I have remarked very clearly that I am often of one opinion when I am lying down and of another when I am standing up...

Man is a gregarious animal and much more so in his mind than in his body. A golden rule; judge men not by their opinions but by what their opinions have made of them.

We accumulate our opinions at an age when our understanding is at its weakest.

So-called professional mathematicians have, in their reliance on the relative incapacity of the rest of mankind, acquired for themselves a reputation for profundity very similar to the reputation for sanctity possessed by theologians.

The American who first discovered Columbus made a bad discovery.

The most perfect ape cannot draw an ape; only man can do that; but, likewise, only man regards the ability to do this as a sign of superiority.

If this is philosophy it is at any rate a philosophy that is not in its right mind.

We often have need of a profound philosophy to restore to our feelings their original state of innocence, to find our way out of the rubble of things alien to us, to begin to feel for ourselves and to speak ourselves, and I might almost say to exist ourselves.

We say that someone occupies an official position, whereas it is the official position that occupies him.

A vacuum of ideas affects people differently than a vacuum of air, otherwise readers of books would be constantly collapsing.