"The fool doth think he is wise, but the wise man knows himself to be a fool."

"The only thing I know is that I know nothing."

"The only thing we have to fear is fear itself."

"The only true wisdom is in knowing you know nothing."

"The mind is everything. What you think you become."

"To know what you know and what you do not know, that is true knowledge."

"The measure of intelligence is the ability to change."

"Patience is the companion of wisdom."