Uexküll, J. v. 1903. Studien über den Tonus. I. Der biologische Bauplan von Sipunculus nudus. Zeitschr. f. Biol., Bd. XLIV, pp. 269-344. Wallengren, H. 1902. Zur Kenntnis der Galvanotaxis. I. Die anodische Galvanotaxis. Zeitschr. f. Allg. Physiol., Bd. II, pp. 341-384, Pl. 11. 1903. Zur Kenntnis der Galvanotaxis. II. Eine Analyse der Galvanotaxis bei Spirostomum. Zeitschr. f. Allg. Physiol., Bd. II, pp. 516-555. EDITORIAL. PHYSIOLOGY AND PSYCHOLOGY. The recognition in daily life as well as in scientific description of two classes of reaction, the psychic and the non-psychic, is the basis of the separation of the science of organic functions into physiology and psychology. Without any assumptions as to the relations of consciousness to organic processes we may, and in fact constantly do, deal with the reactions of organisms according to certain characters which are commonly spoken of as indicative of automatism or intelligence. It is true that we can no more draw a sharp line between the psychic and the non-psychic in reaction than we can between the reflex and the instinctive. Certain aspects or relationships of reactions are so prominent as to furnish the basis of types. Modifiability in high degree is said to be a mark of the psychic, yet no one would deny that the non-psychic reaction is also modifiable. There is surely a difference of degree, but by whom and how is the point at which this characteristic passes from an indication of one type to that of the other to be fixed? Some physiologists and psychologists have chosen ability to learn as the criterion of the psychic reaction, but this if used alone is evidently of limited and uncertain value, for all reactions, it is safe to assume, change with repetition; organisms profit by experience more or less rapidly. Thus far the critical point which those who have implicit faith in the applicability of this criterion necessarily posit—the point at which ability to learn appears as a distinctive character of the organism, or in the light of the criterion, the point at which the psychic reaction appears in the animal series-has not been discovered. important question is, Does such a critical point exist? The Few will venture to deny probability to the assumtion that modifiability of reaction varies in degree, not in kind; yet, if ability to profit by experience is to be a satisfactory criterion of the psychic there must be either reference to a difference in kind of modifiability, or the choice, by those who attempt to use the criterion, of an arbitrarily selected degree or rapidity of change in reaction as indicative of the transition from the non-psychic to the psychic. At this point there are at least two possibilities: either we may choose a certain standard of modifiableness as indicative of the psychic reaction, or we may seek for other characteristics in addition to modifiability as means of distinguishing the psychic from the non-psychic in organic reaction. That the latter alternative is the more desirable of the two all who have attempted to use the criterion of ability to profit by experience will grant more or less freely, according to their various prejudices. Although the physiologist deals primarily with the nonpsychic, he is no more able to ignore the psychic than is the chemist to avoid the use of physical concepts and terms. Similarly the psychologist is dependent upon the physiologist, and in turn upon the chemist and physicist, as is the physiologist himself. Granting validity and scientific value to the separation of reactions into the psychic and non-psychic, the existence of physiology and psychology as coördinate sciences needs no justification. Both are natural sciences; both deal with organic reactions. From certain points of view the psychic reaction is more difficult of description than the non-psychic, but the same methods of investigation apply to the two classes of reaction. Physiologists and psychologists must coöperate in discovering, and must agree upon the distinguishing characteristics of the psychic and the non-psychic reaction. By mutual agreement they must fix the limits of their sciences. The most keenly felt need at present in the science of organic reaction is for careful, detailed, patient, and extensive study of the forms and modifications of reaction. Whether physiologists or psychologists, we must know our materials thoroughly before we can classify them or profitably consider their relations to the materials of allied sciences; in fact even before we can distinguish physiology from psychology in any accurate sense we must know the possible methods of classification of reaction, and be able, in the light of accurate and extensive knowledge of the peculiarities and unimportant variations of reactions as well as their fundamentally important differences, to select as criteria those characters which are most constant and which taken together form the most valuable working basis for the sciences of reaction. There is a tendency among physiologists-among natural scientists generally—to look upon psychology with distrust, if not with indifference or scorn. The average German physiologist uses very different tones of voice for the "Physiolog" and the "Psycholog." Some of them apparently feel that psychoogy is too near akin to metaphysics to be a safe favorite for the natural scientist, while others are evidently satisfied in their own minds that the psychic is not and cannot be material of a natural science. In America too there is a strong prejudice against psychology, among the natural scientists especially, or, if not prejudice, there is a distrustful curiosity which makes the life of the truly scientific student of psychic reactions at times unpleasant. This general distrust and ridicule of psychology is doubtless due, first, to the fact that the naturalistic movement of the last century was accompanied by a wide speading and deep distrust of the speculative sciences of which psychology was then, and is still by many, reckoned as one; and second, perhaps almost as largely, to the semi-scientific and too often carelessly used methods of that new psychology which called itself experimental. Even the honest and sincere defender of psychology, or of the possibilities of such a science, cannot deny that much work which has been placed upon record as experimental psychology is pure rot. But, admitting this with regret, he well may ask, What of the early stages in the development of astronomy, of chemisty, of physics, of anthropology, of sociology? Natural sciences are not born to perfection of method, they develop; and psychology is even now approach ing a stage of development which will justify its recognition by the most timid, narrow, or prejudiced naturalist as an increasingly exact natural science. Sciences, differ widely in degree of exactitude; at present, for example, the biological sciences are far less exact than the physical, but one may reasonably argue that this is due to inherent difficulties in dealing with the materials rather than to the impossibility of applying exact methods. Psychology as a natural science, or rather psychology in so far as it is considered as a natural science, is in its infancy. As physiology gradually approaches the standard which physics has set for it, so psychology approaches, and will the more rapidly approach as those in allied fields recognize its progress, this same standard. For those of us who have at heart the establishment and advancement of comparative psychology as a science coördinate with physiology there is the clear duty to make our work eminently worthy of scientific recognition and reliance. Casting philosophical implications aside, so far as our scientific work is in question, we should apply ourselves to the study of psychic reactions with intent to place our knowledge of them on a level with or above that of the non-psychic as represented by the condition of present day physiology. In attempting to do this we should ever be willing and eager to take advantage of the assistance which the closely allied biological and less directly related phys ical sciences can give us. Speculative sciences have their place, but we shall accomplish most for the science of psychic reactions if we keep our metaphysical longings in the background and strive ceaselessly for accurate and complete descriptions of the reactions with which we are concerned-reactions which are the most complex and interesting of biological phe nomena. ROBERT M. YERKES. |