CHAPTER II
THE PROBLEM OF SOUL AND BODY
[§ 1.] The problem of psychophysical connection has to do with the correlation of scientific abstractions, not of given facts of experience. [§ 2.] The “consciousness” of Psychology is thus not the same thing as the finite individual subject of experience, and Reality must not be said to consist of “minds” in the psychologist’s sense. Again, we must not assume a priori that there can be only one working hypothesis of psychophysical connection. [§ 3.] The possible hypotheses may be reduced to three, Epiphenomenalism, Parallelism, and Interaction. [§ 4.] Epiphenomenalism is legitimate as a methodological principle in Physiology; it is untenable as a basis for Psychology because it implies the reduction of psychical facts to mechanical law. [§ 5.] Parallelism. The arguments for Parallelism as necessarily valid to Psychophysics because of its congruity with the postulates of mechanical Physics, are fallacious. We cannot assume that Psychology must necessarily conform to these postulates. [§ 6.] As a working hypothesis Parallelism is available for many purposes, but breaks down when we attempt to apply it to the case of the initiation of fresh purposive reactions. A teleological and a mechanical series cannot ultimately be “parallel.” [§ 7.] We are thus thrown back on the hypothesis of Interaction as the only one which affords a consistent scheme for the correlation of Physiology and Psychology. We have, however, to remember that what the hypothesis correlates is scientific symbols, not actual facts. The actuality represented by both sets of symbols is the same thing, though the psychological symbolism affords a wider and more adequate representation of it than the physiological.
§ 1. Few questions have more constantly attracted the attention of philosophers, especially perhaps of those philosophers who have lived since the establishment of Christianity as the religion of the Western world, than that of the relation between the soul or mind and the body; and perhaps no question has given rise to graver misconceptions for want of a correct insight into the true logical character of the problem under discussion. Both in the half-scientific speculations of ordinary persons and in the more systematic theories of metaphysicians and psychologists, the subject is constantly approached under the totally erroneous preconception that the dualistic separation of human life into a bodily and a mental part or aspect is a datum of immediate experience which we can directly verify in ourselves, and that the task of philosophy is by ingenious but unverifiable hypothesis to transcend this chasm between given realities. From the standpoint of our previous chapter we can easily see that such a view fundamentally misrepresents the real philosophical problem.
So long as we are concerned with human existence as we directly find it in our immediate experience, or assume it in our practical social relations with our fellows, no question of the relation between body and mind can arise, because neither term of the relation is as yet before us. For my own immediate experience I am neither a body nor a soul, nor yet a composite of the two, but simply an individual subject of experiences in direct intercommunion with other individuals. Under the influence of conscious or unconscious dualistic prepossessions, we often speak as if it were a directly experienced fact that I can communicate with my fellow-subjects only indirectly through the medium of an alien “material” body, and we sometimes contrast this supposed restriction with an imagined higher state of existence, in which “disembodied spirits” may conceivably have direct intercourse with each other. But the truth is, that this direct intercourse and influence of one intelligent and purposive individual on another is no privilege reserved for our enjoyment in “a better world than this”; it is, as we can see if we will only forget our dualistic prepossessions, the very truth about our actual life. In actual life, before we have contaminated our direct enjoyment of it with psychological prejudices, we know nothing of the interposition of an inert “material” organisation between ourselves and the members of our social environment. The severance of the original unity of experience into a physical and a psychical aspect is entirely a product of our own abstraction-making intellect. “Body” and “soul” are not given actualities of experience, but artificial mental constructions of our own derived from the actual “facts” of life by the elaborate processes which we have just been studying.
As we have seen in constructing our concept of a mechanical physical order, we abstract certain elements of our direct experience from the whole, and consider them under the name of our “bodies” as if they had a separate existence; we then, by the aid of the hypothesis of “introjection,” represent those elements of direct self-experience which were omitted from the physical order as forming by themselves a second distinct whole or system called the “soul.” When we have reached this point, we are, of course, compelled to raise the question how these two systems, the bodily and the mental, must be supposed to be connected. But the important fact to remember is that the two systems are not facts of experience, but products of abstraction. Our task in discussing their relation is not to transcend a given dualism, but to get rid of one which we have manufactured for ourselves by the manipulation of experience in the interests of certain special scientific problems. Hence, as Münsterberg[Münsterberg] well puts it, we have not to find the connection which subsists, as an actual fact, between body and soul, but to invent a connection in keeping with the general scheme of our artificial physical and psychological hypotheses.[[174]]
§ 2. As far as the interests of Metaphysics are concerned, this recognition that the problem of soul and body has to do solely with highly artificial products of scientific abstraction, and not with anything which can be called a “given” actuality, is the one principle of supreme importance which emerges from the discussion of the subject. Two very significant inferences may at once be drawn from it. (1) We clearly must not call the finite subjects of experience, of whom we saw reason to hold that ultimate Reality is exclusively constituted, “minds” or “souls” in the psychologist’s sense.[[175]] To call them so would inevitably be to imply that exclusion from the physical order of “bodies” apart from which the psychological concept of the “soul” or “mind” has no significance. Or, in other words, it would identify them not with what they are for their own direct experience, but with what they become for one another’s theoretical reflection under the influence of “introjection.” As we have seen, it is legitimate and necessary for special scientific purposes to treat ourselves and other individuals as if we were such series of “mental states,” but it is never legitimate to forget that, when we do this, we are substituting a highly unreal symbolism for directly experienced facts.
One consequence of confusing the symbolism with the fact may be noted in passing: when we have substituted the series of mental states for the felt unity of actual conscious life, we go on to ask ourselves how the fact and its symbol—the symbolic nature of which we have forgotten—are related. And thus arise all the unanswerable, because fundamentally unmeaning, questions as to the way in which the “self” has or owns the succession of “states.” Failing to see that the succession of states is simply the unitary subject itself, as it appears from the point of view of the “introjection” hypothesis, we then find ourselves confronted by the alternatives of foisting upon our Psychology the useless and unthinkable fiction of a changeless “substratum” of mental states—the soul-substance of the pre-Kantian psychologists—or resolving real life into a succession of discontinuous “mental images.” With the recognition that Psychology never deals directly with experienced reality, but always with the hypothetical products of an abstraction which is only justified by its usefulness for the special purposes of the psychologist, all these difficulties disappear.
(2) Another important consequence of our principle is that we cannot dogmatically assert that there can be only one legitimate theory of the “connection between mind and body.” If “mind” and “body” were really given as distinct but connected in direct experience, it might well be that there could only be one account of their connection answering to experienced fact. But since the separation is itself of our own intellectual manufacture, as we are dealing throughout with artificial creations of our own abstraction, any theory of their connection which is desirable for the solution of a special problem or class of problems will be legitimate for that particular class of problems. Thus the physiologist may legitimately, if it answers his special purposes, adopt a working hypothesis which the psychologist may find untenable, and again different types of psychological problem may legitimately assume different working hypotheses.[[176]] I shall aim at showing in the immediately following paragraphs that there is one typical psychophysical hypothesis which, on the whole, lends itself better than its rivals to the general purposes of both Physiology and Psychology, but we shall see, as we proceed, that the hypotheses we reject are also legitimate for the solution of important special problems. In fact, our chief interest, as students of Metaphysics, in the further discussion of psychophysical connection will be to point out the fallaciousness of the metaphysical arguments which are commonly used to establish some one hypothesis as necessarily and exclusively true.
§ 3. Turning now to consider the chief types of hypothesis which have been, or are at present, actually put forward by metaphysicians and psychologists, we may perhaps group them under the five main heads of (1) Pre-established Harmony, (2) Occasionalism, (3) Epiphenomenalism, (4) Psychophysical Parallelism, (5) Interaction. For our purpose in the present chapter the number of alternatives may be further reduced by the omission of the first two. Neither the Pre-established Harmony of Leibnitz nor the Occasionalism advocated by Geulincx and Malebranche, and in a one-sided form by Berkeley, is likely to find much support from the philosophy of the present day. Both doctrines are, moreover,—that of Leibnitz avowedly and that of the Occasionalists by implication,—much more than special psychophysical hypotheses. They are in principle attempts to get rid of all transeunt causality, and have been discussed in their general bearings in our chapter on the Causal Postulate, where we satisfied ourselves that any science which recognises, as Psychology has to do, the existence of finite things must also admit the principle of transeunt causality, at any rate as a working hypothesis.
Each of the three remaining types of view has its supporters among contemporary students of science and philosophy. The epiphenomenalist theory is largely adopted by the workers in the physical sciences, and though not much countenanced by psychologists and metaphysicians, has the explicit support of Dr. Shadworth Hodgson, while some versions of the parallelist doctrine, notably that of Münsterberg, approach it very closely. The parallelist hypothesis is perhaps at present the most popular among the psychological specialists, and is represented by writers of such eminence as Wundt, Münsterberg, Ebbinghaus, Höffding[Höffding] and Stout. Finally, Interaction has powerful champions in Bradley, Ward, and James; to say nothing of its adoption by so sound a physiologist as Mr. McDougall. Both the latter doctrines, again, have historical connections with the great philosophical systems of the past, Parallelism with that of Spinoza, and Interaction with those, to mention no other names, of Descartes and Locke. In the philosophy of the ancient world the psychophysical issue can hardly be said to appear in a well-defined form, but we may perhaps state that Plato’s psychological doctrine is decidedly one of Interaction, while the view of Aristotle, though too complex to admit of very precise formulation, inclines rather towards Parallelism.