What the Word Metaphysics means.—In the last chapter we handed the question of free-will over to 'metaphysics.' It would indeed have been hasty to settle the question absolutely, inside the limits of psychology. Let psychology frankly admit that for her scientific purposes determinism may be claimed, and no one can find fault. If, then, it turn out later that the claim has only a relative purpose, and may be crossed by counter-claims, the readjustment can be made. Now ethics makes a counterclaim; and the present writer, for one, has no hesitation in regarding her claim as the stronger, and in assuming that our wills are 'free.' For him, then, the deterministic assumption of psychology is merely provisional and methodological. This is no place to argue the ethical point; and I only mention the conflict to show that all these special sciences, marked off for convenience from the remaining body of truth (cf. p. 1), must hold their assumptions and results subject to revision in the light of each others' needs. The forum where they hold discussion is called metaphysics. Metaphysics means only an unusually obstinate attempt to think clearly and consistently. The special sciences all deal with data that are full of obscurity and contradiction; but from the point of view of their limited purposes these defects may be overlooked. Hence the disparaging use of the name metaphysics which is so common. To a man with a limited purpose any discussion that is over-subtle for that purpose is branded as 'metaphysical.' A geologist's purposes fall short of understanding Time itself. A mechanist need not know how action and reaction are possible at all. A psychologist has enough to do without asking how both he and the mind which he studies are able to take cognizance of the same outer world. But it is obvious that problems irrelevant from one standpoint may be essential from another. And as soon as one's purpose is the attainment of the maximum of possible insight into the world as a whole, the metaphysical puzzles become the most urgent ones of all. Psychology contributes to general philosophy her full share of these; and I propose in this last chapter to indicate briefly which of them seem the more important. And first, of the

Relation of Consciousness to the Brain.—When psychology is treated as a natural science (after the fashion in which it has been treated in this book), 'states of mind' are taken for granted, as data immediately given in experience; and the working hypothesis (see p. 6) is the mere empirical law that to the entire state of the brain at any moment one unique state of mind always 'corresponds.' This does very well till we begin to be metaphysical and ask ourselves just what we mean by such a word as 'corresponds.' This notion appears dark in the extreme, the moment we seek to translate it into something more intimate than mere parallel variation. Some think they make the notion of it clearer by calling the mental state and the brain the inner and outer 'aspects,' respectively, of 'One and the Same Reality.' Others consider the mental state as the 'reaction' of a unitary being, the Soul, upon the multiple activities which the brain presents. Others again comminute the mystery by supposing each brain-cell to be separately conscious, and the empirically given mental state to be the appearance of all the little consciousnesses fused into one, just as the 'brain' itself is the appearance of all the cells together, when looked at from one point of view.

We may call these three metaphysical attempts the monistic, the spiritualistic, and the atomistic theories respectively. Each has its difficulties, of which it seems to me that those of the spiritualistic theory are logically much the least grave. But the spiritualistic theory is quite out of touch with the facts of multiple consciousness, alternate personality, etc. (pp. 207-214). These lend themselves more naturally to the atomistic formulation, for it seems easier to think of a lot of minor consciousnesses now gathering together into one large mass, and now into several smaller ones, than of a Soul now reacting totally, now breaking into several disconnected simultaneous reactions. The localization of brain-functions also makes for the atomistic view. If in my experience, say of a bell, it is my occipital lobes which are the condition of its being seen, and my temporal lobes which are the condition of its being heard, what is more natural than to say that the former see it and the latter hear it, and then 'combine their information'? In view of the extreme naturalness of such a way of representing the well-established fact that the appearance of the several parts of an object to consciousness at any moment does depend on as many several parts of the brain being then active, all such objections as were urged, on pp. 23, 57, and elsewhere, to the notion that 'parts' of consciousness can 'combine' will be rejected as far-fetched, unreal, and 'metaphysical' by the atomistic philosopher. His 'purpose' is to gain a formula which shall unify things in a natural and easy manner, and for such a purpose the atomistic theory seems expressly made to his hand.

But the difficulty with the problem of 'correspondence' is not only that of solving it, it is that of even stating it in elementary terms.

Before we can know just what sort of goings-on occur when thought corresponds to a change in the brain, we must know the subjects of the goings-on. We must know which sort of mental fact and which sort of cerebral fact are, so to speak, in immediate juxtaposition. We must find the minimal mental fact whose being reposes directly on a brain-fact; and we must similarly find the minimal brain-event which can have a mental counterpart at all. Between the mental and the physical minima thus found there will be an immediate relation, the expression of which, if we had it, would be the elementary psycho-physic law.

Our own formula has escaped the metempiric assumption of psychic atoms by taking the entire thought (even of a complex object) as the minimum with which it deals on the mental side, and the entire brain as the minimum on the physical side. But the 'entire brain' is not a physical fact at all! It is nothing but our name for the way in which a billion of molecules arranged in certain positions may affect our sense. On the principles of the corpuscular or mechanical philosophy, the only realities are the separate molecules, or at most the cells. Their aggregation into a 'brain' is a fiction of popular speech. Such a figment cannot serve as the objectively real counterpart to any psychic state whatever. Only a genuinely physical fact can so serve, and the molecular fact is the only genuine physical fact. Whereupon we seem, if we are to have an elementary psycho-physic law at all, thrust right back upon something like the mental-atom-theory, for the molecular fact, being an element of the 'brain,' would seem naturally to correspond, not to total thoughts, but to elements of thoughts. Thus the real in psychics seems to 'correspond' to the unreal in physics, and vice versa; and our perplexity is extreme.

The Relation of States of Mind to their 'Objects.'—The perplexity is not diminished when we reflect upon our assumption that states of consciousness can know (pp. 2-13). From the common-sense point of view (which is that of all the natural sciences) knowledge is an ultimate relation between two mutually external entities, the knower and the known. The world first exists, and then the states of mind; and these gain a cognizance of the world which gets gradually more and more complete. But it is hard to carry through this simple dualism, for idealistic reflections will intrude. Take the states of mind called pure sensations (so far as such may exist), that for example of blue, which we may get from looking into the zenith on a clear day. Is the blue a determination of the feeling itself, or of its 'object'? Shall we describe the experience as a quality of our feeling or as our feeling of a quality? Ordinary speech vacillates incessantly on this point. The ambiguous word 'content' has been recently invented instead of 'object,' to escape a decision; for 'content' suggests something not exactly out of the feeling, nor yet exactly identical with the feeling, since the latter remains suggested as the container or vessel. Yet of our feelings as vessels apart from their content we really have no clear notion whatever. The fact is that such an experience as blue, as it is immediately given, can only be called by some such neutral name as that of phenomenon. It does not come to us immediately as a relation between two realities, one mental and one physical. It is only when, still thinking of it as the same blue (cf. p. 239), we trace relations between it and other things, that it doubles itself, so to speak, and develops in two directions; and, taken in connection with some associates, figures as a physical quality, whilst with others it figures as a feeling in the mind.

Our non-sensational, or conceptual, states of mind, on the other hand, seem to obey a different law. They present themselves immediately as referring beyond themselves. Although they also possess an immediately given 'content,' they have a 'fringe' beyond it (p. 168), and claim to 'represent' something else than it. The 'blue' we have just spoken of, for instance, was, substantively considered, a word; but it was a word with a meaning. The quality blue was the object of the thought, the word was its content. The mental state, in short, was not self-sufficient as sensations are, but expressly pointed at something more in which it meant to terminate.

But the moment when, as in sensations, object and conscious state seem to be different ways of considering one and the same fact, it becomes hard to justify our denial that mental states consist of parts. The blue sky, considered physically, is a sum of mutually external parts; why is it not such a sum, when considered as a content of sensation?

The only result that is plain from all this is that the relations of the known and the knower are infinitely complicated, and that a genial, whole-hearted, popular-science way of formulating them will not suffice. The only possible path to understanding them lies through metaphysical subtlety; and Idealism and Erkenntnisstheorie must say their say before the natural-science assumption that thoughts 'know' things grows clear.

The changing character of consciousness presents another puzzle. We first assumed conscious 'states' as the units with which psychology deals, and we said later that they were in constant change. Yet any state must have a certain duration to be effective at all—a pain which lasted but a hundredth of a second would practically be no pain—and the question comes up, how long may a state last and still be treated as one state? In time-perception for example, if the 'present' as known (the 'specious present,' as we called it) may be a dozen seconds long (p. 281), how long need the present as knower be? That is, what is the minimum duration of the consciousness in which those twelve seconds can be apprehended as just past, the minimum which can be called a 'state,' for such a cognitive purpose? Consciousness, as a process in time, offers the paradoxes which have been found in all continuous change. There are no 'states' in such a thing, any more than there are facets in a circle, or places where an arrow 'is' when it flies. The vertical raised upon the time-line on which (p. 285) we represented the past to be 'projected' at any given instant of memory, is only an ideal construction. Yet anything broader than that vertical is not, for the actual present is only the joint between the past and future and has no breadth of its own. Where everything is change and process, how can we talk of 'state'? Yet how can we do without 'states,' in describing what the vehicles of our knowledge seem to be?

States of consciousness themselves are not verifiable facts. But 'worse remains behind.' Neither common-sense, nor psychology so far as it has yet been written, has ever doubted that the states of consciousness which that science studies are immediate data of experience. 'Things' have been doubted, but thoughts and feelings have never been doubted. The outer world, but never the inner world, has been denied. Everyone assumes that we have direct introspective acquaintance with our thinking activity as such, with our consciousness as something inward and contrasted with the outer objects which it knows. Yet I must confess that for my part I cannot feel sure of this conclusion. Whenever I try to become sensible of my thinking activity as such, what I catch is some bodily fact, an impression coming from my brow, or head, or throat, or nose. It seems as if consciousness as an inner activity were rather a postulate than a sensibly given fact, the postulate, namely, of a knower as correlative to all this known; and as if 'sciousness' might be a better word by which to describe it. But 'sciousness postulated as an hypothesis' is practically a very different thing from 'states of consciousness apprehended with infallible certainty by an inner sense.' For one thing, it throws the question of who the knower really is wide open again, and makes the answer which we gave to it at the end of Chapter XII a mere provisional statement from a popular and prejudiced point of view.

Conclusion.—When, then, we talk of 'psychology as a natural science,' we must not assume that that means a sort of psychology that stands at last on solid ground. It means just the reverse; it means a psychology particularly fragile, and into which the waters of metaphysical criticism leak at every joint, a psychology all of whose elementary assumptions and data must be reconsidered in wider connections and translated into other terms. It is, in short, a phrase of diffidence, and not of arrogance; and it is indeed strange to hear people talk triumphantly of 'the New Psychology,' and write 'Histories of Psychology,' when into the real elements and forces which the word covers not the first glimpse of clear insight exists. A string of raw facts; a little gossip and wrangle about opinions; a little classification and generalization on the mere descriptive level; a strong prejudice that we have states of mind, and that our brain conditions them: but not a single law in the sense in which physics shows us laws, not a single proposition from which any consequence can causally be deduced. We don't even know the terms between which the elementary laws would obtain if we had them (p. 464). This is no science, it is only the hope of a science. The matter of a science is with us. Something definite happens when to a certain brain-state a certain 'sciousness' corresponds. A genuine glimpse into what it is would be the scientific achievement, before which all past achievements would pale. But at present psychology is in the condition of physics before Galileo and the laws of motion, of chemistry before Lavoisier and the notion that mass is preserved in all reactions. The Galileo and the Lavoisier of psychology will be famous men indeed when they come, as come they some day surely will, or past successes are no index to the future. When they do come, however, the necessities of the case will make them 'metaphysical.' Meanwhile the best way in which we can facilitate their advent is to understand how great is the darkness in which we grope, and never to forget that the natural-science assumptions with which we started are provisional and revisable things.

THE END.