"For seeing that the whole world is but motion, and there is nothing in it but motion, it is impossible that any part of it should remain always in the same state."

"The science of every man's duty, which is called ethics, is nothing else but the knowledge of what is good and evil in the actions of men."

"And from this, that every man desires his own good, it followeth, that every man desires to preserve himself."

"For there is no such Finis Ultimus (utmost aim) nor Summum Bonum (greatest good) as is spoken of in the books of the old moral philosophers."

"For if we could not see the motions of the stars, we should not know that there were any stars."