"I think, therefore I am — this is the first and most certain conclusion that anyone who philosophizes in order should arrive at."

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

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

"Cogito, ergo sum. (I think, therefore I am.)"

"For the mind is not nourished by anything but truth."