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: 1686, 1689, 1697

"'Tis so many times in the capacities of Youth: they who can receive any impression like the Virgin-wax, will as easily suffer a defacement unless it be hardned and matur'd by Time: whereas others who are hard to be wrought upon like Steel, retain the Images which are Engraven on them with much m...

— Nourse, Timothy (c.1636–1699)

Date: 1690, 1694, 1695, 1700, 1706

"And our Minds represent to us those Tombs, to which we are approaching; where though the Brass and Marble remain, yet the Inscriptions are effaced by time, and the Imagery moulders away."

— Locke, John (1632-1704)

Date: 1690, 1694, 1695, 1700, 1706

"How much the Constitution of our Bodies, and the make of our animal Spirits, are concerned in this; and whether the Temper of the Brain make this difference, that in some it retains the Characters drawn on it like Marble, in others like Free-stone, and in others little better than Sand, I shall ...

— Locke, John (1632-1704)