Essays in Experimental Logic

by John Dewey

We come to the question passed over. Can such terms as "visual," "sensory," be neglected without modifying the force of the question—that is, without affecting the implications which give it the force of a problem? Can we "know that objects of sense, or very similar objects, exist at times when we are not perceiving them? Secondly, if this cannot be known, can we know that other objects, inferable from objects of sense but not necessarily resembling them, exist either when we are perceiving the objects of sense or at any other time" (p. 75)?

I think a little reflection will make it clear that without the limitation of the term "perceiving" by the term "sense" no problem as to existence at other times can possibly arise. For neither (a) reference to time nor (b) limitation to a particular time is given either in the fact of existence of color or of perceiving color. Mr. Russell, for example, makes allusion to "a patch of color which is momentarily seen" (p. 76). This is the sort of thing that may pass without challenge in the common-sense world, but hardly in an analysis which professes to call that world in question. Mr. Russell makes the allusion in connection with discriminating between sensation as signifying "the mental event of our being aware" and the sensation as object of which we are aware—the sense object. He can hardly be guilty, then, in the immediate context, of proceeding to identify the momentariness of the event with the momentariness of the object. There must be some grounds for assuming the temporal quality of the object—and that "immediateness" belongs to it in any other way than as an object of immediate seeing. What are these grounds?

How is it, moreover, that even the act of being aware is describable as "momentary"? I know of no way of so identifying it except by discovering that it is delimited in a time continuum. And if this be the case, it is surely superfluous to bother about inference to "other times." They are assumed in stating the question—which thus turns out again to be no question. It may be only a trivial matter that Mr. Russell speaks of "that patch of color which is momentarily seen when we look at the table" (p. 76, italics mine). I would not attach undue importance to such phrases. But the frequency with which they present themselves in discussions of this type suggests the question whether as matter of fact "the patch of color" is not determined by reference to an object—the table—and not vice versa. As we shall see later, there is good ground for thinking that Mr. Russell is really engaged, not in bringing into question the existence of an object beyond the datum, but in redefining the nature of an object, and that the reference to the patch of color as something more primitive than the table is really relevant to this reconstruction of traditional metaphysics. In other words, it is relevant to defining an object as a constant correlation of variations in qualities, instead of defining it as a substance in which attributes inhere—or a subject of predicates.

a) If anything is an eternal essence, it is surely such a thing as color taken by itself, as by definition it must be taken in the statement of the question by Mr. Russell. Anything more simple, timeless, and absolute than a red can hardly be thought of. One might question the eternal character of the received statement of, say, the law of gravitation on the ground that it is so complex that it may depend upon conditions not yet discovered and the discovery of which would involve an alteration in the statement. If 2 plus 2 equal 4 be taken as an isolated statement, it might be conceived to depend upon hidden conditions and to be alterable with them. But by conception we are dealing in the case of the colored surface with an ultimate, simple datum. It can have no implications beyond itself, no concealed dependencies. How then can its existence, even if its perception be but momentary, raise a question of "other times" at all?

b) Suppose a perceived blue surface to be replaced by a perceived red surface—and it will be conceded that the change, or replacement, is also perceived. There is still no ground for a belief in the temporally limited duration of either the red or the blue surface. Anything that leads to this conclusion would lead to the conclusion that the number two ceases when we turn to think of an atom. There is no way then of escaping the conclusion that the adjective "sense" in the term "sense object" is not taken innocently. It is taken as qualifying (for the purposes of statement of the problem) the nature of the object. Aside from reference to the momentariness of the mental event—a reference which is expressly ruled out—there is no way of introducing delimited temporal existence into the object save by reference to one and the same object which is perceived at different times to have different qualities. If the same object—however object be defined—is perceived to be of one color at one time and of another color at another time, then as a matter of course the color-datum of either the earlier or later time is identified as of transitory duration. But equally, of course, there is no question of inference to "other times." Other times have already been used to describe, define, and delimit this (brief) time. A moderate amount of unbiased reflection will, I am confident, convince anyone that apart from a reference to the same existence perduring through different times while changing in some respect, no temporal delimitation of the existence of such a thing as sound or color can be made. Even Plato never doubted the eternal nature of red; he only argued from the fact that a thing is red at one time and blue at another to the unstable, and hence phenomenal, character of the thing. Or, put in a different way, we can know that a red is a momentary or transitory existence only if we know of other things which determine its beginning and cessation.

Mr. Russell gives a specific illustration of what he takes to be the correct way of stating the question in an account of what, in the common-sense universe of discourse, would be termed walking around a table. If we exclude considerations to which we have (apart from assuming just the things which are doubtful) no right, the datum turns out to be something to be stated as follows: "What is really known[66] is a correlation of muscular and other bodily sensations with changes in visual sensations" (p. 77). By "sensations" must be meant sensible objects, not mental events. This statement repeats the point already dealt with: "muscular," "visual," and "other bodily" are all terms which are indispensable and which also assume the very thing professedly brought into question: the external world as that was defined. "Really known" assumes both noting and belief, with whatever complex implications they may involve—implications which, for all that appears to the contrary, may be indefinitely complex, and which, by Mr. Russell's own statement, involve relationship to at least two other terms besides the datum. But in addition there appears the new term "correlation." I cannot avoid the conclusion that this term involves an explicit acknowledgment of the external world.

Note, in the first place, that the correlation in question is not simple: it is threefold, being a correlation of correlations. The "changes in visual sensations" (objects) must be correlated in a temporal continuum; the "muscular and other bodily sensations" (objects) must also constitute a connected series. One set of changes belongs to the serial class "visual"; the other set to the serial class "muscular." And these two classes sustain a point-to-point correspondence to each other—they are correlated.

I am not raising the old question of how such complex correlations can be said to be either "given" or "known" in sense, though it is worth a passing notice that it was on account of this sort of phenomenon that Kant postulated his threefold intellectual synthesis of apprehension, reproduction, and recognition in conception; and that it is upon the basis of necessity for such correlations that the rationalists have always criticized sensationalist empiricism. Personally I agree that temporal and spatial qualities are quite as much given in experience as are particulars—in fact, as I have been trying to show, particulars can be identified as particulars only in a relational complex. My point is rather (i) that any such given is already precisely what is meant by the "world"; and (ii) that such a highly specified correlation as Mr. Russell here sets forth is in no case a psychological, or historical, primitive, but is a logical primitive arrived at by an analysis of an empirical complex.

(i) The statement involves the assumption of two temporal "spreads" which, moreover, are determinately specified as to their constituent elements and as to their order. And these sustain to each other a correlation, element to element. The elements, moreover, are all specifically qualitative and some of them, at least, are spatial. How this differs from the external world of common-sense I am totally unable to see. It may not be a very big external world, but having begged a small external world, I do not see why one should be too squeamish about extending it over the edges. The reply, I suppose, is that this complex defined and ordered object is by conception the object of a single perception, so that the question remains as to the possibility of inferring from it to something beyond.[67] But the reply only throws us back upon the point previously made. A particular or single event of perceptual awareness can be determined as to its ingredients and structure only in a continuum of objects. That is, the series of changes in color and shape can be determined as just such and such an ordered series of specific elements, with a determinate beginning and end, only in respect to a temporal continuum of things anteceding and succeeding. Moreover, the determination involves an analysis which disentangles qualities and shapes from contemporaneously given objects which are irrelevant. In a word, Mr. Russell's object already extends beyond itself; it already belongs to a larger world.

(ii) A sensible object which can be described as a correlation of an ordered series of shapes and colors with an ordered series of muscular and other bodily objects presents a definition of an object, not a psychological datum. What is stated is the definition of an object, of any object in the world. Barring ambiguities[68] in the terms "muscular" and "bodily," it seems to be an excellent definition. But good definition or poor, it states what a datum is known to be as an object in a known system; viz., definite correlations of specified and ordered elements. As a definition, it is general. It is not made from the standpoint of any particular percipient. It says: If there be any percipient at a specified position in a space continuum, then the object may be perceived as such and such. And this implies that a percipient at any other position in the space continuum can deduce from the known system of correlations just what the series of shapes and colors will be from another position. For, as we have seen, the correlation of the series of changes of shape assumes a spatial continuum; hence one perspective projection may be correlated with that of any position in the continuum.