LitCharts assigns a color and icon to each theme in As I Lay Dying, which you can use to track the themes throughout the work.
Self-Interest Versus Heroic Duty
Mortality and the Nature of Existence
Family, Birth, and Death
Religion and Faith
Language versus Action
Summary
Analysis
After the Bundren wagon passes, Tull takes out his mule and decides to follow the family. Tull notices Anse and the rest of the family members gathering at the edge of the river, despite the news of the sunken bridge. He watches the family looking at the submerged bridge, wondering what to do in order to cross with Addie's coffin.
Tull's presence throughout the novel as a peripheral figure and frequent helping-hand for the Bundrens calls attention to the family's neediness, ignorance and fundamental lack of heroism, despite all of Anse's references to duty.
Active
Themes
Tull feels as though he is the object of the Bundrens' scorn, noticing in particular Dewey Dell and Darl's cold stares and Cash's meticulous look, as though Tull were the coffin Cash was trying to build carefully. Jewel does not move and looks with apparent anger at Tull, eventually berating him for following the Bundrens all the way to the river. Cash quiets his brother. Tull suggests that the Bundrens might want to wait until the water level decreases, but the family proceeds to make plans to drive the wagon carrying Addie's coffin across the shallow part of the river.
Tull's narrations are perhaps most telling about the Bundrens, as he observes them with a familiar but detached eye. He notices the idiosyncrasies about each family member—Dewey Dell's anxiety, Darl's coldness, Cash's obsessive eye, and Jewel's fierce hostility. Tull's opinions and observations help to destabilize the romantic idea of family as a united front.
Active
Themes
Tull stands around as the family members argue, trying to figure out the least dangerous way of making it across the river. Tull sternly lets them know that he will not allow his mule in the water to help them. Jewel curses the mule and Darl taunts Tull for his decision. Regardless, Tull repeats his statement that he will not allow the mule to go into the water.
Jewel's initial anger at Tull's involvement indicates his independence. It also presents him as perhaps the only character who truly believes in keeping the promise to Addie a private matter. That said, Jewel then becomes angry at Tull for not lending them his mule, acting rash in his state of grief. Even Jewel is revealed to be caught between personal matters (his grief) and heroism.