This chapter uses the question of what caused the late Ming epidemics from the 1570s to the 1640s as a heuristic device to explore the historiography of epidemics and late imperial epidemiology in China. It introduces two opposite approaches to the history of disease – termed natural-realist and historical-conceptualist – that have influenced the history of medicine in European and American institutions since the 1970s. It first explains these two approaches and then examines how the natural-realist approach to retrospective epidemiology characterised scholarship on the history of disease in China from the 1870s to the 1930s. Between the 1940s and 1970s, economic and social historians as well as anthropologists also took a natural-realist approach to Chinese sources on epidemics but they asked different questions of them such as what they revealed about demographic shifts or how responses to epidemics can be used to illuminate social, economic, and religious dimensions of Chinese culture. Over the first century of scholarship on the history of disease in China, there was a shift from retrospective epidemiology following new Western disease concepts to using evidence of past epidemics as a means for other ends. Historical actors and modern scholars alike have used the occurrence of epidemics to diagnose problems of the body politic and other contemporary issues.