The book opens with a portrait of Iago, and considers the nature and moral significance of the evil that he represents. Raatzsch addresses the boundaries dividing normality and pathology, conceptualizing evil as a pathological form of the good or ordinary. Seen this way, evil is conceptually dependent on the ordinary, and Iago, as a form of moral monster, is a kind of nonbeing. Therefore, his actions might be understood and defended, even if they cannot be justified. In a brief epilogue, Raatzsch argues that literature's presentation of what is monstrous or virtuous can constitute an understanding of these concepts, not merely illustrate them.