Protestan theology heretofore has largely been concerned with the concept of sin as an abstract quantity: the sinfulness of man (as opposed to Roman Catholic tendencies to concretize sin as a here-and-now, tangible, aberration from an inflexible moral norm). In this work, the author insists, problematically, that sin, contrary to that common Protestant notion, can exist only in practice, and never as an abstraction. First, May discusses sin with respect to the world in terms of the worship of false gods, false fear, and false mastery. Then he analyses a more subtle category: the sins of man against man. Finally, he treats the sins of man against himself: pride (""the shadow of solitude"") and sloth (""the shadow of death""). There is no pietism in the book, and little legalism (which establishes a specific difference with respect to the traditional Catholic interpretation). On the other hand, the book is perhaps a bit too formidable, from the standpoint of style and approach, for the audience who would profit most from May's thought--i.e., the intelligent layman. The market therefore will comprise only the professionally concerned theologian, the minister in pastoral work, and the seminarian.