"The more a thing has perfection, the more it acts, and the less it suffers."

"Man, in so far as he is determined to act, is a part of nature, and is necessarily determined to do whatever he does."

"He who wishes to revenge injuries by reciprocal hatred will live in misery."

"Freedom is absolutely necessary for the progress in science and the liberal arts."

"It is impossible for a man to be affected by any emotion unless he imagines something which excludes the existence of an external cause of that emotion."