True opinions are a fine thing and do all sorts of good so long as they stay in their place; but they will not stay long. They run away from a man's mind, so they are not worth much until you tether them by working out the reason. Once they are tied down, they become knowledge, and are stable.

Justice in the life and conduct of the State is possible only as first it resides in the hearts and souls of the citizens.

One cannot make a slave of a free person, for a free person is free even in a prison.

Opinion is the medium between knowledge and ignorance.

There is a ... matter - much more valuable and divine than natural philosophy . ... On this matter I must speak to you in enigmas.

We understand why children are afraid of darkness ... but why are men afraid of light?

Man's greatest victory is over oneself.