The more I study the things of the mind the more mathematical I find them. In them as in mathematics it is a question of quantities; they must be treated with precision. I have never had more satisfaction than in proving this in the realms of art, politics and history.

There are four types of men in the world: lovers, opportunists, lookers-on, and imbeciles. The happiest are the imbeciles.

Amid this vast and overwhelming space and in these boundless solar archipelagoes, how small is our own sphere, and the earth, what a grain of sand!

History is nothing but a problem of mechanics applied to psychology.

A fixed idea is like the iron rod which sculptors put in their statues. It impales and sustains.

His tongue is by turns a sponge, a brush, a comb. He cleans himself, he smooths himself, he knows what is proper.

The more I study the things of the mind the more mathematical I find them. In them as in mathematics it is a question of quantities; they must be treated with precision. I have never had more satisfaction than in proving this in the realms of art, politics and history.