“I think therefore I am. ”

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

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

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

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

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

“I should attempt to treat human vice and folly geometrically... the passions of hatred, anger, envy, and so on, considered in themselves, follow from the necessity and efficacy of nature... I shall...”

“If you can't test it, it's not theorics -- it's metatheorics. A branch of philosophy. So, if you want to think of it this way, our test equipment is what defines the boundary separating theorics fr...”

“Physicists have come to realize that mathematics, when used with sufficient care, is a proven pathway to truth.”