Henri Poincare

A very small cause which escapes our notice determines a considerable effect that we cannot fail to see, and then we say that the effect is due to chance.

Science is built up of facts, as a house is with stones. But a collection of facts is no more a science than a heap of stones is a house.

It is through science that we prove, but through intuition that we discover.

The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful.

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.

If we knew exactly the laws of nature and the situation of the universe at the initial moment, we could predict exactly the situation of the same universe at a succeeding moment.

If nature were not beautiful, it would not be worth knowing, and if nature were not worth knowing, life would not be worth living.

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.

Science is built of facts the way a house is built of bricks but an accumulation of facts is no more science than a pile of bricks is a house.