are in a way special psychologies, and subordinate to psychology as such. The truth seems to be, however, that what psychology concerns itself with here is not the valuation process itself, but the mode of action of the mind engaged in the valuation process. The problems of economics and of aesthetics, therefore, can in no, legitimate sense be considered as subordinate to psychological problems, nor can these sciences be looked upon as special psychologies. This independence and practical equality of the sciences for which we have contended are supported by the practical ends of social investigation. Viewed from this standpoint, all social science is bound to be selective. This is a well-recognized characteristic of scientific method. We go to science because we wish to control the forces at hand so as to realize better some human purpose. What we seek is to comprehend the existing situation from the standpoint of the purpose or interest in question. It follows that all scientific investigation is bound to be highly specialized. We do not seek to understand the existing situation as a whole -- i. e., in all its aspects and relations; that would be both practically useless and scientifically impossible; but we do seek to understand the situation in its relation to the interest at stake, the problem in hand. This is just as true, and ( 751) must be, of the sociologist who has risen above the level of mere narration or description, as of the economist or the moralist. On