We are all instruments endowed with feeling and memory. Our senses are so many strings that are struck by surrounding objects and that also frequently strike themselves.

My ideas are my whores.

Evil always turns up in this world through some genius or other.

In order to shake a hypothesis, it is sometimes not necessary to do anything more than push it as far as it will go.

One declaims endlessly against the passions; one imputes all of man's suffering to them. One forgets that they are also the source of all his pleasures.