Beauty has no obvious use; nor is there any clear cultural necessity for it. Yet civilization could not do without it.

We know less about the sexual life of little girls than of boys. But we need not feel ashamed of this distinction; after all, the sexual life of adult women is a 'dark continent' for psychology.

Only the real, rare, true scientific minds can endure doubt, which is attached to all our knowledge.

Even if all parts of a problem seem to fit together like the pieces of a jigsaw puzzle, one has to remember that the probable need not necessarily be the truth and the truth not always probable.

These patients have turned away from outer reality; it is for this reason that they are more aware than we of inner reality and can reveal to us things which without them would remain impenetrable.

Love and work, work and love...that's all there is.

To be completely honest with oneself is the very best effort a human being can make.