Date: 1714

"But when a monad has organs that are adjusted in such a way that, through them, there is contrast and distinction among the impressions they receive, and consequently contrast and distinction in the perceptions that represent them [in the monads] (as, for example, when the rays of light are conc...

— Leibniz, Gottfried Wilhelm (1646-1716)

Date: 1718

"Epicurus, that it [sperm] is a Fragment torn from the Body and Soul."

— Plutarch (c. 46-120)

Date: 1718

""Lausippus and Zeno, [sperm] 'tis a Body, and it is a Fragment of the Soul."

— Plutarch (c. 46-120)

Date: January 1739

"The attention is on the stretch; the posture of the mind is uneasy; and the spirits being diverted from their natural course, are not governed in their movements by the same laws, at least not to the same degree, as when they flow in their usual channel."

— Hume, David (1711-1776)