"My purpose is not to teach a method which everyone ought to follow to guide his reason, but only to show how I have tried to guide mine."

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

"I have never made any distinction between the sciences, but have always held that all are linked together, and that it is easier to learn them all at once than to learn one separately."

"He who has a firm and stable mind will find that in all conditions of life he can be master of himself."

"It is not enough to apply our mind to things, but we must also apply it to ourselves."