If a thing is worth doing, it is worth doing badly.

Poets do not go mad, but chess players do.

Science must not impose any philosophy, any more than the telephone must tell us what to say.

You shouldn't take a fence down until you know the reason it was put up.

The object of opening the mind, as of opening the mouth, is to shut it again on something solid.

The modern habit of saying "This is my opinion, but I may be wrong" is entirely irrational. If I say that it may be wrong, I say that is not my opinion. The modern habit of saying "Every man has a different philosophy; this is my philosophy and it suits me" – the habit of saying this is mere weak-mindedness. A cosmic philosophy is not constructed to fit a man; a cosmic philosophy is constructed to fit a cosmos. A man can no more possess a private religion than he can possess a private sun and moon.