"The will is by its nature so free that it can never be constrained."

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

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

"For it is not enough to have a good mind, but rather it is necessary to apply it well."

"The nature of the mind is entirely distinct from that of the body."