In many ways, Darl is different from the other Bundren family members. He is highly intelligent, sensitive, and intuitive. His language is perceptive, observant, poetic.
Consider all the family members' motives for going to bring their mother's and wife's remains to Jefferson. Darl is the one who is truly troubled by the terrible disrespect to their mother's memory on their journey. The coffin gets lost in the river, the wet body begins to decompose, vultures are following the family, and as they pass through town, people cover their noses in disgust and curse at the family's backwardness and insolence.
Darl finally sets fire to the barn where Addie's coffin lies, to "free" her from the indignity she has been put through. He wants to lay her to rest. However, he is the one who gets sent to an insane asylum so that Anse can avoid a law suit for destroying another man's property.
The most poignant chapter is the one where Darl speaks about himself in third person, "Darl has gone to Jackson. They put him on the train, laughing, down the long car laughing, the heads turning like the heads of owls when he passed. 'What are you laughing at' I said. Darl is our brother, our brother Darl."
Emily Dickinson has written, "Much madness is divinest sense to a discerning eye."
So with Darl. On the surface, his repeating "yes yes yes yes yes" nonsensically and laughing maniacally seems that he has gone mad. But in the context of his family's behavior, who are selfish, insensitive, callous--his actions are the only sane ones.
While many people think that Darl is a main character of the novel, Addie certainly should be considered to be the novel’s main character.
First of all, she is the central fulcrum of the novel. Without her, the story does not exist. The story surrounds her decomposing corpse and its journey to Jefferson. Despite the fact that she is dead throughout the journey, there are many instances when she is very much alive. Vardaman constantly sees her as a living entity. He bores holes in her casket so that she can “breathe,” and he says that his mother “is a fish.” Darl wants to free her by burning her casket in the barn scene.
The novel is also entitled As I Lay Dying that provokes one to think that she is the main character observing the degraded family toting her body as she “lays dying.” One can not help to think that Faulkner intended his readers to view the story from Addie's eyes as a main and omniscient character from which we can judge the Bundren's actions.