How to get rid of having anything to unlearn.
Wealth and poverty do not lie in a man's estate, but in men's souls.
Pay attention to your enemies, for they are the first to discover your mistakes.
As iron is eaten away by rust, so the envious are consumed by their own passion.
We must not contradict, but instruct him that contradicts us; for a madman is not cured by another running mad also.
The advantages of philosophy? That I am able to hold converse with myself.