In "To Build a Fire," Jack London contrasts the main character's civilized sense of "judgment" against the wolf dog's more primitive "instinct" (13). While the man's judgment seems to draw on his personal experience, the wolf dog's instinct draws on the experience of every blood ancestor the animal has ever had, which is really saying something. The dog's primitive knowledge tells it to remain close to the fire on such a cold day, but the man's judgment leads him onward to the camp. The man's judgment therefore seems to fail him, while the dog's instinct and natural adaptation to the Yukon ensures its survival.