Some years ago, Bill Moyers conducted a series of televised interviews with Joseph Campbell, writer of Myth and Metaphor and The Hero with a Thousand Faces and many other books.

CLICKY.

These interviews are available on DVD. Second paragraph of the web site I provided a link to just above. They are well worth getting and watching (maybe your local public library).

Among many other things, Campbell says that there are great truths to be found in myths. But—where man and religions go wrong is when they take the myth—and the metaphors therein—as literal historical facts.

Don Firth