Illusionistic art appeals to what the public knows not about art but about things. This ability to brush art aside is the secret of the popularity of illusionism. Ever since the Greeks told of painted grapes being pecked by real birds, wonder at skill in deceiving the eye has moved more people than appreciation of aesthetic quality. But for art to depend exclusively upon reproducing appearances has the disadvantage of requiring that the painting or sculpture conform to the common perception of things.

p. 239, "Reality Again: The New Photorealism" - Art on the Edge, (1975)