Rene Descartes

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

“I am indeed amazed when I consider how weak my mind is and how prone to error.”

“I think; therefore I am.”

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

“Common sense is the most fairly distributed thing in the world, for each one thinks he is so well-endowed with it that even those who are hardest to satisfy in all other matters are not in the habit of desiring more of it than they already have.”

“Whenever anyone has offended me, I try to raise my soul so high that the offense cannot reach it.”

“When it is not in our power to follow what is true, we ought to follow what is most probable.”

“Everything is self-evident.”

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

“Perfect numbers like perfect men are very rare.”

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

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

“There is nothing so strange and so unbelievable that it has not been said by one philosopher or another.”

“The first precept was never to accept a thing as true until I knew it as such without a single doubt.”

“Each problem that I solved became a rule, which served afterwards to solve other problems.”

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

“Illusory joy is often worth more than genuine sorrow.”

“In order to improve the mind, we ought less to learn, than to contemplate.”

“Travelling is almost like talking with those of other centuries.”

“I am accustomed to sleep and in my dreams to imagine the same things that lunatics imagine when awake.”