Peter Schjeldahl in the current (Dec. 14) New Yorker :
The phrase “outsider art” was coined in 1972 by a
British art historian, Roger Cardinal, to translate
the sense of “art brut ,” which Dubuffet had
considered rendering as art “raw,” “uncouth,” “crude,”
or “in the rough.” But the term misses the full thrust
of Dubuffet’s elevation of “people uncontaminated
by artistic culture,” as he called them. He aspired not
to make outsiders respectable but to destroy the
complacency of insiders. He disqualified even tribal
and folk artists, and spirited amateurs like Henri
Rousseau, for being captive to one tradition or another.
Art brut must be sui generis, from the hands and minds
of “unique, hypersensitive men, maniacs, visionaries,
builders of strange myths.”
The literary art of Fritz Leiber and Stephen King seems to
fit this definition.
Somewhat less brut — the literary art of Plato.
A non-literary illustration:
Time as "a moving
image of eternity.”
— Plato