Whatever authority I may have rests solely on knowing how little I know.
The life of which meaning one never ponders is not worth living
Falling down is not a failure. Failure comes when you stay where you have fallen.
I only know one thing, and that is I know nothing
An unexamined life is a life of no account.
One should never do wrong in return, nor mistreat any man, no matter how one has been mistreated by him.