The psychic development of the individual is a short repetition of the course of development of the race.

In the last analysis the entire field of psychology may reduce to biological electrochemistry.

The individual does actually carry on a double existence: one designed to serve his own purposes and another as a link in a chain, in which he serves against, or at any rate without, any volition of his own.

It sounds not only disagreeable but also paradoxical, yet it must nevertheless be said that anyone who is to be really free and happy in love must have surmounted his respect for women and have come to terms with the idea of incest with his mother or sister.

I do not in the least underestimate bisexuality... I expect it to provide all further enlightenment.

The true believer is in a high degree protected against the danger of certain neurotic afflictions; by accepting the universal neurosis he is spared the task of forming a personal neurosis.

I prefer the company of animals more than the company of humans. Certainly, a wild animal is cruel. But to be merciless is the privilege of civilized humans.