EDITORIAL.

PSYCHOLOGY AND NEUROLOGY.

In an earlier number of this Journal the need has been urged of some category common to the neurologist and psychologist in terms of which the problems of neural structure and mental function may be discussed without immediately arousing metaphysical prejudices. Such a category is action or behavior. The former is perhaps the more abstract concept and hence will lend itself more readily to the discussion of the philosophical questions which sooner or later are bound to arise. The latter has the advantage of being a term of popular as well as of scientific usage and is more commonly employed to describe the action of organisms. Mr. MORGAN'S latest book is entitled "Animal Behavior" and under this term he is successful, for the most part, in discussing the actions of organisms without prejudging the nature of the question of the psychical and its relation to the material processes. Likewise Mr. JENNINGS in the valuable article which appeared in the last issue of the Journal discusses the behavior of Paramecium in terms of "action-systems" in a way which does not preempt the field for either the mechanical or teleological interpretation of the phenomena. Researches carried on in this spirit are greatly needed at the present time. Only thus is it possible to construct a platform whose planks shall consist of facts interpreted in terms of a common technique.

It is too early in the history of the movement to predict in detail the lines along which the two sciences will get together, but it is safe to say that there will have to be considerable revision of working concepts on the part of both neurology and psychology. By this is meant that the newer insight into the energic nature of matter will in time inevitably

affect the biologist's conception of the nature of what he calls an organism. Biology, in so far as it pretends to be an exact science, regards the organism as a complicated mechanism whose elements are to be understood in terms of the physical laws which hold for these elements outside the organism. Hence, if, for example, the study of the electrical properties of matter results in transforming our chemical and physical notions, and some form of an energic is substituted for the atomic theory, this dynamic view ultimately must reach into biology with transforming effect.

In a similar way, the conception of the nature of consciousness is undergoing reconstruction in psychological science, in part due to this same energistic theory which is transforming physical science. The traditional formula which is satisfied to postulate a soul back of consciousness, just as it postulates material atoms back of motion or force, appears likely to be eclipsed by the results of inquiries which seek to discover the nature of the intimate relation which certainly seems to exist between mind and matter. There is no blinking the facts of brain structure nor of mental functioning; the problem is to understand what we mean by each in terms of the other.

This it has been almost impossible to do in the past because of the diverse historical conditions and techniques associated with the two sciences. Biology had its roots in the natural and positive sciences; psychology arose as a branch of philosophy and was long known as "mental philosophy." But now that the basis has been laid for a scientific psychology, there is hope of its being possible for the psychologist and neurologist to get together in their work on this common problem.

As has been intimated, this will involve a revision of psychological conceptions on many fundamental points. That this is already taking place is evident from recent tendencies in psychological thought. Consciousness is coming to be stated more and more in terms of action, in terms of the motor aspect of the organic circuit, instead of being stated exclusively in terms of the sensory aspect, which was the tendency with the older intellectualistic psychology. Great emphasis is now being placed

on the motor character of attention, on the dynamogenic nature of ideas, on ideomotor impulses, on tactile-kinaesthetic imagery, on the emotions as vestiges of motor attitudes, on the growth of voluntary movement, on the constructive and reconstructive character of thought. Says Mr. MARSHALL:

are compelled to assume a unity of process in conscious life. From this point of view, the distinctions between reflex and instinctive activities and between habit and instinct are not fundamental. The sharp distinction between instinct and intelligence implies denial of the unity of consciousness" (Mind, Vol. XI, No. 44). Professor LLOYD says: "Nothing in philosophy is so much needed at the present time as the adjustment of the science of abstract thought to the science of organic action, and every little hint as to how this adjustment can be brought about cannot but be at least a little help. The evolution of consciousness must be almost meaningless until the simplest case of accommodation as seen by the biologist is identified with the most perfect case of abstract thought that the logician knows" (Psy. Rev., Vol. III, p. 426). And a recent writer has gone so far as to define perception as "an attitude toward the object perceived." He says: "Perception is an attitude toward an object as well as a complex of sensations." "All that objects mean to us is largely due to the sensations that flow backward from the bodily reverberations they excite directly in us. Perception is an attitude toward the objects perceived" (BOLTON, Biological View of Perception, Psy. Rev., Vol. IX, No. 6).

How far these particular suggestions may prove fruitful in bringing about the desired synthesis is a matter of relatively little moment here. The important consideration is to note the fact of this tendency in recent literature and to keep in touch with the almost kaleidoscopic changes which are marking the progress of the comparative method as employed in this field.

The further investigations of animal reactions are carried, the more difficult appears the problem of the distribution of consciousness. But, as if to counterbalance this, the further research in comparative psychology is carried, the more is the conviction forced upon the investigator that the reactions of

human beings (including their psychical processes, their conscious acts) will never adequately be understood until we have formulated the laws of the behavior of these simpler types of organisms.

The value of a study of the animal mind for human psychology has been emphasized by various writers. But its full significance, methodologically, has not always been realized. This deeper significance lies in the dynamic conception of consciousness, as itself a phase of the ultimate energic system, a balance or tension of forces, admitting, like all other energic phenomena, of examination, description and explanation. The conditions of consciousness as represented in the complicated structures of the brain in the higher forms are too intricate to admit of exact statement as yet in scientific terms. Hence the promising character of researches upon the lower forms where the conditions are simpler, and where, if anywhere, the precise function of the brain as an organ for the transformation of energy can be determined. Here first may we expect the laws of equilibration or tension of energies which we call conscious to be elucidated. The solution of the deepest problems of psychology, there is good reason to believe, lies in the hands of the comparative psychologist.

SCHULTZ, in a recent article entitled "Gehirn und Seele" (Zeitschr. f. Psy. u. Physiol. d. Sinnesorg., XXXII, Heft 3 u. 4, pp. 246-7) calls attention to the apparent dilemma in which the comparative psychologist finds himself. It is certainly a safe assumption that the higher, more complicated mental life of man and the higher animals can best be explained by a knowledge of the simpler conditions of mental life in the lower forms. On the other hand, it is a general principle that in explanation we should proceed from the known to the unknown. Now my own human individual consciousness is best known to me and most immediately given. We here seem to be under the compulsion equally of following what Professor BALDWIN has called the leveling up" and the "leveling down" methods, the mechanical and the teleological (or what some would call the anthropomorphizing) tendencies.

The limitations of the one method lie in the incredible chasm in degree (if not in kind) which must lie between my complicated conscious life and that of the simplest organisms (if they have any at all). This would seem to check any anthropomorphizing tendency at the start. BINET'S mistake, for example, lies not chiefly in his assumption that the lower organisms have consciousness (this may or may not be true), but in his uncritical use of the categories of adult human psychology in describing the reactions of micro-organisms. It is, of course, an inference that any organism besides my own has consciousness, but it is an inference, in certain cases, of extreme probability. But that perception, association, preference, choice, mean the same in these lower forms is a point to be demonstrated, not to be assumed. The great need of comparative psychology at the present time is the reduction of human conscious reactions to the lowest terms, especially as they are represented in the human infant, in the savage. and in primitive man, in order to make the comparison between human and animal behavior more direct.

On the other side, the difficulty lies in the fact that the terminology of tropisms and animal reactions has grown up almost exclusively under the domination non-psychological science, with the result that the answer to the question as to the presence of mental life in these lower forms is prejudged from the outstart. Evidently there is need of some common basis of method in biology and psychology. This is supplied, in a general way, in the conception of conscious states as themselves acts, as truly as the more obvious activities of the motor organs, but more subtle because remotely conditioned in the brain processes. One of the common problems thus, of comparative neurology and comparative psychology becomes, as has been said before, the problem of the evolution of action, and particularly the problem of the determination of the conditions of conscious action.

H. HEATH BAWDEN.