A collection of three 1990 essays on the general theme of diabolism in a monotheistic religion. The outlook is specifically Jewish, and not what would be called ecumenical. The first essay covers the theme of devils and devil worship, with an emphasis on satanic cults, which were believed to be real and a major concern in the media at the time this was written. The second speaks more generally to cults. The third questions the need for a devil, and suggests that true human potential can only be reached by accepting the idea that both good and evil have a common source and that, ultimately, human beings lack the objective viewpoint that alone can determine which is which. The author has added a number of new notes, and some more recent perspective, for this new edition.