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

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!

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.

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.

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

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

I wish to reproduce things as they are or as they would be even if I myself did not exist.