Toxic Cures: Poisons and Medicines in Medieval China

This dissertation explores the medicinal use of poisons in China from the third to the tenth century, which is when the major outlines of Chinese toxicological thought took shape. Challenging a widespread view that contrasts the benign naturalness of Chinese herbal remedies with the dangerous side effects of Western synthetic drugs, my research highlights the centrality of poisons to the practice and theory of medicine in China. Chinese doctors regularly relied on a large number of substances that they recognized as toxic to combat sickness, and identified toxicity as the central pillar for the classification of drugs. I argue that the boundary between poisons and medicines was always hazy in medieval China; it was not the substance itself, but how it was used and experienced that mattered. To examine this crucial yet ignored feature of Chinese medicine, my dissertation develops the following themes. The first is that drugs in medieval China were not fixed entities with unique effects. The effect of a given substance—whether it healed as a medicine, or sickened or killed as a poison, or altered a person in myriad other ways—varied both with usage and with processing. Subsequently, Chinese doctors developed a variety of techniques (the dosage, the drug combination, and the drug preparation) to mitigate the toxicity of a poison while preserving its therapeutic potency. Secondly, I highlight the intimate relation between bodily experience and the understanding of poisons. By studying the alchemical practice of ingesting toxic minerals, I show that the violent bodily effects induced by these substances were often perceived as confirmations of efficacy rather than worrying signs of pathology. My third theme is the circulation of toxicological knowledge across geographical and social domains. I argue that standardized textual knowledge propagated by the state was fluidly transformed in practice, contingent upon the availability of pharmacological ingredients and the needs of local people. Finally, I turn to non-poisons, especially foods, in Chinese pharmacy, and identify a distinctive character of Chinese medicine—the ingestion of mild substances to nourish the body and prolong life. Chinese medicine thus developed through the interaction of two related, but distinct enterprises—the fight against sickness, and the quest for ever-enhanced vitality.History of Scienc