The author have suggested that Greek mythology, partly as a consequence of these effects of literacy, is unusual in three respects: the thematic restrictions of the divine myths, the elaborate but conventionalised heroic myths, and the shortage of fantasy and imagination by comparison with many other mythologies. The myths of savage societies avoided that fate, and a few surprising thematic resemblances, like the primeval separation of earth and sky, perpetuated the idea of Greek myths as somehow still archetypal. A more significant cause is the unusually diverse origin of the Greek gods and goddesses as compared, once again, with the Nordic deities or the city-gods of ancient Mesopotamia. The Greeks did not have to bother much about floods or droughts, and that is why certain Mesopotamian obsessions like the great flood and the destruction of mankind, when they appear in Greek form, seem halfhearted and badly integrated into the total mythological context.