This is an interesting book concerning the phenomena of leaving a group, i.e. defecting, in ancient Judaism, Christianity, and Graeco-Roman philosophical groups. Positive: serve as a pseudo-source book noting ancient literary texts, as well as some epigraphical, which discuss people who have moved away from a tradition. Negatives: Final chapter focuses on sociological models to help understand this phenomena better placed at beginning of book. It is disjointed from the rest of the book since the models were not integrated well into the book. Also, discussion of Paul questionable. Treatment of Qumran sparse. ( )