Those persons who are burning to display heroism may rest assured that the course of social evolution will offer them every opportunity.

Courtship, properly understood, is the process whereby both the male and the female are brought into that state of sexual tumescence which is a more or less necessary condition for sexual intercourse. The play of courtship cannot, therefore, be considered to be definitely brought to an end by the ceremony of marriage; it may more properly be regarded as the natural preliminary to every act of coitus.

To live remains an art which everyone must learn, and which no one can teach.

The prevalence of suicide, without doubt, is a test of height in civilization; it means that the population is winding up its nervous and intellectual system to the utmost point of tension and that sometimes it snaps.

At the present day the crude theory of the sexual impulse held on one side, and the ignorant rejection of theory altogether on the other side, are beginning to be seen as both alike unjustified.

I regard sex as the central problem of life. And now that the problem of religion has practically been settled, and that the problem of labor has at least been placed on a practical foundation, the question of sex—with the racial questions that rest on it—stands before the coming generations as the chief problem for solution. Sex lies at the root of life, and we can never learn to reverence life until we know how to understand sex.

Mankind is becoming a single unit, and that for a unit to fight against itself is suicide.