It is not without fear and trembling that a historian of religion approaches the problem of myth. This is not only because of that preliminary embarrassing question: what is intended by myth? It is also because the answers given depend for the most part on the documents selected by the scholar. From Plato and Fontenelle to Schelling and Bultmann, philosophers and theologians have proposed innumerable definitions of myth. But all of these have one thing in common: they are based on the analysis of Greek mythology. Now, for a historian of religions this choice is not a very happy one. It is true that only in Greece did myth inspire and guide epic poetry, tragedy and comedy, as well as the plastic arts; but it is no less true that it is especially in Greek culture that myth was submitted to a long and penetrating analysis, from which it emerged radically ‘de-mythicised’. If in every European language the word ‘myth’ denotes a ‘fiction’, it is because the Greeks proclaimed it to be such twenty-five centuries ago. What is even more serious for an historian of religion: we do not know a single Greek myth within its ritual context. Of course this is not the case with the paleo-Oriental and Asiatic religions; it is especially not the case with the so-called ‘primitive’ religions. As is well known, a living myth is always connected with a cult, inspiring and justifying a religious behaviour. None of this of course means that Greek myth should not figure in an investigation of the mythical phenomenon. But it would seem unwise to begin our kind of inquiry by the study of Greek documents, and even more so to restrict it to such documents. The mythology which informs Homer, Hesiod and the tragic poets represents already a selection and an interpretation of archaic materials, some of which had become almost unintelligible. In short, our best chance of understanding the structure of mythical thought is to study cultures where myth is a ‘living thing’, where it constitutes the very ground of the religious life; in other words, where myth, far from indicating a fiction, is considered to reveal the truth par excellence.