There is no study of "esotericism" (hereafter referred to without scare quotes) in which the literature and legacy of the ancient Mediterranean world do not play a primary role.1 To take several examples, the so-called Yates paradigm derived from Frances Yates's celebrated work Giordano Bruno and the Hermetic Tradition may be understood as not just relating a history of a neglected Renaissance philosopher and practitioner of magic, but the reception and revival of ancient Platonism and Hermetism in the fourteenth and fifteenth centuries (Yates, 1964). The Yates paradigm has also been formative to Wouter Hanegraaff's many studies on (Western) esotericism, a history of modern "rejected knowledge" which deals in some way with the "gnosis" experienced by ancient philosophers making claims to eastern wisdom, a phenomenon called "Platonic Orientalism" (see below). Kocku von Stuckrad, meanwhile, has employed the term esotericism to denote wider cultural discourses that deal with the mediation of secrecy, concealment, and revelation of "absolute knowledge" in both antiquity and modernity, central topoi of which include Neoplatonism, Gnosticism, and Jewish mysticism (von Stuckrad, 2010; esp. von Stuckrad, 2015)."Where there's smoke, there's fire." Specialists in the study of Mediterranean antiquity have already for some time been debating the difficult status of roughly the same body of ancient evidence (Burns, 2015b, p. 103). In early twentieth-century scholarship, one reads of a kind of "occult syncretism" of the later Roman empire, exemplified in Neoplatonic theurgy, a "spineless syncretism" which was "sucking the life-blood out of Hellenism," in Eric Robertson Dodds's memorable phrasing (Dodds, 1947, pp, 58-59). John Dillon's classic textbook The Middle Platonists closes with an appendix on what he loosely termed the "Platonic Underworld," i.e. Gnosticism, Hermeticism, and the Chaldean Oracles, viz. Neoplatonic theurgy (see below).2 Garth Fow-1 For valuable comments and emendations to the present text I thank the volume's editors, Egil Asprem and Julian Strube, as well as Nicholas Banner. All judgments and especially errors therein remain, of course, my own. 2 Cf. Victoria Nelson's discussion of the theme of the "grotto" "as neither a garden ornament nor a chamber of horror, but a place of worship," exemplified by Hellenistic and Roman Alexandria, where Hermetic, Gnostic, and Platonic literature flourished (Nelson, 2003, p. 31).