What is the theme in The Accidental Tourist by Anne Tyler?

Death is a major theme in this book. Ethan's death triggers the novel's initial conflict. At first it leads to the dissolution of Sarah and Macon's marriage. The past year had been "miserable" for both of them, with "months when everything either of them said was wrong." When Sarah admits, "Now that Ethan's dead I sometimes wonder if there's any point to life," Macon responds, "It never seemed to me there was all that much point to begin with." This pessimism spurs Sarah's decision to leave Macon. She feels he is not grieving as much as she, nor is he providing her with the comfort she requires. Macon looks for someone to blame for Ethan's death, including Sarah and himself.