Pestilence in Renaissance Platonic medicine : from astral causation to pharmacology and treatment

The nature of Fernel's treatment of plague and pestilence is the focus of this chapter. Fernel explored this theme in his theoretical and practical account of “occult” diseases throughout his works. His approach to these diseases in De abditis rerum causis was above all a philosophical treatment of the concept Centered on the notion of “occult” causation, his interpretation has been explored by historians of science from the angle of the Platonic philosophy of Ficino. However, it also suggested some therapeutic application, which was further explained in his didactic works included in the Universa Medicina (1567). This investigation will be focused on Fernel's explanation of “pestilential diseases” as a category of epidemic and often fatal diseases, whose outbreak, causes and treatment were challenging to explain in his time.

With this in mind, I will trace Fernel's interpretative path from his cosmological explanation of plague and pestilence to his explanation of drug action and its practical impact on therapy. To do so, I will delineate the ancient, medieval and Renaissance medical approaches to these questions, which Fernel synthetized in developing his own pathology, pharmacology and therapeutics of pestilential diseases. In the final section, I will appraise to what extent Fernel's explanation of occult causes shaped his therapy of plague. What type of treatment, ingredient and preparation did Fernel recommend for the cure of pestilential diseases? What was the role of practical tools and knowledge, such as alchemy, in these medicinal preparations? Before tackling these questions, I shall now address Fernel's account of pestilence within the category of occult diseases. [Publisher's text]