What I do not like about our definitions of genius is that there is in them nothing of the day of judgment, nothing of resounding through eternity and nothing of the footsteps of the Almighty.

A schoolteacher or professor cannot educate individuals, he educates only species.

He who says he hates every kind of flattery, and says it in earnest, certainly does not yet know every kind of flattery.

I have often noticed that when people come to understand a mathematical proposition in some other way than that of the ordinary demonstration, they promptly say, "Oh, I see. That's how it must be." This is a sign that they explain it to themselves from within their own system.

What is the good of drawing conclusions from experience? I don't deny we sometimes draw the right conclusions, but don't we just as often draw the wrong ones?

A clever child brought up with a foolish one can itself become foolish. Man is so perfectible and corruptible he can become a fool through good sense.

One of our forefathers must have read a forbidden book.