Saving Sanctity: The Roman Inquisition and the Initial Prosecution of Girolamo Cardano

Abstract

The impact of the Protestant Reformation and Catholic Reform movement on the ecclesiastical censorship of science, philosophy and magic has been an enduring theme in the historiography of early modern Italy. In this paper, I consider how the Church’s desire to defend the truth of miracles from Protestant criticisms on the one hand and their efforts to centralise the process of verifying miracles on the other affected the investigation of philosophical works. Taking the case of Girolamo Cardano, whose works were the subject of intensive investigation by the Catholic Church from the 1570s, I examine the issues that censors flagged as points of concern. One recurring theme was the fact that his accounts of the cosmos appeared to offer natural explanations for miracles and the actions of the martyrs. Although the intellectual problems raised by Cardano’s work were far from new, I suggest that the events of the sixteenth century raised their salience with Church authorities.

1. Introduction

In 1570, the Roman Inquisition began to investigate the writings of the physician and philosopher Girolamo Cardano (1501–76) (on Cardano, see Siraisi 1997; Grafton 1999). This process was initiated by a letter that Gaspare Sacco, the Inquisitor of Como, wrote to the Holy Office in Rome, in which he raised concerns about Cardano’s 1558 work De rerum varietate and, more broadly, about his teachings in the University of Bologna. That Sacco should express these concerns was, perhaps, less surprising, than the fact that, hitherto, Cardano had seemingly escaped the Inquisition’s attention. The content of Cardano’s teaching had previously been subject to scrutiny and he had left a previous role at the University of Padua under a cloud of suspicion (Baldini and Spruit 2009, p. 1035). Furthermore, his numerous writings contained considerable amounts of material that could be readily construed as unorthodox, and many ecclesiastical censors regarded them as such. As Sacco noted, De rerum varietate addressed such matters as astral determinism and divination. Discussion of these subjects had long been a cause for concern within the Church and this continued throughout the late fifteenth and sixteenth centuries. Furthermore, several of his books, including De rerum varietate, had been previously entered into the Indices of Forbidden Books prepared by the University of Paris in 1551 (de Bujanda 1985, p. 500) and those promulgated by the Spanish and Portuguese Inquisition in 1559 and 1561, respectively (de Bujanda 1984, p. 653; 1995, p. 613). Despite these concerns, his works were included in neither of the first two Roman indices of 1559 and 1564 (de Bujanda 1990; Baldini and Spruit 2009, pp. 1033–41; Valente 2017, pp. 534–37). Once the Roman Inquisition’s investigations finally began, however, its censors appeared particularly ill-disposed towards his works and read them with what Jonathan Regier has termed an ‘hermeneutics of presumed guilt’ (Regier 2019, p. 675).

There are two facts, then, that come immediately to the fore. First, doubts about the orthodoxy of Cardano’s works had been circulating for many years. Second, the problems contained in those works seemed self-evident to Roman censors once they began their investigations. Given these facts, we may ask: why did the Roman Inquisition only begin to investigate Cardano in 1570? Ugo Baldini and Leen Spruit and Michaela Valente have pointed to the fact that Cardano enjoyed the patronage of Cardinals Francesco Alciati, Carlo Borromeo and Giovanni Morone and suggested that they may have offered him a degree of political protection throughout the earlier stages of his career. Baldini and Spruit have further contended that their support may explain why Cardano avoided an earlier inquisitorial investigation (Baldini and Spruit 2009, p. 1035; Valente 2017, p. 535). If we accept this plausible contention, the question then becomes why did this political support fail in Rome in or around 1570?

Part of the explanation for the failure of Cardano’s political support lies in the fact that, from 1566, the incumbent pope was Pius V (1566–72). Not only was he a former inquisitor general but he was also a close associate of Gianpietro Carafa (1476–1559). Carafa maintained serious concerns about Morone’s orthodoxy because the latter had been closely associated with the spirituali, a network of evangelical Catholics who, prior to the first period of Trent (1545–47), had advocated for emphasising faith in the economy of salvation. When acting as inquisitor general, Carafa had used the Inquisition to prevent Morone from ever becoming pope, and when the former ascended the papal throne in 1555, assuming the name Paul IV, he imprisoned his erstwhile adversary in the Castel St Angelo (Firpo 2014; Firpo and Maifreda 2019, ch. 16). During his pontificate, Pius V continued Paul IV’s campaign against the remaining spirituali, notoriously pursuing Pietro Carnesecchi (1508–67) and ensuring that he was condemned to death. These ongoing trials underline the fact that the suspicions aroused by earlier soteriological disputes remained prominent in the minds of senior ecclesiastics during the 1560s and 1570s (Del Col 2006, pp. 424–41; Black 2009, pp. 123–30). In these circumstances, it was perhaps inevitable that Morone’s influence in Rome would have been seriously curtailed. Borromeo, meanwhile, left Rome to take up residence in his archbishopric of Milan soon after Pius’s election. For his part, Alciati remained in Rome and kept Borromeo informed of developments within the city (Raponi 1960). Valente has further suggested that Cardano’s association with Morone caused censors to scrutinise his philosophical arguments in order to reveal hidden Protestant beliefs. Indeed, she concluded, ‘the real problem in Cardano’s thought, one that was noticed by different censors, is the uneasy balance between determinism and free will that seems to lean him towards solafideism’ (Valente 2017, p. 537).

While Valente was certainly correct that Cardano’s account determinism was central to the Inquisition’s investigation of his works, these ideas had no necessary connection to Protestant soteriology. Christians had condemned determinism long before Martin Luther (1483–1564) or John Calvin (1509–1564) were born and both men explicitly rejected deterministic forms of judicial astrology. More fundamentally, though common in the secondary literature, the argument that the Catholic Church conflated astrological determinism with predestination, and especially its Protestant forms, is misplaced (Poppi 1988, pp. 661–67; Gorman 1999; Donato 2023, p. 656). Astrological determinism implied that the stars necessitated human actions and that humans could use knowledge of the stars’ movements to predict the future; Catholics and Protestants alike understood that God could foresee human actions, but representatives of neither faith believed that He determined them. Each maintained that original sin had so corrupted human nature that it was impossible for humans to perform unaided actions pleasing in God’s eyes, but they nevertheless held that Christians performed those actions freely and remained responsible for any sins that they committed. It was only possible to be saved if God chose to impart his grace, thereby obviating the effects of original sin. He dispensed this gift according to his inscrutable will, predestining those to whom it would be offered: the elect. While Catholics believed that the elect could choose whether to accept this gift, thereby participating in their own salvation, Protestants maintained that those who received His grace could do nothing other than have faith in Him. This remained their only root to salvation.

While accepting that determinism was indeed an important component of Cardano’s trial, I suggest that we need to situate the Inquisition’s investigation of his work in another context. In his original letter, Sacco indicated that his primary concern was Cardano’s philosophical naturalism, which questioned the causes of the actions of the saints and martyrs, undermined belief in demonic magic and disputed the reality of divine intervention in the created order, thereby casting doubt on the truth of miracles. I suggest that this issue, rather than latent concern for philo-Protestant tendencies, drove the investigation of Cardano in the early 1570s. To explore this theme, I intend to build on the work of a number of scholars who have explored the close association between the investigation of heresy and sanctity (Gentilcore 1995; Schutte 2001; Gotor 2002; Bouley 2018). In response to the Protestant rejection of post-biblical miracles, the Tridentine fathers reaffirmed their significance and the related possibility of sainthood. They also emphasised the importance of reasserting official control over cults of saints and the process of saint making. These efforts were reinforced by a further project, initiated by the Tridentine fathers but completed under the auspices of Pius V: the reform of the breviary and the liturgy (Ditchfield 1995, 2007). Collectively, these efforts raised the salience of controlling the boundaries between natural, preternatural and supernatural causation, a task that, by the mid-sixteenth century, the Roman Inquisition had claimed as part of its purview (Gotor 2002; Tarrant 2022). Following the establishment of this new intellectual and theological culture, it became increasingly difficult for philosophers to maintain ideas that threatened to collapse those boundaries.

2. The Roman Inquisition and the First Investigation of Cardano

On 7 May 1570, Gaspare Sacco, the Inquisitor of Como, wrote to Cardinal Scipione Rebiba, the Dean and Vice-Prefect of the Holy Office in Rome. He recalled ‘Some months ago a book was brought to me, composed by Girolamo Cardano, a Milanese, who lectures in medicine in Bologna. In this book, entitled De rerum varietate, he, Cardano, shows himself to be a misbeliever, rather [than] an unbeliever, and in my judgement he teaches errors, heresies and superstitions’1 (Baldini and Spruit 2009, p. 1042) Sacco then proceeded to list Cardano’s various offences. In book 2, chapter 13 of the work, Cardano described the power of celestial influences, making them so great that he appeared to deny God’s active involvement in the natural order. In other words, he appeared to be attributing miraculous events to astrological influence. Furthermore, he denied the power of demons and called ‘Holy Martyrs mad-men and disturbed by the celestial influences so as to lose their wealth and their life for uncertain things’2 (Baldini and Spruit 2009, p. 1042) In later chapters, Cardano seemingly doubled down on these offences by condemning the judges of witches and apostates as ‘impious, unjust and rapacious wolves’ and mocked Augustine. Returning to the theme of miracles, Sacco wrote that Cardano ‘says that miracles are fictions and that most of them are found by means of the testimony of priests, who characteristically lie.’ Further compounding his offences, Cardano also apparently taught divinatory arts, including chiromancy and hydromancy, that had been proscribed at Trent. Rebiba concluded his letter by expressing his hope that the book would be prohibited and its ‘capricious composer’ (compositore capriccioso) punished. These measures would, he believed, prevent Cardano from teaching these and other grave errors (Baldini and Spruit 2009, p. 1043).

We do not know the precise details, but Sacco’s letter set in train an investigation into Cardano. Responding to Sacco’s concerns, the Holy Office appears to have written to Antonio Balducci, the Inquisitor of Bologna, asking him to begin an investigation. In a letter dated 27 September, Balducci replied to Rebiba in Rome indicating that he was, as instructed, drawing up an inventory of Cardano’s books, although it is unclear whether he was listing books that the philosopher had written or owned (Baldini and Spruit 2009, p. 1068). Over the coming months, Balducci remained in close contact with the Holy Office. On 7 October, he sent a letter to Rome in which he related that Cardano had been arrested and imprisoned. Four days later, he wrote again, stating that he had resumed his examination of De rerum varietate and that he had identified ‘some follies’ (alcune pazzie), about which he intended to question Cardano. He also requested that, when it was ready, Rebiba should send him a copy of a ‘nota’ containing the Holy Office’s examination of the text (Baldini and Spruit 2009, p. 1069). By 28 October, Balducci acknowledged receipt of this document. Baldini and Spruit have plausibly argued that this document was an anonymous Censura that was written over the course of the summer of 1570 (Baldini and Spruit 2009, p. 1073, fn. 38). Presumably, it was intended to assist Balducci during his interrogation of Cardano (Baldini and Spruit 2009, pp. 1073–74; for the text of the tribunal of the Holy Office’s Censura, see pp. 1044–68).

The anonymous censura, prepared by examining the 1558 edition of Cardano’s text, provides a systematic and detailed account of the De rerum varietate (Baldini and Spruit 2009, pp. 1044–68). Cardano’s work was composed of seventeen books treating themes such as the structure of the cosmos, the properties of metals, stones and plants, forms of divination and witches and sorcerers. Working through each of the volume’s component books in turn, the censor concluded that at least some (books 3–5 and 9–12) contained no errors. He nevertheless found various passages of concern in the remainder and especially in books 1, 2 and 8 and 14–16. Many of the issues raised by the anonymous censor were consistent with those noted by Sacco, but he also identified a number of further problems. In what follows, I shall offer a selection of examples from the anonymous censor’s observations, seeking to illustrate rather than definitively chronicle his concerns.

The censure of book 1, ‘De universo’, opened with the observation that it followed a similar structure to Aristotle’s Physics. The censor continued that, in chapter 1, Cardano did not offer a clear opinion on whether the cosmos was, as Aristotle had argued, eternal. Instead, Cardano referred the interested reader to another of his works, De archanis aeternitatis. ‘Although this is not heretical, it seems to be scandalous (scandalosum) that doubts of this sort are clearly left unresolved and undetermined, especially at the start of the work’3. Such ambiguity, he remarked, was acceptable in the writings of a pagan or gentile but could not be tolerated in those of a Christian (Baldini and Spruit 2009, p. 1045). Elsewhere in the same chapter, the anonymous censor began to identify similar problems to those mentioned by Sacco when he examined Cardano’s discussion of the formation of comets. At this time, comets were widely believed to be transient sublunary phenomena. Cardano suggested that they tended to form at times when the air was thinnest. For this reason, he argued that the appearance of comets was often accompanied by other phenomena that were likewise caused by a thinness of air. These effects included the production of winds and the death of those who were weak, those distracted by cares or those who had over-indulged in fine foods or sex. Cardano further noted that, in such conditions, all who were either old or prone to sickness would also be liable to death and tend to sleep badly. The censor remarked that ‘All these things can be granted, because in the Meterology Aristotle and his expositors have uttered the same things, which according to Cardano he accepts. But because Cardano asserts a necessary future, and places necessity in things, this passage, therefore, requires correction’4 (Baldini and Spruit 2009, p. 1046). The censor made clear that although Cardano argued that he simply maintained the views expressed by the ancients, he believed that this position veered dangerously close to a form of determinism that made illness the necessary consequence of meteorological phenomena. Later in the same chapter, the censor noted a further problem, observing that Cardano ‘appears to doubt, albeit occultly, the truth of miracles’5 (Baldini and Spruit 2009, p. 1046).

Although the censor did not cite any examples of Cardano seemingly denying the veracity of miracles in book 1, chapter 1, he specifically cited an example during his discussion of chapter 9. Here, he complained that Cardano had attempted to offer a natural explanation for an outbreak of head colds, accompanied by coughing that had seized the population of the Province of Insubria for a period of ten days. ‘This way of writing’ the censor wrote, ‘is not pleasing, because in this manner afflictions, pestilence, famine, and associated inconveniences which sometimes proceed from divine justice, could be ascribed to the stars and natural causes’6 (Baldini and Spruit 2009, p. 1047). Although it was widely accepted in the early modern period that illnesses such as the outbreak of plague could be caused by environmental conditions, the censor’s point was that it was necessary also to allow for the possibility of divine intervention in the natural order. By seeking to provide a natural explanation for an apparently wondrous event, Cardano was threatening to diminish belief in the possibility of direct divine intervention in the created order. This may seem a relatively trivial example, or at least a reasonable point of contention, since contemporaries acknowledged that establishing the true cause of such direct divine interventions was sometimes hard and should be subject to robust investigation. As we shall see, however, Cardano’s work contained further examples of his naturalistic philosophy that posed further and more direct challenges to Catholic orthodoxy.

The anonymous censor identified a number of examples of suspect passages in his analysis of book 2. Discussing the content of chapter 13, one of the sections highlighted by Sacco in which Cardano discussed celestial influxes or influences, the censor observed that Cardano ‘writes many absurd things’ (plura scribit absurda) (Baldini and Spruit 2009, p. 1047). Among the specific issues that the censor identified was Cardano’s apparent contention that ‘it is necessary to refer everything that occurs back to some cause, namely to such influence’7 (Baldini and Spruit 2009, p. 1047). Such an analysis had clear deterministic implications, which the censor argued Cardano brought to the fore. He noted that ‘Cardano in this place, by means of heavenly influence, sets aside the providence of God, he asserts, clearly secretly, that the most holy Christian martyrs suffered for Christ, not indeed from the will, but from the necessary influence of the stars, and also that the apostles, on account of the same influence, abandoned their goods’8 (Baldini and Spruit 2009, p. 1047). The censor noted similar themes in book 8, ‘De homine’, where he complained that Cardano had ascribed the martyrs’ ability to withstand torture to natural causes rather than divine assistance (Baldini and Spruit 2009, p. 1050). The censor also noted that, in this book, Cardano ascribed catastrophes that befell individual humans, such as the destruction of houses during an earthquake, cases of drowning caused by floods or the destruction of homes by wind, solely to natural causes. If accepted as true, these propositions implied a reduction in God’s active involvement in His creation. Invoking scripture, the censor observed ‘Contrary to Cardano, however, if these things are necessarily made by natural causes, how can the story of Job be saved?’9 The censor was here referring to Job 1: 13–19, a passage in which, he noted, God had permitted winds to destroy Job’s home (Baldini and Spruit 2009, p. 1058).

The censor also identified two further aspects of Cardano’s thought as potential causes for concern. The first was the idea that it might be possible to produce privileged information about either past or future events by natural means. This was evident in the censor’s comments about book 14, ‘De divinatione occultiore’. Here, the censor noted that ‘He admits fate, and he does not explain the manner in which it should be accepted. He also states that the Sybyl could predict the future from the influence of the star of Venus herself’. In this passage, there is a clear reference to Cardano’s apparent belief in ‘fate’, but the censor indicated that he believed that Cardano has left this concept largely undefined. His observation that the Sybyl made her predictions by means of astral influences suggests, however, that future events were indeed affected by astral influences. Such a concept would have been on the boundaries of orthodox Catholic belief. Rule IX of the Tridentine index had indicated that it was acceptable for humans to use the stars to predict some categories of future events, but contemporaries debated its precise meaning and especially whether it permitted the use of astrology to predict future human actions (Tarrant 2020). The censor then proceeded to criticise a series of further ideas and practices, including a form of divination using a jug of water, which, he observed, ‘appeared exceedingly superstitious’, and Cardano’s suggestion that he was advised to write both De varietate and De subtilitate in a dream. In his comments on book 15, ‘De divinatione artificiosa’, the censor began by once more condemning Cardano’s discussion of the art of chiromancy. He described how Cardano named certain parts of the hand and lines upon it and other information useful for performing this art, but he did not explicitly note why this art was of concern other than stating that it was proscribed in the Index (Baldini and Spruit 2009, p. 1061; on chiromancy and the Roman indices see Tarrant 2019).

The censor next addressed another aspect of Cardano’s philosophy: his interpretation of the powers ascribed to witches and magicians, which the philosopher discussed in chapter 80, ‘Striges seu lamias & fascinationes’. The censor suggested that Cardano appeared to argue that the powers ascribed to witches should be explained by reference to natural causes. To make his case, Cardano took the example of a certain peasant who was said to practise magical arts. Ascribing the reported phenomena to natural causes, including the effects of black bile, the position of the planets, the airs, the witches’ salve and the retention of blood or semen, Cardano systematically debunked the idea that witches achieved their desired effects by preternatural means. Furthermore, echoing Sacco, the censor lamented that Cardano had called inquisitors who prosecuted witches ‘rapacious wolves’ and charged that they only conducted these investigations because they believed that they could confiscate the property of those they convicted (Baldini and Spruit 2009, p. 1062). According to Cardano, Inquisitors were not simply wrong, but deliberately prosecuting the innocent for financial gain.

This brief overview of the content of the initial censures of Cardano’s work has shown that the censors identified three challenges of varying degrees of severity in his work. First, they noted that he offered natural explanations for contested operative arts; both cited the disputed art of chiromancy as an example. Secondly, the censors identified the fact that Cardano was disputing the reality of superstitious magic, that is, the use of operative arts that either explicitly or tacitly invoked demons in order to produce their effects. Related to this argument was Cardano’s sceptical approach to the issue of witchcraft. This was a specific category of superstitious practice that was based on a novel cluster of beliefs that developed over the course of the fifteenth century. At the heart of the new concept of witchcraft lay the idea that humans were conspiring with the devil to attack Christian society, and in some iterations the new stereotype of the witch could include the idea that humans gathered at Sabbats to worship the devil (Bailey 2001). Finally, and perhaps most dangerously, Cardano had sought to offer natural explanations for supposed instances of direct divine intervention in the created order, such as miracles and the actions of the saints and martyrs. In sum, the Inquisition’s investigations of Girolamo Cardano’s works were caused by his philosophical naturalism and the provocative conclusions that he drew from these principles.

3. The Roman Inquisition and Philosophical Naturalism

To understand why the censors were concerned by these issues, it is necessary to trace key aspects of the intellectual and institutional history of the Church. Since the patristic era, Christians had been conscious of the dangers posed by philosophical naturalism and had sought to affirm the boundaries between natural, preternatural and supernatural causation in an effort to safeguard key tenets of the faith (Carleton Paget 2011; Ward 2011). These issues became relatively less important following the disintegration of the Western Roman Empire and an attendant decline in philosophical knowledge. Attempts to arrive at clear definitions of these boundaries became more pressing once more following the intellectual revival of Western Europe that began in the tenth century. They found perhaps their most influential expression in the works of the Dominican friar Thomas Aquinas (1225–74), whose writings came to form the basis of Catholic understanding of the created order. In the following section, I will identify the precise theological basis for the censors’ condemnations and indicate the challenges created by Cardano’s work and the methods that Christians had constructed to deal with them.

In addition to raising specific ideas that appeared to contradict Catholic doctrine, philosophical naturalism raised a broad epistemological challenge. By the dawn of the sixteenth century, it was an accepted principle of Christian thought that a truth established in philosophy could not contradict the truth established by theology. Both censors noted, however, that Cardano believed that it was acceptable for a philosopher to advance accounts of the natural order that appeared to contradict the truth established in theology if that philosopher were merely arguing in the manner of the ancients. This means of presenting philosophical ideas was well known to ecclesiastical authorities. The condemnations issued in 1277 by Steven Tempier, the bishop of Paris, condemning certain ideas apparently taught at the University of Paris in the 1270s, provide perhaps the most obvious example. In addition to criticising the discussion of specific concepts, including astrological determinism, Tempier lamented the fact that philosophers appeared to maintain that there were two truths (Lerner and Mahdi 1963, pp. 337–54). He was likely referring to the philosophers’ claim that they could offer accounts of the natural order that contradicted the truth established in the discipline of theology if they maintained that their conclusions were philosophically necessary but ultimately false (Dales 1984; Martin 2007). Echoing the language used by Tempier, this idea is often unhelpfully referred to as the ‘doctrine of double truth’ or ‘Averroism’ (Dales 1984; Martin 2007). The use of this strategy to discuss ideas that appeared to contradict the faith was also opposed by such prominent friars as the Dominican Thomas Aquinas, who developed his synthesis of knowledge in response. He maintained that philosophy was subalternated to theology because the former discipline derived its source material from human observation whereas the starting point of the latter was revealed truth. On this basis, Aquinas concluded that theologians could ultimately determine the truth of any contested philosophical account of the natural order (Tarrant 2022, pp. 56–60).

The so-called Averroist mode of discussing philosophical ideas was largely eradicated in northern Europe by the fourteenth century, but it continued to be widely used in Italian universities. Adhering to this principle allowed philosophers working in these institutions publicly to teach and defend ideas that appeared to contradict the faith. This allowed a strong tradition of philosophical naturalism to thrive on the Italian peninsula. This situation began to change in the later fifteenth century as a result of a programme of reform driven by mendicant friars, especially those from Observant congregations (Mixson 2013; Mixson and Roest 2015). Acting as preachers, confessors and inquisitors, they drove efforts to extirpate heresy and superstition from Catholic society. This led them to make renewed efforts to demarcate clear and correct boundaries between natural, preternatural and supernatural causation and determine the most appropriate means to establish them. During this period, the detailed discussion of superstition provided in the Summa theologiae, used in conjunction with the principles of his synthesis of knowledge, provided the key means to evaluate the natural efficacy of contested operative arts (Tarrant 2022, pp. 62–68). On the one hand, this led to an enhanced effort to combat popular superstition; on the other, it led to a renewed effort to tackle philosophical naturalism in the universities of Italy.

The renewed effort to control Averroism in the Italian universities was not only intended to curtail the discussion of specific philosophical ideas but, more importantly, to define the correct methods to establish true knowledge. While the primary cause of concern was the use of ‘Averroism’ to discuss the immortality of the soul (Grendler 2002, pp. 281–93), some clerics also drew attention to accounts of the natural order that sought to explain reported phenomena without making reference to either preternatural or supernatural causation. During the Fifth Lateran Council, Giles of Viterbo (1472–1532) wrote a Historia in which he warned of the danger caused by philosophers rejecting preternatural causation (O’Malley 1968, pp. 42–44). The Lateran fathers also acted to address these concerns by passing the decree Apostilici regiminis, which regulated the public teaching of philosophy. It stated that, when lecturing, philosophers should indicate when an account of a particular natural phenomenon deviated from the truth of theology, and that they should, ideally, provide an alternative philosophical explanation that accorded with that truth (Tanner 1990, vol. 1, pp. 605–06; Constant 2002; Tarrant 2022, pp. 131–54). In essence, the decree Apostilici regiminis was designed to ensure that university teaching respected the principles enshrined in Aquinas’s synthesis of knowledge (Beretta 2005; Tarrant 2022). Philosophers such as Pietro Pomponazzi (1462–1525) nevertheless continued to discuss and publish works of philosophical naturalism that called into question the immortality of the soul and the reality of demonic and angelic interventions in the natural order and, some believed, threatened belief in miracles (Pine 1986, pp. 235–74; Poppi 1988, pp. 653–60; Maclean 2005; Copenhaver 2015, pp. 272–84; Spruit 2017).

The mendicants continued to pursue their ambition to define the boundaries of the natural order and combat superstition throughout the sixteenth century. They were provided with a new means to impose them following the establishment of the Roman Inquisition in 1542. Working through the Roman Inquisition, the mendicants and especially the Dominicans reiterated their understanding of the boundaries of natural causation by defining as heterodox a series of arts, such as chiromancy, that were once of contested orthodoxy. These developments are reflected in documents such as the indices of Forbidden Books published under the auspices of the Inquisition during the 1540s and 1550s that universalised these principles. As Sacco observed, chiromancy was one of several operative arts previously banned in the Tridentine Index of 1564.

While Sacco’s observation was quite correct, the prohibitions enshrined in the 1564 Rule IX of the Tridentine index—and in similar prohibitions contained in the 1557 and 1559 indices—built upon concerns that dated back to the patristic era. Church fathers, notably Augustine, had explicitly stated that although practitioners of these arts might believe that they worked by natural means, they were inherently inefficacious and could only produce their effects with the assistance of demons. This analysis was reiterated by Thomas Aquinas, especially in his Summa theologiae. His writings subsequently provided the basis for the investigation of magic by local tribunals of the Inquisition in medieval Europe and, in turn, for the centralised Roman Inquisition’s later investigation of disputed operative arts (Tarrant 2022, pp. 62–68). They were therefore very likely to have informed Sacco and the anonymous censor’s analysis of the forms of prognostication that Cardano characterised as natural. Sacco and the anonymous censor therefore objected to passages of Cardano’s work in which he described arts such as chiromancy because they believed that, since they were unable to produce their effects naturally, they must be superstitious. The censors recognised that, by describing such arts, Cardano was jeopardising his own salvation and that of other Christians who might accept his contested understanding of the natural order.

4. Saints and Superstition in Post-Tridentine Italy

Philosophical naturalism had been a persistent concern to the mendicant friars since at least the late thirteenth century. As we have seen, the foundation of the Roman Inquisition provided a new means to define the boundaries of nature by such means as prosecuting philosophers who seemed to violate the principles that they sought to enforce or by censoring their works. Having established this context, we can return to the question ‘Why was Cardano’s work not investigated earlier?’ It may have been the case that, by the 1570s, Cardano no longer enjoyed the political protection of powerful patrons. There are also reasons to believe that the specific ideas that Cardano was putting forward were more likely to come to the censors’ attention at this time. Under the leadership of Carafa and during his subsequent pontificate and that of his protégé Michele Ghislieri (Pius V, pp. 1566–72), the Holy Office had undoubtedly become more powerful (Firpo 2005; Prosperi 2009, pp. 135–53). Numerous historians have also noted that, by the 1570s, the Roman Inquisition was investigating magic, both popular and learned, with increased enthusiasm. This latter development has often been explained by the suggestion that, by this time, the Inquisition had successfully eradicated Protestantism and turned its apparatus of censorship onto new targets (Tarrant 2022, pp. 8–10). This is, however, a reductive explanation for a multi-faceted problem. In what follows, I would like to suggest one possible additional cause for both the increased prosecution of magic in the latter half of the sixteenth century and the investigation of Cardano: the need to safeguard sanctity.

To understand the threat posed by Cardano’s work, it is necessary to analyse his work in more detail. We have seen that the censors were concerned by his discussion of the operative arts; both singled out chiromancy as a notable example. Consideration of the legitimacy of specific operative arts depended upon defining how the natural world operated, a fact that pointed to a deeper problem within works of philosophical naturalism. Clerics feared that offering natural explanations for contested arts and disputed phenomena threatened to collapse the boundaries between levels of explanation of the natural order. This was evident in ecclesiastical authorities’ attitudes towards the work of Cardano’s contemporary, Giambattista Della Porta, who was also placed on trial in the late 1570s (Valente 1999, p. 2017; Tarrant 2013). In his most famous work, Magia naturalis (the first edition of which was published in 1558), the Neapolitan philosopher had sought to explain how to produce mira, that is, wonders beyond ordinary human comprehension, by manipulating the natural order. He provided recipes that he claimed could enable his readers naturally to perform feats ranging from ripening strawberries out of season to producing a ‘witches’ salve’. Della Porta presented the latter as a natural unguent that could give the person to whom it had been applied hallucinations, which could, in turn, lead them erroneously to believe they had attended a witches’ sabbat. For these reasons, Della Porta argued that the transportation of witches by demons to attend gatherings was, in some—perhaps all—cases, simply a delusion (Eamon 1994, p. 202).

Della Porta was feted through Europe: his work was widely read and translated and aroused the interest of such powerful figures as the Habsburg emperor Rudolf II (r. 1576–1612) (Eamon 1994, p. 222). Despite this widespread acclaim, his 1577 trial underscored the fact that many members of the Church viewed his work with suspicion. The precise reasons for why he was placed on trial remain unknown (Valente 1999; Tarrant 2013). It is, however, clear that at least some contemporaries doubted the truth of his claims that the wonders that he described could be produced by natural means. To take one example, in the early 1570s, the Jesuit Robert Bellarmine criticised Della Porta’s work in a treatise on magic appended to his Lectiones lovanienses, a series of lectures on Aquinas’s Summa theologica delivered at the University of Louvain. In this text, Bellarmine acknowledged the existence of both natural and demonic magic but asserted that, in Magia naturalis, Della Porta described a third form of magic that he referred to as ‘mixed’. According to Bellarmine, ‘mixed magic’ involved performing an ostensibly natural art, which, in fact, only produced its effects with the assistance of a demon (Bellarmine, forthcoming, p. 393). Bellarmine’s comments indicate that he believed that Della Porta’s work threatened to collapse the boundaries between natural and preternatural causation. It is likely no coincidence that, by the mid-1570s, Roman censors were drawing attention to Pomponazzi’s writings, including De incantantionibus, a work that ascribed wondrous events solely to natural causes (Baldini and Spruit 2009, pp. 2277–78). Inquisition censors also identified this problem in Cardano’s works. In their eyes, he was using an erroneous understanding of the natural order to justify the practice of arts such as chiromancy that were in fact superstitious.

Della Porta and Cardano’s work opened a second, related, challenge to ecclesiastical authority. As Augustine cautioned in De Civitate Dei, the ambiguous boundaries between natural phenomena, magical effects and miracles could be exploited to challenge the truth of the faith (Augustine 2003, pp. 974–76). By the sixteenth century, intellectuals were openly exploiting these ambiguities. In Magia naturalis, Della Porta argued that it was possible to use natural magic to create wonders that the uneducated could mistake for genuine miracles (Della Porta 1560, 1) Although this was not Della Porta’s stated intention, his insight implied that a disreputable individual could use magic, whether natural or demonic, to deceive their fellow Catholics into believing that they were witnessing a genuine miracle. Alternatively, they could use their understanding of magic to discredit seemingly genuine miracles by ascribing them to natural causes. Sacco and the anonymous censor both identified the latter threat in Cardano’s writings. Each highlighted the fact that, by ascribing events regarded as miraculous to natural causation, notably astral influence, Cardano offered a means to challenge the reality of both past miracles and those that continued to be reported in his own age. While Cardano may have been expressing this idea in a new and vigorous form, it was well known to and had been previously denounced by theologians. To take one example, in his 1495 work Tractato contra li astrologi, the Dominican Girolamo Savonarola (1452–98) fiercely opposed philosophical accounts that appeared to ascribe miracles or martyrs’ divine inspiration to the effects of the stars (Savonarola 1495, f. 10r).

While concern for protecting the integrity of miracles was far from new, by the 1560s, this issue had gathered a new salience within the Catholic Church. This situation was partly caused by the need to respond to a challenge posed by Protestant reformers. During the process of explicating their ideas, both Martin Luther and John Calvin intimated that miracles, in the sense of thaumaturgical events, had ceased to occur in the post-Apostolic era (Walker 1988). Although belief in miracles did not completely end within the Protestant tradition, the magisterial reformers’ cessationist beliefs (that miracles ceased to occur in the post Apostolic Age) provided a useful means to attack contemporary Catholicism. Since miracles were widely accepted as the distinguishing feature of the saint, a refusal to admit that they had occurred undermined belief in the saints and the legitimacy of the cults that had grown up around them (Ditchfield 2007, pp. 208–9; Del Colle 2011, pp. 240–44). Moreover, most Protestants regarded the cult of saints as idolatrous, that is, as a form of superstition in the technical sense of a practice that involved offering the reverence that was due only to God to something other than Him. This meant that at the core of the Protestant critique of the cult of saints was not simply the belief that such ideas were false but the suspicion that any wonders produced by invoking them were either the product of Catholic credulity, deception or, most alarmingly, accomplished through demonic assistance (Walsham 2005, pp. 276–78; Bouley 2017, 16). In this sense, debates about sanctity and the cult of saints were closely intertwined with contemporary concerns about magic and witchcraft, which were similarly conceived as forms of superstition by Protestants and Catholics alike.

The Protestant assault on sanctity had mixed implications for Catholics. It has been frequently noted in the secondary literature that canonisation was suspended in 1523 and not resumed until 1588. While this was true, Clare Copeland has observed that ‘despite the absence of universal canonizations in the period of the Reformation, the saints continued to dominate Catholic lives and identities: existing devotions continued, older saints’ cults were revived and new devotions to people thought to be saints sprang up’ (Copeland 2013, p. 226). Moreover, non-universal cults of individuals continued to receive papal approval throughout the so-called ‘hiatus’ in saint making. Between 1524 and 1588, no fewer than fourteen holy men and women were so honoured (Ditchfield 2007, p. 207). Despite the ongoing commitment to the cult of saints, Catholics also recognised the need for reform and in fact had done so since the late medieval period (Walsham 2005, p. 276; Bouley 2017, pp. 13–18). The concerns raised by reformers both Catholic and Protestant and the importance of sanctity to Catholic religious practice notwithstanding, it was addressed in neither of the first two sessions of the Council of Trent. Discussion of these matters in fact began only on the insistence of the French delegation who arrived late to the final period of the Council (1562–63). During the council’s 25th session, held on 4 December 1563, the Tirdentine fathers produced the decree ‘On the Invocation, Veneration, and Relics, of Saints, and on Sacred Images’ (Tanner 1990, pp. 774–76; de Boer 2021, pp. 102–9).

This decree addressed a series of concerns about the cult of saints and not simply those raised by Protestants. It opened by stressing the need for ‘bishops, and others who sustain the office and charge of teaching’ of their obligation to instruct diligently the faithful with regard to the saints. It continued by stating that they were to ensure that Catholics understood that the saints offer prayers on their behalf and that it is ‘good and beneficial’ to pray to them to obtain benefits from God through Christ. They should also make it known that the Church has condemned, and continues to condemn, both the idea that invoking the saints was false and idolatrous and the false contention that martyrs and relics should not be venerated (Tanner 1990, vol. 2, pp. 774–75). This decree thereby reaffirmed the Catholic Church’s teachings in relation to the saints, clearly demarcating their position from those of the Protestant Churches. It also offered a clear warning to Catholics such as Cardano that questioning the truth of the saints and martyrs was unacceptable.

If the foregoing measures were designed to reinforce devotional practices associated with the saints and martyrs and, indirectly, belief in the truth of post-Apostolic miracles, it was also clear that the Tridentine fathers recognised the need for reform. The decree continued by affirming the importance of ensuring that the saints were both represented and venerated in an appropriate manner. It also expressed the Tridentine fathers’ earnest desire ‘to root out utterly any abuses that may have crept into these holy and saving practices, so that no representations of false doctrine should be set up which give occasion of dangerous error to the unlettered.’ The decree thus made it clear that it was essential to ensure that no images conveyed false doctrine, lest they lead the uneducated into error. It therefore instructed that ‘All superstition must be removed from invocation of the saints, veneration of relics and use of sacred images; all aiming at base profit must be eliminated; all sensual appeal must be avoided, so that images are not painted or adorned with seductive charm’. Furthermore, the decree added that the faithful were not to use a visit to a shrine as an excuse for drunken revelry. The use of the word superstition was of pivotal importance in this context, for it here referred to inappropriate or misguided religious practice that resulted in giving the reverence due either to God or the saints to demons (Tanner 1990, vol. 2, p. 775; see too de Boer 2021).

The decrees of the 25th session of Trent also reaffirmed established saint-making practices. Since at least the twelfth century, canonisation had been a two-stage procedure. The first stage was the episcopal processus ordinarius, while the second, the processus apostolicus, was overseen by the papacy. The episcopate was also acknowledged to be responsible for the recognition of non-universal cults (Ditchfield 2007, pp. 207–9). While the Tridentine fathers did nothing to diminish the papacy’s right officially to recognise saints, they reiterated the bishops’ responsibility to ensure that cults of saints within their dioceses were properly regulated. The decree also invested them with not only the authority but also the duty to oversee the development of any new cults. It required local bishops to ensure that no ‘unusual image’ was erected in any place, including churches, and that no new miracles were acknowledged or relics recognised without his approval. The bishop should investigate all such cases and consult with theologians and other pious men before reaching any decisions. In sum, the bishop was to take primary responsibility for controlling the development of local cults of saints, with the explicit duty to prevent genuine religious fervour, with its attendant reverence for the miraculous, curdling into superstition (Tanner 1990, vol. 2, p. 776)

During the same period, the Tridentine fathers initiated a further project: the reform of the Roman Breviary. The aim was to reduce the number of saints’ days in the liturgical calendar in order to make more room for the recitation of the ferial office. Although the project started at Trent, most of its work was undertaken after the council’s closure by a committee overseen by Pius V. The committee’s work produced a new Tridentine Breviary, which was published in 1568. The work was prefaced by the papal bull Quod a nobis, which declared that it was no longer acceptable to use local editions of the breviary, and, more specifically, the local saints’ offices (officia propria), if they could not be shown to have an unbroken history of use over a period of two-hundred years. With these measures, the papacy attempted to control the number of feast days and, in effect, prevented local dioceses from observing relatively recent feasts that the central Church had not approved. As Simon Ditchfield has stressed, local authorities continued to negotiate with the papacy about the liturgy, indicating the limitations of any crude top-down model of reform. Partly in response to local petitions, the Roman Breviary went through two further editions during the first sixty years of its existence, a process that led to the incorporation of new cults of saints and the restoration of some of those that had been previously removed (Ditchfield 2007, pp. 201–5).

The Tridentine decree and the ongoing measures to reform the liturgy demonstrate the importance placed on controlling cults of saints in the period leading up to Cardano’s trial. It is possible to draw a connection between these interests and inquisitors’ well-documented efforts to root out superstition. In a strict theological sense, the validity of local cults of saints turned on the question of whether the powers of the saint in question genuinely derived from God, were merely a form of deception or whether the individual concerned was co-operating with or possessed by a demon. As the Tridentine fathers had recognised, the unchecked proliferation of local cults and the veneration of fake or deluded saints left Catholicism vulnerable to the charge advanced by Protestants that these cults of saints were, at best, credulous, while, at worst, fraudulent and superstitious. Proper investigation and verification of the miraculous was therefore an important means to buttress these beliefs and practices. Such investigations were not simply directed at an ‘external’ audience. Cases of alleged false sanctity raised the suspicion that the cults surrounding the putative saint were superstitious and required extirpation (Zarri 1991; Tutino 2021). In this respect, the verification of genuine miracles and the pursuit of superstition were two sides of the same coin. Achieving this end required clerics to be able to reliably assign observed effects to the correct level of causation, whether natural, preternatural or supernatural. The possibility of making such decisions was predicated on the existence of an accepted epistemological framework that made it possible to arrive at such determinations.

5. Disciplining Expertise

How do these considerations help us to understand Cardano’s trial, and perhaps also that of Della Porta? At the most general level, they provide an interpretative context for these investigations. This was a period in which central ecclesiastical authorities were asserting the need for clerics at all levels to exert a greater control over the interpretation of the created order in order to eradicate superstition and protect sanctity. This shared effort was conducted by differing authorities in the Church. The Council of Trent had sought to empower and encourage the local episcopate (O’Malley 2013). Leading reform at a diocesan level, bishops were expected inter alia to examine local cults of saints and play a central role in the work of censorship. For its part, in the years after the conclusion of the Council of Trent, the Inquisition continued to assert its authority not only in the sphere of book censorship but also in the pursuit of superstition, including, as we have seen, cases of false sanctity (Fragnito 1997; Frajese 2008, pp. 39–220; Gotor 2002). By taking such steps as refusing to acknowledge the authority of the Tridentine Index, which, in principle, replaced the Inquisitorial Index of 1559, the Inquisition asserted its independence and authority to determine the boundaries of orthodoxy. This included attempts to arrogate to itself the authority to determine the appropriate boundaries between natural, preternatural and supernatural causation and establish the appropriate criteria to do so (Fragnito 2001, pp. 18–19; Tarrant 2019, p. 191).

By the later sixteenth century, the Roman Inquisition had also begun to exert its authority over new areas, including saint making and the regulation of local cults of saints. The Tridentine decrees had left local bishops responsible for regulating local cults of saints and overseeing the first stage of the canonisation process. Many local bishops nevertheless chose to consult with Rome about specific questions concerning local practice. In 1588, Sixtus V established the Congregation of Rites and Ceremonies to govern the process of canonisation and determine questions about local practices, an innovation that formed part of a wider effort to strengthen the central authority of the papacy. The Inquisition nevertheless started to intervene in these areas, albeit in a less formal manner, when, from around 1580, its local officials began to investigate cases of false sanctity (Del Col 2006, pp. 659–66). The rationale for their intervention was, because cases of false sanctity could involve superstitious religious practice, the investigation of new cults of saints should be considered to fall under their jurisdiction.

The Roman Inquisition’s interventions in these areas raised important questions about the relative authority of the papacy and the episcopate. These tensions were exposed during the deliberations of the Congregazione de Beati, an ad hoc committee convened in the 1590s by Clement VIII to consider the legitimacy of cults of those who had recently died with the odour of sanctity, the so-called beati moderni. During these meetings, influential figures such as the Jesuit Robert Bellarmine defended the Tridentine settlement while others such as Franciso Peña—an auditor of the Rota, consultor to the Index and editor of Nicholas Eymerich’s inquisitorial handbook Directorium inquisitorum—disagreed. Peña explicitly argued that Inquisition officials, rather than bishops, should be responsible for determining whether a locally revered individual did indeed enjoy the odour of sanctity or was tainted by the smack of heresy. Surprised by the vehemence of the debate within the Congregazione de beati, Clement VIII prohibited further discussion of these questions in 1603. The Roman Inquisition’s efforts to expand its authority nevertheless persisted into the seventeenth century. In 1625, for example, the Roman Inquisition issued a decree that superseded the work of both the Congregazione de Beati and bypassed the Congregation of Rites to determine the appropriate procedures for regulating local cults that also redefined the procedures of saint-making (Gotor 2002, pp. 107–202; Ditchfield 2007, pp. 207–16; Ditchfield 2024).

The Roman Inquisition’s efforts to assert its institutional authority in the sphere of saint-making and the regulation of local cults of saints was, I suggest, paralleled by an attempt to exert its epistemological authority in this area. Specifically, the members of this institution enacted measures to regulate the use of external medico-philosophical expertise and the criteria that could be used to investigate the boundaries of the created order. As numerous historians have demonstrated, since at least the thirteenth century, physicians and university professors had been employed by ecclesiastical institutions to comment on issues pertaining to the definition of the boundaries of the natural order (Park 1994; Ziegler 1999). This continued to be the case in the post-Tridentine period. The Tribunal of the Rota and the Congregation of Rites, for example, both made use of such expert knowledge to determine whether saints’ bodies could provide physical evidence of sanctity (Gentilcore 1995; Vidal 2007; Pomata 2007; Bouley 2016, 2017). By contrast, the Roman Inquisition rarely, if ever, employed medical expertise to serve such purposes (Bouley 2018). Evidence from Venice suggests, however, that local tribunals of the Inquisition often consulted physicians to determine whether cases of unexplained illness were natural or in fact caused by preternatural maleficiant magic (Seitz 2009). It is also notable that the Congregation of the Index convened expert panels of university professors to consider the content of medical and philosophical texts when preparing its ill-fated Index expurgatorio. The aim was to use expert knowledge to advise on which passages of texts should be removed in order to allow for their continued circulation (Marcus 2020, pp. 96–130).

While institutions such as the Congregations of the Rota and Rites and the Holy Office considered expert opinion useful, they observed a strict social and epistemological hierarchy in the relationship between ecclesiastical and medico-philosophical authority. Physicians were consulted to comment on cases when required and they were expected to provide testimony in accordance with their expertise, that is, to assist in the process of demarcating natural phenomena from those that potentially were not. This evidence made it possible to identify whether an individual might be a candidate for sanctity or the potential victim or perpetrator of superstitious magic. In these cases, the expert’s role was not to make a definitive pronouncement, whether in cases of sanctity or magic, but to assist in the process of arriving at such a determination by assembling a potential body of evidence for consideration. The final decisions in such cases were always made by an ecclesiastical authority, whether that was an inquisitor or a member of the Tribunal of the Rota (Gentilcore 1995, pp. 132–33; Seitz 2009). Such an arrangement was consistent with the epistemic relationship established in the Thomist synthesis between philosophical and theological knowledge. Philosophers could provide expert analysis of empirical evidence that could make a significant contribution to efforts to determine disputed cases of sanctity or magic, but it was ultimately the preserve of theologians to determine the truth of the matter.

This insight may help us to interpret the censors’ reaction to Cardano’s work. He not only justified the practice of operative arts proscribed by the Roman Inquisition but also appeared to suggest that the miracles ascribed to saints and recognised by the Church might be false and that the acts of martyrs were not divinely inspired. As a physician and philosopher, he was considered to be an expert on nature whose opinion could be used to assess putative miracles. Sceptical opinions were welcomed by those investigating miracles. Indeed, from 1631, this attitude was personified by the figure of the promotor fidei, otherwise known as the ‘devil’s advocate’, an official of the Congregation of Rites charged with the task of challenging the reliability of evidence in canonisation trials (Vidal 2007, pp. 489–95; Bouley 2017, pp. 35–37). Yet, Cardano’s naturalistic arguments went further than mere scepticism: they directly challenged the cosmology that underpinned the Roman Inquisition’s definition of the boundaries of nature. His analyses of phenomena observed within the created order therefore threatened to undermine the credibility of the decisions reached by this institution, whether in relation to the saints or practitioners of magic. The censors explicitly recognised this point when they complained that Cardano accused inquisitors of being ‘rapacious wolves’ who falsely condemned witches and heretics for their own financial gain. This statement was not only insulting but it also threatened inquisitors on a political level because it directly challenged the legitimacy of their investigations.

More significantly, Cardano’s position constituted a violation of the received socio-epistemological order in a manner that paralleled the offence later caused by Galileo Galilei. In each of these cases, lay philosophers were challenging the Thomist synthesis of knowledge that asserted philosophy’s subalternation to theology. While Galileo used his natural knowledge to arrogate to himself the right to interpret scripture, in works such as De rerum varietate, Cardano used philosophy to make knowledge claims that contradicted truths about the natural order established in the higher discipline of theology (Blackwell 1991; Beretta 2005). Specifically, he used his understanding of the cosmos to undermine the credibility of verdicts reached by clerics about the status of saints, martyrs, witches and magicians. This was a form of disciplinary trespass that threatened not only the verdicts reached in individual cases but also endangered the whole edifice of knowledge that sustained orthodox belief in preternatural and supernatural causation that underpinned these trials. In these circumstances, it was considered necessary to prevent him from circulating these opinions not only because they were innately dangerous but because they could influence the views of other potential philosophical and medical experts.

6. Conclusions

The first investigations of Cardano’s work, which, in turn, led to his trial for heresy, were triggered by concerns about the implications of his philosophical naturalism. Censors lodged objections to his apparent defence of principles of astrological determinism and of specific operative arts, but these issues pointed to two more significant problems. First, Cardano’s works threatened to collapse the boundaries between categories of causation established by the Roman Inquisition. Cardano’s trial was therefore not simply about restraining the actions of one individual—although this is clearly part of the problem—but also about the real-world ramifications of knowledge that threatened to undermine a core aspect of Catholic religious practice. Secondly, in setting forth his ideas, Cardano challenged both the epistemic authority and the political power of the Inquisition. By using philosophical knowledge to challenge the reality of magic and miracles, Cardano contravened the synthesis of knowledge erected by the mendicants and especially the Dominicans, which was, in turn, enshrined in the principles guiding the practice of teaching articulated in the decree Apostilici regiminis. Cardano’s trial was thus important because it illustrated the Inquisition’s efforts to restrain the power of individual intellectuals who challenged not only the epistemic foundations of the Roman Inquisition’s processes but also the integrity and authority of its officials.

These events occurred during a period when the Roman Inquisition was beginning to expand its power. Cardano’s trial occurred immediately prior to a period in which we know that the Roman Inquisition was taking increased interest in sanctity and how it could be accurately distinguished from cases of superstition and false sanctity. Its members wanted to ensure that the right decisions were made in the correct way by the most appropriate authority. This involved not only reasserting the epistemological order discussed above but also attempting to ensure that the Roman Inquisition, rather than other institutions within the curia, played the leading role in making these decisions. Placed in this context, it appears as an early intimation of the direction in which the Inquisition’s investigations would travel. We might want to consider the trial of Cardano and indeed that of Della Porta as the first stages in the Inquisition’s efforts to expand its authority in the field of saint making and the regulation of the cult of saints that would ultimately culminate in its battles with the Congregation of the Rites during the seventeenth century.