We must interpret a bad temper as a sign of inferiority.

In the investigation of a neurotic style of life, we must always suspect an opponent, and note who suffers most because of the patient's condition. Usually this is a member of the family.

There is no such thing as talent. There is pressure.

War is organized murder and torture against our brothers.

To all those who walk the path of human cooperation war must appear loathsome and inhuman.

The human mind shows an urge to capture into fixed forms through unreal assumptions, that is, fictions, that which is chaotic, always in flux, and incomprehensible. Serving this urge, the child quite generally uses a scheme in order to act and to find his way. We proceed much the same when we divide the earth by meridians and parallels, for only thus do we obtain fixed points which we can bring into a relationship with one another.

The mathematical life of a mathematician is short. Work rarely improves after the age of twenty-five or thirty. If little has been accomplished by then, little will ever be accomplished.