Traditional Chinese medical theory holds that medicine and food come from the same source. As means of both preventive remedies and treating disease, medicine and food are categorized according to their “effectiveness,” which in turn connects things with their specific phases in the natural world. The Shanhaijing (the Classic of Mountains and Seas) is largely a fabled geographical and cultural account of pre-Qin China as well as a collection of myths. Through a textual analysis of this ancient text with an emphasis on its account of medicine and food, this essay argues that the practice of medicine in ancient times was often associated with belief systems and religious ritual practices. The author attempts to show that the Chinese view of medicine, including that of Daoism, is largely based on a conception of natural life and the environment that is atheistic and a form of naturalism that is essentially theistic.