In Demonic Desires, Ishay Rosen-Zvi examines the concept of yetzer hara, or evil inclination, and its evolution in biblical and rabbinic literature. Contrary to existing scholarship, which reads the term under the rubric of destructive sexual desire, Rosen-Zvi contends that in late antiquity the yetzer represents a general tendency toward evil. Rather than the lower bodily part of a human, the rabbinic yetzer is a wicked, sophisticated inciter, attempting to snare humans to sin. The rabbinic yetzer should therefore not be read in the tradition of the Hellenistic quest for control over the lower parts of the psyche, writes Rosen-Zvi, but rather in the tradition of ancient Jewish and Christian demonology.

Rosen-Zvi conducts a systematic and comprehensive analysis of the some one hundred and fifty appearances of the evil yetzer in classical rabbinic literature to explore the biblical and postbiblical search for the sources of human sinfulness. By examining the yetzer within a specific demonological tradition, Demonic Desires places the yetzer discourse in the larger context of a move toward psychologization in late antiquity, in which evil—and even demons—became internalized within the human psyche. The book discusses various manifestations of this move in patristic and monastic material, from Clement and Origin to Antony, Athanasius, and Evagrius. It concludes with a consideration of the broader implications of the yetzer discourse in rabbinic anthropology.