There are savages without God in any proper sense of the word, but none without ghosts.

It is because the body is a machine that education is possible. Education is the formation of habits, a superinducing of an artificial organization upon the natural organization of the body.

The rules of the game are what we call the laws of nature.

Follow humbly wherever and to whatever abyss Nature leads, or you shall learn nothing.

Mathematics may be compared to a mill of exquisite workmanship, which grinds your stuff to any degree of fineness.

The most considerable difference I note among men is not in their readiness to fall into error, but in their readiness to acknowledge these inevitable lapses.

It is far better for a man to go wrong in freedom than to go right in chains.