Reviewed by: A Threat to Public Piety: Christians, Platonists, and the Great Persecution by Elizabeth DePalma Digeser Raymond Van Dam A Threat to Public Piety: Christians, Platonists, and the Great Persecution. Elizabeth DePalma Digeser. Ithaca and London: Cornell University Press, 2012. Pp. xv + 218. ISBN 978–0-8014–4181–3. By the end of the third century, Christians were becoming more prominent in Roman society. During the 250s the emperors Decius and Valerian had sanctioned the persecution of Christians; but by the 290s Christians were serving at the court of the emperor Diocletian. Then Diocletian reversed course. In February 303 he issued an edict that deprived Christians of any offices and ranks; subsequent edicts ordered the arrest of clerics and commanded everyone to perform religious sacrifices. In the retrospective opinion of bishop Eusebius of Caesarea, the Roman state had suddenly declared a “war against us.” This last, great persecution became an integral component of Eusebius’ master narrative of the development of Christianity: the persecuting emperors would die in horrible pain, the last emperor standing would be a Christian, and the church triumphant would rise from the church of the martyrs. Elizabeth Digeser now proposes a totally different explanation for the outbreak of persecution under Diocletian and his fellow emperors. In her interpretation the important catalysts were not the emperors themselves, as dutiful pagans who supported traditional cults, nor stubbornly devout Christians, whose obstinacy goaded emperors and their magistrates to extreme reactions. Instead, the motivating forces were the abstract ideas of philosophers and theologians. Sectarian religious violence was a consequence of “ideas about correct ritual and metaphysical doctrine” (ix). Digeser’s argument follows two tracks, one concerning intellectual history, the other political events. Her analysis of intellectual history details the extensive connections among the philosophers and theologians of the later third century. Their common intellectual pedigree derived from the philosopher Ammonius, who was credited as the teacher of both the Christian theologian Origen and the pagan philosopher Plotinus (chapter 1). Digeser hence concludes that in these scholarly communities Christians and “Hellenes” (non-Christian intellectuals) shared and discussed the same teachings, based usually on the dialogues of Plato (chapter 2). They also sharply disagreed with each other about the application of those ideas. Porphyry was especially contentious. He attempted to claim the legacy of Plotinus by writing a Life of his master and by accepting his notion that divine worship shaped the identity of states (chapter 3). This mixture of religious observance and political philosophy was a recipe for intolerance. Porphyry opposed the theology of Iamblichus, a fellow Hellene and one of his own students. Iamblichus seemed to [End Page 378] extend a path to divine union even to ordinary people by proposing that “all forms of divination, properly done, are the gifts of the gods leading all souls heavenward” (122). In contrast, Porphyry insisted that only philosophers could achieve unity with the divine One (chapter 4). He likewise opposed the theology of Origen and his followers for their misuse of exegetical tools when interpreting the Bible. As a result, even as Origen’s supporters criticized Porphyry, some of them, such as Methodius of Olympus, began to distance themselves from Origen’s teachings (chapter 5). “Origen’s brand of Christianity and Iamblichus’s form of Platonism together felt the heat of Porphyry’s attack” (97). Highlighting the centrality of Porphyry’s critiques in these intellectual debates is an important outcome of Digeser’s argument, even if many of the details remain contentious. Her attempt to link these erudite controversies back to political decisions is less effective (chapter 6). It is especially difficult to conjecture how abstract ideas could become policy among emperors who were trained as soldiers, not learned scholars. Even though Diocletian invited rhetoricians and sophists to his court, other emperors were more noted for their hostility to learned culture. The teacher Lactantius shuddered at the anti-intellectualism of the emperor Galerius, who enjoyed the ferocious antics of his pet bears but considered the study of literature to be evil. As a result, Digeser instead stresses the influence of “a loose network of Hellenes, intellectuals, and religious professionals working behind the scenes” (188). This network included imperial magistrates, local priests, augurs...