A man's heterosexuality will not put up with any homosexuality, and vice versa.

The facts which have caused us to believe in the dominance of the pleasure principle in mental life also find expression in the hypothesis that the mental apparatus endeavours to keep the quantity of excitation present in it as low as possible or at least to keep it constant.

The communal life of human beings had . . . a two-fold foundation: the compulsion to work, which was created by external necessity, and the power of love.

The pleasure of satisfying a savage instinct, undomesticated by the ego, is uncomparably much more intense than the one of satisfying a tamed instinct. The reason is becoming the enemy that prevents us from a lot of possibilities of pleasure.

The defense against childish helplessness is what lends its characteristic features to the adult's reaction to the helplessness which he has to acknowledge - a reaction which is precisely the formation of religion.

Where questions of religion are concerned, people are guilty of every possible sort of dishonesty and intellectual misdemeanor.

Obsessional prohibitions are extremely liable to displacement. They extend from one object to another along whatever paths the context may provide, and this new object then becomes, to use the apt expression of one of my women patients, 'impossible' - till at last the whole world lies under an embargo of 'impossibility'.