862 THE AMERICAN JOURNAL OF SOCIOLOGY
improvement of a social group. By way of illustration let me refer to the question of sex. In society at large the question as to how far the fundamental distinction between man and woman affects the psychical life is an extremely important problem. Whether the chief difference lies in the realm of the feelings or in the intellect, it cannot be denied that the difference exists. Some go so far as to insist with Von Hartman that the distinction of sex separates men and women by an impassable gulf. " Man," he says, 11 is by nature active, woman, passive, and this difference has a pro- found effect on the occupation of both parties." " Hard manual labor," he declares, "consumes the feminine capacity for work much sooner than the masculine. It leads to premature old age and exhaustion. It weakens the power to resist the insidious influence of disease, and in this way considerably curtails life's duration. Immoderate mental work is often more harmful to women, for the female brain and nervous system cannot bear nearly as much strain as the male. It is on this account that the education and training of both sexes must always remain different." He is even of the opinion that in the "domain of social morality, the demand for equality and equal judgment of the sexes is not less untenable than in politics and employment." I present this view, not to agree with it, but in order to suggest the problem which arises from individual distinctions, and to make it clear that in every contemplated change of social con- ditions or institutions due regard must be paid to them.
But something more than a knowledge of individual differ- ences is necessary in social study. Everyone should have a knowledge as complete as possible of the individual himself. This knowledge may be obtained from the various natural and social sciences, some acquaintance with which on the part of anyone who would enter deeply into social study is presupposed. Physiology and anatomy tell us of the structure of the individ- ual and his physical needs. History, political economy, and political science tell us of his social nature and its results. In view of the importance of this kind of knowledge it will be profitable, I think, for me to summarize the study of the indi-
