Date: 1692

"[T]he Explanation whereof is allowed by all men as satisfactory, 'tis this, in Tab. 41. Fig. 2. the Image a b of the Object A B is painted on the Retina inverted, and yet the Eye (or rather the Soul by means of the Eye) sees the Object erect and in its natural Posture."

— Molyneux, William (1656-1698)

Date: 1751, 1777

"And, indeed, without such a correction of appearances, both in internal and external sentiment, men could never think or talk steadily on any subject; while their fluctuating situations produce a continual variation on objects, and throw them into such different and contrary lights and positions."

— Hume, David (1711-1776)