"Give me matter and motion, and I will construct the universe."

"It is not enough to walk with great strides, it is necessary to walk in the right road."

"The whole of philosophy is like a tree, whose roots are metaphysics, whose trunk is physics, and whose branches are all the other sciences."

"I am a thinking substance, that is, a mind, or soul, or intellect, or reason."

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