A thing is not proved just because no one has ever questioned it. What has never been gone into impartially has never been properly gone into. Hence scepticism is the first step toward truth. It must be applied generally, because it is the touchstone.

It has been said that love robs those who have it of their wit, and gives it to those who have none.

The philosopher forms his principles on an infinity of particular observations. He does not confuse truth with plausibility, he takes for truth what is true, for false what is false, for doubtful what is doubtful, and probable what is probable. The philosophical spirit is thus a spirit of observation and accuracy.

What is a monster? A being whose survival is incompatible with the existing order.

You risk just as much in being credulous as in being suspicious.

For me, my thoughts are my prostitutes.

First move me, astonish me, break my heart, let me tremble, weep, stare, be enraged-only then regale my eyes.