"Common sense is not so common."

"In a gentle way, you can shake the world."

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

"A wise man can learn more from a foolish question than a fool can learn from a w..."

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

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

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

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