"I have said more than once, that I hold space to be something merely relative, as time is; that I hold it to be an order of coexistences, as time is an order of successions."

"God alone is the primary unity, or the original simple substance, of which all created monads are products."

"The pleasure we obtain from music comes from counting, but counting unconsciously. Music is nothing but unconscious arithmetic."

"The true method of advancing the sciences is to first lay solid foundations."

"If geometry were as much opposed to our passions and present interests as is ethics, we should contest it and violate it but little less, notwithstanding all the demonstrations of Euclid and Archimede…"