True knowledge exists in knowing that you know nothing. And in knowing that you know nothing, that makes you the smartest of all.
To Believe without evidence and demonstration is an act of ignorance and folly
Man must rise above the Earth - to the top of the atmosphere and beyond - for only thus will he fully understand the world in which he lives.
Do not do to others what angers you if done to you by others.
Nobody knows anything, but I, knowing nothing, am the smartest man in the world.
I believe that we cannot live better than in seeking to become better, nor more agreeably than having a clear conscience.