“Madison Avenue is afraid of the dark.”

Jace to Clary, pg. 192
Source: The Mortal Instruments, City of Bones (2007)
Context: "Don't order any of the faerie food," said Jace, looking at her over the top of his menu. "It tends to make humans a little crazy. One minute you're munching a faerie plum, the next minute you're running naked down Madison Avenue with antlers on your head. Not," he added hastily, "that this has ever happened to me."

Usher II (1950)
The Martian Chronicles (1950)
Source: Fahrenheit 451
Context: They began by controlling books of cartoons and then detective books and, of course, films, one way or another, one group or another, political bias, religious prejudice, union pressures; there was always a minority afraid of something, and a great majority afraid of the dark, afraid of the future, afraid of the past, afraid of the present, afraid of themselves and shadows of themselves.

Source: Curse of the Bane

Source: City of Lost Souls

This quotation, often attributed on the Internet to Plato, cannot be found in any of Plato's writings, nor can it be found in any published work anywhere until recent years. If it really were a quotation by Plato, then some author in the recorded literature of the last several centuries would have mentioned that quote, but they did not. The sentiment isn't new, however. The ancient Roman Seneca, in his work on "Morals," quoted an earlier Roman writer, Lucretius (who wrote about the year 50 B.C.), as saying "we are as much afraid in the light as children in the dark." (Seneca was paraphrasing a longer passage by Lucretius from De Rerum Natura (On the Nature of Things), Book II, lines 56 et seq.)
Misattributed