Thoughts are only thoughts

“Thoughts are only thoughts” is Dr. Karen Singh’s principle for distinguishing a person from the unwanted thoughts that can dominate attention and provoke action. For Aza Holmes, whose fears of infection repeatedly turn ordinary sensations into emergencies, the distinction is neither an easy reassurance nor a claim of total control. It offers a narrower possibility: a thought may occur without defining its thinker, and having it is not the same as acting on it.

Meaning and therapeutic use

Dr. Singh tells Aza that thoughts are thoughts, not Aza herself, even when Aza feels that they belong to her so completely that they determine who she is. When Aza objects that thought is the basis of existence, Dr. Singh counters with Descartes’ fuller formulation: doubting demonstrates that the doubter exists, even amid uncertainty about what is real. The exchange places the principle inside Aza’s larger fear that she lacks an independent self, rather than presenting it as a simple instruction to stop thinking.

The principle also draws a practical boundary between mental experience and conduct. Dr. Singh tells Aza she need not fear a thought because thought is not action. That distinction becomes especially important when Aza cannot stop thinking about Clostridioides difficile and wants certainty that she is not infected. Dr. Singh directly tells her that drinking hand sanitizer will not help: the frightening thought may be present, but it does not make the dangerous response necessary or effective.

The contamination cycle

The novel shows why the distinction is difficult to maintain. At White River High School, Aza hears her stomach rumbling and searches for information about her microbiome and Clostridioides difficile. She finds that abdominal noise can be associated with infection, despite lacking the other symptoms she reads about, and her mind immediately supplies a future possibility: she may not have a fever yet. A bodily sensation becomes a threat through a chain of searching, interpretation, and escalating doubt.

A recurring wound on Aza’s finger gives that chain a concrete ritual. She presses her thumbnail into a callus until the skin opens, then covers it with a Band-Aid; fear that the wound is infected can make her reopen and drain it. After remembering that the wound may have been exposed to dirty river water, she interprets moisture on the bandage as a possible sign of infection. She applies hand sanitizer, scrubs while singing the alphabet to time the wash, then digs into the wound until it bleeds and re-bandages it. The act brings a brief easing of tension, but the uncertainty returns: perhaps there was pus, perhaps she did not remove it all. The temporary relief therefore does not settle the fear; it leaves room for another round of checking.

Aza understands the thoughts as invasive, a word she prefers to Dr. Singh’s term intrusives because they seem to arrive from elsewhere and spread through her mental landscape. Yet recognizing that a thought is unwanted does not, by itself, make it quiet. On the couch beside her mother, she tries to dismiss the urge to inspect the bandage, only for the infection worry to return with new arguments about the cafeteria, the river, and possible contamination. The principle names a distinction she wants to trust while the recurring thought keeps demanding proof.

Body, self, and uncertainty

Aza’s contamination fears extend beyond the finger wound. After kissing Davis, she pulls away and searches for information about whether bacteria exchanged in a kiss remain in the body. She reads that an average kiss exchanges about eighty million microbes and that gut microbiomes may remain modestly but consistently altered at a six-month follow-up. The numbers turn intimacy into a feared bodily consequence: Aza imagines Davis’s bacteria remaining inside her, and her panic intensifies. The scene links the principle to her uncertainty about where one self ends and another begins, rather than only to the fear of a particular illness.

That uncertainty is also philosophical. Aza asks whether there is a self independent of circumstances, given that she cannot choose her thoughts or control what happens to her body. She describes herself as a story told by forces outside her. Dr. Singh’s response—that Aza belongs to herself even when her thoughts do not—does not deny her experience of constraint. It refuses to make involuntary thoughts the final authority on her identity.

Agency without certainty

The principle’s limits are as important as its promise. Aza can repeat that thoughts are not actions and that thoughts are only thoughts, yet her distress persists; on another occasion, she drinks aloe-scented hand sanitizer in an attempt to feel clean, then becomes alarmed about its possible effects. The narrative does not portray insight as an instant cure. It shows a person trying to act within the narrow interval between a frightening thought and the compulsion it urges, while anxiety repeatedly threatens to close that interval.

Dr. Singh’s image of a passing car gives Aza a way to describe that interval: the choice is not whether an unwanted thought appears, but whether she gets into it and lets it carry her away. Aza recalls this guidance after a nerve-racking car trip and tells herself that thoughts are not dangerous actions. The image preserves both sides of the struggle. Thoughts arrive without permission, but their arrival does not settle what Aza must do; still, recognizing a choice does not guarantee that she can exercise it in every moment.

In a conversation about fear, Aza also describes darkness as a loss of orientation and control: without light or the senses that reveal boundaries, a person can feel shapeless and alone in a body they do not command. Turning on a flashlight, she calls it a way to know where the walls are and which way is in or out. The principle offers a comparable, limited form of orientation. It cannot remove uncertainty from Aza’s mind or body, but it helps distinguish the presence of a thought from the self who experiences it and the action that may follow.