Abstract
Girolamo Cardano makes a number of surprising, even shocking claims about the soul in his De subtilitate, one of the most widely read works of natural philosophy in the sixteenth century. When he was finally investigated by the Roman Inquisition and the Index, these daims did not go unnoticed. This study will narrow in on three passages marked as heretical by the first Holy Office censor of De subtilitate. It will consider the Inquisition's priorities and ask about materialism, determinism, and conceptual inconsistency in Cardano's views on the soul. The study will give special attention to the claim made by Cardano that souls can be reduced to celestial heat. In addition to De subtilitate, several of Cardano's other works will be considered for added perspective, especially Contradicentium medicorum libri duodecim.