Passions are defects or virtues in the highest power.

A school of art or of anything else is to be looked on as a single individual, who keeps talking to himself for a hundred years, and feels an extreme satisfaction with his own circle of favorite ideas, be they ever so silly.

Whoever wishes to keep a secret must hide the fact that he possesses one.

There is nothing in the world more shameful than establishing one's self on lies and fables.

No two people see the world exactly alike, and different temperaments will often apply the same principle, recognized by both, differently. Even one and the same person won't always maintain the same views and judgments: earlier convictions must give way to later ones.

Mathematicians are like Frenchmen: whatever you say to them they translate into their own language and forthwith it is something entirely different.

A clever man commits no minor blunders.