Date: 1684

"For certainly there must be some change in our mind when we have some thoughts and then others, and, in fact, ideas of things we are not actually thinking about are in our minds as the shape of Hercules is in rough marble."

— Leibniz, Gottfried Wilhelm (1646-1716)

Date: 1765

"If all [the mind] had was the mere capacity to receive those items of knowledge--a passive power to do so, as indeterminate as the power of wax to receive shapes or of a blank page to receive words--it would not be the source of necessary truths"

— Leibniz, Gottfried Wilhelm (1646-1716)