Intellectuals solve problems; geniuses prevent them.

The bitter and the sweet come from the outside, the hard from within, from one's own efforts.

And the high destiny of the individual is to serve rather than to rule, or to impose himself in any other way.

If we knew what we were doing it wouldn't be research.

Possessions, outward success, publicity, luxury -- to me these have always been contemptible. I assume that a simple and unassuming manner of life is best for everyone, best for both the body and the mind

I never think of the future. It comes soon enough.

As far as the laws of mathematics refer to reality, they are not certain, and as far as they are certain, they do not refer to reality.

One need only think of the weather, in which case the prediction even for a few days ahead is impossible.

The true sign of intelligence is not knowledge but imagination.

The only source of knowledge is experience.