Mathematical discoveries, small or great are never born of spontaneous generation They always presuppose a soil seeded with preliminary knowledge and well prepared by labour, both conscious and subconscious.

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

Sociology is the science with the greatest number of methods and the least results.

Every good mathematician should also be a good chess player and vice versa.

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.

Why is it that showers and even storms seem to come by chance, so that many people think it quite natural to pray for rain or fine weather, though they would consider it ridiculous to ask for an eclipse by prayer.

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