You must always be puzzled by mental illness. The thing I would dread most, if I became mentally ill, would be your adopting a common sense attitude; that you could take it for granted that I was deluded.

Almost in the same way as earlier physicists are said to have found suddenly that they had too little mathematical understanding to be able to master physics; we may say that young people today are suddenly in the position that ordinary common sense no longer suffices to meet the strange demands life makes. Everything has become so intricate that for its mastery an exceptional degree of understanding is required. For it is not enough any longer to be able to play the game well; but the question is again and again: what sort of game is to be played now anyway?

If a person tells me he has been to the worst places I have no reason to judge him; but if he tells me it was his superior wisdom that enabled him to go there, then I know he is a fraud.

Suppose someone were to say: 'Imagine this butterfly exactly as it is, but ugly instead of beautiful'?!

I think one of the things you and I have to learn is that we have to live without the consolation of belonging to a Church.... Of one thing I am certain. The religion of the future will have to be extremely ascetic, and by that I don't mean just going without food and drink.

A French politician once wrote that it was a peculiarity of the French language that in it words occur in the order in which one thinks them.

Man has to awaken to wonder - and so perhaps do peoples. Science is a way of sending him to sleep again.