"Every present state of a simple substance is a natural consequence of its preceding state, in such a way that its present is big with its future."

"I am convinced that the unwritten knowledge scattered among men of different callings surpasses in quantity and in importance anything we find in books, and that the greater part of our wealth has yet…"

"Each soul is a little world, a microcosm."

"The world is not a machine. Everything in it is force, life, thought."

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