This novel is short, but it contains a profound naturalistic philosophy. This is an analogy story and a novel about philosophy and belief. This paper is based on the topic that this novel is actually a life portrayal of Jack London. In this paper, the author will make a study of the thoughts of naturalism and realism, the ecological thoughts, the contradiction between the human nature and the wild, the reasons for Jack London’s main thoughts reflected in the novel, and the philosophical thought and even conflicting values.