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: 1751

"Tho' an impression is made upon the mind, by means of the image painted upon the retina, whereby the external object is perceived; yet nature has carefully concealed this impression from us, in order to remove all ambiguity, and to give us a distinct feeling of the object itself, and of that only."

— Home, Henry, Lord Kames (1696-1782)