Roderick Firth, Sense Data and the Percept Theory, 1949-50.


(a) The Unity of Perceptual Consciousness

The thesis that ordinary perception is, as James puts it, "one state of mind or nothing", has been systematically defended by advocates of the Percept Theory. They have tried to show that perceptual consciousness is not a twofold state by proving that all those things which are in any way present to consciousness in perception are present in exactly the same way. Or, to describe their method more precisely, they have tried to show that it is impossible to discover within perception the two types of consciousness which are essential not only for the truth but for the very meaningfulness of the Sense-datum Theory. The Gestalt psychologists, in particular, deserve credit for the patient and methodical manner in which they have presented evidence against this distinction; they have begun by showing how artificial it is and have ended by presenting arguments to destroy it completely.

The Sense-datum Theory has been made particularly vulnerable to such criticism by a shift of opinion among its supporters concerning a certain phenomenological question -- the question namely, whether or not we are ever directly aware of depth in visual perception. There are still a few contemporary epistemologists who seem to believe, along with Locke and Berkeley, that depth is a conceptual or interpretational element in visual perception; they regularly speak of visual sense-data as "patches" of colour and describe their shapes in the language of plane geometry. But among contemporary psychologists who are investigating perceptual phenomena, there seems to be general agreement that there is no phenomenological justification for making this traditional distinction between visual depth and the other two spatial dimensions. And Price, an epistemologist whose analysis of perceptual consciousness is extremely acute, says specifically that our sense-datum when we look at a tomato has "a certain visual depth"29

From the point of view of those who defend the Percept Theory, the important fact about this shift of opinion within the older school of thought is not the manner in which the area of direct awareness is now delimited within perceptual consciousness. The important fact is that this shift of opinion represents a first step towards the recognition that in perception we are conscious of many qualities and relations which do not differ in their phenomenological status from those few which have traditionally been attributed to sense-data. Thus it is but one small step, as the Gestalt psychologists have shown, to the recognition that such qualities as simplicity, regularity, harmoniousness, clumsiness, gracefulness, and all the innumerable so-called "shape qualities" can also have the same phenomenological status as colour and shape.30 And it is but one small additional step from this to the recognition that the same holds true of qualities fittingly described by such adjectives as "reptilian", "feline", "ethereal", "substantial", and perhaps most of the adjectives in the dictionary. And this, of course, finally forces the admission that the qualities belonging to objects of direct awareness cannot be thought of as limited in the manner traditionally assumed, by the use of one or another particular organ of sense. For it may sometimes, indeed, be quite correct to say that the experience of a man looking at a distant mountain from a warm room comprises both whiteness and coldness, each in precisely the same manner, and neither in any other manner.

John Dewey has discussed some of these phenomenological facts in his Art as Experience and has pointed out that they do not clash in any way with our knowledge of physiology. The organic processes which condition perceptual experience are not limited to processes in a particular sense organ; the eye or the ear, as Dewey puts it, is "only the channel through which the total response takes place". Hence it should not be very surprising to discover that the so-called "visual qualities" do not always occupy a unique or central place in visual perception. "When we perceive, by means of the eyes as causal aids, the liquidity of water, the coldness of ice, the solidity of rocks, the bareness of trees in winter, it is certain that other qualities than those of the eye are conspicuous and controlling in perception. And it is as certain as anything can be that optical qualities do not stand by themselves with tactual and emotive qualities clinging to their skirts."31

Dewey's primary objective in the discussion from which these sentences are quoted is to refute what I have called the first point of agreement among philosophers and psychologists who accept the Sense-datum Theory; his primary objective, in other words, is to show that we cannot find within ordinary perceptual consciousness a limited set of qualities having the unique phenomenological status which has been thought to distinguish the objects of direct awareness. But Dewey's description of perceptual experience also contains an implicit criticism of the second point of agreement among those who accept the Sense-datum Theory, and thus serves as an introduction to the final, and perhaps most important step, in the development of the Percept Theory.

(b) the Consciousness of Ostensible Physical Objects

The final step in the development of the Percept Theory consists in showing that the qualities of which we are conscious in perception are almost always presented to us, in some obvious sense, as the qualities of physical objects.32 We are not conscious of liquidity, coldness, and solidity, but of the liquidity of water, the coldness of ice, and the solidity of rocks. Dewey has pointed out this phenomenological fact more explicitly in a number of other places by insisting that ordinary perceptual experience is the experience of physical nature. In Experience and Nature, for example, he says: "It is not experience which is experienced, but nature -- stones, plants, animals, diseases, health, temperature, electricity, and so on. Things interacting in certain ways are experience: they are what is experienced."33 Other philosophers and psychologists have preferred to express this fact in somewhat different terms; it is quite common, for example, to find them asserting that what is presented in perception is a "substantial whole", or a "whole physical object". Whatever the manner of expression, however, the phenomenological fact is simply that in perception we are conscious, in one sense of the word, of physical objects, without at the same time being conscious, in another sense of the word, of the entities which have traditionally been called "sense-data". Perception, in short, is not a twofold state; and since we are conscious of physical objects we cannot possibly be conscious of sense-data in the distinctive manner required by the Sense-datum Theory.

It must not be inferred, however, that James and others who deny that perception is a twofold state would not admit that there are certain types of disposition of the perceiving organism, or possibly even certain types of conscious experience, which invariably accompany our perceptual consciousness of physical objects. Such possibilities must be considered in determining the epistemological implications of the Percept Theory and will be briefly discussed in Part II of this paper, but they are irrelevant to the central thesis of the Percept Theory. For the duality denied by those who accept this theory is a duality of what we may perhaps call the sensuous aspect of consciousness at the moment of ordinary perception. At that moment, they maintain, we are conscious in a certain manner of a physical object which is somehow presented to us completely clothed in sensuous qualities. These qualities are presented as qualities of the object; indeed they are in no sense abstracted or otherwise distinguished from the presented object; and they are not limited to the qualities which have traditionally been mentioned in descriptions of sense-data. And finally, according to those who accept the Percept Theory, the sensuously clothed object is the only sensuous content of consciousness during ordinary perception. Sense-data, of course, if they exist as the objects of pure states of direct awareness, may properly be described as having sensuous qualities; but sense-data do not occur as constituents of perceptual consciousness.

There is, of course, considerable disagreement about the proper way to express this conclusion. The traditional Sense-datum Theory is based on a supposed distinction between the direct awareness of sense-data and the mediated consciousness or "perception" of physical objects; those who reject this distinction, therefore, are rejecting not only the traditional concept of sense-datum but also the theory that ordinary perception is mediated in some manner or other,34 by the presence of sense-data. Since both aspects of the traditional distinction must stand or fall together, there is no unambiguous way in which the traditional terminology can be used to express the positive conclusions of those who accept the Percept Theory. On the one hand it is probably misleading for advocates of the Percept Theory to assert bluntly, as they frequently do, that in perception we are directly aware of physical objects. For in addition to suggesting the very distinction which the Percept Theory rejects, the word "directly", when used in such a context, may have certain epistemological connotations which are not relevant to the phenomenological issue.35 On the other hand it would create an unnecessary paradox if advocates of the Percept Theory were to assert that in ordinary perceptual experience we are not directly aware of anything; and this too might have confusing epistemological connotations. Consequently, even though either of these two modes of expression would be adequate if it were carefully explained, I shall avoid both of them in the following pages.

William James sometimes used the word "percept" to refer to the content of consciousness during perception; it is this fact which has made the name "Percept Theory" seem to me appropriate for the particular theory of perceptual consciousness which he himself supported. If we were to adapt this terminology to satisfy our present need we could say that according to the Percept Theory we are presented in ordinary perception not with a sense-datum but with "object-percept" only, and we could speak more specifically, when necessary, of "cat-percepts", "mountain percepts", etc.

For the problems to be discussed in the following pages, however, the terminology used by Price is even more convenient. Price uses the term "ostensible material object" to refer to that part of the content of perceptual consciousness which is not a sense-datum; it is thus possible to express the fact that in perception we are conscious in a certain manner of a physical object, by saying that we are presented with an ostensible physical object. Price himself does not accept the Percept Theory, but those who do may describe their position by saying that in ordinary perception we are presented with ostensible physical objects but not with sense-data.36 The following passage from Price, as a matter of fact, provides a fitting conclusion for this section of the discussion, for it aptly describes the unmediated character of perceptual consciousness to which supporters of the Percept Theory have tried to draw attention. That Price could write a passage like this and still accept the Sense-datum Theory, is a mystery of the kind which the next section is intended to solve
"Somehow it is the whole thing, and not just a jejune extract from it, which is before the mind from the first. From the first it is the complete material thing, with back, sides, and insides as well as front, that we 'accept', that 'ostends itself' to us, and nothing less; a thing, too, persistng through time both before and after . . . and possessed of various causal characteristics. . . . Already in this single act, even in a momentary glance, we take all these elements of the object to be there, all of them, as Mr. Joseph has said in another connection, we must not suppose that because there is only a little definite before the mind, therefore there is only a definite little."37

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29 Perception, p. 3

30 See W. Köhler, Gestalt Psychology, ch. vi, Liveright, New York, 1929.

31 John Dewey, Art as Experience, pp. 122-124, Minton Balch, New York, 1934.

32 The word "physical" is not used here, of course, in any technical sense which would limit physical objects to entities like electrons and protons which constitute the special subject-matter of physics.

33 P. 42, W. W. Norton, N.Y., 1935.

34 The nature of this mediation is discussed in Part II of this paper.

35 This matter is discussed at length in Part II of this paper.

36 This terminology is not intended to commit the Percept Theory to an "act-object" analysis of sense-experience. See Author's Note at the end of this essay. [Footnote revised in 1964. Ed.]

37 Perception, pp. 151-152.

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