The modesty of women, which, in its most primitive form among animals, is based on sexual periodicity, is, with that periodicity, an essential condition of courtship.

Even the most scientific investigator in science, the most thoroughgoing Positivist, cannot dispense with fiction; he must at least make use of categories, and they are already fictions, analogical fictions, or labels, which give us the same pleasure as children receive when they are told the "name" of a thing.

Socialism also brings us up against the hard rock of eugenic fact which, if we neglect it, will dash our most beautiful social construction to fragments.

The by-product is sometimes more valuable than the product.

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

The second great channel through which the impulse towards the control of procreation for the elevation of the race is entering into practical life is by the general adoption, by the educated—of methods for the prevention of conception except when conception is deliberately desired.

The sanitary and mechanical age we are now entering makes up for the mercy it grants to our sense of smell by the ferocity with which it assails our sense of hearing.