Gottfried Wilhelm Leibniz — "The happier the man, the less he needs to be amused; like a healthy man who does…"

"Why is there anything at all rather than nothing whatsoever?"

"The monads are centers of force, not points of matter."

"There is a certain destiny of everything, regulated by the foreknowledge and providence of God, who has established an infallible connection between the antecedent and the consequent."

"Every substance is a perpetual living mirror of the universe."

"Certainly the condition of our affairs [in Europe], slipping as we are into ever greater corruption, seems to be such that we need missionaries from the Chinese who might teach us the use and practice…"