A "myth" is a narrative that iconically encapsulates a people's essential relationships with each other and with the world about them.
Have you ever heard anyone exclaim "Oh, that is just an old myth!" It is often assumed in our "modern" society that a myth is an untrue tale told by our ignorant ancestors to explain away that which they really didn't understand. Admittedly, the surface of myth may not be literally true -- there are over 20,000 creation myths, after all, and one might reasonably expect at least 19,999 of them to be wrong. But a living myth is at the very least psychologically true. And that myth strikes a deep chord in us is confirmed by psychologists' studies of our dreams, psychoses and neuroses, and by the ease with which we are moved and sometimes manipulated by advertisers and artists, politicians and religious figures who play upon these deep things in us. For religious people, of course, myth is truer than the merely "real" things of our everyday life. And all of us -- doctors, lawyers, Marines, professors, entrepreneurs, police - finally have a mythic self-understanding, however muted.
Mark Shorer:
"Myth is fundamental, the dramatic representation of our deepest instinctual life, of a primary awareness of man in the universe, capable of many configurations, upon which all opinions and attitudes depend. Myth is the essential substructure of all human activity.
Alan Watts:
"Myth is to be defined as a complex of stories -- some no doubt fact, and some fantasy -- which, for various reasons, human beings regard as demonstrations of the inner meaning of the universe and of human life."
George Whalley:
"Myth is a direct metaphysical statement beyond science. It embodies in an articulated structure of symbol and narrative a vision of reality. It is a condensed account of man's Being and attempts to represent reality with structural fidelity, to indicate at a single stroke the salient and fundamental relations which for a man constitute reality...Myth is not an obscure or oblique or overly-elaborate way of expressing reality -- it is the only way."