London also uses this chapter to set the stage for Buck’s eventual break with the world of men by telling us that this love for Thornton is the only thing that keeps Buck from going wild. Buck remains merciless, for one thing, holding on to the lessons that he learned from Curly’s death and from his war with Spitz—namely, that “he must master or be mastered.” His love for Thornton coexists with his knowledge that “kill or be killed, eat or be eaten, was the law.” His ability to still feel love is significant and suggests that London is not content with the bleakness of a Darwinian cosmos or with the pure cruelty and struggle for mastery of a Nietzschean worldview. But while Buck’s love is strong, it is for Thornton alone and not for mankind in general; he has learned well, especially from Hal and Charles, that mankind at large does not deserve his love. “Thornton alone held him,” London writes, and then describes how Buck ranges away from the fire and senses a “call” beckoning him into the deep forests and wilderness. For the time being, Buck resists this call for Thornton’s sake, but we are left to wonder what will happen if and when he and Thornton separate. Thus, Buck stands poised on the brink of a final break with the world of men, and the stage is set for the developments of the final chapter.