Quote 5

[Each] day mankind and the claims of mankind slipped farther from him. Deep in the forest a call was sounding, and as often as he heard this call, mysteriously thrilling and luring, he felt compelled to turn his back upon the fire, and to plunge into the forest. . . . But as often as he gained the soft unbroken earth and the green shade, the love of John Thornton drew him back to the fire again.

This quotation is from Chapter VI, “For the Love of a Man,” and it depicts the tension building within Buck during his time with John Thornton. Thornton is the ideal master, and his relationship with Buck represents a perfect partnership between man and dog. London tells us that this is the first time that Buck has truly loved a human being. Yet, at the same time, it is clear that Buck’s destiny lies in the wild, and so he is torn between the urges that pull him away from humanity and his intense loyalty to Thornton. That love, it becomes clear, is the only thing tying him to the world of men—which means that when Thornton is killed, there is nothing left to hold him, and he embraces his destiny as a wild creature.