"He who has a why to live can bear almost any how."

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

"Judge a man by his questions rather than his answers."

"Science is organized knowledge. Wisdom is organized life."

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

"Common sense is not so common."

"By three methods we may learn wisdom: first, by reflection, which is noblest; se..."

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