Reading Cardano with the Roman Inquisition: Astrology, Celestial Physics, and the Force of Heresy

Abstract

In the first decades after the founding of the modern Roman Inquisition in 1542, Girolamo Cardano was the most prominent natural philosopher to face imprisonment and trial. A trove of Inquisitorial letters, decrees, and censurae have survived, offering a detailed picture of how, in the early years of its existence, the Roman Inquisition placed theological boundaries around astrology and natural philosophy. This essay covers the trial and identifies a critical point of contention: that Cardano allegedly naturalized heresy. It suggests that we view the Cardano affair as a reaction against a natural philosophy which threatened to constrain the Inquisition’s right to judge enemies and execute that judgment. Finally, it discusses how, in light of the Inquisition’s reading, we might consider Cardano’s astrology as accommodating Christian doctrine.