"It is not absurd for discerning Europeans . . . to see something today which is not adequately known by the Chinese erudites, and to be able to interpret their ancient books better than the erudites t…"

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

"Every mind has a horizon in respect to its present intellectual capacity but not in respect to its future intellectual capacity."

"I do not like X as a symbol for multiplication, as it is easily confounded with x."

"Pre-established harmony is the only way to explain the agreement of substances without their interaction."