Daemons in Hellenic and Christian Antiquity is a groundbreaking analysis of the interplay between Greek and Christian ideas in Late Antiquity, with a focus on how daemons were conceived of by intellectuals in both traditions. Its protagonists are Origen, the great third-century philosopher and theologian, and Porphyry, a philosopher of the next generation whose ideas were strikingly influenced by Origen. By critical comparative study of Origen’s Contra Celsum and Porphyry’s De Abstinentia, author Panayiotis Tzamalikos establishes beyond doubt that Porphyry’s conception of daemons took its cue overwhelmingly from his predecessor’s theories on the subject. Porphyry adopted Origen’s ideas (and, at crucial points, his vocabulary) on daemons, at times very closely, thereby setting his daemonology apart from that of other Greek schools, while also he employed terminology interweaving Greek and Christian language. Throughout this inquiry, the author also builds further evidence that there was only one Origen, and that the modern invention of ‘two Origens’ (one ‘Platonist’, the other ‘Christian’) is untenable. This book is set to revolutionise understanding of the relationship between Greek philosophy and Christianity in Late Antiquity.