The novel presents a discussion of the philosophy of love and sex, written in the form of a series of letters between two men, "Herbert Wace," a young scientist, and "Dane Kempton," an elderly poet. Writer Jack London wrote "Wace's" letters, and Anna Strunsky wrote "Kempton's." In the late 19th century, the authors were part of a San Francisco radical literary group known as "The Crowd."
Kempton makes the case for feeling and emotion, while Wace proceeds "scientifically" and analyzes love in Darwinian terms:
"I purpose to order my affairs in a rational manner....Wherefore I marry Hester Stebbins. I am not impelled by the archaic sex madness of the beast, nor by the obsolescent romance madness of later-day man. I contract a tie which reason tells me is based upon health and sanity and compatibility. My intellect shall delight in that tie."
Initially the public was piqued by the anonymity of the writers and the book was moderately successful. London biographer Russ Kingman praised the book; he quoted the Buffalo Commercial as admiring the "sheer charm of its prose" and saying the book "holds firmly its place in the front rank of the best of the season's publications."