In De iusta haereticorum punitione, the Franciscan Alfonso de Castro (1498-1558) issues a cautionary note about heresy, likening it to a "pestilential" force. He emphasizes its pervasive spread and the ensuing difficulty in curing it. Indeed, in his heresiological treatises medical language abounds, with the ongoing metaphor likening the process of addressing heresy to a healing process. This volume explores the concept of social disease in Hispanic heresiography and medical literature. Individual contributions delve into the clinical paradigm shaping views on heresy, the humoral profile of the heretic, and the connections between heresy, melancholy, pestilence, and sedition. Methodologically, it employs conceptual history, critical semantics, and metaphorology. The book proposes analysis of the history and conceptual mapping of heresy in the sixteenth century as well as an examination of the epistemological metaphors of heresy and dissent. It also aims to map the literary production of physicians in early modern Spain and their tendency towards religious heterodoxy. The transdisciplinary nature appeals to researchers from various fields such as medical history, religious studies, theology, and philology.