"The existence of God is demonstrated by the fact that I have an idea of a perfect being."

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

"The senses alone are not sufficient to give us a clear and distinct knowledge of things."

"The first precept was never to accept anything for true which I did not clearly know to be such."

"I resolved to feign that all the perceptions I had ever received were no truer than the illusions of my dreams."