The professors of the new science of sociology are beginning, it is true, to deal with human nature in its relation not only to the family and to religion and industry, but also to certain political institutions.

Sociology, however, has had, as yet, little influence on political science.
I believe myself that this tendency to separate the study of politics from that of human nature will prove to be only a momentary phase of thought, that while it lasts its effects, both on the science and the conduct of politics, are likely to be harmful, and that there are already signs that it is coming to an end.
It is sometimes pleaded that, if thorough work is to be done, there must, in the moral as in the physical sciences, be division of labour.
But this particular division cannot, in fact, be kept up.

The student of politics must, consciously or unconsciously, form a conception of human nature, and the less conscious he is of his conception the more likely he is to be dominated by it.

If he has had wide personal experience of political life his unconscious assumptions may be helpful; if he has not they are certain to be misleading.

Mr.Roosevelt's little book of essays on _American Ideals_ is, for instance, useful, because when he thinks about mankind in politics, he thinks about the politicians whom he has known.