This article investigates the historical method of Karl Sudhoff (1853– 1938), Germany’s first professor of medical history. It argues that in order to understand his ideas more fully, we need to step outside the historiography of medical history and assess his methodology in relation to the norms and ideals of German academic history writing in general. The article demonstrates that the philology-based “critical method” of Leopold von Ranke (1795–1886) was central to Sudhoff’s methodological thinking. It investigates the underlying philosophical and epistemological assumptions of Ranke’s method, which tend to be less appreciated than his overt empiricism and explores how Sudhoff applied these to the new professionalizing subdiscipline of the history of medicine. The article argues that Sudhoff’s concerns with the methodology of history, which involved a particular conception of the relationship between the human sciences and the medical sciences, offers compelling addresses to our times.