"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."

"The art of discovering the causes of phenomena, or true hypothesis, is like the art of deciphering, in which an ingenious conjecture often greatly shortens the road."

"The monads can only be changed by God."

"The doctrine that the world is governed by perfection was introduced to exclude the arbitrary will of God."

"I do not believe that a world without evil, preferable in order to ours, is possible; otherwise it would have been preferred. It is necessary to believe that the mixture of evil has produced the great…"