"Allegory, in some sense, belongs not to medieval man but to man, or even to mind, in general. It is of the very nature of thought and language to represent what is immaterial in picturable terms" (C.S. Lewis).

"The whole point of allegory is that it does not need to be read exegetically; it often has a literal level that makes good enough sense all by itself. But somehow this literal surface suggests a peculiar doubleness of intention, and while it can, as it were, get along without interpretation, it becomes much richer and more interesting if given  interpretation"  (Fletcher).

http://bis.midco.net/galendg/aguild/index.html

The Allegory Guild

http://religion.rutgers.edu/iho/allegory.html

Philosophy & Allegory

http://www.artistresource.org/Nendza.htm

An Allegory of Art and Science