is the same as determines him, when he has observed that a wire possesses all the properties of a conductor charged with an electric current, except one which has not yet been directly demonstrated, to conclude that the wire possesses this one property as well. Thus, since he does not perceive the sensations of his fellowmen or of animals but only supplies them by analogy, while he infers from the behaviour of his fellow-men that they are in the same position over against himself, he is led to ascribe to the sensations, memories, etc., a particular A B C . . . K L M . . . of a different nature, always differently conceived according to the degree of civilisation he has reached; but this process, as was shown above, is unnecessary, and in science leads into a maze of error, although the falsification is of small significance for practical life.

These factors, determining as they do the intellectual outlook of the plain man, make their appearance alternately in him according to the requirements of practical life for the time being, and persist in a state of nearly stable equilibrium. The scientific conception of the world, however, puts the emphasis now upon one, now upon the other factor, makes sometimes one and sometimes the other its starting-point, and, in its struggle for greater precision, unity and consistency, tries, so far as seems possible, to thrust into the background all but the most indispensable conceptions. In this way dualistic and monistic systems arise.

The plain man is familiar with blindness and deafness, and knows from his everyday experience that the look of things is influenced by his senses; but it never occurs to him to regard the whole world as the creation of his senses. He would find an idealistic system, or such a monstrosity as solipsism, intolerable in practice.

It may easily become a disturbing element in unprejudiced scientific theorising when a conception which is adapted to a particular and strictly limited purpose is promoted in advance to be the foundation of all investigation. This happens, for example, when all experiences are regarded as " effects " of an external world extending into consciousness. This conception gives us a tangle of metaphysical difficulties which it seems impossible to unravel. But the spectre vanishes at once when we look at the matter as it were in a mathematical light, and make it clear to ourselves that all that is valuable to us is the discovery of functional relations, and that what we want to know is merely the dependence of experiences or one another. It then becomes obvious that the reference to unknown fundamental variables which are not given (things-in-themselves) is purely fictitious and superfluous. But even when we allow this fiction, uneconomical though it be, to stand at first, we can still easily distinguish different classes of the mutual dependence of the elements of " the facts of consciousness "; and this alone is important for us.

A B C . . . K L M a b c . . .

K' L' M' ... a' b' c' ..

K" L" M"... a" B" C"

The system of the elements is indicated in the above scheme. Within the space surrounded by a single line lie the elements which belong to the sensible world, - the elements whose regular connexion and peculiar dependence on one another represent both physical (lifeless) bodies and the bodies of men, animals and plants. All these elements, again, stand in a relation of quite peculiar dependence to certain of the elements K L M - the nerves of our body, namely - by which the facts of sense-physiology are expressed. The space surrounded by a double line contains the elements belonging to the higher psychic life, memory-images and presentations, including those which we form of the psychic life of our fellow-men. These may be distinguished by accents. These presentations, again, are connected with one another in a different way (association, fancy) from the sensational elements A B C . . . K L M; but it cannot be doubted that they are very closely allied to the latter, and that in the last resort their behaviour is determined by A B C . . . K L M (the totality of the physical world), and especially by our body and nervous system. The presentations a' b' c' of the contents of the consciousness of our fellow-men play for us the part of intermediate substitutions, by means of which the behaviour of our fellow-men, - the functional relation of K' L' M' to A B C - becomes intelligible, in so far as in and for itself (physically) it would remain unexplained.

It is therefore important for us to recognise that in all questions in this connexion, which can be intelligibly asked and which can interest us, everything turns on taking into consideration different ultimate variables and different relations of dependence. That is the main point. Nothing will be changed in the actual facts or in the functional relations, whether we regard all the data as contents of consciousness, or as partially so, or as completely physical.

The biological task of science is to provide the fully developed human individual with as perfect a means of orientating himself as possible. No other scientific ideal can be realised, and any other must be meaningless.

The philosophical point of view of the average man - if that term may be applied to his naive realism - has a claim to the highest consideration. It has arisen in the process of immeasurable time without the intentional assistance of man. It is a product of nature, and is preserved by nature. Everything that philosophy has accomplished - though we may admit the biological justification of every advance, nay, of every error - is, as compared with it, but an insignificant and ephemeral product of art. The fact is, every thinker, every philosopher, the moment he is forced to abandon his one-sided intellectual occupation by practical necessity, immediately returns to the general point of view of mankind. Professor X., who theoretically believes himself to be a solipsist, is certainly not one in practice when he has to thank a Minister of State for a decoration conferred upon him, or when he lectures to an audience. The Pyrrhonist who is cudgelled in Moliere's Le Mariage force, does not go on saying " Il me semble que vous me battez," but takes his beating as really received.

Nor is it the purpose of these " introductory remarks " to discredit the standpoint of the plain man. The task which we have set ourselves is simply to show why and for what purpose we hold that standpoint during most of our lives, and why and for what purpose we are provisionally obliged to abandon it. No point of view has absolute, permanent validity. Each has importance only for some given end. ...