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."

"You can't expect to be happy if you're surrounded by mess."

"Health and happiness - these are true wealth"

"How can you live like this? It's like a pigsty!"

"You're going to get sick living like this."