In England it was enough that Newton was the greatest mathematican of his century; in France he would have been expected to be agreeable too.

There are only two kinds of certain knowledge: Awareness of our own existence and the truths of mathematics.

Push on and faith will catch up with you.

I am worn out by the insults and vexations that this work brings down on us.

Music that paints nothing is only noise.

Gaming is the destruction of all decorum; the prince forgets at it his dignity, and the lady her modesty.

Just go on . . . and faith will soon return. To a friend hesitant with respect to infinitesimals.