This paper examines the reasons why Physician He (Yi–He, sixth century BCE) was regarded as a founder in the classical medical tradition of China. By most accounts, Physician He’s importance owes much to his theoretical innovations. In contrast to earlier healers, Physician He purportedly framed the aetiology of illnesses solely in terms of natural causes, as opposed to attributing sickness to gods or demons. In this paper, I reread a famous episode in the Commentary by Zuo, which is often cited as evidence of the physician’s naturalism. By paying close attention to the formal elements of the narrative as well as its larger discursive context, I argue that the standard reading of Physician He falls short. The episode provides little evidence of any secular challenge to religious conceptions of illness, and Physician He was, in fact, patterned after occult experts. A careful look moreover at the reception of Physician He in premodern histories of medicine reveals that the physician was extolled for his attunement to the will of the spirits as well as his powers of examination. Physician He’s reputation as a naturalist furthermore represents a modern interpretation, one that reflects efforts to defend the indigenous medical tradition against its biomedical detractors.