This book explores how late medieval and early modern physicians (c. 1250-1600) teased out the complex relationships between poison, medicine, and disease. It argues how such discussions must revise the standard history of toxicology, which does not adequately account for these early developments. Drawing from a wide range of medical and natural philosophical texts--especially treatises on poison, pharmacy, pharmacology, plague, and the nature of disease--this new approach to the concept and category of poison explores a neglected ontological debate about the existence of a category of substance fundamentally harmful to the human body and the corresponding implications for medical theory and practice. In considering the example of poison, this book explores the broader questions that flummoxed physicians, such as how to differentiate poison and medicine both in theory and practice, and reveals how changing definitions of poison forced physicians to rethink processes of change inside the human body, especially corruption and putrefaction. It also carefully considers how physicians used the model of poison to understand the origin and spread of disease.
With its multi-faceted approach, this study complicates and complements the tendency to address poison primarily as an unproblematic and unambiguous label that was used uniformly throughout both medical and literary texts. On the whole, this innovative analysis of physicians' arguments about the definition of poison, the nature of poisonous properties, and its interaction within the body fundamentally reshapes the standard histories of toxicology, pharmacology, and etiology, and provides a new perspective on how these disciplines overlapped and informed each other far more than has been recognized.