The figure of Orpheus has long exercised a potent influence on religious thought. Yet what we know directly about Orphism comes from a scatter of isolated and often very short fragments quoted in the works of Platonists of the Roman period, notably Proclus, Damascius and Olympiodorus. The author's concern here is to establish the context in which these passages were cited, and to trace the development of the written tradition, from the texts which contain a critique of the beliefs of the Homeric era to those, whether newly composed or transformed, which show signs of adaptation to later religious and philosophical movements, among them Stoicism and Platonism. In sharp contrast to views held by others, it is argued that it is possible to map out a process of evolution, amongst other criteria by focusing on the role and place of Chronos in the Orphic theogony. The author also asks whether there really ever existed true Orphic sects with a cult with specific rites, and would conclude that the present evidence cannot be held to substantiate this. Orph e a pendant longtemps exerc une puissante influence sur la pens e religieuse. Cependant, ce que nous connaissons directement de l'Orph sme se r duit une poign e de fragments isol s et souvent tr s courts qui se trouvent parpill s dans les oeuvres de Platoniciens ayant v cu sous l'Empire romain, surtout Proclus, Damascius et Olympiodore. Dans les articles qui composent ce recueil, l'auteur s'est attach reconstituer les contextes dans lesquels ces passages sont cit s, et comprendre comment s'est d velopp e la tradition crite laquelle ils appartiennent, depuis les textes qui critiquent les croyances v hicul es par Hom re et par H siode et qui, ayant fait l'objet d'une r daction ou d'une transformation r cente, pr sentent les signes d'une adaptation des mouvements religieux ou philosophiques tardifs, le Sto cisme et le m dio-Platonisme entre autres. S'opposant en cela b