The greater the knowledge, the greater the doubt.

If you treat men the way they are you never improve them. If you treat them the way you want them to be, you do.

Normally, the sciences distance themselves from life and the return to it via a detour.

What sort of faults may we retain, nay, even cherish in ourselves? Those faults which are rather pleasant than offensive to others.

Piety is not a goal but a means to attain through the purest peace of mind the highest culture.

There is no permanence in doubt; it incites the mind to closer inquiry and experiment, from which, if rightly managed, certainty proceeds, and in this alone can man find thorough satisfaction.

What we do not understand we do not possess.