140 Quotes by Henri Poincare

What is it indeed that gives us the feeling of elegance in a solution, in a demonstration?

Absolute space, that is to say, the mark to which it would be necessary to refer the earth to know whether it really moves, has no objective existence.... The two propositions: "The earth turns round" and "it is more convenient to suppose the earth turns round" have the same meaning; there is nothing more in the one than in the other.

No more than these machines need the mathematician know what he does.

The mind uses its faculty for creativity only when experience forces it to do so.

Thus, they are free to replace some objects by others so long as the relations remain unchanged.

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.

The mathematical facts worthy of being studied are those which, by their analogy with other facts, are capable of leading us to the knowledge of a physical law. They reveal the kinship between other facts, long known, but wrongly believed to be strangers to one another.

Just as houses are made of stones, so is science made of facts.

Thus, be it understood, to demonstrate a theorem, it is neither necessary nor even advantageous to know what it means . . . .