Each chapter is increasingly more coherent and easy to understand. First, Benjy is mentally disabled, and he can't tell the difference between past or present, which makes the reader confused as to which time period he is referring to. Despite this, he gives a fairly direct depiction of the characters in the story because he is able to only tell us what happens without mixing it up with how he feels. Next, Quentin looses his sanity throughout the chapter and ultimately kills himself. He is under immense amounts of pressure from his parents at Harvard, and he has a strong desire to "save" his sister Caddy from her marriage. He too begins to loose his sense of time. Quentin feels much more complex emotions than Benjy, or any character for that matter, which makes him quite the enigma. Third, Jason has a belief system that seems crazy to us, which is the only thing that makes him hard to understand. He speaks coherently, though not always intelligently, which is a big change from either Benjy or Quentin. Finally, Dilsey's chapter is told from the third-person voice, which makes her completely coherent and easy to understand because we don't also have to try to understand her feelings or beliefs.
Faulker probably presented the book in this order to first introduce characters in an unbiased manner through Benji, and also present to the reader the overarching theme of time in the book. Quentin further gives us an insight into time, and also shows readers other sides of the characters that Benjy could not show. For example, we learn of the horrible pressure that Mr. and Mrs. Compson put Quentin under at Harvard, which tells us that they are not the best parents. More importantly, though, we learn more about Caddy and her marriage, and how Quentin tried to save her from that marriage by telling her father that they had committed incest. Then, through Jason, we are able to learn even more about the characters, such as Mrs. Compson's oblivion to Jason's terrible nature. We learn even more about Caddy in the present day (because Quentin's chapter was set 18 years before), and about her love for her daughter and desire to help her family, despite Jason's evil efforts to intercept the money coming from Caddy. Lastly, Dilsey's third-person narration nicely ends the story in a pragmatic, emotionless way that tells readers what transpires. This makes the narration much more interesting because it continually changes. It is a very effective way of showing readers the many sides of each character.
The Sound and the Fury definitely parallels the Deep South in the time period in which it was written. Jason is the embodiment of these southern values, mostly rooted in hatred for those who are different and deemed inferior to you. But the progression of the narrators also shows the changing South throughout this period, from a crazy, disorienting place to a place that is much easier to understand.
This novel is about the presence of idiocy in everyone. All characters have some degree of idiocy, and this is shown through the series of narrations. Benjy shows us the true idiot that cannot help being an idiot because he is mentally disabled. He is the idiot that is innocent, what we think of when we think of idiots. But Quentin is an idiot in the way he deals with his emotions and the way he thinks too much. He allows his emotions to lead him to insanity and eventually suicide. Jason is an idiot because he has an insane belief system that revolves around his egocentricity. This is supported by the Macbeth quote "life is a tale told by an idiot, signifying nothing." Faulker's tale is told four times, yet the plot development is in no way coherent. The four stories told all have different themes and things to take away from them, and only the events that occur are parallel through each narration (though each tells different parts of the entire story, so they do not all match up). What this really shows is that in every story, there are separate stories for each character because everybody has their own story. Every person has their own interpretations and perception of each event, which gives us our individuality, but also provides a source of confusion.