"All things are subject to interpretation. Whichever interpretation prevails at a given time is a function of power and not truth."

"The tree that would grow to heaven must send its roots to hell."

"All psychology hitherto has remained stuck in moral prejudices and fears; it has not dared to descend into the depths."

"Only sick people have a right to be doctors of mankind."

"I teach you the overman. Man is something that shall be overcome. What have you done to overcome him?"