8lO THE AMERICAN JOURNAL OF SOCIOLOGY
process, or life-activity, functioning to secure control over its own life-conditions, and thereby its own development. The resulting interpretation of the facts of the psychical life yields a psychology whose chief categories are coordination, adaptation, habit, instinct, selection, evaluation, and the like ; in brief, an evolutioTiary psychology.'
The value of such a psychology to the social sciences must be evident, even from such a schematic and fragmentary state- ment as we have given. Such a psychology comes into contact with life at every point and interprets functionally the processes of life ; it is no formal, over-abstracted science, but shows us the actual workings of the psychic reality. The question at once suggests itself: Are not these categories, which have been so successfully applied to the interpretation of the psychical life of the individual, also applicable to the interpretation of the life of society on its psychical side ? Cannot the fundamental princi- ples of such a functional psychology be transferred at once from the interpretation of the life of the individual to that of society? If it be granted that social groups function, act, as unities, and that therefore they, as well as individual organisms, may be regarded as functional unities, then there would seem to be no logical objection to such a procedure. On the contrary, when both society and the individual are regarded as functional uni- ties, it would seem highly probable that the fundamental princi- ples and categories employed in the interpretation of the psychical life of the one would apply equally in the interpretation of the psychical life of the other. Thus the transference of principles of interpretation from the individual to society may be easily justified as a working hypothesis. Professor Dewey's point of view, if fully stated, would, indeed, be favorable to such an exten- sion of his psychological principles of interpretation to society. He recognizes that the individual life-process is not an isolated fact, but only a differentiated center within a larger life-process of the group. This position implies, not only the possibility of
' Of course, other psychologists have made use of the evolutionary point of view in their interpretation of the psychical life ; but their systems have been incapable of assimilating thoroughly evolutionary concepts and principles, and it is only fair to say that their psychologies have not been distinctively evolutionary in their character.
