The Conciliarist Idea of Islam in the Quattrocento—Prelude and Legacy

Abstract

This contribution intends to examine the impact of Conciliarism (1414–1439) on the Christian vision of Islam in the Quattrocento. The analysis of the thought of bishops such as Nicholas of Cusa (d. 1464) and John of Segovia (d. 1458) is understandable only through the evolution of the Latin world with regard to Islam, moving from the Corpus Toletanum (12th century) and the impact of the Crusades in the Levant (1096–1291) and in Europe. This forwardness is rooted in the process of “Islamic Christianization,” an analytical operation lasting three centuries, during which Koranic Christology was to play a primary role. It will be through this “Christ-centric” process that from the Renaissance, the Ottoman empire, the great enemy of Western Christianity, will be appreciated for some of its peculiar facets. The weakening of the concept of heresy and of Catholic ecclesiastical authoritarianism in decreeing what heresy was probably one of the “indirect” outcomes of that dialogical “Moment of Vision” between Christianity and Islam. The further fragmentation of the Church of Rome, after the failure of Conciliarism and the outgrowth of the reformed Churches in the 16th century, favored a preliminary different understanding of the religiosity of others.

1. Introduction. What Is Conciliarism about and the Delay of the Latin World in Relation to Islam

Conciliarism is one of the internal attempts by the Catholic Church at reform during its 2000-year history. Even if this word had not been adopted at the beginning of the “Quattrocento”, it would have been used to define “the greater authority of a general council over the Pope, at least in certain cases,” in the following years (Christianson 2017, p. 75).

In the history of the Church, at least after the “Edict of Milan” (313 AD), the proclamation of Ecumenical councils (Kung 1997, p. 457ff.)1 was to clarify and solve internal problems in relation to dogmatic-theological anxieties, the emergence of heresies as well as internal difficulties in the ecclesiastical institutions. The importance of those “Ecumenical councils” also reflects on the fact that Constance (1414–1418), like Basel-Ferrara and Florence (1431–1442), did not invent Conciliarism. The internal tendency of the Church to be reformed through decisions taken during assemblies had been institutionalized since the beginning of its history, as the Jerusalem assembly, reported in Acts 15, clearly shows (Kung 1997, p. 90Ff; Bihlmeyer and Teuchle 1955–2003, p. 69ff.).

To better understand the importance of Conciliarism in the 15th century, it is relevant to place it in relation to the fragmentation of the Church due to the attempt by France’s Philip IV (d. 1314) to rule its government and leadership. With the Avignon papacy (1309–1376) and the Great Schism of 1378–1418, two rival Popes co-existed in leading the Ecclesiastical institution, and the high level of corruption and personal enrichment of part of the clergy increased the difficulties of cohesion of the Church. Orders such as the Fraticelli, the Waldesians, and the Hussites of Bohemia were declared heretical during the 13th–14th centuries, even though their evangelical actions were clearly more rooted in the Gospels than those of some figures in the Church hierarchies (Mews and Welch 2016; Swanson 1999, pp. 217–39). Before the European wars of religions of the 16th–17th centuries, the Hussite Wars (1419–1434) highlighted the level of devout ‘fundamentalism’ that could be reached with the de-population of entire regions (Bohemia and Moravia) and the attempt to purify them of the presence of heresy. In parallel, the impact of the University system as well as that of Scholasticism, Averroism, and scholars such as William of Ockham (d. 1349) and Marsilius of Padua (d. 1342), who developed the idea of distinguishing between the spiritual–pastoral and the earthly–political rule of the Church, increased the importance of reforms that were necessary for this institution.

The hierarchical order of the Church is supposed to be of divine origin, and therefore, the Pope’s authority concerning dogma and morality is derived from the direct investiture of Christ and Peter. This, however, does not preclude the existence of an outlook of temporal power and jurisdiction because, after Peter, the Popes were chosen by human designation through the election by a college of cardinals. Therefore, in Ockham’s opinion, the Pope, when he legislates in the context of the evangelical Council, needs to take into account the tacit and explicit consent of the ecclesiastical community (Ockham 1992, p. 71ff.).

This work, however, does not focus in depth on the relations between the empire and the Papacy in the 14th–15th centuries or on the Conciliarist impact on the history of the Church. The idea is to analyse the outcome and legacy of Conciliarism on the evolution of the Christian understanding of Islam starting from that “Moment of Vision” emphasized by Richard W. Southern in his famous publication (Southern 1962, p. 67ff.).

The main purpose is to clarify whether some “Conciliarist” fathers and works provoked a concrete change in the West’s understanding of this Abrahamic religion. The evolution of the Latin understanding of Islam, moreover, is based on two main premises: the delay of the Latin world, compared to the Greek-based East world, in comprehending the Islamic faith and its complexity and the production of writings on this heresy and its prophet (Muhammad) not based on the Islamic revelation but on apocalyptic and messianic examples of Christian literature. The “ideological” and mostly negative depiction of Islam that emerged in the Iberian Christian literature of Paul Albar (d. ca. 861) and Eulogious of Cordoba (d. 859) was not based on the Christological debates that since the 8th and 9th centuries had begun to emerge in the literature on Muslim–Christian controversy in the Middle East but on their personal attitude, broadened by Christian martyrological literature (Daniel 1981, p. 73ff.; Tolan 2002, p. 89ff.; Tischler 2018, pp. 7–54).

For Eulogious, Muhammad is the praecursos Antichristi, not in reference to Christian Oriental literature, which in the 9th–10th centuries identified the Prophet of Islam as a false one, because he was trained by the Christian heretical Nestorian monk Sergius, nicknamed Nestorius and/or Johannes, known as Bahira. Instead, it was in association with the Biblical sources of the Book of Daniel (7: 23–27), Matthew (24: 24), the Apocalypse of Pseudo-Methodius,2 and his own writings such as the Memoriale Sanctorum and the Liber Apologeticus martyrum. These writings show the adoption of hagiographic narratives of the early Martyrs of the Church by the new ones: the Martyrs of Cordoba, who preferred being beheaded rather than join a new Islamic–Umayyad-led kingdom and society (Kh. B. Wolf 2019; Christys 2002, chaps. 4 and 5).

When, at the beginning of the 8th century, the Apocalypse of Pseudo-Methodius was translated into Latin from Greek, the common interpretation of the Arab conquests in the West, as it had been in the East, was associated with and interpreted as the arrival of the End of Time as well as God’s punishment against Christians becoming corrupt. The text association with Biblical literature, such as the myth of Gog and Magog, prophet Daniel’s Revelations, and eschatological–apocalyptic sources, emphasizes the general sense of punishment against Christians and Christianity for their unfaithful behavioral attitude.

The Latin world would have to wait until the 12th century to move from the rambling insults against Islamic otherness to a first analysis of the Islamic revelation and, therefore, a preliminary interpretation of this Christian heresy.

2. The Church’s Paradigms on Islam from the 12th to the 14th Century

Peter of Cluny (d. 1156), the Abbot of the famous monastery, and his collaborators made an enormous effort to collect and translate a compendium of texts on Islam: the Corpus Toletanum, including the Qur’ān. (Kritzeck 1964; Peter the Venerable 2016; Burnam 2011, p. 36ff.). The recognition of this effort, the first in Latin Europe, could be efficaciously resumed through the Abbot’s words: “Non uti nostri sepe faciunt armis sed verbis; non vi sed ratione, non odio, sed amore”, which can be translated as “Our fences are not made with arms, but with words; not by force but by reason, not by hatred but by love”, which, despite the spirit of the time, is commendable at least in the effort made.

The history of the inter-religious relationship between the Latin Church and the “Islamic Mediterranean world” needs to be considered in relation to two levels of analysis: the Latin perception of Islamic alterity and the historical shift that impacted the Latin-Islamic world between the 12th and 14th centuries. If, in the next two centuries, the Christian perspective towards Islam did indeed change through some paradigmatic passages, the Islamic world itself was to undergo substantial actions going from the Abbasid Seljuk era to the Mamluk–Ottoman one.

However, it is about the relationship between the Latin world and al-Andalus that a first paradigm must be further explored.

The Corpus Toletanum is affected by the “segregationist–isolationist” approach that the narratives and the stories concerning the “Martyrs of Cordoba” institutionalized against Islam in the following centuries; in other words, the idea that Muslims and Christians need to live separately and far from each other without any interaction. Even though illusory and impracticable, this first paradigmatic approach was adopted to frame and depict Muslim religiosity as based on licentiousness and violence. The latter aspect was logically based on the Arab–Berber conquerors who from North Africa reached Iberia, subduing it through violence; the former seems to emerge from the Istoria de Mahomet and is reaffirmed in the Liber apologeticus martyrum of Eulogius while the limited information about Muhammad are on his various marriages and the polygamous status of his religiosity (Wasilewsky 2008, pp. 333–53).

The irrationality of segregation to prevent the spread of heresy is not related to a mindset that sought to keep the Christian faith away from contact with the Islamic heresy (of which, moreover, very little was known) but to the fact that even before the formation of the Corpus Toletanum, Pope Urban II, in Claremont (1095) had declared the need to free the Holy Land from the Seljuk Turkish presence. This equally paradigmatic event would have effectively undermined the intention of segregation. On the contrary, the organization of military expeditions (11th–13th centuries) to the Levant decreed the departure of thousands of Christians, many of whom would decide to live in the Near East in the same urban areas as Jews and Muslims, not to mention the effect of the Crusades on trade activities in the Mediterranean (Burnett 2000, pp. 1–78; Savage-Smith 2006, pp. 99–112).

The coexistence of these two opposed ecclesiastical approaches was further confirmed by Canon 67, 68, 69, and 70 of the IV Lateran Council (1215), where the clear intention was to avoid any kind of “aesthetic” confusion between Christians, Jews, and Muslims with the risk of problematic inter-religious unions or excessive common “affairs” in the economic sphere. The “dress code” distinction would have to fix this kind of problem to preserve “Christian purity” from the corruption of heresy (Kedar 1999, pp. 310–35; Powell 1990, pp. 135ff., 175ff.).

Moreover, it had been the Latin Church that promoted the “Crusades”, favoring the formation of a plural society in the Levant where, apart from moments of military conflict, the understanding of this Islamic otherness was to have facilitated a more effective knowledge.

The transition, therefore, from the approach of segregation to the cognitive one was not introduced from the outside but by the actions of the Latin Church itself.

Starting then from the 13th century, the foundation and the Papal recognition (both by Pope Honorius III) of the Franciscan (1223) and Dominican (1216) orders made not only the intention of promoting the conversion of Muslims to the “true faith” more concrete but also the “face to face” knowledge of Islamic alterity in the Levant and Spain, where the hybrid society was already more inclined to that (Carpini 1900, pp. 228–35; Martì 1983, pp. 9–63; Zwemer 1902).

The paradigm of “segregation” would, therefore, be transformed into that of “knowledge and encounter”. William of Tyre (d. 1186), from a more historical and narrative point of view, William of Tripoli (d. 1277), Ramòn Llull (d. 1315), and Riccoldo of Monte Croce (d. 1320), only to name the most important, were to have modified the preliminary idea of Islamic heresy precisely due to their direct knowledge of the Islamic world in the Mediterranean.

It would have been astonishing for the Latin world to consider the complexity of the Levant; peace and violence were preserved and bestowed as a rule, battles were fought with and against each other, but the front between Christians and Muslims was not clearly framed. Latins, little by little, grew accustomed to the Oriental way of life as their understanding of the image of their enemies became foggier (Schwinges 2001, p. 125; Runciman 1960, pp. 22–24). William of Tyre (d. 1186) was one of the main propagators of this idea and approach: born in Jerusalem into a Latin-French family and educated at the Universities of Paris and Bologna, he was able to speak Latin, French, Greek, and probably Arabic and became an “Oriental-Latin”. This definition, far beyond mere economic and political pragmatism, made the conflict between Christians and Muslims there far removed from the ideological approach of the Crusade as propagandized in the Latin world. For the Bishop William of Tyre, Islam remained synonymous with “infidelity” to Christ’s message, like Judaism. He did not define it as a pagan religion because these religions do not deny the existence of God; on the contrary, there is a fundamental consensus on many aspects of the Abrahamic tradition and he recognized Islam as a religious system that, with its limits, improved human life supporting a pious one. This vision favoured the need to deepen this closeness (Schwinges 1977, p. 21, n. 10, 158ff., pp. 234–40).

The age of this new “paradigm” is certainly linked, on the one hand, to the transformation of the “Crusade” from an expedition of conquest/liberation of the Holy Land to the attempt to preserve and populate the territories under Latin rule. On the other hand, the impact of the “Universities,” like the debate between Avicennian and Averroist thought in Europe, provoked a fracture in the understanding of Islam between those who sought to study its doctrine, usually clerics, and those who, by studying Falsafa (Islamic philosophy), deepened its relationship with nature that between the human soul and the Spirit of God and its eschatological outcome (Rubenstein 2004, pp. 216–17; Bertolacci 2013, pp. 242–69).

Ramon Llull, in his Book of the Gentile and the Three Wise Man (written in Arabic, Catalan, and Latin) and composed around 1272–1276, proposed a fictional approach to allow different figures to discuss which of the three Abrahamic faiths—Judaism, Christianity, or Islam—was the correct one; moreover, even though the author shows a Christian identity, in the end, the Gentile (the protagonist) will not publicly declare the decision to embrace one of the three Abrahamic faiths.

The Gentile will decide to remain there, waiting for the arrival of two other Gentiles, lost in their spiritual search, to show them the faith he considered the most truthful (Llull 1985, pp. 294–304).

Llull adopts a mixed inter-religious approach to consider not only the complex artifice of dogmatic rationality but also “tolerance” for the mystics and philosophers who encounter each other, presuming to be in the truth but without the arrogance of proclaiming to know the Truth. Llull’s methodological approach to knowing the “Other” is evidenced in his life through the intentional decision to learn Arabic, write in Arabic, and to travel toward the most populated Islamic-Arab areas of the North African world. During the Council of Vienne (1311–1312), the impact of Lullism became evident in the attempt to encourage the creation of study plans on oriental languages in European universities. Even if this amounted to nothing, it is clear that the Scholastic rational revolution underway had a clear impact on the search to better understand Islam. Latin Europe, through the Crusades, experienced a new spirit of venture that would have led it to revolutionize the relationship with heterogeneity from not only economic but also political and diplomatic points of view, which was no longer automatically identified with a negative meaning but with more lively interest.

Riccoldo’s3 description of Baghdād (even though it was already destroyed by the Mongols in 1258), a city rarely visited by Westerners, is based on the fascination for a town that was described as populated by 200,000 Muslims, many Christians, divided into numerous patriarchates, as well as a huge numbers of Jews (40,000) divided into 28 synagogues: “sarraceni habent maxima studia et magnos magistros, et sunt ibi religiosi eorum, et ipsorum diverse secte ibi conveniunt” (ed. by Monneret de Villard 1948, p. 81). The Franciscan missionary William of Rubruck, for example, who travelled to Karakorum (1253–1255) to meet Mongol chiefs, also tried to convert them without the insulting attitude of denigrating their original and animistic tradition but showing the Truth of the Gospels during open debates with other religious representatives.

The dynamism of this historical phase allows the Other to enter a new dimension which is not exclusively that of the “barbarian” who is unaware of Latin-centric Christianity but that of a Christian world that needs to reframe itself in relation to an unknown complexity: the historical passage from the Saracen Muslim to the Turkish one is also emblematic and paradigmatic. Latin Europe will again need a certain amount of time to recognize how to understand the differences in the Islamic world, about which very little was known before the 12th century.

3. Conciliar Irenicism: The Way of Peace

Richard Southern (1962, p. 67ff.) defined the historical phase from the fall of St. John of Acre (1291) to the middle of the 15th century as The Moment of Vision, a further paradigmatic change during which a set of factors led to renewing the visio of the Church towards Islamic otherness in a new dimension that we could define as Christological. After the “segregationist–isolationist” way to avoid the proximity of belief with unbelief and directly invalidated by the same Church through the Crusades, the revolutionary impact of Scholasticism and Islamic Falsafa in Europe favoured a more academic–scientific approach towards Islam. This new paradigm is introduced not only by a different approach to the otherness of the religious but also by the internal difficulties of the Latin Church in preserving its unity as by the Byzantine empire’s weakness in the face of Ottoman expansionism (14th century). The Irenic posture of the Latin and of the Greek Church, however, unfolds from a different starting position.

1. The Greek world was in a situation of being geographically absorbed by the Ottomans. While its concrete intention to reach reconciliation with Rome fell on deaf ears, and vice versa, people and institutions decided that the Ottoman Turban was better than the Papal Tiara. In other words, Greek Irenicism was more political than spiritual, even though in the 14th century, Gregory Palamas (d. 1360), a Hesychast4 author, showed, in the Anatolian peninsula, the closeness of Greek monastic mysticism to Islamic mysticism and Sufism (Kallistos 1992, pp. 6–35; Grierson 2011, pp. 96–124). The proximity of the Christ of the Gospels to the “Muslim” Jesus and to the ‘Isa ibn Maryam emerging in the Islamic revelation was emphasized in a geographical area where the local Turkish, Turkoman, and Greek population found their unity against the Ottoman attempt to conquer these territories.

Palamas argued that the Turks know Jesus, his peculiarity as a Prophet, as a Word and Spirit of God and that he ascended to Heaven and remained immortal; at the same time, they did not recognize him as Christ, but as God-Man Word (Sahas 1980, p. 414). Palamas, who lived in Ottoman captivity around 1354–1355, residing in different places, including the capital, shows a persistent search for “peaceful” confrontation supported by his mystical and spiritual temperament.

While remaining faithful to his faith, the monk recognized a sort of spiritual continuity in the areas where Christian Hesychasm came into contact with the Turkish one, the latter becoming predominant in the following centuries (Balivet 2011, pp. 125–57).

On an ongoing basis, after the Ottoman conquest of Constantinople (1453), figures such as Gennadius Scholarius (d. 1473), the future and first Orthodox patriarch (1454–1464) under Ottoman rule, and the humanist George Amiroutzes of Trebizond (d. 1486) developed an irenic-political faith in framing an “imaginary” of continuity from the Byzantine world to the Ottoman one.

Gennadius, chosen by Meḥmet II for his anti-Latin posture, supported the policy of the Christian repopulation of Constantinople by embracing the universal monarchical vision of the Sultan.

Gennadius, as reported by Papadakis (1972, p. 94), was not only the first patriarch under the Turks but also the last Byzantine who tried to explain Christianity to the Muslims. The dialogical dimension of Gregory Palamas, started one century before, would have continued under Gennadius, caused by the true interest of the Sultan about Christianity: the three known conversations with Gennadius attended in the Church of Pammacaristos during which the patriarch was interrogated on the Christians dogma, is reported by many sources and also prompted Gennadius to write two treatises on the subject (Turner 1969, p. 445ff.; Khoury 1967, p. 25ff.; Sakel 2008, pp. 227–338; Inalcik 1991, pp. 407–36; Akasoy 2013, pp. 245–56).

Mehmet II probably visited the monastery in 1455 or 1456, and the written sources of these encounters remained largely unpublished until they were found in the Chios Municipal Library (those sources report that they were written in 1577).

Their relationship is of particular interest because it focuses on the rights that the Sultan conferred on the leadership of his Christian subjects during this patriarchate that persisted into later Ottoman times. Sultan Mehmet allegedly displayed an interest in Christianity that was greater than any of his successors, which earned Mehmet a reputation throughout Europe, culminating in Pope Pius II’s well-known literary exercise: a letter to the Sultan in which he asks him to convert to Christianity in exchange for eternal glory as Emperor of the East. (D’Ascia 2001).

In parallel with the Orthodox patriarch, we have another important “humanist” who extended the dialogue between Christianity and Islam in this historical phase of war and Turkophobia: George of Trebizond (d. 1486). In this case, once again, the relationship between the Greek philosopher and the Sultan looks peculiar, even more than the previous one. In the Dialogue on Faith in Christ held with the King of the Turks, the irony is adopted: Mehmet II accuses George of being an “old fox”, saying nothing using empty words, trivializing concepts that even a child would be able to confute, and showing a sense of familiarity between them. The dimension of the verbal exchange is deep: the arguments are quite unique, and the explicative-theoretical action is pedagogical, even if deeply pervaded by George’s personal understanding of Christianity (Ziaka 2015, pp. 150–65). The Greek philosopher would like to convince the Sultan that an “Islamic-Christian” concordance, on a religious basis, would make him the emperor of an innate universal kingdom. Like Gennadius, George did not criticize Islam, its Prophet, or the Qur’an but tried to establish a concordance between the two religions, emphasizing the common aspects that unite them, explaining the three main differences that seem incontrovertible: the unity of God, the divinity of Christ, and the death of Jesus (Balivet 1997):

Les autres divergences, notre manière de vivre, par example, ne méritent pas d’être évoquées ici. Car si, dans une famille composée du père, de la mère, du fils et des filles, des gendres et des brus, on n’est pas du même avis sur la manière de vivre, il serait fou, me semble-t-il, d’imposer à toute la maisonnée une unique règle de vie. C’est pourquoi il faut s’occuper d’abord du plus important d’où découle tout le reste. Les plus importantes différences sont donc les trois que nous venons de mentionner.

(Balivet 1997, p. 31)

Adopting the same Koranic verses (II, 87, 253; V, 110) that made Jesus a Spirit and a Word from God, George (Balivet 1997, p. 32) demonstrates that Jesus coincides with God because he is God’s Word, but at the same time, he is a real man, the son of Mary who is also a Virgin for the Islamic faith. If Christ is considered the Word of God in the three main revelations—the Old Testament, the New Testament, and the Qur’an—it is clear that this aspect made Jesus an emblematic figure for the Abrahamic tradition. Christ, the carnal son of Mary, is the envoy of God and also God’s Word, a Word that was inserted in her through the Holy Spirit (IV, 169).

It is hard to decrypt whether George of Trebizond’s Irenic position was due to an unshakable faith in the search for an all-encompassing rationalistic approach to a Christian-Islamic concordance, or he was simply looking for a different way of dialogue and comparison with that Islamic–Ottoman world.

Differently from Papastathis’ conclusions (Papastathis 2015, pp. 146–48), the idea that the Greek humanist left the “universalist discourse, empty”, a “signifier without a signified” is not completely true.

George has a clear idea about to whom to attribute this superior role, this role of Basileus: Mehmet II, as long as he has the courage to achieve this syncretic reunion of the two faiths, of course.

However, we also need to put George’s irenic stance and political vision into relation to his “peregrinatio” around the Mediterranean in his ongoing search for a wealthy patron.

If we insert this “Ottoman” phase in his life, it is evident that, unlike Gennadius II who, by rejecting the “unionist” position with the Catholic Church, decided to reside for his entire life in Constantinople, George’s life, like his ideas, remained more related to his geography of affection than to an effective coherence of thought. His Ottoman parenthesis, after different phases spent in Rome (his conflict with Poggio Bracciolini is reported in the chronicles), Venice, and at the court of Alphonse V of Aragon, is emblematic that more than the faith in the Pseudo-Methodius apocalyptic story about the prediction that the sons of Ishmael would have conquered the Latin empire5, George needed, presumably, a solid mecenate (George of Trebizond 1997, pp 128–34).

2. Latin Conciliarism establishes a relationship with the Islamic world following the Ottoman conquest of Constantinople (1453), showing, on the one hand, growing political apprehension. It was clearly thought that the Italian peninsula and Rome would have been the next Turkish target and shaping, on the other hand, the Christological paradigm of Islam: a precise and clear analysis of the Quranic passages on Jesus. This political weakness, highlighted by the fictional letter of Pius II (d. 1464) to the Sultan, exhibits the complexity of a papal attitude in which the religious and political dimensions and the dogmatic and the diplomatic ones are evidently interconnected. In the analysis made by N. Bisaha on Pius II in the Christian-Muslim Relations volume the complexity of a long scholarly debate on the Pope’s concrete intention as well as to identify the offer as real emerged: the proposal as elaborated would have been not only unacceptable in form, but also in substance because the offenses against both, Islam and the figure of the Sultan, were excessive (Bisaha 2002, pp. 183–200; Bisaha 2010, pp. 456–61). The rhetorical exercise seems much more likely to interest the Latin world and the European princes than the Turkish Sultan. It is plausible that the concrete intention was to move the European princes to embrace an effective crusade against the enemy and eradicate growing Italian Turcophilia, warning that the Pope had the power to make the Sultan a concrete Christian emperor, a latter aspect that must not be underestimated. Pius II’s Irenicism, if it existed at all, had turned into a game of parties and power without any real understanding of who he was up against. The idea that the Other can be converted for greater power is a very Catholic-centric aspect that will become evident in Counterreformism.

If the Church’s Conciliarism failed, its legacy, at least in the Christian–Islamic dimension, was able to frame a vision for a few enlightened protagonists:

We recognize the same God that you recognize: in this, we agree perfectly. For you there is one God; for us, too. You say that God is the beginning of all things; we maintain the same. Where is the disagreement then? There are many differences between the Christian conception of God and that of the Saracens or Turks. You consider God corporeal, we are incorporeal. You attribute earthly events to chance and think that God doesn’t care, we have no doubts: whoever created the All governs it. You deny divine paternity, we recognize the Father and the Son. You deny the divinity of the Spirit, we affirm and venerate it.

(D’Ascia 2001, pp. 177–78)

The contrast between a vision of peace and the “classic” Crusade asserts itself in all its strength. The Pope’s letter, like the subsequent attempt to announce a new military expedition against the infidel in Mantua (1459), is emblematic of the Church’s “escamotage” to gain more support from Italians and European princes; Nicholas Cusanus (d. 1464) and Juan of Segovia (d. 1458) are those who tried, at least in part, to share a different track. The Cardinal of Brixen in De Pace Fidei shows the idea that if God is one, the way to reach God’s unity could be plural—in other words, Una Religio in Rituum Varietate. If this was paradigmatic for the time, Cusanus also affirms that the Una Religio is an expression of faith in Christ and all the “different praxis” are a plural orthopraxy of the unitary God that is Christ himself; Cusanus seems to manifest the idea that Islām is an alternative display of faith in Jesus and that the Muslims do not have to be properly converted (Monaco 2016, pp. 87–88). If interpreted in that sense, it would be even more paradigmatic; moreover, its reading could be bi-univocal: (1) Christian faith is the Una Religio, and in this specific case, Islam is a heretical praxis of it, and (2) Christianity is one of the rites of the Una Religio. In this case, all human religions are imprecise and hypothetical manifestations of the “metaphysic”; in this second case only, “conversion” becomes superfluous.

Moreover, this dilemma shows a more complex nature of the German Cardinal, who took up a different position during the Conciliarist phase, assuming with Julian Cesarini a sort of intermediate posture between Segovia and more Papalist figures such as Juan de Torquemada.6 From 1439, Segovia and Cusanus would find themselves on two opposing fronts, the former in defence of the Council, and the latter, opposing it for a more ample concordance. The Cribatio Alkorani is one of the last works of Cusanus (written 7–8 years after De Pace Fidei) and was dedicated to Pope Pius II, arguing from the epigraph that Islamic heresy has a Nestorian origin, and just as Pope Leo I (d. 461) condemned it in the past, “you will learn about it, to reach the same outcome”. It seems that Cusanus almost wants to suggest to the Pope, his friend Pius II, that he should elaborate a condemnation of Islam as Leo I did against Nestorianism.

It is historically evident that in the same years when Nicholas of Cusa was finalizing the Cribatio, the Pope at Mantua (1459) was planning a new Crusade against the Ottomans, as De Pace Fidei, written three years before, had not been written by the German cardinal himself. Cusanus returned to take a less conciliatory posture, adopting an already-known and more denigrating narrative against Islam and Muhammad: the Qur’an is a false revelation because it was produced by a human being. It also contradicts sacred scriptures and contains mistakes about the figures mentioned. The Trinity is explained as being a manuductio ad Trinitatem, rooted in the ternary of fertility, birth, and love, as an expression of the fecundity of the Father and his offspring, the Son, with the nexus, the love between them, included in the Spirit. It is a passage difficult to understand for any Muslim who clearly rejects a filial and carnal conception of divinity (Cusanus 1971, pp. 782–83). The Cribatio is a full-blown refutation of the Islamic revelation; in the first part, the analysis shows the Qur’an as a text that contains truthful aspects about Christ but which have been completely misunderstood in Islamic terms: the concepts of true man and true God are not conceived at all. In the second part, the Cardinal tries to explain the true nature of Christian theology on Jesus, the Trinity, and his salvific role; in other words, he elaborates a cognitive basis for the conversion of Muslims. Finally, in the third section, there is a broader attack on the Islamic revelation and Muhammad through a comparison with Christian orthodoxy and the Abrahamic ignorance that emerges in the Qur’an.

De Pace Fidei remains a “pacifist” text ante-litteram, which was to find a wide following in the Renaissance-humanism of the 16th century, and despite the Cusanian retraction in the Cribatio, it remains an ‘avant-garde’ text that cannot be forgotten (Euler 2022, pp. 297–307; Levy et al. 2014). On the contrary, Cusanus and Juan de Torquemada (d. 1468) were among those who would most influence Pope Pius II (d. 1464) and Nicholas V (d. 1455) on issues concerning the Ishmaelite heresy, as well as the role and the attitude towards Conversos in the Church of Rome, need to be inserted in their “political” context. Cusanus was perfectly aware of what had happened to Segovia for having remained more inclined to a strong Conciliarist stance: isolated in Aiton (Savoy), he worked and lived there because he deliberately self-segregated himself in a place where he could continue to work on his ‘Islamic’ project, but certainly away from any decision-making power in the ecclesiastical assembly. On the contrary, Cusanus continued to play a significant role in the Church, like Juan de Torquemada. De Torquemada, who came from a family of Jewish origin in the Tractate against the Midianites and Ishmaelites (Torquemada 2023), shows all his personal involvement in defending the honour of Jewish converts to Catholicism on Spanish soil. It is, therefore, evident that in this post-Conciliar historical phase in which deep conflicts related to aspects of the political and religious, dogmatic, and theological spheres remained, the coherence of a cognitive and rational path was still extremely difficult to conceive.)

More intense, even though less known, was Juan of Segovia’s approach to Islam. A convinced Conciliarist who remained “politically” isolated after the failure of Basel, dedicating the last years of his life to the dialogue with Islam and to the production of a first trilingual Qur’an (Arabic, Latin, and Castilian) with the decisive help of an al-faqih (scholar), Iḉa Gidelli (‘Isa Ibn Jabir Ash-Shadili), who travelled from Spain to the priory of Aiton (Savoy), living and working there together for four months.

If the paradigm of “Islamic Christology” also remained for Segovia, the starting point of the dialogical dimension with Islam, the academic from Salamanca would have accepted and planned peace and dialogue as the only satisfactory form of conversion of Muslims to Christianity. It was in De Mittendo gladio divini Spiritus in corda sarracenorum (On sending the sword of the divine Spirit into the hearts of the Muslims, written in 1453–1457) that Segovia started the text by revealing that in October 1431 in Medina del Campo, he had had many meetings with the “first of two Ambassadors of the Emir of Granada”. Different meetings between Segovia and other Islamic figures in various geographical locations are mentioned in this text, but what emerges from the beginning (to the certain surprise of the bishop) was the ignorance on the Muslim side about the main assumptions of the beliefs of the Christian faith (Wolf 2014, p. 238Ff; Cabanelas 1952, p. 265ff.). Segovia thus started to widen his attention to the three main facets that made Christianity and Islam irreconcilable: the “sonship” of God, the Trinity, and the salvific role of Jesus’ death (Cabanelas 1952, p. 266).

It is evident, therefore, that at the end of this dialogical experience, Segovia is convinced that the Saracens, even the more acculturated ones, have a very distorted image of Christianity and, in parallel, that with the possibility of obtaining more sessions with them, “there would be great hope of converting a vast number of them” (Wolf 2014, p. 251), which seems to have been the main goal for Segovia since the beginning. However, it is the “metodo pacifista”, the via pacis et doctrinae, that would never been used by European powers, which remained Segovia’s main theoretical approach, disliked within the Church itself, but clearly appreciated within secular humanism, from Erasmus to Bodin. Segovia’s criticism of the Crusades in the Levant is emblematically linked not only through their incapability to preserve the control of the territory but also to the possibility of fostering a sincere process of conversion (Wolf 2014, pp. 155–56; Cabanelas 1952, p. 266).7 On the contrary, Segovia realized that, during the Council of Basel, the diplomatic and conciliatory option towards the Hussites of Bohemia was finally preferred to the ineffective use of violence, reaching the end of the war (1419–1434).

The agreement of the Compactata (ratified by the Council in 1437) between the moderate Hussites (Utraquists) and the Council was framed, and a solution was found. After lengthy controversies, Basel was able to find an agreement that interested the liturgical, temporal, and theological controversies with the Utraquists. The freedom to preach the word of God in the popular language and by laypeople as well (not only by priests); the possibility of receiving communion of two types, bread and wine, thus leading to an alteration of a universal liturgy; and the outcome that the punishment of sins can only be carried out by the competent judge in accordance with the Bible and the holy orders and not by the orders of private individuals were important aspects that allowed peace to be reached. They were also an important step to avoid summary actions and mass slaughters (Pàlka 2023, pp. 534–58). At the same time, while the partial success achieved would have temporarily weakened the easy attribution of the concept of heresy, it would have favored a Catholic reaction to the Compactata, facilitating, in the long run, their abrogation (1576).

Segovia believed that the core of the Catholic faith was rooted in the obligation of following the example and the message of Christ, as the Gospel of Matthew (26, 51–52) reports: “Converte gladium tuum in locum suum; omnes enim qui acceperint gladium gladio peribunt/Turn your sword into its place; for all who take the sword will perish by the sword” and John (18, 10–11), in a similar way argues: “Mitte gladium tuum in vaginam. Calicem, quem dedit mihi Pater, non bibam illum?/Put your sword into the scabbard. Shall I not drink the cup that the Father gave me?”, which shows emblematically that the peaceful way must be the only one. Segovia’s faith and interpretation of the Gospels as the Word of God is metaphorically compared with the Sword of Christ sent to the Earth:

The word of God was the sword of the Spirit, which was part of the arms that belong to the Christian militia, along with the breastplate of justice and other such armaments. This sword was also the fire of divine love, and the peace was the food that Christ told the disciples he was about to eat. In Juan’s mental universe, the peace that he equated with the word of God blurred into a sword, fire, food, and a buried treasure. Each image represented in some way Christ’s mission in the world or his plan for the church.

(Wolf 2014, p. 159)

The way of peace is a prologue for others. As explained by Madrigal Terrazas, Segovia’s approach is preliminarily related to peace as a first indispensable step, a requirement to move the Christian and the Islamic world in a common direction. Through peace, it is possible to generate a more impactful cultural exchange between the communities already living together, beginning by weakening mutual prejudices. Once this second target has been reached in due time, it will be necessary to organize a series of meetings during which the main common and uncommon ethical and theological aspects will be discussed for both religions, always starting from what unites and not from what divides (Madrigal Terrazas 2004, p. 347).

Even though the bishop recognized that one of the main problems in reaching the way of peace is the reciprocal ignorance that Muslims show about Christianity, like that of Christians concerning the Islamic world, Segovia himself was not free from the same prejudicial ignorance that he demonstrated on some occasions. If the collaboration with Iḉa Gidelli was fundamental to frame the first trilingual version of the Islamic revelation (unfortunately lost, Consuélo Lopez-Morillas 1999, pp. 277–92; Davide Scotto 2018, pp. 61–81), Segovia focused exclusively on the Qur’an. The opinion, therefore, inherent to the scarce presence of literati in the Islamic world and the reasons attributed to it are symptomatic of a prejudice that, without denying his merits, shows how Segovia himself welcomed the propaganda of his time about Islam and Muslims in general without asking too many questions.

To conclude, for Juan of Segovia, peace is the main instrument to reach conversion; conversely, for the “early” Nicholas of Cusa, peace was the inter-relational instrument to admit that the unity and adoration of God can be reached through different paths (in De Pace Fidei): conversion is desirable (“non est nisi religio una in rituum varietate”), but emblematically the pious, just and merciful person can also “perhaps” exempt themselves from an effective conversion (Santacruz 2007, p. 188). This is a position that would have been completely denied in the Cribatio Alkorani.

4. Conclusions. The French Renaissance and the Visio of the Islamic Alterity

The Latin Church’s improvement in fully understanding the Quranic verses on Christ was reached in the Conciliarist era; nevertheless, the “Christological paradigm” had a limited impact on the Church’s concrete attitude towards Islam, and the “Crusade” forma mentis was to persist in being the preferred way of confrontation. At the same time, since John of Damascus’ idea that Islam was a Christian heresy, the process of the “Christianization of Islam” remained peculiar in the relationship between these two religions. However, if Cusanus and Segovia, along the path already traced by others, had clearly modified the Latin Christian cognition of Islam, it was the methodological peaceful approach established by both that framed a different religious and secular visio of the Ottoman Islamic world. This is evident in Erasmus:

The best solution of all would be to conquer the Turks’ empire in the way in which the apostles conquered all the peoples of the earth for their master, Christ; but the second alternative must be to have as the chief object of an armed campaign that the Turks will be glad to have been defeated. This task will be made easier if, firstly, they see that Christianity is not mere words, and can observe that our deeds are worthy of the Gospel; secondly, if honest preachers are sent in to reap the harvest, men will further Christ’s interests, not their own. Thirdly, if any infidel cannot so quickly be persuaded, he should be allowed to live under his own laws, until gradually he comes to agree with us. Long ago, Christian emperors used this method to abolish paganism in degrees. At first, they allowed the pagans to live on equal terms with our Christians, in such a way that neither interfered with the others. Then they deprived the idolaters’ temples of their privileges, and finally, after forbidding the sacrifice of victims in public, they abolished the worship of idols completely. In this way our religion gradually grew stronger, paganism was stamped out, and the signs of Christ’s triumph filled the world”.

(N. Ron 2019, pp. 117–18)

This method also seems more affected by the via pacis et doctrinae of Segovia than by De Pace Fidei of Cusanus. The conquest of the Ottoman world should be realized in an apostolic manner by showing the closeness between Christianity and Qur’anic Christology, the moral action of believers, and the tolerant inclusion that, with time, is transformed into effective inclusion also from a normative point of view. This approach still has to emphasize, according to the Conciliarists themselves, the great difference between apostolic Christianity and the violence of Muhammed and Islam: the “religion of the sword” that Cusanus persists in highlighting in the Cribatio (Ron 2019, p. 127), and it is an idea that contemporary academia is only now beginning to partially deny. If, however, the ecumenical strategy of Cusanus and Erasmus is ineluctably based on the superiority of Christ and Christianity, the more secular Renaissance vision exalts the Ottoman army as a symbol and expression of courage, obedience, and sacrifice.

There was great admiration for the preparation and discipline of the army, whose qualities are to be found in the respect and obedience towards authority; the absence of an effective nobility and, therefore, the fairness of the Ottoman society in question; and finally, its tolerance towards religious and non-religious diversity, an aspect that will be given even greater consideration starting from when, in the 16th century, Europe demonstrates unprecedented religious intolerance and fragmentation (Bisaha 1999, p. 185ff.; Bisaha 2004, p. 135ff.; Malcolm 2019, p. 62ff.)

Turcophilia, emblematic of the historical passage in which the enemy was previously dehumanized from a religious point of view, contrasts with the discovery of the enemy from a political and humanistic one.

It is difficult to prove that Conciliarism was one of the main factors that led to change. Moreover, through Conciliarism, the Latin Church would have definitively realized that Islam was a Religio in continuatione traditionis biblicae. If this process, which had already started during the Crusades, was managed by clerical figures who predominantly analyzed the “Islamic otherness” from a religious point of view, the more precise and specific “humanization” of Islamic Christology during the Quattrocento opened the gates to the “humanistic” attempt to better understand this Ottoman world. We can, therefore, distinguish the emerging Turcophilia according to three main views that are deeply interconnected with one another: the irenic and inter-religious dimensions of Turkish tolerance, the diplomatic-political image of Ottoman power, and the military superiority of their integrated army.

These aspects will find a narrative of evident impact in Giovio (2005), Bodin (1577), Postel (1543), and others (Bélon, Thevet, Cambini, Busbecq, etc.); it is a narrative that is rooted, not so much in a more “Christian” appreciation of Islam, which remains rare, but in a more secular contempt for the disunity of the European world and the intra-Christian violence caused by religious reasons (the Protestant and Calvinist revolution). Bodin and Postel remain an exception. There is a clear complexity in both religious syncretic views that clearly goes beyond the intra-Christian violence of the period; the 16th-century approach of these two authors towards Ottoman Islam certainly corresponds to an attempt to identify in the Eastern dominion a concrete inspiration for a political–religious visio.

There is an evident fracture between the religious understanding of the Council Fathers, dogmatically linked to Catholic doctrine, and the Kabbalistic-social and political one of Postel and Bodin; nevertheless, the propensity towards religious otherness as an expression of “others’ truths” clearly finds inspiration in Conciliarism. What the Conciliarists would not have seen and therefore evaluated was the further internal fracture within Christianity and the outbreak of religious civil wars until at least 1648; this would have caused a process of strong secular criticism, from Machiavelli onwards, towards the assumption that Christianity was rightfully the “best of religions”. This doubt, which would have led the Catholic Church to a rather useless and very belated self-criticism, finds an identification in the paradigmatic attempt of the Conciliar dialogue and in placing the Papal autocracy at the service of its own apostolic community. The Council of Trent (1545–1563) was the paradigmatic event through which the Catholic Church attempted to reassert its centrality; the Counter-reformation process would be fostered by an attempt at dogmatic and territorial restoration based on violence and oppression. The secular and intellectual reaction towards a doctrine increasingly linked to praxis, sacramental sacredness, and dogma would easily have favoured an increasingly secular vision and one of appreciation towards state entities (the Ottoman world) where inter-religious differences were understood in their universality.