Abstract

This article examines the reconfiguration of the normal/pathological dichotomy in the second half of the 20th century in both medicine and public health under the influence of a style of thought in terms of «risk» and the consequent emergence of liminal categories such as «risk factors» both «of the individual» and «of the group», as well as «risk behaviours». The analysis rests on a comparative study of the two domains where this transformation in conceptualizing the origin of diseases initially occurred and which historiography has usually treated separately: research on the aetiology of cancer (starting with pulmonary cancer) and on cardiovascular diseases. After quickly tracing the evolution of epidemiology after its disciplinary institutionalization during the nineteenth century and the growing role played by statistical calculations in this field, the study turns toward the conditions that led to the emergence of a probabilistic approach toward pathologies and to the controversies it gave rise to. Finally, in its final part, this article details the effects of these innovations on the sphere of prevention in both public health and clinical medicine with the appearance of long-term treatments for a considerable number of people who could not be characterized as sick.