The Kempton-Wace Letters was a 1903 epistolary novel written jointly by Americans Jack London and Anna Strunsky, then based in San Francisco, California. It was published anonymously. 
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.