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 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.

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.

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

For thirty centuries, from her sacred seat the cat looked down, and crouching at her feet, beheld the race of conquering Pharaohs kneel.

I've met many thinkers and many cats, but the wisdom of cats is infinitely superior.

Kindly politeness is the slow fruit of advanced reflection; it is a sort of humanity and kindliness applied to small acts and every day discourse: it bids man soften towards others, and forget himself for the sake of others: it constrains genuine nature, which is selfish and gross.