This study of the popularity of phrenology in the second quarter of the nineteenth century concentrates on the social and ideological functions of science during the consolidation of urban industrial society. It is influenced by Foucault, by recent work in the history and sociology of science, by critical theory, and by cultural anthropology. The author analyses the impact of science on Victorian society across a spectrum from the intellectual establishment to working-class freethinkers and Owenite socialists. In doing so he provides the first extended treatment of the place and role of science among working-class radicals. The book also challenges attempts to establish neat demarcations between scientific ideas and their philosophical, theological and social contexts.