The Cambridge World History of Human Disease

In the evolution of East Asian disease conceptions, the imagination of menacing outsiders represents not a transient stage of superstitions, which the rise of philosophy would supersede, but a thematic pole to which reflection on sickness would repeatedly return. In the philosophical ferment of the late Zhou and Warring States periods, a new conception of disease was emerged. Disease in the Han dynasty became a seasonal phenomenon. Earlier observers had recognized that different afflictions tended to characterize different seasons, such as the Zhou li. The Buddhist concept of karmic disease also traced sickness to an individual's past actions. The popularity of three-shi etiology derived in no small part from the fact that it united many streams of East Asian reflection on disease. The physicians of the Song and Yuan dynasties inherited a tradition of medicine and its key theme was the quest to reduce that distance.