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.

Change a virtue in its circumstances find it becomes a vice; change a vice in its circumstances, and it becomes a virtue. Regard the same quality from two sides; on one it is a fault, on the other a merit. The essential of a man is found concealed far below these moral badges.

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.

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

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.

The production of a work of art is determined by the material and intellectual climate in which a man lives and dies.

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!