Histories of medicine and science are histories of political and social change, as well as accounts of the transformation of particular disciplines over time. Taking their inspiration from the work of Charles Webster, the essays in this volume consider the effect that demands for social and political reform have had on the theory and, above all, the practice of medicine and science, and on the promotion of human health, from the Renaissance and Enlightenment up to the present. The eighteen essays by an international group of scholars provide case studies, covering a wide range of locations and contexts, of the successes and failures of reform and reformers in challenging the status quo. They discuss the impact of religious and secular ideologies on ideas about the nature and organization of health, medicine, and science, as well as the effects of social and political institutions, including the professions themselves, in shaping the possibilities for reform and renewal. The Practice of Reform in Health, Medicine, and Science, 1500-2000 also addresses the afterlife of reforming concepts, and describes local and regional differences in the practice and perception of reform, culminating in the politics of welfare in the twentieth century. The authors build up a composite picture of the interaction of politics and health, medicine, and science in western Europe over time that can pose questions for the future of policy as well as explaining some of the successes and failures of the past.