What is mental illness? Who has mental capacity? Questions like this lie at the heart of anxieties inherent in Western liberal governance. Drawing on perspectives from medical humanities and disability studies as well as the history of science, technology, and medicine, this course offers comparative historical perspectives on these enduring questions and why they are so difficult to answer by examining premodern ideas linking badness and madness, the emergence and evolution of disease models of insanity, the rise and fall of the mental asylum movement, the broken promises of deinstitutionalization and community health models, the dual carceral and pharmaceutical characteristics of psychiatric treatment, and the implications of mental capacity and things like the insanity defense across criminal and civil law. Reading the work of leading scholars, including Rabia Belt, Susanna Blumenthal, Nancy Campbell, Kim Nielsen, Andrew Scull, Nancy Tomes, and Courtney Thompson, gives us conceptual frameworks to think through difficult questions surrounding the contingent nature of disease concepts of mental illness, the stigmatization and incarceration of people diagnosed with mental illness, and the classification of people deemed mentally ill as unfit for full citizenship.