A definition of myth is dependent on one’s theory of it. As Karl Popper has shown in the fields of science, people do not collect data and then form a theory from the data; rather, they develop a theory into which they hope most or all the data consistently fits. If this is true for the sciences it is especially true for metaphysical branches of knowledge including the studies of myth, religion, and folklore.
The broadest definition of myth is a story that is told about the ancient past dealing with the creation or origin of things. Myth also provides a framework of cultural norms through the exploits of heroes and gods by which a society functions.
This broad definition soon becomes conceptualized within the framework of theory. Ritualists will show that myth deals with sacred rites which are connected to fertility, cosmology, and sociological constructs. Structuralists break down myth into individual components and using fundamental motifs, show how these components organize the thought and worldview of those employing the myths. Psychologists interpret myth as psychological archetypes which emerge from the inner world of the unconscious and manifest themselves in the mythic imagery of dreams, passions, and even neurosis.
The modern mind cannot leave ancient myth alone. There is something fundamental about these primordial stories which fascinates and endures. Modern society continues to use mythic motifs in their arts and literature, in advertising and business, and in politics and religion. The symbols of ancient myth are embedded in the human psyche showing that the study of ancient myth is not just a study of the hoary past, but also the perennial study of the self.