[Irving's] first three novels gave him the reputation of an interesting but minor writer. ("Garp," thinks the hero of Irving's next novel, "hated the reputation of 'small but serious.'") Commercially, he appeared to be one of those novelists who would eventually have to be published by an outfit like the Fiction Collective. Then, in 1978, along came The World According to Garp, a success both critical and commercial. People not only bought this, Irving's fourth novel, they read it; they not only read it, they loved it….

The World According to Garp is not so much salted as drenched in sex and violence, but so is the world drenched in sex and violence, and so, too, in recent years have a large number of novels been drenched. The sex and violence in Garp do not, in any case, go very far toward explaining the novel's immense popularity, for...