René Descartes

“Divide each difficulty into as many parts as is feasible and necessary to resolve it.”

“It is not enough to have a good mind; the main thing is to use it well.”

“Except our own thoughts, there is nothing absolutely in our power.”

“Perfect numbers like perfect men are very rare.”

“To live without philosophizing is in truth the same as keeping the eyes closed without attempting to open them.”

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

“Conquer yourself rather than the world.”

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

“Common sense is the most widely shared commodity in the world, for every man is convinced that he is well supplied with it.”

“To know what people really think, pay regard to what they do, rather than what they say.”

“Doubt is the origin of wisdom.”

“The senses deceive from time to time, and it is prudent never to trust wholly those who have deceived us even once.”

“An optimist may see a light where there is none, but why must the pessimist always run to blow it out?”

“The reading of all good books is like a conversation with the finest minds of past centuries.”

“I think, therefore I am.”