interactions between their minds. Thus on the one hand all social
phenomena are vital phenomena and on the other hand nearly all social
phenomena are mental phenomena. Every social problem has, in other
words, its psychological and its biological sides, and sociology is
distinguished from biology and psychology only as a matter of
convenience. The scientific division of labor necessitates that certain
scientific workers concern themselves with certain problems. Now, the
problems with which the biologist and the psychologist deal are not the
problems of the organization and evolution of society. Hence, while the
sociologist borrows his principles of interpretation from biology and
psychology, he has his own distinctive problems, and it is this fact
which makes sociology a distinct science.

Sociology is not so easily distinguished from the special social
sciences like politics, economics, and others, as it is from the other
general sciences. These sciences occupy the same field as sociology,
that is, they have to do with social phenomena. But in general, as has
already been pointed out, they are concerned chiefly with certain very
special aspects or phases of the social life and not with its most
general problems. If sociology, then, is dependent upon the other
general sciences, particularly upon biology and psychology, it is
obvious that its relation to the special sciences is the reverse,
namely, these sciences are dependent upon sociology. This is only saying
practically the same thing as was said above when we pointed out that
industry, government, and religion are but expressions of human social
life. In other words, sociology deals with the more general biological
and psychological aspects of human association, while the special
sciences of economics, politics, and the like, generally deal with
certain products or highly specialized phases of society.