Themes

Late in the novel Huff remarks that he never thought of his victim, Mr. Nirdlinger, as a living human being, but only as an imaginary construct.

(And Cain does not allow the reader to "know" Nirdlinger in the sense that the other characters are known, for he appears but twice in the novel.) This statement reveals one of Cain's main themes in the novel, the latent instinct man harbors to kill without logical forethought. The irrepressible attractions of sexuality and greed are part of Huff's motivation to kill, but Cain realizes that an ordinary working man with no outward criminal tendencies can allow himself to be driven to murder — certainly one of the most nightmarish visions of modern man in literature. Cain's other major theme in Double Indemnity is guilt and how it operates in the minds of his characters.

Huff becomes physically ill after the murder...