One should be light like a bird, and not like a feather.

What one wrote playfully, another reads with tension and passion; what one wrote with tension and passion, another reads playfully.

It is a law of nature that we defend ourselves from one affection only by means of another.

We are wont to condemn self-love; but what we really mean to condemn is contrary to self-love. It is that mixture of selfishness and self-hate that permanently pursues us, that prevents us from loving others, and that prohibits us from losing ourselves.

I thought it necessary to study history, even to study it deeply, in order to obtain a clear meaning of our immediate time.

The purpose of psychology is to give us a completely different idea of the things we know best.

Man is only man at the surface. Remove the skin, dissect, and immediately you come to machinery.