In what is called a picaresque, a subgenre of fiction which depicts the life of an unconventional hero in humorous and often satirical fashion. The World According to Garp includes the writing career of Garp whose work is depicted as a novel within a novel and covers four motifs: wrestling, writing, sex, death. Chapter 15, "The World According to Arden Bensenhaver" is part of Garp's third novel and covers the motif of sex.
The world according to Bensenhaver is one that rails against rape and condemns its perpetrators in the worst way possible. In this chapter, Hope Standish has her home invaded by the degenerate Oren Rath. When a neighbor inadvertently interrupts Rath's plans to rape Hope in her home, Hope yells to her to grab her baby and call the police. Rath, then, takes Hope in his pickup truck; however, she proves tougher than he has expected and works his knife out of his discarded pants pocket and proceeds to slit his throat and disembowel him.
When detective Arden Bensenhaver follows the path of Oren Rath and interrogates Rath's brothers about the whereabouts of the black truck that Rath is probably driving, he employs some rather unorthodox methods, one of which is that he tells the brothers of Oren that any sexual crime is punishable by castration, and if people assist in a sexual crime or do not help to stop it, they, too, can be castrated.
To Arden Bensenhaver there was no crime as serious as rape--not even murder, except perhaps the murder of a child.
For, Bensenhaver's pregnant wife had been raped and killed. So, in his world no crime was as serious, and "no trivial detail should make less of rape's outrage," as well. This is why he throws away Rath's condom; he does not want the violating act mitigated in any way.