Darl possesses the special ability to see into other people's minds in consequence of his mother's lack of recognition; his insaneness is actually a reflection of everybody else's mind since he reaches a point where he becomes everyone but himself. In his speech:
"I don't know what I am. I don't know if I am or not.
Jewel knows he is, because he does not know that he
does not know whether he is or not" (72).
Darl states that he does not know what he is due to the lack of recognition his mother has for him. This weak sense of self leads him to entirely lose himself and replace it with the other characters of his family. Darl's last thought is: "Darl is our brother, our brother Darl. Our brother Darl is in a cage in Jackson [...] looking out he foams" (85). The fact that it is written in third person means that he has replaced himself for his sibling's point of view because he has lost his sense of self.
Anse fails to understand that Darl's act of burning down the barn is not an act of insaneness but quite the opposite; Darl opposes the madness that is carrying the rotting body any longer and decides that the logical thing to do is burn it. This is a perfect excuse for Anse to send Darl away to a mental institution, however his motifs are incorrect. What Cash says to Darl is perhaps more accurate: "It'll be better for you [...] Down there is will be quiet, with none of us bothering and such" (227). Maybe isolation from his family members will bring a stronger sense of self to Cash. never figure out who he truly is. The insight he possesses over the rest of the...