Muslims in Medieval Inquisitorial Thought: Nicolau Eymeric and His Contexts

Abstract This article analyzes the scant treatment of Muslims in medieval inquisitorial thought, focusing mainly on the late fourteenth-century Aragonese inquisitor Nicolau Eymeric's Directorium inquisitorum (1376). It argues for four contexts in which to understand his engagement with Islam. First, as background, is a longstanding Christian (although not inquisitorial) tradition categorizing Islam as a heresy, with which he did not substantially engage. Second is his own goal to extend inquisitorial authority to new subjects, in which he drew on previous inquisitorial thought about Jews. The third involves conflicts between church officials and the Crown of Aragon about jurisdiction over non-Christian subjects. The fourth centers on the supposition that he did not view Muslims living within Christendom as an especially covert or insidious threat requiring special investigation to uncover, which speaks to how he and other inquisitors viewed their role and the nature of the threats they aimed to counter. In broad terms, this article contributes to our understanding of one important way in which medieval Christianity engaged with other religions. It also provides a basis for understanding later developments in early modern Europe.

religion; or rather, since the modern concept of "religion" does not fully pertain to the Middle Ages, and certainly not to medieval uses of religio, 2 it constituted a different "law." The medieval church's own canon law never directly categorized Muslims as heretics. 3 Within inquisitorial thought, one treatise from the mid-thirteenth century specifically defined heretics as those who had been received into the Christian faith through baptism and then knowingly rejected it. Those who had never been baptized were either Jews or heathens (gentiles), into which category Muslims would presumably fall. 4 Some interesting conclusions can nevertheless be teased out of medieval inquisitors' reticent treatment of Muslims. This matters for our understanding both of how medieval Christian authorities engaged with other religions and how later frameworks of persecution developed. I should note that my analysis will not delve into actual Christian-Muslim interactions, either through inquisitorial courts or via other mechanisms. 5 As David Nirenberg has stressed, Christian conceptions of Islam were typically quite disconnected from actual experiences with Muslims. 6 My focus will therefore remain on inquisitorial theorizing about Muslims (as well as Jews), albeit grounded, at points, in certain social realities. I will also necessarily focus mainly on the inquisitorial theorist who dealt most extensively with the matter of Islam, the aforementioned Nicolau Eymeric.
Eymeric is often regarded as a kind of culminating figure in medieval inquisitorial thought, especially as it developed through a sequence of handbooks and manuals for inquisitors written during the thirteenth and fourteenth centuries. 7 This reputation rests mainly on his encyclopedic Directorium inquisitorum, completed in 1376. Here he discussed Muslims in two related sections (questiones). One dealt with the issue of conversion: of Christians who might convert to Islam but, more practically, of Muslims who became Christian and then might backslide. This followed a similar section that addressed Jews. The other section presented a variety of ways that both Jews and Muslims could be subject to inquisitors even within the practice of their own faith. Because of Directorium's later influence, and because it largely summarizes Eymeric's own thinking, I will mainly address this text, although I will touch on some of his other works as well. 8 There is a tendency, rooted in the French scholar Antoine Dondaine's pioneering analysis, to see inquisitorial manuals developing along a steady trajectory from simple and pragmatic collections in the mid-thirteenth century to expansive and systematic treatises in the fourteenth. 9 From that perspective, one might conclude that Eymeric addressed Islam more than any earlier inquisitorial writer simply because he sought to develop a more complete statement about the full extent of inquisitors' powers. As we will see, he definitely expanded upon earlier arguments for their authority over Jews, both as converts and for other reasons. Lucy Sackville has persuasively argued, however, that it is better to approach inquisitorial literature in terms of its specific contexts rather than through any overarching teleological framework. 10 With that in mind, I will present four different contexts that can inform our understanding of Eymeric's treatment of Muslims.
The first context is quite broad and provides a backdrop against which his approach to Islam must be viewed. While Muslims were never categorized as heretics in medieval canon law, they were frequently castigated as such in Christian polemic. This tradition did not powerfully influence inquisitorial thought, but it was not entirely unavailable to inquisitors. That Eymeric never mentioned it reinforces the argument that his engagement with Islam arose from more specific concerns, not some encyclopedic impulse.
The next two contexts reflect more immediate intellectual and socio-political frameworks within which Eymeric developed his thinking about Muslims. One was his wellknown desire to expand inquisitors' authority over new groups and new categories of activity. 11 Here he built on already established arguments for inquisitorial authority over Jews. The other entailed jurisdictional confrontations between church officials, particularly inquisitors, and the Crown of Aragon itself concerning their respective authority over non-Christians. Jews and Muslims were both considered to be the special "treasure" of the crown, and monarchs jealously guarded their direct authority over them. 12 Although Jews were less numerous, they were by far the richer part of that treasure, which, I will suggest, was one reason Eymeric continued to focus mainly on them, even as he expanded his analysis to include Muslims.
For my final context, I will return to a broader perspective-and perhaps a bit of teleology. As processes of inquisition evolved over the thirteenth and fourteenth centuries, they came to focus increasingly on the interior state of the heretical suspect. From a 8 In the absence of a full modern edition, I have used the widely available early modern edition by the canon lawyer Francisco Peña. mechanism designed to prosecute preconceived groups (real or imagined) engaging in set forms of heretical behavior, inquisition evolved into a means to investigate, and in many ways to construct, hidden interior worlds of belief. 13 While other factors motivated Eymeric to include Islam explicitly in his discussion of inquisitorial jurisdiction, this development, I will suggest, served to blunt his interest somewhat. Although the evidence is slightly elusive, certain passages in his manual show why he did not think that Muslims presented the same threat of hidden corruption for surrounding Christian populations as did Jews. Inquisitors, therefore, did not need to scrutinize them or their practices nearly so carefully.

I. Islam as a Christian Heresy
Some Christian authorities categorized Islam as a heresy almost from its beginnings. The first to do so was the Syrian monk John of Damascus (ca. 675-749), who had intimate knowledge of Muslim beliefs due to this previous service at the Umayyad court. 14 He addressed Islam in one long chapter of his Concerning Heresies (Peri aireseon, known as De haeresibus in the West). 15 Here he introduced what became an often-repeated Christian assertion: that Muhammad was instructed in monotheism by a heretical Christian monk, an Arian in John's account. Other Eastern Christian writers followed in this vein, including the historian Theophanes, whose important Chronographia was translated into Latin in the ninth century (while John's De haeresibus was only translated in the thirteenth). 16 Much more could be said of this Eastern tradition, but my focus here is on the Latin West. Perhaps the first mention of Muslims as heretics made by a Western writer is found in the sermons of Ademar of Chabannes (d. 1034), 17 but most experts agree that Latin Christendom did not really engage conceptually with Islam until the twelfth century in the wake of the First Crusade. Expanding Christian control over former Muslim territories in southern Italy and Iberia also played an important role. 18  have further set this new intellectual engagement with Islam in the context of the post-Gregorian reordering of Christian society itself. 19 Whatever their motivations, several significant twelfth-century writers continued to label Islam as a heresy, although they also recognized that this categorization was debatable.
While a number of northern European writers described Islam as a heresy in the early 1100s, 20 the most influential depiction came from a former Iberian Jew. 21 Petrus Alfonsi, born Moses Sephardi, converted to Christianity in 1106 and soon thereafter wrote Dialogus contra Iudaeos. 22 Within this work, he created an occasion to discuss Islam when he had his Jewish interlocutor ask why he chose to convert to Christianity rather than to the faith (fidem) of the Saracens, under whose rule he had been raised. 23 Petrus responded with the by now time-honored position that Muhammad had been instructed by heretical Christians, here Jacobites rather than Arians, and also by Jews who "held the law of Moses heretically." 24 Thus Islam was grounded in heresy against two traditions. The Dialogus proved extremely popular, surviving in some eighty known manuscripts. 25 While the relatively brief account of Islam as a heresy in Dialogus contra Iudaeos circulated widely, the most extensive treatment of this point in the twelfth century came from another "Petrus": Peter the Venerable, abbot of Cluny. Like Petrus Alfonsi, he initially addressed the "Mohammedan heresy" (Mahumetica heresis) in a treatise against the Jews. 26 He then wrote two works directed exclusively against Islam, first the relatively brief Summa totius haeresis Saracenorum and then the expansive Contra sectam Saracenorum.  Much has been written about Peter's extensive engagement with Islam, which also included commissioning the first Latin translation of the Qur'an. 28 Here we need only note that, in his Summa, he, too, described Muhammad as having been instructed by both Jews and a heretical Christian monk-now a Nestorian named Sergius. 29 Indeed, Peter presented Islam as the culmination of all earlier heresies, with Muhammad "vomiting back up almost all the dregs of previous heresies, which he had swallowed under the devil's instruction." 30 Importantly, however, he also questioned whether Muslims were really best identified as heretics. "Although I would name them heretics because they believe some things with us," he wrote, "in most things they differ from us, so perhaps more correctly I should name them pagans or heathens, which is worse." 31 He repeated this equivocation in Contra sectam Saracenorum, noting that "whether Muhammad's error ought to be called heresy, and his followers called heretics or heathens, I do not discern sufficiently." Instead, he advised his readers to "choose, therefore, what you prefer." 32 Through Peter we can see a Western European clergyman thinking about Islam in relation not just to Judaism but to other Christian heresies, and not exclusively those of centuries past. Peter's other great work of polemic in defense of Christian orthodoxy was Contra Petrobrusianos hereticos, and his consideration of that contemporary heretical threat may have influenced his approach to Islam as well. 33 Despite his overall standing in the religious world of the twelfth century, however, his treatises on Islam do not appear to have circulated widely. 34 Even when his positions were known, his successors often exercised the choice he offered and labeled Muslims as pagans rather than heretics.
At the end of the twelfth century, for example, Alain of Lille was probably familiar with Peter the Venerable's writings on Islam, at least indirectly. 35  "Contra paganos," and he referred to them as pagans throughout. 36 In only one place did he break with that decision, noting that, like the Jews, the "aforesaid heretics" (Muslims) tended to deride Christianity for its reliance on devotional images. 37 While the categorization of Islam as a heresy was muted after the twelfth century, it did not disappear. Indeed, in the early thirteenth century, at least one Western writer with considerable exposure to Islam bemoaned the fact that it was not commonly labeled a heresy. In the early 1220s, the German cleric Oliver of Paderborn described Islamic beliefs and practices in his account of the Fifth Crusade, Historia Damiatina. There he noted that, particularly because Muslims accepted Christ's more-than-human nature but still denied his divinity, "truly they ought to be called heretics rather than Saracens, but the use of the false name prevails." 38 Around 1260, the Franciscan bishop Benedict of Alignan appears to have conflated Muslims and heretics in his Tractatus fidei contra diversos errores, at least in terms of justification for crusades against them. 39 Benedict's Tractatus brings us into the mid-thirteenth century, when papally appointed inquisitors and the first inquisitorial manuals also appeared. Compared to these sources, the mainly twelfth-century texts surveyed above tended to deploy the term heresy "untechnically," as one still influential survey would have it. I would contend, however, that they did not deploy it "casually and carelessly." 40 There were clear reasons for them to consider Islam as a heretical deviation from Christianity, and Peter the Venerable, especially, thought carefully about how it should best be categorized. Nevertheless, these works were all broad polemics, not narrower considerations of Islam's status under Christian law.
Regarding that legal status, I have already noted that Islam was never categorized as a heresy in Christian law. 41 Indeed, canon law presented little systematic treatment of Muslims prior to the thirteenth century. 42 That began to change when Pope Gregory IX commissioned the first great extension of canon law, the so-called Liber extra or Decretals. Compiled under the direction of the Dominican Raymond of Peñafort, this collection was issued in 1234. Drawing together previous legislation, it included a substantial section De Iudeis, Sarracenis, et eorum servis. 43 Here Muslims appeared as a discrete category, linked to Jews but not to heretics. 36 Edition in d'Alverny, "Alain de Lille," 325-350. 37 D'Alverny, "Alain de Lille," 344: "Nobis etiam insultant predicti heretici cum Iudeis, quia habemus ymagines in ecclesiis nostris et sculptilia." Even here, d'Alverny's apparatus indicates that one manuscript reads "pagani" for "heretici," and the term is omitted entirely in several others. Both Jews and Saracens were, however, implicitly associated with heretics, schismatics, and apostates, all covered in the next three sections of Gregory's Decretals. 44 Moreover, as Raymond later commented in his Summa de poenitentia et matrimonio, this section of the Decretals also established that church law extended to non-Christians under certain circumstances. 45 For example, neither Jews nor Muslims should be allowed to disparage Christ or the crucifixion. 46 Such claims were further developed during the pontificate of Innocent IV (1234-1254). 47 Indeed, Innocent drew on this legislation when, in 1254, he enjoined Dominican and Franciscan inquisitors in Italy to proceed not only against heretics and their supporters ( fautores) but also against non-Christians who either had carnal relations with Christians or showed contempt for the Christian faith. 48 The older tradition of labeling Islam a heresy as a polemical if not legalistic statement also had at least some resonance in inquisitorial thought, although what conclusions can be drawn from this are unclear. The so-called Passau Anonymous, composed in central Europe in the 1260s, is a ramshackle assemblage. While its compiler, who was almost certainly an inquisitor, appears to have had direct experience only with Waldensian heretics, he intended his collection to help defend the church from many enemies: "Jews, heretics, pagans, and false Christians." 49 The text exists in a bewildering number of variants, but many include a brief section derived from Petrus Alfonsi's treatment of Islam in Dialogus contra Iudaeos. 50 It repeated the old saws that Muhammed was instructed in his faith by Christian heretics (here Jacobites) and by heretical Jews.
What use inquisitors in central Europe might have made of this text is difficult to see. There were no Muslim communities in the region at this time. 51 Moreover, even in Christian lands that had considerable Muslim populations, throughout the thirteenth century Dominicans and members of other religious orders who regularly staffed papal inquisitions operated toward non-Christians primarily as missionaries seeking conversion, not as magistrates set on punishing erroneous beliefs. 52 Under civil law, too, Muslim populations living in Christian lands were regularly accorded the status of a protected minority, as were Jews. 53 Nevertheless, some perception of Muslims as heretics still persisted, creating a "tension" in terms of their accommodation within Christian law codes. 54 The Passau Anonymous seems to show that such tension lurked in at least some corners of inquisitorial thought as well.

II. Nicolau Eymeric on Muslims and Jews
Papally appointed inquisitors began operating in Europe following Pope Gregory IX's bull Ille humani generis, first issued in 1231, and standing inquisitorial tribunals emerged in southern France in the wake of the Albigensian Crusade. 55 These developments necessitated a rapid codification of procedures, and almost immediately a new genre developed, that of the inquisitor's manual. 56 The first of these is generally held to be a set of guidelines for inquisitorial operations produced under the direction of Raymond of Peñafort at the Council of Tarragona in 1242. 57 As we have seen, just a decade earlier Raymond had supervised the expansion of canon law in the Decretals that had included a section on Muslims. He made no reference to them in his instructions for inquisitors, however. One year later, a set of guidelines emerging from the Council of Narbonne did refer to Muslims but only as the object of a potential penance that could be prescribed for heretics. It advised inquisitors that convicted heretics might be "obliged to defend the faith and church for a fixed number of years, months, or days, with arms and at their own expense . . . against Saracens." 58 Aside from the curious case of the Passau Anonymous, inquisitorial literature remained largely silent about Islam throughout the thirteenth century. In the midfourteenth century, the Carmelite bishop, theologian, and sometime inquisitor Guido Terreni wrote his Summa de haeresibus. In one manuscript, a list of "Twenty-Five Errors of the Saracens" is found appended to this work. However, while the Summa itself dates to around 1340, the authorship, and hence dating, of this list remains uncertain. If it was not written by Terreni, then it could have been composed as late as 1455, when the single manuscript in which it is found was copied. 59 In that case, it would reflect the concerns of a later era, which I discuss in my conclusion below. Inquisitorial reluctance to discuss Muslims ended definitively only when Nicolau Eymeric addressed inquisitors' jurisdiction over them in a succession of works in the second half of the fourteenth century.
Eymeric was born in Girona, in northern Catalonia, sometime before 1320. 60 He entered the Dominican order in 1334 and studied theology first in Barcelona and then in Paris. In 1352, he was back in Barcelona, teaching. By 1357, he was acting as an inquisitor in the Crown of Aragon. Although the full extent of his authority remains unclear, he was certainly the most important inquisitorial official in Aragon in his day. 61 He had a tumultuous career to say the least, clashing repeatedly with a succession of Aragonese monarchs, frequently being removed from and reinstated to various offices, and enduring several periods of exile. 62 It was often while he was relieved of his regular duties that he was able to write some of his major works, particularly Directorium inquisitorum, composed in exile at the papal court in Avignon in 1376.
Although Eymeric is often regarded as marking a culmination of medieval inquisitorial thought, especially through his Directorium, Derek Hill has recently argued that he also represented an important innovation. Previous manuals, including those produced earlier in the fourteenth century, had generally envisioned inquisitors operating against established threats. Thus, in his great manual Practica inquisitionis, completed around 1325, the Toulouse inquisitor Bernard Gui had identified and described at considerable length six major groups against whom inquisitors were regularly empowered to act. Among these were Jews but not Muslims. 63 Eymeric, however, saw the need for inquisitors to respond dynamically to a series of new and changing threats to the Christian faith. 64 He left the nature of these threats open-ended, but his proposed response certainly entailed further expansion of inquisitorial jurisdiction over non-Christians, now explicitly including Muslims.
Inquisitorial jurisdiction over non-Christians occupied Eymeric for much of his career. He first addressed the question at length in a treatise ostensibly devoted to another of his major concerns: whether demonic magicians should be considered heretics. 65  espoused in Christian, Jewish, and Islamic law alike, investigating the supposed invocation and supplication of demons represented one way for inquisitors to extend their authority over other faiths. Having already written a treatise Contra christianos demones invocantes in 1359, Eymeric wrote a continuation, Contra infideles demones invocantes, probably around 1370. 66 The full title of this treatise was De iurisdictione ecclesie et inquisitorum contra infideles demones invocantes vel alias fidem catholicam agitantes (On the Jurisdiction of the Church and Inquisitors against Infidels Invoking Demons or Others Disturbing the Catholic Faith), and it actually focused much more on inquisitorial jurisdiction over Jews and other infidels in general than on the specific issue of demonic magic. It also served as a basis for the longest section dealing with non-Christians in the subsequent Directorium, written in 1376. 67 Still not having had his full say, Eymeric returned to the issue again in his Tractatus brevis super iurisdictione inquisitorum contra infideles fidem catholicam agitantes, written in the 1380s. 68 Here we can focus on Directorium, which encapsulated much of Eymeric's thought and was certainly his most influential work. He addressed jurisdiction over non-Christians in three consecutive questiones, numbers 44 to 46 in part 2 of this extensive manual. The first dealt with inquisitors' jurisdiction over Christians who converted to Judaism or over Jews who converted to Christianity and then relapsed to their original faith. Both were to be treated as heretics, as was anyone, Christian or Jew, who might support or defend them. 69 Here Eymeric drew on well-established precedents in canon law and inquisitorial thought. Already in the twelfth-century Decretum, the fundamental medieval collection of canon law that had preceded the thirteenth-century Decretals of Gregory IX, the church had proclaimed that, while Jews were not to be converted to the Christian faith by force, "once converted they are not permitted to leave it." 70 Likewise, Jews who in any way promoted or facilitated the conversion of Christians or the reconversion of former Jews were also subject to inquisitors just as "supporters" (fautores) of any other heresy would be.
The growing concern of ecclesiastical authorities in the thirteenth century over such secret Jewish conniving to win converts is exemplified by the papal decree Turbato corde, first issued by Clement IV in 1267 and then reissued in 1274, 1288, and 1290. Here the pope declared that "exceedingly numerous reprobate Christians . . . have gone over . . . to the rite of the Jews." Dominican and Franciscan inquisitors were enjoined to proceed against such people just as they would against any other heretics, and Jews "whom you shall have discovered inducing Christians of either sex into their execrable rite" were to be punished "with due penalty." 71 These provisions quickly became standard references in inquisitorial literature. They were, for example, cited in the short French manual Doctrina de modo procedendi contra hereticos, written in the late thirteenth century. 72 In addition, separate, free-standing formulae of interrogation designed for Christian converts to Judaism and former Jews accused of returning to Judaism circulated in conjunction with other inquisitorial literature. 73 Likewise, collections of papal rulings and other legal opinions regarding inquisitorial jurisdiction over Jews also circulated. One such text, clearly of Italian provenance, began with Turbato corde and concluded with consultations of jurists and magistrates from Bologna, Ferrara, and Padua. 74 In his first questio regarding non-Christians, therefore, Eymeric did not need to innovate. As his main justification, he presented the bull Turbato corde, which he cited in full. 75 In his second, parallel questio, he merely extended the same reasoning to Christians who might convert to Islam or Muslim converts to Christianity who might then relapse to their original faith. 76 This was no innovation either, as the principle was already well established that, for the most part, laws pertaining to Jews could be applied to Muslims as well. 77 Eymeric merely rendered this principle explicit by offering a separate questio addressing Muslims. He also offered a separate papal decree to support his argument: Gregory XI's bull Admodum dolenter, composed at Eymeric's own urging in 1371. 78 In it, the pope bemoaned the number of Saracens who had converted to Christianity but then relapsed into their original "impiety" as well as the many Christians supposedly converting to Islam. 79 While the case of converts was relatively clear-cut, Eymeric addressed other, more complicated circumstances in which both Jews and Muslims, as well as "other infidels," could be considered heretics or otherwise fall under inquisitorial jurisdiction in his third and longest questio on this matter. 80  from them on many points. Both Jews and Muslims could, therefore, become "heretics" within their own faith if they rejected certain fundamental beliefs. 81 For a Christian inquisitor, this was of no concern so long as the beliefs in question were not among those held in common with Christianity. In such cases, Christian authorities should "condemn" (reprobare) but nevertheless "tolerate" (tolerare) the lapse as, essentially, no business of theirs. 82 Where the lapse involved an article of faith common to Christianity as well, however, such as the belief that God created all things, that Christ was born of a virgin (applicable only to Muslims, not Jews), or that one should not invoke and worship demons in magical rites, then Christian inquisitors absolutely could step in and enforce proper faith. 83 Eymeric was relatively innovative in bringing all this material together and explicitly applying it to Muslims. Such principles were not, however, entirely without precedents in inquisitorial thought regarding Jews. The mid-thirteenth-century manual De inquisicione hereticorum had declared that Jews could be considered heretics if they "corrupted" teachings of the Old Testament in any way (in Christian judgement, of course). 84 In the early fourteenth century, Bernard Gui argued that inquisitors could seize and burn copies of the Talmud because it contained what Christian authorities deemed to be errors, and indeed "horrors," contradicting the true faith. 85 There was not, however, complete agreement on these matters even within inquisitorial thought. Just a few years after Gui completed Practica inquisitionis, the Italian jurist Zanchino Ugolini composed his important Tractatus super materia hereticorum (ca. 1330). He echoed Gui and other inquisitorial texts on many points about the Jews, including the right of inquisitors to punish them if they "transgressed" against the laws of their own faith. 86 Yet especially on this last point, Ugolini was considerably more reserved than Gui. While he felt that inquisitors had a right to pursue such cases, he also argued that church authorities should only act if, by such a violation, Jews did some direct harm to Christians, as through the practice of usury. Even in that case, he concluded, punishment was better left to bishops than to inquisitors, who should only act in direct defense of Christian doctrine, not of Christian society more generally. 87 Another principle whereby either Jews or Muslims could fall under inquisitorial jurisdiction, only briefly stated by Eymeric but potentially quite sweeping, was very much geared toward the protection of Christian society. It focused on whether they had "impeded" the Christian faith in any way. This might involve blaspheming against Christianity, attempting to lead Christians into some evil actions, or even "openly persecuting" Christians in some fashion. 88 Again there were precedents, at least in terms of 81 Eymeric, Directorium, 352-353 (2.46.1-3, on Jews), 355 (2.46.12, on Jews and Saracens). 82 Eymeric, Directorium, 355 (2.46.12). 83 Eymeric, Directorium, 353 (2.46.4), 355 (2.46.12). Ugolini, Tractatus de haereticis 36, p. 221. 88 Eymeric, Directorium, 354 (2.46.7). the Jews, in earlier inquisitorial thought. Bernard Gui had justified inquisitors taking action against Jews by arguing that they often sought to harm Christians by praying for their destruction and that they regularly denigrated Christianity by blaspheming or insulting Christ and the Virgin Mary in their writings. 89 Ugolino agreed that Jews could come under inquisitorial jurisdiction if they showed any "insult" (contumelia) to Christianity, specifically a church, altar, or sacral object, and especially if they tried to impede an inquisitor in his work. 90 Perhaps most daringly, Eymeric appears to have asserted a principle that had first been advanced, somewhat vaguely, by Innocent IV; namely, that the pope had authority to enforce natural law over all peoples-Christian, Jew, and heathen alike-if their own rulers failed to do so. 91 In this questio, Eymeric focused mainly on otherwise unspecified heathens (gentiles), and he argued this power naturally devolved onto papally appointed inquisitors. 92 The only example he provided of such a violation was sodomy, however, and he did not develop the point at any length.

III. Muslims and Jews Between Church and State
From the intellectual underpinnings of Eymeric's engagement with Muslims, which built on previous inquisitorial thought regarding Jews, we move to the more immediate, practical context he encountered as he sought to expand inquisitors' jurisdiction over both Muslims and Jews. Here he had to confront the claim of secular powers, above all the Crown of Aragon itself, to similar authority. In the mid to late fourteenth century, the Aragonese crown was locked in a struggle with the church in general and more particularly with the Aragonese inquisition regarding the degree of each institution's control over non-Christian subjects. 93 This struggle was a personal one for Eymeric. Around 1370, a Catalonian Jew, Astruc de Piera, was accused of invoking demons to perform magic. The Crown of Aragon claimed jurisdiction, but Eymeric appealed to the papal curia, which ruled that the case should be handled by the inquisitor. Eymeric was clearly thrilled with this victory, as he recounted the case in both Directorium and also his later Tractatus brevis super iurisdictione inquisitorum contra infideles. 94 In fact, the case may have inspired him to write his first major work on inquisitorial jurisdiction over non-Christians, Contra infideles demones invocantes, although he did not mention it directly there (perhaps because the case remained undecided at that time). 95 In Directorium, Eymeric acknowledged many arguments contending that cases in which either Jews or Saracens acted in some way against the Christian faith should be handled by "temporal lords" rather than bishops or inquisitors. He responded, however, that all such arguments dealt with infractions against the faith more generally, not heresy in particular. He was perfectly ready to admit that non-Christians could offend against Christianity in many ways that did not rise to the level of heresy, and in all of 89 Gui, Practica, 290-292 (5.5.4). 90 Ugolini, Tractatus de haereticis 36, p. 220. 91 Muldoon, Popes, Lawyers, and Infidels, 10-11, 47-48. 92 Eymeric, Directorium, 353 (2.46.6). 93 Perarnau, "El Tractatus brevis," 79-80; Heimann, "Quis proprie," 621; and Heimann, "Nicolaus Eymerich OP," 146-147. 94 Eymeric, Directorium, 357-358 (2.46.17); and Eymeric, Tractatus brevis, as presented in Perarnau, "El Tractatus brevis," 120-222. 95 Perarnau, "El Tractatus brevis," 83; and Mesler, "Jurisdiction of Medieval Inquisitors," 165-166. these, secular lords could rightly exercise their own jurisdiction. In cases of heresy, however, "it is for ecclesiastical judges to recognize and judge" the crime. Secular authority only became involved when it was needed to execute a punishment decreed by an ecclesiastical court, such as in cases involving the death penalty. 96 Complications could arise, of course. Eymeric noted that in the Kingdom of Sicily, the monarch had specifically commissioned bishops to punish Muslims who "abused" Christian woman and children. In such cases, the principal example of which was rape, jurisdiction clearly lay with secular authorities, but this did not preclude them from delegating that authority to ecclesiastical officials. This allowed Eymeric to ruminate briefly on the authority bishops could exercise "through their own ordinary power," as opposed to power they might exercise "by commission." 97 Eymeric did his best to present his conclusions as self-evident and grounded in unquestionable ecclesiastical rulings. In fact, however, his positions were not universally accepted even by other churchmen in Aragon. His contemporary and fellow Catalan, the Carmelite Felip Ribot (d. 1391), wrote a Tractatus de haeresi that sharply restricted inquisitorial jurisdiction to Christians alone. Drawing on time-honored definitions, Ribot maintained that only baptized Christians could be categorized as heretics and that Jews, Muslims, or other non-believers living in Christian lands fell solely under the jurisdiction of secular princes, no matter what the nature of their errors or offenses. 98 In particular, he maintained that the pope, and hence papally appointed inquisitors, had no authority to police heresy within other faiths, even if non-Christians violated a religious tenet that happened to be held in common with Christianity. 99 His arguments did not extend to converts who then relapsed to their original faith because they were considered to have become irrevocably Christian from the moment of their conversion. Otherwise, however, he maintained that church inquisitors should always defer to temporal lords in cases involving non-Christians. 100 Although Ribot strongly countered Eymeric's positions, those who have studied his treatise closely do not think that he was responding directly to Eymeric at any point. Rather, they suspect that he, as a clergyman with ties to the royal court, was simply addressing issues that were regularly being raised at the court itself. 101 Neither does Eymeric appear to have addressed Ribot directly. He was, however, clearly aware that his positions faced considerable contemporary opposition. Already around 1370, he ended Contra infideles demones invocantes with a set of "replies to the arguments of [my] adversaries" that mainly focused on the proper extent of secular authority in these matters. 102 Later, in the mid-1380s, he ended his Tractatus brevis by addressing papal decrees bearing specifically on the jurisdiction and authority of Aragonese inquisitors against rights claimed by the crown, and he rebuked certain "adversaries of truth" who claimed that the bull Turbato corde, which had extended inquisitorial authority over Jews, had been superseded. 103 96 Eymeric, Directorium, 354-355 (46.8-11), quote at 355 (46.11). 97 Eymeric, Directorium, 355 (46.11-12). Puig, "El Tractatus de haeresi," 147; and Heimann, "Quis proprie," 621. 102 Eymeric, Contra infideles demones invocantes, as presented in Mesler, "Jurisdiction of Medieval Inquisitors," 193-198. 103 Eymeric, Tractatus brevis, 122-124.
Eymeric's discussion of inquisitorial jurisdiction over both Jews and Muslims was more systematic, and for Muslims certainly more extensive, than any that had come before. It was driven by his own desire to extend the scope of inquisitorial authority, but it took shape within the context of broader debates in the Crown of Aragon about inquisitorial, and indeed ecclesiastical, jurisdiction versus that of the crown itself over its non-Christian subjects. This more practical political context is also probably why, even though Eymeric addressed Muslims more directly than any earlier inquisitorial theorist, he remained predominantly concerned about Jews. While Muslims were more numerous in the Crown of Aragon, Jewish communities were far richer and so the far more important part of the "royal treasure" that monarchs sought to keep under their control and the church sought to prize loose. 104 It is surely not coincidental that one of the last points Felip Ribot made in his pro-monarchical De haeresi was that inquisitors should never be allowed to impose "pecuniary" punishments on Jews, leaving that prerogative to the king (Muslims going, as they so often did, unmentioned at this point). 105 This is not to say that these debates were directly reflective of or necessarily driven by actual inquisitorial practice in the Crown of Aragon. Although Eymeric made much of the case of Astruc de Piera, that seems to have been an isolated incident. What records remain of his inquisitorial activity in Aragon suggest that Jews, to say nothing of Muslims, did not figure heavily in his caseload, and those who did come to his attention typically represented more straightforward cases of converts suspected of relapsing. 106 In the face of varying levels of royal opposition, an inquisitor's jurisdiction over converts was always the most secure area of his authority. 107

IV. Muslims as (Not So) Hidden Threat
A final context in which to situate Eymeric's approach to Muslims is more speculative, but it carries broad implications. It aims to connect one particular facet of his argument to a more generalized development within medieval inquisitorial thought. If correct, it would offer a more conceptual reason why Eymeric continued to focus primarily on Jews rather than Muslims in his discussions of non-Christians, beyond the practical realities of Aragonese politics. It might therefore shed additional light on how Christian authorities envisioned the threat that they imagined Muslims represented for Christian society as a whole.
As I noted in my introduction, scholars of medieval inquisition recognize a growing emphasis over time on the need to root out increasingly covert and insidious forms of heresy rather than to counter the putatively evident heretical groups, such as Cathars or Waldensians, that had initially attracted most inquisitorial attention. 108 Eymeric certainly reflected this development in his concern to expand inquisitors' jurisdiction over new kinds of heretical behavior, such as the occult practices of demonic magicians, that might threaten to disrupt Christian society in less obvious ways. 109 An emphasis on heretics' guile and duplicity was also a hallmark of his thinking, as was a certain approval of deviousness on the part of inquisitors themselves to uncover such heresy. 110 What has this to do with Muslims or Jews, though, both of whom comprised evident and established groups within medieval Aragonese society? For one thing, the overriding inquisitorial focus on Muslim and Jewish converts to Christianity refocused attention away from their public identity and onto their capacity to harbor hidden beliefs. Converts were, of course, publicly Christian. What inquisitors needed to detect was whether they continued to observe any of the rites of their original faith in secret. Let us leave this most common circumstance aside, however, precisely because it would appear to apply equally (in theory, at least) to Muslims and Jews. I want instead to explore an element of Eymeric's argument that suggests inquisitors needed to police Jews as Jews more closely than Muslims as Muslims. Ironically, this was because Jews were permitted to perform their faith more openly than Muslims in the Crown of Aragon.
Although Eymeric certainly suspected that Jews might lead Christians into error in many ways, he nevertheless maintained that they should generally be allowed to practice the rites of their faith publicly. This was because those rites would often "signify" or "represent" some Christian truth, albeit indirectly. 111 This harkened back to a standard medieval argument for the continued toleration of Jews, originating with the early church father Augustine of Hippo. He had reasoned that God had allowed Jews to survive into the era of the Christian dispensation because they served as witnesses to Christianity's own validity. 112 Jews could perform this valuable function, however, only if they practiced Judaism properly according to Christian understanding. The fear was that any subtle deviance they introduced into their own practices might indirectly corrupt Christians. This justified inquisitorial oversight. I have already highlighted the strand of inquisitorial thought that argued the Talmud and other Jewish texts needed to be suppressed because they improperly or even heretically misrepresented certain fundamental truths found within Judaism itself.
Interestingly, traces of a similar attitude toward Muslim texts are evident in some of the traditions I have surveyed here. In the twelfth century, Peter the Venerable had declared that Islam, originally grounded at least partly in scripture, had come to be based more on what he termed "fables" about Muhammad's life, just as Judaism had come to be based on the Talmud rather than the Torah. 113 Earlier still, the important Mozarabic text Liber denudationis, originally composed by an Iberian Christian most likely in Toledo in the late eleventh or early twelfth century, described how Muhammed's early followers had argued over the text of the Qur'an, ultimately excising 109 Hill, Inquisition in the Fourteenth Century, 172-173 and 204-205, contrasts Eymeric to Gui in this regard. 110 many verses. 114 This, too, could lead to the conclusion that what had originally been an at least partly valid tradition had become corrupted and needed to be carefully scrutinized by Christian authorities. Eymeric, however, shows how Christian concerns moved in a different direction.
While the rites and tenets of Judaism could impart some value to Christians, Eymeric estimated that those of Islam offered no such "utility." There was, therefore, no reason that Christian authorities should ever allow them to be performed publicly. They could, however, be tolerated inside any mosques that continued to exist in lands Christians had wrested from Muslim control or in private homes. 115 This general position had been established more than a century earlier by the great Dominican theologian Thomas Aquinas. 116 Eymeric explicated its particular consequences for inquisitorial action. Inquisitors did not need to police the private performance of Islam because it posed no danger of secretly corrupting the surrounding Christian population. Any subtle deviations that Muslims introduced into their practices, either maliciously or inadvertently, could only harm Muslims themselves. Conversely, any elements of Islam that might be enacted publicly were rendered automatically illicit. Christian authorities did not need to discern if they varied from some original truth that Christians ascribed to them in order to suppress them. There would, in short, be no need for any careful "examination and inquiry" (probatio et inquisitio), such as only expert inquisitors could provide. The only thing required was simple punishment whenever an act occurred outside of allotted private spaces. Even Eymeric, who broadly sought to champion the authority of the papacy and papally appointed inquisitors, concluded that jurisdiction over such straightforward matters could safely be left to secular princes. 117 Certainly, Muslims could be suspected of secretly blaspheming the Christian God or desecrating Christian rites, just as Jews were. Nevertheless, Eymeric suggests why, within inquisitorial thought and perhaps that of Christian authorities more generally, Muslims were the focus of less concern than Jews. Because of Islam's different theological relationship to Christianity, Muslim practices required less precise scrutiny and control. Ironically, because they were shielded from Christian view, they represented less of the kind of hidden menace that inquisition was increasingly being used to expose.

V. Conclusion
Richard Southern once declared that "the existence of Islam was the most far-reaching problem in medieval Christendom." 118 He meant this primarily in terms of the stark geopolitical reality that the Islamic world presented to the Latin West. Conversely, his student R. I. Moore has suggested how Western clerical elites came to regard Jews as a more sinister threat lurking within Christendom. He saw this as part of the same dynamic that drove the identification and persecution of Christian heretics. 119 Nicolau Eymeric's stance toward Muslims, particularly when compared to his stance toward Jews, seems to align with these different perceptions of threat. He clearly felt that Muslims could fall under inquisitorial jurisdiction in many ways. He articulated these more thoroughly than any previous medieval theorist of inquisition, and he argued against some contemporary opponents for an expansive notion of inquisitorial authority. Ultimately, however, while Jewish behavior required the kind of careful scrutiny that only trained inquisitors could provide (or at least that they were ideally suited to provide), he seems to have regarded the control of Muslims living within Christian society to be more generally a political problem, and he was content to leave such control to secular princes.
The labeling of Islam as, in its origin, a deviation from Christianity, and therefore fundamentally a Christian heresy, had always been more of an externally focused political statement than an internally directed legalistic one. Perhaps not surprisingly, then, in the fifteenth century, mainly in response to the political ascendency of the Ottoman Turks, a number of important Christian writers revived the notion of Islam as a heresy but paid no attention to Eymeric's more focused arguments, even when they clearly knew his work. Around 1460, for example, Nicholas of Cusa produced his Cribratio Alkorani at the request of Pope Pius II. In dedicating that work to the pontiff, he reasserted the old allegation that Islam arose out of Nestorian heresy, and he exhorted Pius to take action against Muslims just as Pope Leo I had against Nestorians a millennium before. 120 Nicholas's friend Juan of Segovia was even more forceful. In his prologue to a new translation of the Qur'an, he repeatedly labeled Islam the greatest heresy that had ever existed, 121 and in his De gladio divini spiritus, written in the 1450s immediately after the fall of Constantinople, he described how Islam was rooted in Christian heresy through Muhammad's instruction by the heretical monk Sergius. 122 119