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

"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."

"every feeling is the perception of a truth..."

"The soul follows its own laws, and the body also follows its own laws, and they agree with each other by virtue of the pre-established harmony between all substances, since they are all representation…"

"Every substance is as a world apart, independent of everything else except God."