At the basis of several mythological interpretations of Hermes Tris- megistus (the personification of the cosmopolitan Hellenistic Hermes and the Egyptian god Thoth), there is a strong tension characterizing his dual nature, human and divine. The aim of this essay is to investigate the differ- ent instances of this tension in the Asclepius, in the Arabic sources of the prologue De tribus Mercuriis, in the Liber Planetarum ex scientia Abel, in De quindecim stellis, quindecim lapidibus, quindecim Herbis et quindecim imaginibus, in the Glosae super Trismegistum, in the Asclepius’s manuscript tradition. These texts feed the medieval imagination while also informing the con- figuration of Hermes’s modern identity, which is in turn represented as a primal source of wisdom, as a prophet of monotheism (or as the author of an extensive output sacral aura of a prophet in the guise of pagan Christ- ian revelation), as the repository of three ancient traditions of wisdom (logic, physics, ethics) and as the founder of astrology, alchemy, and magic. A brief analysis of the iconological representation of Siena Cathedral and Florence manuscript of the Laurentian Library, Ashburn. 1166, 1475, c. 1v. completes this overview. The legendary fortune of Hermes Trismegistus is bound to live on, in its different adaptations, after the discovery of the origin of the apocryphal literature by Isaac Causabon.