Date: 1763 (repr. 1776); 1794 (repr. 1799)

"Sensible ideas gradually decay in the memory if they be not refreshed by new sensations; the traces perhaps wearing out: yet they may last many years."

— Doddridge, Philip (1702-1751)

Date: 1763 (repr. 1776); 1794 (repr. 1799)

"The analogy upon this hypothesis between sensation and memory, the one arising from impressions made on the brain, the other depending on traces continued there."

— Doddridge, Philip (1702-1751)

Date: 1775

"To account for the idea of time, it appears to me to be sufficient to attend to a few well known facts, viz. that impressions made by external objects remain a certain space of time in the mind, that this time is different according to the strength, and other circumstances of the impression, and...

— Priestley, Joseph (1733-1804)

Date: April, 1871

"Constantly impressed ideas are brought back by the world around us, and if they are so often, get so tied to our other ideas that we can hardly wrench them away."

— Bagehot, William (1826-1877)