Wisest is he who knows he knows not.
Lies are the greatest murder. They kill the Truth.
No citizen has a right to be an amateur in the matter of physical training... what a disgrace it is for a man to grow old without ever seeing the beauty and strength of which his body is capable.
I know that I am intelligent, because I know that I know nothing.
If he who does not know kept silent, discord would cease.
Improve yourself by other men's writings thus attaining effortlessly what they acquired through great difficulty.