The Corpus Hermeticum (CH) must represent one of the most complex textual phenomena of the Roman period, and as a collection of pseudonymous works, the reconstruction of its context of production, circulation and use poses considerable problems for historians of religion. Christian Bull’s monograph, a revised version of his 2014 doctoral thesis, represents one of the most successful attempts to come to grips with these problems. Ambitious in its scope, it aims not only to understand the ritual ‘Way of Hermes’, but also the lived reality behind the texts. In these goals the author draws considerably upon other recent scholars, notably Garth Fowden, David Frankfurter, and Jacco Dieleman, whose extensive use of the Greek and Demotic magical papyri allowed them to argue that the Hermetica should be seen as originating from the same linguistically and culturally diverse priestly milieux as these texts. But while these authors may have left us with a commonly-held consensus on these questions, they did not, as Bull notes, provide a fully argued form of the hypothesis, a task that he sets out to perform.
The monograph begins with a helpful presentation of the status quaestionis of hermetic studies, summarising past research and major problems before ending with a helpful theoretical discussion of the role of Hermes within the texts, understood through the theoretical lens of cultural memory. The remainder of the book is divided into three main parts, the first of which, Who is Hermes Trismegistus? introduces more fully the central protagonist of the Hermetica. This section begins with an investigation into the origin of his title “Thrice Greatest” in Egyptian and Greek-language sources, and it continues with a survey of early discussions of Hermes-Thoth in Greek literary texts. This search for a prehistory of the Hermetica is followed by one of the monograph’s boldest sections, an exploration of the writings of the Egyptian priest and Greek author Manetho. Bull’s argument, too rich to resume in full here, makes the case for the authenticity of the letter of Manetho to Ptolemy II Philadelphus preserved by George Syncellus, suggesting it to be the introduction to Manetho’s work on Egyptian history usually known as the Aigyptiaka. This work’s ultimate goal, he argues, was to demonstrate that the beginning of Ptolemy III’s reign marked a new Sothic cycle, and hence a new golden age.
The importance of this work for the Hermetica lies in the fact that it refers to a succession of figures named Hermes, the latest of whom, Hermes Trismegistos, is associated with familiar later Hermetic topoi such as the recovery and transmission of primeval wisdom. Indeed, the letter seems to attest to the existence of Greek-language texts attributed to Hermes-Thoth as early as the reign of Ptolemy III. Bull’s argument here goes well beyond the sphere of religion, linking the writing and circulation of these ‘Proto-Hermetica’ to the production of Ptolemaic, and later Roman, political propaganda.
This leads into a discussion of the theory of kingship, already present in Manetho, but more fully expressed in the Hermetic tractates proper (principally SH XXIII, the Korē Kosmou), which makes the case for the divine origin of royal souls. Traces of this doctrine can be found in Hellenistic and Roman astrological material more broadly, suggesting that the “proto-Hermetic” layer may be taken to include the fragmentarily-attested but highly influential Hellenistic authors Nechepsos and Petosiris, legendary Egyptian king and priest respectively. Again, the intricacy of the argument prevents a full summary, but the cosmology implied by this doctrine—centred on kings, and valorising various categories of ritual experts—implies for Bull an origin in priestly milieux whose goal was the legitimation of pharaonic kingship and their own authority.
The second part, What is the Way of Hermes? reconstructs the cursus followed by an initiate of Hermetism using the evidence of the philosophical Hermetica. While the phrase “Way of Hermes” does not, in fact, appear in the Hermetica, but we do find comparable discussions of a “Way of Immortality”, and the mention of an order (suntaxis) in CH XVI and of various different categories of discourses (genikoi, diexodikoi) in the Coptic Discourse on the Eighth and the Ninth(Disc.8–9) demonstrate that the authors of these texts did imagine them as following a sequence.
Bull’s principal innovation in this section is in his reconciliation of the ‘monistic’ and ‘dualistic’ tendencies of the different tractates. While previous authors proposed multiple schools of Hermetism, or a cursus that moved from a world-affirming monism for initiates to a world-denying dualism for the initiated, Bull proposes a movement in the other direction, from dualism to monism. The initial stages (“conversion”, “knowing oneself”, “becoming a stranger to the world”) consist in a recognition of the need to separate oneself from the Way of Death followed by the masses, and instruction in the nature of humanity and the cosmos, leading to a recognition that goodness exists only in the divine. This separation sets the stage for a ritual of rebirth represented in CH XIII. Despite the challenges of reconstructing a ritual from an idealised mythic representation, Bull convincingly suggests a real ritual context through linguistic parallels to the magical papyri. This assimilation of the initiate to God effected by the ritual now reveals the divine origin of the cosmos, resulting in the monism of the later tractates. The final stage, “Heavenly Ascent”, is reconstructed based on Disc.8–9, and consists of a guided ascent to the eighth hypercosmic sphere, where the Hermetist hymns the ineffable ninth sphere, gaining a preview and guarantee of his blessed afterlife. Again, this section is informed by a careful attention to the ritual context, noting again the parallels to the magical papyri in the chanting of vowels and the idea of recording the ritual on a temple stela protected by curses.
The third part of the monograph, Who were the Hermetists? turns to the question of the social context of the authors and users of the Hermetica. This section draws most heavily on the often-underutilised technical Hermetica, with Bull stressing the insufficiency of distinct modern categories such as philosophy, ‘magic’, and the mysteries. The author follows earlier studies in pointing out references to communal activities such as the singing of hymns and the sharing of meals, to which he adds the observation that both strands of Hermetica presuppose an interest in astrological contemplation and calculation. This introduction is followed by an extended reconstruction of the relationship between the Egyptian priesthood, the Hermetica, and the magical papyri, delving more fully into seams already identified by Fowden and Frankfurter. In particular, this section uses the archive often known as the Theban Magical Library (here the ‘Thebes Cache’) to demonstrate the clear parallels between the Hermetica and magical texts, and demonstrate the implication of priests in both. The key text used here is the so-called Mithras Liturgy of PGM IV.475-829, already recognised by Fowden as parallel to the Hermetic ascent ritual. This section integrates the story of Thessalos, the Greek doctor who visited Thebes to seek a magical revelation, as a prototype of the exchange between a Hellenic seeker of knowledge and the Egyptian priesthood that might lie behind the Hermetica.
The final part of this section discusses the distinctive contribution of Egyptian priests to the Hermetica in more theoretical terms, using Frankfurter’s idea of the appropriation by the priesthood of the Hellenic stereotype of the oriental sage, nuanced by Richard Gordon’s argument that this development arose in part from the priests’ own sense of their vocation. As with the discussion of Thessalos, this section uses material found in similar discussions of religious interculturality in Roman Egypt—Chaeremon’s idealised description of the priesthood, the apocalypticism of the Asclepius in the context of the Egyptian Chaosbeschreibung—but Bull succeeds in finding interesting new perspectives; once again he innovatively demonstrates the relationship between the Hermetica and politics, arguing the “impious new law” mentioned by the Asclepius to be the decree of 198/199 CE which outlawed traditional Egyptian divinatory practices.
In his conclusion, Bull returns, albeit cautiously and with careful grounding, to Richard Reitzenstein’s idea of the origin of the Hermetica in a small community of Hellenes interested in both Egyptian wisdom and Greek philosophy, led by Egyptian priests, perhaps in the Fayum of the first century, which may have expanded into a larger number of voluntary associations of the type well attested in Graeco-Roman Egypt.
Bull’s work represents an accessible yet profound and thoughtful introduction and handbook to the Hermetica, providing both a fair and thorough summary of previous work and a lucid approach to understanding them, and it is likely to become an invaluable reference work and source of further ideas in years to come.
Potential readers may be disappointed to find relatively little engagement with the Demotic text published in 2005 by Richard Jasnow and Karl-Theodor Zauzich as the Book of Thoth: A Demotic […] Pendant to the Classical Hermetica.This represents less Bull’s failing than the fact that this text’s connections to the Hermetica have proven less clear than originally hoped. Bull’s solution, rather than seeing the Book of Thoth as a direct predecessor, is to argue that a simple translation of such a text would have been unsatisfactory to a philosophically-oriented Hellenophone, requiring the priests to (re)invent an Egyptian tradition using their knowledge of Greek philosophy. This deep enmeshment of the corpus with Greek texts is apparent from Bull’s able exegesis of the texts in this second part, but it was precisely this feature that led André-Jean Festugière to suggest the Egyptian elements to be largely decorative. This complicates the priest-as-authors hypothesis, intended to explain the presence of Egyptian ideas, to which priestly authors would have unique access, an explanation which loses power according to the degree to which such Egyptian ideas are absent or ambiguous. A second problem, perhaps a resolution to the first, arises from Bull’s convincing demonstration that many of the central ideas contained in the Hermetica were already circulating in Greek in the early Roman period, and likely earlier. If many of the borrowings from Egyptian theology were already accessible to and used by hellenophone authors before the writing of the philosophical Hermetica, this may further reduce the need to presuppose priestly authors writing qua priests, that is, as inheritors of tradition that only they could mediate.
Another problem of chronology is apparent in Bull’s use of Frankfurter’s theory of the commoditisation of priestly knowledge following the decline of the temples, originally intended to explain the high number of magical formularies that survive from the third and fourth centuries CE. Bull proposes that the priests were already seeking non-traditional sources of income in the first and second centuries, yet despite the policies of the Roman administration, a decline is much less apparent at this period.
None of the objections raised here reduce the value of Bull’s work as a major advance in our knowledge of Hermeticism; rather they represent unresolved issues in the studies upon which he builds, and they point the way towards research which may nuance our understanding of socio-ethnic identity and the transmission of knowledge in the Roman Mediterranean even further.
 Garth Fowden, The Egyptian Hermes (Princeton: Princeton University Press, 1986); David Frankfurter, Religion in Roman Egypt: Assimilation and Resistance (New Jersey: Princeton University Press, 1998); Jacco Dieleman, Priests, Tongues and Rites: The London-Leiden Magical Manuscripts and Translation in Egyptian Ritual (100–300 CE) (Leiden: Brill, 2005).
 Frankfurter, Religion in Roman Egypt, pp.225-237; Richard Gordon, “Shaping the Text: Innovation and Authority in Graeco-Egyptian Malign Magic,” in Kykeon: Studies in Honour of H.S. Versnel, edited by Herman F.J. Horstmanshoff et al. (Leiden: Brill, 2002), pp. 71–76.
 Richard Reitzenstein, Poimandres: Studien zur griechisch-ägyptischen und frühchristlichen Literatur (Leipzig: Teubner, 1904).
 Cf. Joachim F. Quack, “Die Initiation zum Schreiberberuf im Alten Ägypten”, Studien zur Altägyptischen Kultur 36 (2007), p.261.
 André-Jean Festugière, La révélation d’Hermès Trismégiste. 4 vols. (Paris: Les Belles Lettres, 1944–1954), vol 1 pp.82–87.
 Frankfurter, Religion in Roman Egypt, pp.214-233.