I am the most travelled of all my contemporaries; I have extended my field of enquiry wider than anybody else, I have seen more countries and climes, and have heard more speeches of learned men. No one has surpassed me in the composition of lines, according to demonstration, not even the Egyptian knotters of ropes, or geometers.

If thou suffer injustice, console thyself; the true unhappiness is in doing it.

It is greed to do all the talking but not to want to listen at all.

Soul and intellect are just the same things.

Nature . . . has buried truth deep in the bottom of the sea.

The brave man is not only he who overcomes the enemy, but he who is stronger than pleasures. Some men are masters of cities, but are enslaved to women.

I would rather discover one true cause than gain the kingdom of Persia.