The body, then, in Bergson’s theory, yes, the brain itself, is no producer, repository nor reproducer of any element of consciousness. The body is a center of reaction, and nothing else. “The size, shape, even the color, of external objects is modified according as my body approaches or recedes from them, ... the strength of an odour, the intensity of a sound, increases or diminishes with distance; finally, ... this very distance represents, above all, the measure in which surrounding bodies are insured, in some sort, against the immediate action of my body. In the degree that my horizon widens, the images which surround me seem to be painted upon a more uniform background and become to me more indifferent. The more I narrow this horizon, the more the objects which it circumscribes space themselves out distinctly according to the greater or less ease with which my body can touch and move them. They send back, then, to my body, as would a mirror, its eventual influence; they take rank in an order corresponding to the growing or decreasing powers of my body. The objects which surround my body reflect its possible action upon them.”[130] Cut a sensory nerve, and the reactive process is destroyed, and with it, perception. “Change the objects, or modify their relation to my body, and everything is changed in the interior movements of my perceptive centres. But everything is also changed in ‘my perception.’ My perception is, then, a function of these molecular movements; it depends upon them.”[131] “What then are these movements?... they are, within my body, the movements intended to prepare, while beginning it, the reaction of my body to the action of external objects ... they foreshadow at each successive moment its virtual acts.”[132] It may seem that my reaction to a body is the same whether I perceive it visually or tactually or otherwise. But movements externally identical may differ internally; there is a different organization of the same gross function with different microscopic functions. The meaning has ultimately an important sameness, since meaning is a function of biological adjustment. But different inner organizations are still the explanation of different ways of perceiving what is, in all biologically important respects, the same object.
Serious fault has been found[133] with Bergson’s attempt to establish, by scientific research in the subject of aphasia, the ontological independence of spirit, the seat of memory, from body. But on other grounds than such scientific investigation the issue of this attempt appears to me at best a futile achievement; for the result is in any case the reinstatement, untouched, of that problem of all radical dualism, a problem which Bergson solves only by metaphor whose brilliance may be luminous itself, but has no illumination for the problem, which is how reactive states are also conscious.
There is a theory which relates consciousness and matter to each each other as the opposite sides of a surface in relief. The objection to this “double aspect” theory that has weighed most, in criticism, is that the ground of the parallelism between convexity and concavity—to wit, a logical implication of each other—is obviously absent in the parallelism of consciousness and matter. Whatever parallelism experience actually finds between them is not deducible from either concept: there is nothing in the definition of the sensation blue to suggest an afferent nervous current; nothing in the latter to suggest a sensation. They are incommensurate. But when you conceive convexity, in that fact you conceive concavity also, and vice versa. They are related as plus and minus. The objection appeals to analysis of the definition of consciousness or of matter, or challenges the advocate of the theory to study his sensation or his neural process and see if there be in either of them anything of the other.
A difficulty which immediately arises when this challenge is accepted has been understood to be decisive against the theory. It is this: Any definition of consciousness which the advocate of the theory may propose as the concept to be analyzed must, in order to fulfil the first requirement of logical definition, be in terms of that which is not consciousness. And this seems to the critic to beg the question. If you define consciousness so, he objects, you make its definition imply matter; but there is then nothing of consciousness in it; what you have got is only matter. That is to assume an equation between them. You state the value of x in terms of y, but then you haven’t got x, but only y. It is otherwise with terms that really have the correlation you claim for consciousness and matter. Thus you can equate convexity with concavity in terms of either alone, as m = -(-m). In this there is no assumption. But what you say of x is that it equals ay, which is something distinguishable from x and whose equality to x is just the problem.
But if it be allowed that the disparity between consciousness and matter must be either a distinction between two kinds of reality, or else the distinction between being and not-being, the predicament just described is worse for the critic of the “double aspect” theory than for its advocate. If the distinction is that of being and not-being, whichever is not-being has an internal constitution and structure by virtue of which parts and relations are recognized within it: matter has physical laws and the interaction of bodies; consciousness has interrelated states. Not-being, so interpreted, is hardly distinguished from being. And if the distinction is within being, and exhausts it, either the connotation of consciousness and that of matter are referable to each other—expressible in terms of each other—or else the distinction is only denotative, and they are not distinguished as different; for difference is a discursive relation between differents: differing from each other is a case of referring to each other.
Excessive emphasis on the “ultimateness” and “absoluteness” of the difference between these two concepts is just the inductive cue that results in the “double aspect” theory. No one can regard consciousness as not different from matter—least of all our critic, who finds them incommensurable. Nay, among real things that are other than each other, experience gives us no fellow to such difference; for difference so utter, they that differ should coincide. And so, in the fact of aspect, we have, indeed, in a thousand forms, disparity that matches the difference between the concepts now before us: e. g., right, left; up, down; plus, minus; convex, concave.
We confess three obvious differences between the two equations which we have taken to represent our critic’s conception of the relation of convexity to concavity and the relation of consciousness to matter. In equation (1), which is m = -(-m), representing the former relation, the same symbol m stands on both sides; in equation (2) the symbols are different, x on one side, y on the other. In (1) the coefficient also is the same on both sides, namely unity; in (2) the coefficients are different, unity on one side, a on the other. And in (1) the signs are opposite on the two sides, while in (2) the sign is the same on both sides.
What do these differences mean? To begin with, is (1) monomial and (2) binomial? No; in spite of the fact that there is only one symbol in (1), this equation is binomial in precisely the same sense as (2) is binomial; for it means that a certain attitude toward m, symbolized by the minus sign, transforms m into something distinguishable from m. If equation (1) expressed an identity, it would not represent the relation of convexity to concavity, which are not identical but distinguishable. But what is thus expressed in (1) by difference of sign is expressed in (2) by difference of coefficient; for (2) means that a certain attitude toward the entity symbolized by x (an attitude symbolized by the phrase “divide by a”) transforms x into y. In short, the connotation differs, on the two sides, in both equations alike. But on the other hand, the denotation is the same on both sides in each equation, for such is the nature of all equations, whether binomial or any other kind. Thus we have identity of denotation with difference of connotation in each of these equations, and they are so far homogeneous with each other. Now connotation is aspect, which is determined by subjective attitude; and attitudes are interrelated in determinate and accurately expressible ways; as, for instance, by antagonism or mutual exclusion, or by any of an indefinite number of forms of implication. The difference of attitude called antipodal oppositeness, or polarity, is the specific difference expressed in equation (1); whereas the coefficient a, in (2), expresses mere difference of attitude, difference in general, including, therefore, that specific difference which is expressed by opposition of sign. Thus equation (1) is a case of equation (2).
To sum up: The objection, stated in these algebraic symbols, was this: m implies -m; x does not imply y. Express the fact of relief in terms of m and you have the correlative fact in -m implied in the very definition of m; while if you express x in terms of y, you have y values, and nothing but y. In short, x and y exclude each other; m and -m imply each other. Our answer is that x implies y just as m implies -m; for ay is an aspect of the same denotation as x; and, since the specificity of every aspect of a given denotation is determinable or definable by relation to all other aspects of the same denotation, any one of such aspects, as x, implies, in its definition, every other, and so y, instead of excluding y.
Turning from such abstract considerations to empirical study of the sensation, the same sort of difficulty reappears. We think we find a dynamic relationship of organic to extra-organic processes; this relationship presents a material aspect, which we call neural activity, and a formal aspect, which we call blue, for instance. But the critic objects that all this is much more than sensation, and that we have read our hypothesis into our data. We must keep to the pure sensation; in that, there is no neural process. So, even as, before, all our attempts to propose a definition of consciousness for analysis were ruled out as begging the question, now every sample of the experience to be observed is rejected as impure. There is no sensation that is pure in such a sense as our critic means, for he means subjectivity that implies no objectivity. If this is more than a word, it is a self-contradiction, since subjectivity is subjectivity only in the fact of correlation with objectivity. Indeed, if our critic were to observe convexity as he proposes that we observe sensation, he would find no implication of concavity in it; nor would he find it convex. His observation would be the convexity; the two would coincide, and so would not be two. Convexity in its essence, as convex, would therein no longer be the object of the observation. You have to get outside of your convexity to observe it and its implication of concavity; just so, you have to get outside of your sensation to know it; in it, you know only the object of it. When convexity is said to imply concavity, convexity is just therein not “pure,” as the sensation is supposed to be. “Pure” convexity, analogous to “pure” sensation or subjectivity, would be convexity without implication of concavity. That would be zero convexity, so to speak—a self-contradiction. Just so, the “pure” sensation, without implication of objectivity, is a fact of consciousness without the essence of consciousness, which is dynamic relatedness to an object. “Pure” consciousness is consciousness of nothing, or no consciousness.