Rupescissa’s Quintessential Medicine
John of Rupescissa's Quintessential Medicine
Origins and Evolutions
Lawrence M. Principe
8 September 2026 – 5 PM (CEST)
While the importance of John of Rupescissa’s alchemical pharmacology for the history of medicine is well-established, much remains to be elucidated in regard to the origins and content of the friar’s ideas and practices as well as in regard to the dissemination, modifications, plagiaries, and deployments of his text by later authors and practitioners.
My continuing project of preparing a critical edition of John’s 1352 De famulatu philosophie (commonly, but incorrectly, known as De consideratione quintae essentiae), based on over two hundred Latin and vernacular manuscript witnesses, both provides new insights onto these issues and poses new and interesting questions.
This presentation will review newly-uncovered information about the background to John’s text, where it travelled, how it was modified during its first hundred years, and what these features mean for our understanding of the history of medicine in the Late Middle Ages.
About the Speaker ...
Lawrence M. Principe is a Professor of Chemistry and the History of Science at Johns Hopkins University.
He holds two doctoral degrees in Organic Chemistry and in History of Science, which inform about his unique approach to studying Late Medieval & Early Modern Alchemy. He focuses on the understanding of the intellectual, social, and experimental contexts of alchemy and the influence it has on the development of modern chemistry. His research often combines traditional historical methods with practical laboratory replication. Among his notable publications there is The Secrets of Alchemy (2013), which aims to make the complex historical alchemical concepts accessible to a broader audience. His contributions to the field of history of alchemy have earned him several prestigious awards, including the Pfizer Prize from the History of Science Society
