Grief
Before The Accidental Tourist has even begun, Macon and Sarah Leary have lost their son in a tragic and senseless way. This loss has directly led to their own relationship also disintegrating. Throughout the book, we see how the couple separately deals with their grief. For Macon, it is a particularly difficult struggle. Instead of trying to confront his pain head-on, he suppresses it with his many strange "systems" of organization that he implements, reflecting this resistance to fully dealing with his own emotions. Among all of the Leary siblings, there is this common reluctance to acknowledge the reality of death and loss. Macon is frustrated by the way no one has uttered Ethan's name since he was killed; it is not until his niece Susan speaks about Ethan that it occurs to Macon that others also mourn his son.
As the book progresses, Macon somewhat comes to terms with Ethan's death, realizing that the only way to truly heal from grief is not to forget Ethan but rather to imagine him as still alive through memory, co-existing in a parallel realm. Yet Macon's ultimate choice at the end of the book—to leave Sarah for Muriel Pritchett—also demonstrates that part of him wants to start anew and cast his old life with Ethan and Sarah into the past, in order to protect himself from more potential loss and have some sense of control over his destiny.
True love
Love and the loss of it haunt the entirety of The Accidental Tourist. The story shows Macon grappling to discover the true meaning of love. It is clear that he loves Sarah and his son Ethan, but he has lost both of them. As a result, Macon struggles with motivation to live, feeling that, through loss, love has been taken from him. Yet Macon gradually comes to recognize that connections with others—whether it be with his deceased son or his estranged ex-wife—endure, despite separation. This is one of the central currents of the novel.
Macon is faced with distinguishing between comfort and true love. When he first parts from Sarah, he misses her deeply and can't imagine life with any other woman; Sarah is the one who "gets" him and his eccentricities. When Muriel crosses his path, he initially resists opening up to her, but when he finally does, he is magnetized into her very different and colorful world. He falls in love with Muriel for totally different reasons than his attraction to Sarah; her contrasting nature helps Macon to come further out of his shell and embrace the messiness of life that he has long feared. For him, this is a new view of love that is something beyond his comfortable routine. His ultimate choice to be with Muriel over Sarah, despite his persevering feelings for his first wife, is a decision to embrace the sort of love that challenges him and helps him to become a better person.
Isolation
Macon has a strong tendency to isolate himself, whether it be physically or emotionally. After Ethan dies, he locks himself even more deeply in his own emotions, refusing to share his thoughts and pains with his wife Sarah, leading to their separation. Macon often reflects on how he has difficulty communicating with others and has isolated himself in a sort of shell that prevents genuine contact with the outside world. Yet this is his comfort zone, and he has a hard time leaving it. Ironically, Macon writes tour guides for a living, but even when he ventures off to exotic foreign cities, he remains in his own bubble, staying in hotel rooms until he can fly back home again to familiar surroundings. He even hides behind a large book on every plane and train ride in order to avoid any social interaction. Starting a relationship with Muriel is one way Macon starts to come out of his isolation to embrace a different type of life.
Control
One common characteristic of the Leary family is the need for control. Macon, for instance, uses a highly controlled routine to feel safe in the world. After a tumultuous childhood, where their unstable mother Alicia was frequently moving the children around, the Leary siblings have learned to cope through implementing strict and often strange modes of organization. This is exemplified after Macon's separation, when he invents bizarre ways of dealing with chores, such as creating a "body bag" so he does not have to wash his linens. His sister Rose is also fond of tightly organizing the household regimen, demonstrated in the way she alphabetically arranges the groceries.
Yet even with all the effort to control, Macon is still left helpless when it comes to his unruly pet dog, Edward. Of course, Edward is merely a mirror for the emotional chaos that Macon suppresses through his carefully planned "systems." The process of training Edward runs parallel to Macon beginning to allow his own inner fears to be tamed, coming out of his self-imposed alienation to date Muriel. He starts to realize that despite his desire for stability, life will never be controllable or predictable: even after the tragedy of losing his son, he still must open up and take risks in life.
Eccentricity
Many of Anne Tyler's characters in The Accidental Tourist are highly eccentric. This is ironic, considering that Macon and Sarah crave to live some elusive "normal" life after the death of their son. They begin to tire of the eccentricities of one another. Sarah, especially, has grown weary of the Leary family's peculiar habits and rituals, such as the endless rules to their after-dinner card games. Both Sarah and Macon discover, however, that "normal" does not really exist. Macon dates Muriel, who has a slew of her own strange qualities. Sarah dates a man whose eccentricities bother her, to the point that she cuts off the relationship.
Macon, who is a quietly observant character, often notes the strange people who populate his neighborhood or the foreign places he visits. His awareness of the little quirks of others brings him a sort of comfort and deeper understanding of humanity, even while he keeps his distance. For instance, the highly frightened old woman he meets on one plane ride helps him to feel more stable and normal.
Modern marriage
The marriage of Macon and Sarah—along with its dissolution—is a central component of the novel. In older times, marriage was seen as an unbreakable vow, where the couple is supposed to work out differences for the sake of the union. In more modern times, divorce has become extremely common, with slight disagreements becoming fodder to permanently part ways. This is at play in Macon's relationship, where the death of a child draws the two apart instead of bringing them closer. In this time period (the 1980s), it has become more acceptable to take space apart in order to figure out which each partner truly wants. Even when Macon is with Muriel, he declines her marriage proposal, remarking that the formality of marriage is overrated. In one way, we can see Macon's point of view, yet in another, it is clear that Macon's argument is less a philosophical one than it is a reflection of his fear of commitment.
Good and evil
Even in the seemingly tranquil suburban setting that Anne Tyler's characters occupy, the battle between good and evil appears as a prominent theme in the story. Macon and Sarah's son, Ethan, has been killed randomly and brutally while at a fast-food restaurant. This senseless death shatters his parents' lives, waking them up to the fact that evil is not an abstract concept but rather something that can deeply touch anyone at any time. After Ethan's murder, Sarah in particular struggles with living in what she now considers to be a dark and evil world.
Despite the obvious evilness that lurks in society, Macon comes to see that there is also much good, such as in the benevolent encounters he has with strangers while traveling. In this way, the novel underscores the idea that good and evil begin in the small and trivial interactions of daily life and that each person has the choice of which side they wish to perpetuate.
