In this article I discuss the ecclesiastical censorship of physiognomy in post–Tridentine Italy. Existing studies of the criteria used by the Roman Inquisition to examine operative arts have rightly emphasized continuities with the opinions of earlier authorities, and especially those of Thomas Aquinas. Historians have, nevertheless, tended to suggest that Aquinas's ideas were transmitted to the Inquisition and Congregation of the Index virtually unchanged by texts such as Nicholas Eymerich's Directorium inquisitorum. In this paper I highlight divergences in the opinions of authorities such as Augustine, Aquinas, Eymerich, and Nicholas Peña, a sixteenth-century consultor to the Congregation of the Index and editor of Eymerich's text. I suggest that during the sixteenth century the Church's centralized organs of censorship drew on each of these approaches, but failed satisfactorily to resolve the precise status of physiognomy. In turn this created considerable ambiguities in the practice of censorship at a local level.