Quote by Descartes, René

"I think, therefore I am."

"The greatest minds are capable of the greatest vices as well as of the greatest virtues."

"Doubt is the key to knowledge."

"If you would be a real seeker of truth, it is necessary that at least once in your life you doubt, as far as possible, all things."

"The best part of living is knowing you survived."

"The world needs heroes."

"Life is too short to live poorly."

"I'd rather be an optimist and be wrong than a pessimist and be right"