The Brittle Self is a history of one of the oldest fears a mind can hold: that the self is fragile, that it can be seen through, broken, switched off, or shown to be unreal. Across six hundred years the fear holds steady while its costume keeps changing, and the book follows that single dread from a medieval palace to a present-day clinic.

It begins in 1393, when Charles the Sixth of France forbade his court to touch him, certain his body had turned to glass and would shatter at a careless hand. From there it moves through the glass men of Europe and the men who believed they were made of butter, through the patient who was sure she had already died, through the London tea broker who drew diagrams of a machine he believed worked his mind from across the city, through the broadcast age and its conviction that the cameras never stopped, and at last to the chatbot built to agree with every word its user types. Each age explains a mind in crisis with its newest marvel. The instrument is always modern. The injury is ancient.

The book is built in two voices. One, the Record, sets down the documented history, the case files and letters and diagrams, with its sources named. The other, the Interior, steps inside the experience to ask what it felt like to be the man who would not be touched or the woman who believed she was a corpse, and every such chapter is marked, so the listener always knows where the record ends and the imagining begins. Written for anyone who has felt, even briefly, that they might come apart, The Brittle Self argues that the terror in the newest ward is the Glass King in a new coat, and that seeing the pattern is its own kind of company.