We also know how cruel the truth often is, and we wonder whether delusion is not more consoling.

In the old days when people invented a new function they had something useful in mind.

One geometry cannot be more true than another; it can only be more convenient.

But all of my efforts served only to make me better acquainted with the difficulty, which in itself was something.

The aim of science is not things themselves, as the dogmatists in their simplicity imagine, but the relation between things.

A scientist worthy of his name, about all a mathematician, experiences in his work the same impression as an artist; his pleasure is as great and of the same nature.

When the physicists ask us for the solution of a problem, it is not drudgery that they impose on us, on the contrary, it is us who owe them thanks.