The Sea-Wolf by Jack London is a tale of opposites. While Humphrey "Hump" van Weyden is initially weak, wealthy, and overly idealistic, Wolf Larsen is masculine, working class, and sociopathic. "Hump" believes in an inherent good in all. He believes in justice and mercy, even to the end.
Wolf is the opposite. He lives in a cutthroat world of manipulation where life has no value. He believes the world is harsh and unforgiving. This reflects Jack London's previous themes in The Call of the Wild.
London focuses on the basics of survival in most of his books. He depicts worlds of primitivism, a back to basics lifestyle. At the root of his writing is a belief that life is bestial. In The Sea-Wolf, London opposes the primitive instincts of Wolf with the spiritual beliefs of "Hump." Overall, London presents the question: are we spiritual beings in physical bodies, or physical bodies clinging to spirituality?