This concluding chapter presents the final collapse of the once great Sutpen dynasty. Of greater importance is that we finally learn how Quentin knew more of the story than did his father or grandfather and therefore we can now give the greater credence to Quentin's narration. Faulkner never makes it clear how long or how much Quentin actually learned, but the reader can assume that he asked enough questions so as to make his narration the most reliable in the novel.
In terms of the entire novel, Quentin has told this story of Sutpen and his sons as a result of Shreve's inquiry as to the nature of the South. The logical implication is that Sutpen's story is in some ways representative of the South.
As stated in the introduction, Sutpen represented all the qualities associated with great heroic actions. But on the other hand, Sutpen represented the failure of the South. Sutpen's basic belief that the ingredients of ethics and morality were the same as the ingredients for any mixture caused him to ignore the ethical values of love, decency, and sympathy for other human beings. His intent upon establishing his design without acknowledging a humanitarian base is analogous to the rise and fall of the antebellum South, which established its design without considering the humanitarian implications of slavery. Sutpen's defeat and the South's defeat is the price they paid for erecting their economic and social structure upon the concept of the enslavement of another people. Likewise, Henry's sanctioning of incest and his crime of fratricide all suggest the most extreme perversion of values — a perversion that is only equaled by the South's willingness to fight with great chivalry for such a perverted system of values as those embedded in the concept of slavery.
Quentin, therefore, has told this story as representative of the South because he needs to understand the story himself. The meaning of Sutpen's story becomes clear to Quentin as he tells it and as he realizes that no man and no nation can set its selfish aims above those of another man or above that of humanity.
The final implication of the story comes not from Quentin but from Shreve, who at the beginning was the purely objective commentator who had no past to haunt him but who became so emotionally involved in the story that he undertook part of the narration. Shreve's final view is one of pessimism about the possible fate of the South and of the modern world; it is a world where a Jim Bond, who is both part black and part white, and an idiot, will be the type who will ultimately inherit the earth.