That Epicurean theology remains a particularly controversial, and hence fascinating, area of study is suggested by the fact that three of the nine essays in Epicurus and the Epicurean Tradition edited by J. Fish and K. Sanders (2011) were devoted to this topic (Sedley, ‘Epicurus’ Theological Innatism', pp. 29–52, Konstan, ‘Epicurus on the Gods’, pp. 53–71 and E., ‘Cicero's Use and Abuse of Epicurean Theology’, pp. 129–51). The controversy has emerged out of the conflict between two very different modern views of what the Epicureans conceived the gods to be. The more traditional view has been labelled ‘realist’ in that it takes Epicurus' gods to be living entities who exist somewhere ‘out there’ and are immortal; we are aware of them because we register the eidola which they emit. The alternative view, and one that has acquired a certain popularity particularly after a version of it was proposed by Long and Sedley in The Hellenistic Philosophers (1987), is that the gods do not exist ‘out there’ as actual entities but that they come to exist due to the way we process certain types of eidola; as Long and Sedley put it so bluntly, ‘Gods, like giants, are thought-constructs’ (p. 145). They are imperishable, but as concepts, not as living beings. This view has been labelled ‘idealist’.

E., who is currently preparing a new edition of Philodemus On the Gods Book 3 based on an examination of the papyrus which preserves the text (Pherc. 152/157), has produced a book which addresses the difficulties encountered in modern interpretations of the key ancient evidence for the Epicurean view of the gods, and also contains a re-issue of a portion of the text from On the Gods Book 3 (with translation and commentary) which he previously edited and published (in ‘Falsche Götter bei Philodem (Di III Kol. 8, 5 – Kol. 10, 6)’, CErc 39 [2009], 161–205). This section, comprising roughly columns numbered 8 to 10 in the text, contains a discussion of the habitations of the gods and the mistaken beliefs in ‘star gods’. In E.'s opinion, and that of others, it is a section which has a significant bearing on the idealist–realist debate.

No work devoted to an investigation into the Epicurean doctrine of divinity can fail to take a position on the so-called idealist–realist debate. E. positions himself explicitly in the realist camp and an important objective of this book is to argue against the interpretations of the idealists and reassert the idea that for all Epicureans the gods were actual living beings whose existence was in no way dependent on mortals. As a result E. is led to focus on sections of Cicero's On the Nature of the Gods which have frequently formed important evidence for interpreters of the idealist persuasion, particularly the statements made by the Epicurean Velleius in 1.49. The two other texts which receive very detailed re-examination are the scholion to Diogenes Laertius 10.139, and the portions of Philodemus On the Gods which he has edited.

Although detailed and covering a sometimes bewildering number of interpretations and arguments, the book is well organised and E. is careful to explain the sequence of topics. An introduction sets out the fundamental problem, provides an outline of the study and makes explicit the methodology to be followed. E. has occasion to review the arguments of a great many scholars throughout the book. He has deliberately not set out to provide a complete doxography but is scrupulous in his treatment of the most significant and recent contributions. There follow three chapters, each subdivided into smaller sections. Chapter 1 deals with the foundations of our awareness of the gods. Here the focus is on several key passages from Cicero's On the Nature of the Gods: the interpretation of 1.43–6 as containing evidence that Epicurus believed that our preconception of the gods is innate (a view that has been restated and argued by Sedley in his 2011 essay mentioned above) is reviewed and, after a necessary excursus on the Epicurean physics of perception, both sensory and mental, E. tackles the notoriously contested testimony contained in sections 49–50 of Cicero's first book. He then proceeds to examine Cotta's refutation of the Epicurean claims in On the Nature of the Gods 1.105–14, concluding the chapter with a consideration of the evidence supplied by the scholion recorded in Diog. Laert. 10.139, a text upon which many realist interpreters rely. E. subjects all these texts to intense scrutiny and gives proper attention to grammatical and syntactic issues. His analysis serves to remind us of how difficult it is to wrestle coherence from On the Nature of the Gods 1.49 in particular, and the text-critical interventions which scholars have been compelled to make in order to have the text mean what they think it should mean. A scholar's commitment to either the realist or idealist cause will determine how the text is read and what emendations are made. E. argues that the passage in On the Nature of the Gods 1.49, like the scholion in Diog. Laert., is concerned with the physics of our perception of the gods, not with their ontological status.

Chapter 3 covers the manner in which the conception of the gods is expanded legitimately on the basis of the impressions humans receive. Consequently, a section of the chapter is devoted to the explication of the Epicurean methods of analogy and epilogismos, and this is followed by sections on the shape and corporeality of the gods and their habitations. As one might expect, E. argues against the idealists on these points.

The fourth chapter contains what is arguably E.'s most valuable contribution to our understanding of Epicurean theology, an edition with translation of Philodemus On the Gods 3 col. 8.5–col. 10.6. This section of Philodemus' book deals primarily with the error of believing that the stars are gods, and contains a number of points – including a reference to the habitations of the gods – which have relevance to the modern debate about the precise nature of the gods themselves. E.'s improved text (issued already in CErc in 2009) makes it more difficult to read as evidence for the idealist interpretation of Epicurean theology. The commentary which follows the text retains some of the material published in CErc in 2009 but, rightly in this context, tends to exclude most of the technical justification for the constitution of the text. Instead, the commentary focusses on aspects relevant to the issues covered in the earlier chapters.

The summary conclusions which end the book are welcome given the sheer quantity of information and the complexity of the arguments covered in the foregoing chapters. Equally valuable are the various indexes (ancient persons mentioned, subjects discussed, passages from ancient authors, key terms in Greek and Latin).

Although I have to confess an inclination towards the realist side myself (I find it hard to accept that any Epicurean could have applied the adjective ‘immortal’ to an entity that depends on us mortals for its existence), I believe that others too will feel that E. has made a forceful case for the realist interpretation of the available evidence. Opponents of the more traditional understanding of Epicurean theology will be required to reply, and if they wish to continue to deploy in their arguments the text from columns 8 to 10 of Philodemus' On the Gods 3 they will need to rethink their strategy in the light of the improvements E. has supplied. One suspects that students of Epicureanism can look forward to further progress in the debate with the appearance of reliable texts of the second part of Philodemus On Piety (Obbink) and On the Gods 3 (E.). The fact that the editors are affiliated to opposing views on the character of Epicurean theology makes the prospect even more interesting.