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.

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

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

Invention consists in avoiding the constructing of useless contraptions and in constructing the useful combinations which are in infinite minority. To invent is to discern, to choose.

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

Science is facts; just as houses are made of stones, so is science made of facts; but a pile of stones is not a house and a collection of facts is not necessarily science.