There are as many kinds of modesty as there are races. To the English woman it is a duty; to the French woman a propriety.

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!

To have a true idea of man or of life, one must have stood himself on the brink of suicide, or on the door-sill of insanity, at least once.

The search for causes must come after the collection of facts.

In the stormy current of life characters are weights or floats which at one time make us glide along the bottom, and at another maintain us on the surface.

We study ourselves three weeks, we love each other three months, we squabble three years, we tolerate each other thirty years, and then the children start all over again.

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.