Thoughts and actions

In Turtles All the Way Down, Thoughts and actions names a distinction Aza Holmes needs but cannot simply will into place: a thought may arrive uninvited and feel frighteningly powerful without being an action or defining the person who has it. The distinction becomes crucial amid obsessive fears of contamination, repeated checking and cleaning, and questions about whether a self can be separate from its thoughts and circumstances. It offers Aza a way to understand limited agency—not as control over what appears in consciousness, but as a possible choice about whether to follow it—without making that choice easy or final.

The problem of ownership

Aza’s difficulty begins with thoughts that seem to come from outside her. Her therapist, Dr. Karen Singh, calls them intrusives; Aza mishears the term as invasives, a name that better captures her sense of thoughts spreading through an inner world she cannot defend. An unwanted possibility can crowd out other thinking until attention is fixed on it, whether Aza wants to consider it or is trying to distract herself from it. The thought’s presence therefore feels like evidence about the self, even when it is not an expression of intention.

That confusion deepens into a question of identity. Aza wonders whether there is a stable person underneath changing circumstances—money, a boyfriend, or school—or whether she is only the conditions surrounding her. She also doubts that her thoughts or body are truly hers when she cannot choose her thoughts or control sweating and illness. For her, the issue is not detached speculation about free will: she needs some way to imagine herself as a coherent person even when some thoughts do not feel like her own.

Dr. Singh answers by separating a person from the contents of consciousness: unwanted thoughts do not make Aza less real or belong to her less securely. She also draws on Descartes’s argument from doubt: the capacity to doubt what is real can establish the reality of the doubter. The reassurance contests Aza’s inference that uncontrollable thoughts erase the self, but it does not claim that she can choose which thoughts arise. The distinction is between having a thought and being reducible to it.

The contamination loop

Aza’s fears about infection show how an unwanted thought can become a repeated course of behavior without becoming a chosen desire. At White River High School, excessive stomach noises draw her attention to Clostridioides difficile. She searches online, checks the symptoms, notes that she has no fever, and then fears that the absence of fever may not last. At the same time, her attention slips away from the cafeteria conversation and toward a frightening question about the microorganisms inside her and whether they complicate the idea of a singular self.

The fear also attaches to a callus on her middle finger, created by years of pressing her right thumbnail into the finger pad. A crack in the skin becomes a possible route for infection, and the possibility of infection creates pressure to reopen and drain the wound. After worrying that the cafeteria was unsanitary and that river water might have reached her hand, Aza removes the Band-Aid and inspects its damp-looking pad under the bathroom’s yellow light. She considers sweat, river water, and signs of infection; then she uses hand sanitizer, washes while singing the alphabet to time the recommended twenty seconds, digs her thumbnail into the crack until it bleeds, squeezes out blood, dries the wound, and applies another Band-Aid.

The action brings a brief easing of tension, not a lasting resolution. Minutes or hours later, uncertainty returns: perhaps the wound was not drained completely, or perhaps the apparent pus was only sweat. The sequence makes clear why calling a compulsion an ordinary decision misses its force. Aza does act, but the action is driven by an escalating demand for certainty; temporary relief leaves the underlying doubt ready to restart the cycle.

The body as a source of uncertainty

The same problem surfaces in Aza’s response to kissing. After pulling away, she searches her phone for information about whether bacteria exchanged in a kiss remain in the body. She finds a study estimating an average exchange of around eighty million microbes per kiss and reporting modest but consistent changes to gut microbiomes at a six-month follow-up. The information does not settle her fear. Instead, she imagines Davis’s bacteria living and multiplying inside her, and her body becomes the site of a consequence she cannot reverse or fully know.

Aza’s anxiety similarly turns a medical explanation of the gut-brain cycle into doubt about who is thinking. Reading that signals from the digestive tract combine with other bodily and environmental information, she fears that her bacteria may be affecting her thoughts. The question expands from whether a particular infection is present to whether her thinking itself has been contaminated. Across these episodes, a thought about illness is not merely an idea she can dismiss at will: bodily sensation, medical information, and catastrophic possibility reinforce one another, while none provides the certainty she seeks.

Treatment and limited agency

Dr. Singh proposes exposure response therapy again, recalling earlier exercises in which Aza touched her callused finger to a dirty surface and then refrained from cleaning it or covering it with a Band-Aid. The treatment had helped for a time, but Aza remembers how frightening it felt and cannot bear to repeat it when asked. Her response shows a gap between understanding a therapeutic approach and being able to tolerate it. She also admits that she does not take Lexapro every day because taking a pill unsettles her: she worries that medication might change what she considers the deepest part of herself, even as she hates the obsessive force she wants it to relieve.

The distinction between thought and action becomes urgent when Aza drinks aloe-scented hand sanitizer after reopening and rebandaging her finger. At night, she checks the old Band-Aid and sees a little pink blood. She tries to reassure herself that the wound is not infected, but the uncertainty keeps returning. She then takes several gulps of sanitizer, becomes dizzy, and feels stomach pain; her thoughts immediately turn to the possibility that sanitizer has cleared healthy bacteria and made infection more likely. The episode demonstrates that recognizing a thought as unwanted does not by itself stop behavior, and that an attempt to feel clean can generate fresh fears rather than security.

Dr. Singh later tells Aza that she need not fear a thought simply because it occurs, and distinguishes thought from action when Aza says she cannot stop thinking about Clostridioides difficile. She also makes clear that drinking sanitizer will not help. The exchange offers a boundary, not a cure: the thought can be present without being a command, while the harmful action remains something to interrupt and address. When Aza later reminds herself that thoughts are not dangerous and need not be acted on, she uses Dr. Singh’s image of a car passing someone at the roadside. The moment of choice, in this account, is not whether the car appears but whether she gets into it. Yet the narrative immediately shows her getting into the car. The metaphor clarifies the possible point of agency while refusing to present it as effortless or reliably available.

Narrative and thematic significance

The idea reaches beyond symptom management because Aza’s illness is bound to her fear that outside forces author her life. The novel opens with her recognizing that forces she cannot identify shape even the timing of lunch, and that a person may feel like the subject of a story while being shaped by forces beyond personal choice. Her later questions about thoughts, bodily sensations, and circumstances develop that opening concern at the level of consciousness: if a thought cannot be selected, Aza wonders, what makes it hers?

The book’s author describes Aza’s obsessive thinking as distinctly unhelpful to detective work: rather than improving observation, it can turn her attention inward and hijack the plot. That design makes the distinction between thought and action more than an abstract philosophical motif. It registers the effort required to live with an intrusive thought without treating it as an intention, a verdict on identity, or proof that agency has vanished. Aza cannot dictate every mental event, and the novel does not imply that she can. Its narrower, more consequential possibility is that a person may still look for a response to a thought, even when the thought itself was never chosen.