The greatest of all mysteries is the man himself.
I only know one thing, and that is I know nothing
The uninitiated are those who believe in nothing except what they can grasp in their hands, and who deny the existence of all that is invisible.
True knowledge exists in knowing that you know nothing.
It is better to make a mistake with full force of your being than to carefully avoid mistakes with a trembling spirit.
Slanderers do not hurt me because they do not hit me.