"Although the whole of this life were said to be nothing but a dream and the physical world nothing but a phantasm, I should call this dream or phantasm real enough, if, using reason well, we were neve…"

"To be is to be a value."

"I maintain that the monads, which are the true atoms of nature, have no windows through which anything could enter or depart."

"Monads have no windows through which anything could enter or depart."

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