The Political Malady examines the transformation of British culture in the era of mass sovereignty and the creative ways nineteenth-century novelists captured that transformation in their approach to characterization. Bringing together a wide range of nineteenth-century cultural material, including Victorian realism, medicine, sociology and evolutionary science, this dissertation locates a defining tension at the heart of British culture that played out as two contradictory claims on the modern subject: the demands of individuality, on the one hand, and an innate belonging to the unthought systems of mass life, on the other. Following the work of Michel Foucault, literary critics often map these claims onto two distinct modes of power, disciplinary and biopolitical. By contrast, this study examines the way nineteenth-century approaches to characterization could describe the experience of embodying both these contradictory claims at once. Engaging with the work of Ann Radcliffe, Charles Dickens, Charlotte Brontë, and George Eliot, The Political Malady reads figures of disability in realist fiction as a representational mode that transformed the symbolic features of collective belonging into the painful sensations of the physical body. Whereas the sciences of this era were divided in their basic assumptions as to whether human life took the form of the individual or the mass, the fiction of this era borrowed from these disciplines to depict this cultural tension as two dimensions of the same self. In doing so, realist aesthetics knitted the materialism and abstraction of different scientific disciplines into the raw material of everyday life.