Marry a good woman, and be happy the rest of your life. Or, marry a bad, and become a good philosopher

As to marriage or celibacy, let a man take which course he will, he will be sure to repent

Is there anyone to whom you entrust a greater number of serious matters than your wife? And is there anyone with whom you have fewer conversations?

Aren't you ashamed to be concerned so much about making all the money you can and advancing your reputation and prestige, while for truth and wisdom and the improvement of your souls you have no thought or car?

The more I know, the more I know that I don't know.

A system of morality that is based on relative emotional values is a mere illusion, a thoroughly vulgar conception that has nothing sound in it and nothing true.

When you want success as badly as you want the air, then you will get it. There is no other secret of success.