2.1 Islam as fulfilment of God’s promise to Abraham

But God said to Abraham: ‘I will make a nation of the son of the slave woman (Hagar) also, because he is your offspring’. (Gen 21:12–13)

The angel of God […] said to Hagar: ‘[…] I will make of him a great nation’. (Gen 21:17–18)

The genesis of the Muslim community lies in Arabia, where there is evidence of the presence of different Christian communities. The historical sources also attest to the various theological discourses which were present among them. We do not have a detailed picture of their opinions about the emerging Muslim community, however. It is only when Muslims began to have an impact on the wider world, particularly through the conquest of Jerusalem in 638 and of the Byzantine provinces of Syria and Egypt in the years following, that information begins to appear about how Christians were seeking to make sense of Islam. One initial interpretation of these events was that they were the fulfilment of these scriptural promises to the Ishmaelites. The Armenian bishop Sebeos, writing in the period before 661, thus describes Muhammad’s mission in terms of teaching the Arabs to know the God of Abraham, and telling them that God was going to realize in them the promise made to Abraham and his successors; it was for this reason that the Ishmaelites set out from the desert to the land around Jerusalem. The chronicle of an anonymous Nestorian monk, written in Iraq during the 670s, also testifies to the perception that Ishmaelites had been making conquests, and that this is in part the result of their following in the footsteps of Abraham (Hoyland 2019).

2.2 Islam as God’s judgment on an erring Christian church

I am bringing evil […] and a great destruction. A lion has gone up from its thicket, a destroyer of nations has set out. (Jer 4:6–7)

It was not long, however, before it became clear that the Muslim community was rather more of a significant challenge to Christians. In seeing itself as having a mission to be a corrective to – or even fulfilment of – the message of Christianity, the Muslim community challenged Christian claims to being the bearer of God’s final revelation to humankind.

At this point the divisions within the Christian world of the day began to come into play, particularly the disagreements between those Christians who had accepted the christological affirmations of the Council of Chalcedon in 451 and those who had not – namely, the Miaphysites (formerly described as Jacobites), and the members of the Church of the East (formerly described as Nestorians). The majority of these two Syriac-speaking Christian communities now found themselves living under Islamic rule, and the interpretation of Islam which some of their writers began to formulate was that it should be seen as God’s judgment on those Christians who had accepted the christological definitions of the Council of Chalcedon. The tenth-century Coptic bishop Severus of Asmounein wrote that the Lord abandoned the army of the Romans as a punishment for their ‘corrupt faith […] on account of the Council of Chalcedon’ (Frend 1972: 353); and the twelfth-century Miaphysite Michael the Syrian commented that the God of vengeance had raised up from the south the children of Ishmael to bring deliverance from the hands of the Romans, and that it was a great benefit to be freed from their cruelty, wickedness, and anger (Moorhead 1981: 585; Penn 2015a; 2015b).

2.3 Islam as a Christian heresy

Who is the liar but he who denies that Jesus is the Christ? (1 John 2:22)

By this you know the Spirit of God: every spirit which confesses that Jesus Christ has come in the flesh is of God, and every spirit which does not confess Jesus is not of God. (1 John 4:2–3)

As Islam became more established and began to develop its own theology, Christians began to articulate a third, more theologically sophisticated, method of interpreting it: namely that Islam should be seen as a Christian heresy. A towering figure in the development of this tradition is John of Damascus (died c.750), who lived in a pivotal era when Islamic rule was being consolidated and Greek was giving way to Arabic as the language of administration in the empire. John lived under Islamic rule, in what was at the time the capital of the Islamic Empire, and his family had for several generations played a significant role in the administration of the city of Damascus. He was probably educated with Muslims until the age of twelve, so that he knew Arabic as well as Greek; and on the basis of his administrative responsibilities he was able to acquire some first-hand knowledge of Muslim beliefs and practices, including at least some knowledge of the Qur’an. Through this he became aware that Muslims had some convictions in common with those of Christians, even if on other points the two communities differed significantly. The simplest way to account for this combination of commonality and distinctiveness, in John’s view, was to describe Islam as a Christian heresy.

He articulated this view in an appendix to his De Haeresibus (On Heresies), which was a supplement to his De Fide Orthodoxa (On the Orthodox Faith). In the appendix, he lists one hundred well-known Christian heresies, with Islam given as the one hundred and first. In his description of Islam, John tells of the idolatrous character of religion in pre-Islamic Arabia, and of Muhammad’s preaching of monotheism in that context – including a summary of Chapter 112 of the Qur’an, which bears the message that there is one God, the Creator of all, who is neither begotten nor has begotten. Alongside a description of various Muslim practices, John then summarizes what the Qur’an says about Jesus: namely that he is a word of (or from) God, God’s spirit, and a servant, miraculously conceived but not crucified. It is on this basis that John concludes that Islam can reasonably be described as a Christian heresy, a view that is reiterated in another work which is commonly attributed to him, the Disputatio Saraceni et Christiani (Disputation of a Muslim and a Christian) (Sahas 1972; Schadler 2018; and Awad 2018).

2.4 Islam as ‘the Antichrist’

As for the fourth beast […] that shall be different from all the other kingdoms; it shall devour the whole earth, and trample it down, and break it in pieces […] This one shall be different from the former ones, and shall put down three kings. He shall speak words against the Most High, shall wear out the holy ones of the Most High, and shall attempt to change the sacred seasons and the law. (Dan 7:23–25)

Finally, a fourth and much more negative interpretation of Islam began to be articulated. This view emerged firstly among Byzantine Christians, for whom Islam posed not only a significant theological challenge but also an existential military threat; and secondly among an important group of Christians living in Spain, for whom Islam posed a threat of a very different, cultural, kind. In these places Islam began to be regarded as being, in some way, ‘the Antichrist’.

The Spanish Martyrs’ Movement emerged in the capital of Islamic Spain, Cordoba, in the decade between 850 and 860 CE. Cordoba at that time was a flourishing and sophisticated city, whose Christian population seems to have been isolated from the rest of Latin Christendom, and in this context Islam had a considerable cultural attraction. It was in reaction to the threat posed by the appeal of conversion to Islam that two Christians, Eulogius (a priest) and Paul Alvarus (a layman), articulated the view that Islam was the precursor of the coming of the Antichrist. They based this interpretation on the apocalyptic literature of the Bible – particularly the book of Daniel in the Old Testament, and the apocalyptic sections of the gospel accounts and the Book of Revelation in the New Testament. Daniel 7, in particular, referred to a vision of a series of four beasts who will arise in human history, and which are understood as four empires which will make life difficult for the people of God. Traditional Christian interpretation of this vision sees the beasts as representing the Empires of Babylon, Persia, Greece, and Rome, the four empires leading up to the coming of Christ. However, Eulogius and Paul Alvarus proposed a very different interpretation: namely that the vision of the fourth beast referred to their own time and circumstances (Southern 1962; Wolf 1988).

Islam, for them, was wearing down the saints of the Most High (i.e. Christians), speaking against the Most High through its scripture, the Qur’an, affecting the balance of power by putting down the empires of Greeks, Franks, and Goths, and setting up its own calendar and legal system. This situation would not last for ever, they assured, as the continuation of Daniel’s vision referred to this force lasting for a time, two times, and half a time, which Eulogius and Paul Alvarus interpreted as meaning 245 (three and a half times seventy) years. By this reckoning, if Islam began in 622, its period of influence was shortly to come to an end. A life of Muhammad which was in circulation in Spain at the time also calculated that Muhammad had died in the year 666 of the Spanish calendar. To Eulogius and Paul Alvarus, this was a clear reference to the number of the beast in Rev 13:18, indicating that Muhammad should be identified as the Antichrist and that the end of human history was nigh.

The response advocated by Eulogius and Alvarus was to seek to arouse Cordoban Christians either to insult Muhammad in public or to call on Muslim officials to convert to Christianity. As a result some fifty Christians, including Eulogius himself, were executed by the authorities during the 850s, coming to be considered as martyrs by their co-religionists. The movement petered out as a result of a strong reaction from the authorities and the fact that the end did not come as had been predicted, but its strongly negative assessment of Islam proved remarkably tenacious, and strongly influential, in the medieval period and beyond (Southern 1962; Wolf 1988).

2.5 Summary

Of these four initial Christian interpretations of Islam, two were in some sense positive, locating Islam within the sphere of God’s activity in human history, whether as a fulfilment of an earlier divine promise (to Abraham) or as an indication of God’s judgment (on an erring Christianity). The other two, by contrast, were much more critical, seeing Islam either as a Christian heresy (though this view did not necessarily rule out some relationship with Christianity), or as being in active opposition to Christians as the Antichrist. All four of these views have continued to be held in different quarters, ebbing and flowing in their influence in different times and places in Christian history, for a range of different reasons.

It is worth noting that, even if each of these views can be identified to some extent with a particular branch of the Christian church (for example, the view that Islam was in some way a judgment of God was most commonly found among Syriac Christians), this does not mean that any of these views was completely coterminous with any of the different Christian churches, in either East or West. The view that Islam was in some sense ‘the Antichrist’ was not only found among Western Christians, in other words, but also among Byzantine Christians, such as the historian Theophanes the Confessor (c.758–c.818) and the ninth-century polemicist Nicetas of Byzantium; and a relatively positive view of Muhammad was found in the writings of (East Syrian) Patriarch Timothy (c.740–823). Within each Christian community, therefore, a diversity of views of Islam was found, indicating that there was normally an active debate taking place within each church about how Islam should be interpreted and understood.

3.1 Developing views in the East: debate and exchange

The years after the era of John of Damascus saw the centre of political power in the Islamic world move eastwards, from Damascus to the new city of Baghdad. It was in that context that the new discipline of kalām (Islamic theology) was developed. Christians played a not insignificant part in this development, which in turn stimulated the growth of Christian kalām in the Arabic language, as well as in the translation movement which made Greek philosophical and scientific works available in Arabic. This in turn led to the emergence of the tradition of falsafa (Islamic philosophy).

Associated with these developments, and particularly in the time of the caliph al-Ma’mūn (813–833), the tradition grew up of discussion being held at court with representatives of a wide variety of religious traditions, including Christians. There are records of two important Christians taking part in these discussions: firstly, Theodore Abū Qurra, a Chalcedonian bishop in northern Syria; and secondly, ‘Abd al-Masīḥ al-Kindī, a member of the Church of the East. Abū Qurra’s arguments can best be summarized as being apologetic in nature, seeking, in other words, to make Christian convictions intelligible to his Muslim interlocuters. Al-Kindī’s style is much more confrontational, including statements to the effect that Muhammad should not be seen as a prophet, since he did not predict the future or perform miracles, and a number of incidents in his life throw a rather negative light on his character. Al-Kindī maintained that the Qur’an should not be recognized as being the word of God, in the light of what he considered its barbaric teachings about women and about holy war, and also because its text has not been faithfully transmitted and preserved. If Theodore’s writings can be seen as apologetic in style, in other words, those of al-Kindī must, by contrast, be seen as polemical.

Other Christian writers of the period – such as Abū Rā’iṭa al-Takrītī (c.770–c.835), a Miaphysite theologian, and ‘Ammar al-Baṣrī, writing within the Church of the East in the first half of the ninth century – also attempted to elucidate Christian convictions in an Islamic milieu. Their respective contributions on the incarnation and the Trinity are particularly significant (Griffith 2002a; 2008).

In the following century, the school of philosophy in Baghdad provided another interesting example of relatively positive interaction between Christians and Muslims. Its headship passed from a member of the Church of the East, Yūḥannā ibn Ḥaylān (died between 908 and 932), to a Muslim, al-Fārābī (c.870–950), and then back to a Miaphysite Christian, Yaḥyā ibn ‘Adī (893–974). Yaḥyā’s contribution to ethical philosophy – in the form of his The Reformation of Morals – demonstrates the importance of Christian contributions, in Arabic, to this aspect of philosophy in particular (Griffith 2002b).

Beyond the boundaries of the world of Islam, historians and theologians among Orthodox Christians in the Byzantine Empire continued to write about Islam. Some, such as Theophanes and Nicetas of Byzantium, go much further than John of Damascus in formulating a negative evaluation of Islam. Theophanes suggested that Muhammad had epilepsy, and that his message of Islam included the idea of a sensual paradise, so that he is described as ‘the chief and false prophet of the Saracens’. Nicetas produced a polemical work entitled Refutation of the Book Fabricated by the Arab Muhammad, in which the Qur’an is described as ‘a lying and pernicious book’, ‘of odious and demoniac origin’; Nicetas argues that, since Islam’s so-called revelation comes from the Devil, it is the Devil that those who hear it are led to worship (Khoury 1969; Meyendorff 1964).

The military background to these works needs to be kept in mind. In other periods, a much more nuanced Byzantine attitude towards Islam can be found: for example, in the exchange of letters which took place between the Emperor Leo III (717–741) and Caliph ‘Umar bin ‘Abd al-‘Azīz (717–720). It is also found much later, in the controversy which broke out between the Emperor Manuel I (1143–1180) and the Patriarch of his day when the emperor insisted that converts from Islam should not be required to anathematize the God of Muhammad. Meyendorff concludes that the contrast between these two approaches

clearly illustrates the existence in Byzantium of two views on Islam: the extreme and ‘closed’ one, which adopted an absolutely negative attitude towards Muhammadanism [sic] and considered it a form of paganism, and another, the more moderate one, which tried to avoid burning all bridges and to preserve a measure of common reference, in particular, the recognition of a common allegiance to monotheism. (Meyendorff 1964: 125)

3.2 The Crusades

Meanwhile in the West, one legacy of the fourth interpretation of Islam outlined above – that Islam was ‘the Antichrist’ – was the movement which gave rise to the Crusades. The Crusade was first preached by Pope Urban II in 1095, partly in response to an appeal from the Byzantine Empire for military assistance but also with a view to facilitating pilgrimage to Jerusalem. In response, a number of European princes took up the cross, and popular itinerant preachers such as Peter the Hermit took up the call alongside them, arguing that Jerusalem and the Holy Land needed to be recaptured from the hands of the infidel Muslims in order to pave the way for the second coming of Jesus Christ. This apocalyptic dimension did much to arouse popular enthusiasm for the venture.

The First Crusade, remarkably, succeeded in capturing Jerusalem in 1099, along with much of the territory that is now coastal Syria, reaching as far inland as Edessa. Yet within fifty years the crusading states were encountering a number of significant difficulties, including the loss of Edessa in 1144. And so the call went out for a Second Crusade, which was preached by Bernard of Clairvaux (1090–1153) at Vézélay in Burgundy in 1146. Bernard is best known today for his stress on God’s love and mercy, as seen in the hymns he wrote, such as ‘O sacred head sore wounded’, ‘Jesus, thou joy of loving hearts’, and ‘Jesus, the very thought of thee’ – but in the context of his own day no contradiction was seen between crusading and the message of these hymns (Riley-Smith 2008).

3.3 Studying Islam

Somewhat paradoxically, while some Latin Christians were heading off on a series of military campaigns against Muslims in and around Jerusalem, other Latin Christians were developing great interest in studying Islam and in texts written by Muslims, especially in the field of philosophy, but also in many other areas such as medicine. The key initiator of this process was Peter the Venerable (c.1092–1156), the abbot of the important monastery at Cluny. Peter was a friend of Bernard of Clairvaux, but he had a significantly different understanding of Islam. Peter argued that a better approach to Islam was to study it comprehensively and from its own sources. This necessarily involved establishing a comprehensive translation programme, much of the work for which was done in Spain, and Peter himself travelled to Toledo – the city in which much of the work was done – in 1142. Included in the programme was the first translation of the Qur’an into Latin, which was undertaken by Robert of Ketton and completed in 1143. To supplement this, Peter wrote a Summa Totius Heresis Saracenorum (Summary of the Entire Heresy of the Saracens) and the Liber contra Sectam sive Heresim Saracenorum (Refutation of the Sect or Heresy of the Saracens). As the titles of these works suggest, Peter broadly followed John of Damascus in his assessment of Islam, namely that it should be understood as a Christian heresy.

In the Refutation, Peter wrote that his approach was to attack Islam – but not, like some of his co-religionists, with arms, but by words; not by force, but by reason; not in hatred, but in love. Support for this method was adduced in part from the New Testament, through 1 Pet 3:15: ‘Always be prepared to make a defence to anyone who calls you to account for the faith that is in you, but do it with gentleness and reverence’. It was also drawn from texts in the Qur’an, including 29:45: ‘Argue not with the People of the Book [i.e. Jews as well as Christians] except in a way that is better’. Indeed, this could be seen as almost a mirror-image of the text from Peter’s epistle (Kritzeck 1964).

A similar approach can be found in some of the writings of the Christian widely regarded as the greatest thinker of the medieval era, if not of all Christian history: Thomas Aquinas (c.1225–1274). In his various expositions of the Christian faith, Aquinas engaged deeply with the works of Islamic philosophers such as Avicenna and Averroes. His early work, On Being and Essence, for example, which has sometimes been described as a summary of his entire system of thought, begins with the sentence:

Because a small error at the outset ends by being great, according to the Philosopher in On the Heavens 1, and because being and essence are what intellect first conceives, as Avicenna says at the beginning of his Metaphysics, therefore, lest ignorance of them give occasion for error, and in order to lay open the difficulty concerning them, it should be said what ‘essence’ and ‘being’ mean, how they are found in different things, and how they are related to logical intentions, namely, genus, species and difference. (Aquinas 1998: 29–30)

This makes absolutely clear Aquinas’ interest in, and indebtedness to, not only the pre-Christian Greek philosophers, especially Aristotle, but also his near-contemporary Islamic (and Jewish) philosophers.

In his contribution to The Cambridge Companion to Aquinas, David Burrell (1993) wrote that the attention given by Aquinas to the writings of Moses Maimonides and Avicenna demonstrated the respect that he gave to them as ‘fellow travellers in an arduous intellectual attempt to reconcile the horizons of philosophers of ancient Greece, notably Aristotle, with those reflecting a revelation originating in ancient Israel’, and commented:

We may wonder at Aquinas’ welcoming assistance from Jewish and Muslim quarters […] yet his overriding concern in reaching out to other thinkers was always to learn from them in his search for the truth of the matters at hand. (Burrell 1993: 60–61)

Part of the explanation for this openness, Burrell suggests, lies in Aquinas’ own origins. He came from Aquino in the region of Naples, which was then part of the kingdom of Sicily. There, Latin, Muslim, and Jewish culture mingled freely, and later in life, when he was asked by his Dominican order to set up a theological school, he chose to do so in Naples rather than in Rome:

So it may be surmised that these dimensions of his own personal history led him to be more open to thinkers from the Islamicate than his co-workers from Cologne or Paris might have been. (Burrell 1993: 62)

Other significant theologians of this period such as Duns Scotus (c.1266-1308) were more critical in their evaluation of the writings of these Jewish and Muslim thinkers (Burrell 1990). The positive Christian interest in Islamic thought evident in the writings of Aquinas, however, gave rise to the Translation Movement, in Spain and Sicily, through which a significant number of ancient Greek and more contemporary Islamic philosophical works were translated from Arabic into Latin. It also subsequently inspired the establishment of a significant number of universities across Europe. These institutions, both in what was taught and how it was taught, owed a huge amount to schools which had grown up in the Islamic world in the previous centuries. Thus while some medieval Christians were enthusiastically participating in military campaigns to recover territory from Muslims – and thereby help to bring about the second coming of Christ – others were enthusiastically seeking to learn from Muslims in order to further their understanding of their own faith and of the world around them.

3.4 Mission to Muslims

Part of the motivation of those Christians such as Peter the Venerable, who were seeking to learn more about Islam, was that they wished to be able to refute it. While part of the reason for doing this was to reassure Christians of the truth of their faith, another factor was the beginning of attempts to carry the Christian message across the Mediterranean to Muslims, with a view to converting them. This was something which had hardly been attempted by Eastern Christians in earlier centuries, regardless of their Christology. For Syriac Christians, this was no doubt partly because they found themselves living under Islamic rule, while Byzantine Christians found themselves engaged in a military conflict with the newly-emerged Muslim state. Some Western Christians, however, became more proactive in the cause of Christian mission, and an early representative of this new trend was the important figure of Francis of Assisi (1182–1226). Following the establishment of the Franciscan order in 1209, Francis demonstrated that the range of his vision extended not only to his homeland of Italy, and Europe more widely, but also to the Muslim world. This was seen in two attempts to travel to this region, to Syria in 1212 and to Morocco in 1214, but these were frustrated by weather and by illness, respectively. A third attempt in 1219 succeeded when Francis travelled first to Acre and then on to Damietta in Egypt, which was being besieged by the army of the Fifth Crusade. Francis, however, denounced the approach being taken by the Crusaders, instead seeking an audience with the Sultan, during which he requested the opportunity to undergo an ordeal. This took the form of entering into a fire, alongside the Sultan’s religious scholars, in order to demonstrate the truth of the Christian faith by emerging unscathed. The Sultan denied him this opportunity, however, so Francis had to return to the Crusader camp. Nevertheless, Francis’ approach represents a radical alternative to the crusading model, demonstrating his conviction that it was better to try and create Christians than to destroy Muslims (Tolan 2009).

The aims and aspirations of these two traditions – the one of study represented by Peter the Venerable and Thomas Aquinas, and the other of mission, represented by Francis of Assisi – were brought together towards the end of the thirteenth century in the influential figure of Ramon Lull (or Llull; c.1232–1316). Born in Majorca, which had recently been reconquered by the Christians, Lull originally became a soldier. Following a vision in 1263, he radically changed his approach, determining to devote his life to three things: writing books explaining the Christian faith to those who did not believe in it; establishing colleges for the training of Christian missionaries; and laying down his life as a martyr. His Book of the Gentile and the Three Wise Men was an attempt at realizing the first of these ambitions. The second was achieved though the setting up of a college in Majorca in 1295, for the education of friars who were seeking to journey to the Muslim world. Lull himself undertook a number of journeys to North Africa, during which he entered into debate with Muslim scholars. During the final debate in 1316, some provocative remarks about Islam seem to have resulted in the fulfilment of his third desire: that of martyrdom. Lull thus brings together the concerns to study Islam and to bear the Christian message to Muslims, representing a significant new development in Christian thinking about Islam (Bonner 1993; Kedar 1984).

3.5 Summary

Alongside the development which took place in the East in the sense of debates and exchange, the significant new options which emerged in the later medieval period in the West were these: to fight (crusade), to study (or even learn from), or to evangelize. As in the earlier period of Christian thinking about Islam, these different approaches happily co-existed alongside each other within the same church communities. The emergence within late medieval Christianity of the different orders within the Roman Catholic Church made this easier to some extent. Templars and Hospitallers served as active supporters of the Crusades, Dominicans advocated the use of study and learning, and Franciscans were most active in the cause of Christian mission. The boundaries between the three approaches were extremely fluid, with members of the Dominican order in particular being supportive (in some contexts) of the crusading ideal, while in others being actively engaged in missionary endeavours in different parts of the Muslim world, alongside their commitment to study.

4.1 Reformation and Enlightenment

Given that their main preoccupation was the purification and reform of the Christian church, Islam was not necessarily the main priority for the Reformers, with the result that in many cases they inherited and reproduced many of the attitudes towards Islam of their medieval forebears. Towards the end of his summary of medieval views of Islam, R. W. Southern comments that Martin Luther saw Islam in rather apocalyptic terms, anticipating that Christendom would be engulfed in Islam, and reckoning that he was writing in the twilight of Christendom. The Antichrist, however, was to be found primarily within the Church, according to Luther, in the person of the Pope, rather than in Islam. Nevertheless, the challenge of the Ottoman Empire raised new questions, with new sources such as the narratives provided by those who had experienced captivity at the hands of the Barbary pirates becoming available. Although there is a frequent conflation in Luther’s writings between Muslims and Turks, he was concerned that the Turks should be represented accurately, and that their admirable qualities of being faithful, friendly, and careful to tell the truth should be recognized. Luther therefore found it possible to respect and even to grudgingly admire Turkish culture even while disparaging the Islamic religion. Towards the end of his life, Luther supported the translation and publication of the Qur’an in order to facilitate a better understanding of Islam (Southern 1962; Francisco 2007; Miller 2018).

John Calvin likewise tended to conflate Muslims and Turks in his writings. Jan Slomp suggests that the small number of references to Islam found in Calvin’s works seem, on the one hand, to set Islam up as a foil for denigrating Christian opponents and, on the other, to provide him with an opportunity to express the christocentrism which is such a prominent theme of his thinking. In Calvin’s view, the failure of the Turks to acknowledge the centrality of Christ thus meant that there can be no true knowledge of God among them, and while they insisted that the creator of heaven and earth is God, by repudiating Christ they were actually substituting an idol for the true God (Slomp 1995). By contrast, other Reformers in Switzerland were not quite so negative about Islam. Ulrich Zwingli and Henry Bullinger in Zurich, and Theodore Bibliander in Basel, were all significantly less polemical in tone and, in the case of Bibliander, displayed a greater knowledge of Islam than Calvin, especially because of his edition of the Qur’an (Vehlow 1995).

The next century saw the development of a tradition of more serious academic study of Islam, with the first Chair of Arabic being established in the University of Oxford in 1636 by Archbishop William Laud. The motives for this development were very diverse, with part of Archbishop Laud’s interest in particular being his desire to draw up a Form of Penance and Reconciliation, through which those who had been made captive in Morocco and had converted to Islam there could be re-admitted into the church. The fact that such a ritual was needed clearly demonstrated the increasing level of contact between the worlds of Christians and Muslims which was developing in this period (Matar 1998).

The first complete English translation of the Qur’an was then made by Alexander Ross, a chaplain to King Charles I, in 1649, though this was based on a French translation rather than being translated directly from the Arabic. In 1705 a Dutch scholar, Adriaan Reland, wrote an account of Islam which was based exclusively on Muslim sources, and then 1734 saw the publication of a more accurate English translation of the Qur’an by George Sale. Through these and other publications a more accurate knowledge of Islam was developed in the English-speaking world, and a more sympathetic evaluation of its teachings and practice began to be established.

If the Reformers essentially continued in the medieval Western traditions of Christian thought about Islam, the leading thinkers of the Enlightenment sometimes seemed to also follow this path. Voltaire, for example, in his earlier works – particularly his play ‘Mahomet’ written in 1736 – presented Muhammad as a charlatan, an imposter, and a fanatic. In a 1748 essay on the Qur’an, he judged the book to be full of contradictions, absurdities, and anachronisms. In some of his later works, however, Voltaire acknowledged that he might have been unduly harsh in his earlier judgements, conceding that Muhammad had removed idolatry from most of Asia and that the civil laws of Islam contain much that is good, particularly with regard to the tolerance of different religious communities.

The difference between the view of Islam in the writings of these Enlightenment thinkers and that of earlier Christian thinkers is that, while the latter were producing polemical writings against Islam in particular, the former were arguing against not only Islam but all religion, Christianity included. Other Enlightenment thinkers, however, adopted a rather different path, painting a considerably more positive portrait of Islam. They perceived Islam as more ‘rational’ than Christianity on the basis of its strict monotheism and the absence of an irrational conviction such as the Trinity, and thus more compatible than Christianity with the Deism which they themselves preferred. The motive behind their attempt to formulate a more positive view of Islam was thus precisely in order to denigrate Christianity (Gunny 1996; Almond 2009).

Edward Gibbon (1737–1794), in chapter fifty of his Decline and Fall of the Roman Empire (1776–1789), suggested that Muhammad had an original and superior genius, and that the Qur’an was a glorious testimony to the unity of God. The idols of Arabia, Gibbon wrote, were broken before God’s throne, and the Muslim rituals of prayer, fasting, and almsgiving were laudable acts of devotion. Gibbon and his contemporaries were able to draw upon, and make use of, the developing tradition of more serious academic study of Islam. This tradition continued into the nineteenth century, with the essayist, historian, and social commentator Thomas Carlyle (1795–1881) delivering a lecture in Edinburgh in 1840 in which he referred to Muhammad as a ‘hero’– one of the series of individuals whom Carlyle considered to have made a positive impact on human history. In the course of the lecture Carlyle recognized Muhammad’s sincerity, arguing on this basis that it was wrong to denigrate his character, as most earlier Western accounts had done. Carlyle’s conclusion was that, even if Muhammad was not the truest of prophets, he should nevertheless be esteemed as a true one (Hourani 1991; Rodinson 1988).

Among theologians, F. D. Maurice (1805–1872) had heard and been significantly influenced by Carlyle’s lectures. He delivered his own series of lectures in 1845–1846, published under the title The Religions of the World and their Relations with Christianity. In these addresses, he suggested that all religious traditions emphasize an important aspect of God, and that the success of Islam in particular could not be explained by force of arms, human credulity, plagiarism from earlier religious traditions, or simply on the basis of the force of Muhammad’s personality. Rather, in an apparent revival of a view from the earliest period of Christian thinking about Islam (see section 2.2), the emergence of Islam should be seen as a judgment of God on Eastern Christians and the pagans of the Middle East. For him, Islam thus has a place in God’s future (Bennett 1992: 46–73).

4.2 Missionary thinking in an age of empire

Alongside these developments in the Christian-majority world, the period after 1500 also saw the further growth of Christian missions in different parts of the Muslim world. These missions were Roman Catholic to begin with, followed by Protestant missions from the end of the eighteenth century.

A pertinent example of Roman Catholic missions is the one undertaken by members of the new Jesuit order to the court of the Moghul Emperor in India. First invited by the Emperor Akbar in 1579, the Jesuits sent three brothers, who took part in several debates with the emperor and Muslim scholars. However, an impasse was quickly reached in these discussions as a result of traditional differences about incarnation and Trinity, and the Jesuits returned in 1583 to Goa. A second delegation was requested ten years later; and, after an initial hiccup, Jerome Xavier (the great nephew of one of the founders of the Jesuits, Francis Xavier) spent the years between 1595 and 1614 at the imperial court. He learned Persian, which was then the language of the court, allowing him to produce Christian literature in Persian, including a life of Christ. A number of his works were composed in the form of discussions between a Jesuit, a Muslim, and a philosopher, in the tradition of Ramon Lull’s work. The Christian liturgy was also used very imaginatively in these texts in order to embody the principles of Christian belief. High hopes were raised in 1610 when Akbar’s successor, Jahangir, ordered his three nephews to be instructed in the Christian faith and baptized, but they renounced the faith three years later. Xavier himself withdrew a year after this, partly as a result of political complications arising from the machinations of different European powers at the Moghul court (Camps 1957).

In another example of Roman Catholic missionary activity during this period, a pair of Carmelite missions were sent to Iran, in 1604 and 1621. The first of these was sent by Pope Clement VIII with three main purposes: to find out about the country, to assess the prospects for an alliance with western powers against the Ottoman Empire, and to make known the Christian faith. The combination of general curiosity, diplomacy, and mission for Roman Catholics in this era is thus made very clear. The report of the first mission provided a great deal of information addressing the first concern. The second mission, however, also provided an opportunity for making Christianity known, in the form of a theological discussion which involved not only the friars but also the (Protestant) chaplain of a small group of English merchants who had settled at the court of the Shah. It was therefore a three-way discussion which ensued, focused on fasting and good works, the cross and images, free-will and predestination, and authority. On each topic, it was the Protestant Christians who found themselves the odd ones out, with the Roman Catholics and the Shī‘ī scholars generally appearing to hold rather similar opinions (McNeill 1973: 373–391).

It took Protestant Christians some time to engage in mission activities themselves. Lyle Vander Werff (1977: 19) suggests that there were four main reasons for this: (1) the belief that the Great Commission of Matt 28:19–20 had been fulfilled by the first generation of Christians; (2) the doctrine of divine election, which made mission redundant; (3) the idea that the task of mission was the responsibility of civil rulers rather than the church; and (4) the argument that the time was not ripe because other matters – such as the struggle against Roman Catholicism – were more urgent. When, towards the end of the eighteenth century, Protestant Christians did begin to engage in mission, the pioneer in mission to Muslims was Henry Martyn (1781–1812). A graduate of Cambridge University, Martyn arrived in India in 1806, and in the remaining years of his life he translated the New Testament into Urdu. He also substantially revised both the Persian and Arabic versions. Having done this, he set out to return to England in 1811, travelling by boat to the Gulf and then overland through Iran and Turkey. He spent almost a year in Shiraz, where he engaged in detailed theological discussions before dying in eastern Turkey, near Sivas. The significance of Martyn’s work lies firstly in his translations, which were of a particularly high quality; secondly in his general approach, which, in contrast to the Jesuits and the Carmelites, was not to engage primarily with political leaders but rather to concentrate on making contact with ordinary Muslims; and thirdly in his general philosophy in debate and public discussion of the conflicting claims of Christianity and Islam. Here, unlike some of his successors, Martyn set himself one important rule: he would not attack Islam publicly (Werff 1977; Padwick 1953).

The British East India Company was initially quite hostile to the activities of Martyn and others, on the basis that they might provoke opposition and thus interfere with the pursuit of profit. However, as the nineteenth century progressed, attitudes changed, and a much greater degree of sympathy and active support for Christian missions emerged among some British officials. An example of such a figure is Sir William Muir (1819–1905). Following study at Haileybury College, Muir rose through the ranks of the Indian Civil Service, becoming Secretary to the government of the North-West Provinces – an area which included the historic city of Agra, the home of the Taj Mahal – and then, in 1868, Lieutenant-Governor of that province. He retired from India in 1876, becoming a member of the Council of India in London until 1885, when he became Principal of the University of Edinburgh, a position which he held until 1903.

Muir was an active supporter of Christian missions, seeing Islam as a formidable antagonist of Christianity – an active and powerful enemy from which it was the destiny of the British to rescue people through the light and teaching of the gospel. European imperialism and Christian mission were thus closely identified in his mind. With regard to the latter in Agra, Muir seems to have offered his support to a German missionary who was then working in Agra, Karl Pfander (1803–1865), who participated in a number of significant religious debates in the city. In these, Pfander did not follow the precedent of Henry Martyn to avoid attacking Islam in public. Muir contributed to the discussion himself by producing a scholarly Life of Mahomet, first published in four volumes between 1858 and 1861, and then an account of early Islamic history in The Caliphate: Its Rise, Decline and Fall in 1891. These works broke significant new ground in that they were based on Arabic, Persian, and Urdu sources, and Muir did recognize some positive features in the life of Muhammad, especially in his Meccan period. However, with regard to later developments, Muir’s conclusion was that Muhammad had devised a system which was inherently anti-Christian. Muslim reviewers, particularly the modernist Sir Sayyid Aḥmad Khān, were bitterly critical of Muir’s conclusions, but this did not prevent reasonable relations continuing, with Khān receiving an honorary doctorate (in absentia) from the University of Edinburgh in 1889, while Muir was principal there (Bennett 1992: 103–127; Powell 2010).

Of the two Protestant figures just discussed, the first was Anglican and the second Reformed. In his study of Protestant missionary thinking about Islam up to 1938, Lyle Vander Werff suggests that this denominational distinction can be helpfully used in order to delineate the two main views of Islam which developed in this period. The two figures whom he selects as leading examples of the two trends are the Englishman Temple Gairdner (1873–1928), who worked with the Anglican Church Missionary Society in Egypt, and the Dutch-American Samuel Zwemer (1867–1952), who was the founder of the Arabian Mission of the Reformed Church of America.

Each of these men stressed the importance of learning Arabic in order to be able to communicate the Christian message to educated Muslims, and both sought to arouse greater interest in mission to Muslims among Christians. Nevertheless, there were significant differences between their interpretations of Islam. Gairdner tended towards a more irenic approach, being ready to compare the two traditions and then to build on the common ground between them. He was also ready to be self-critical, acknowledging the failures of his own Christian community. He therefore saw much good in Islam, especially in the writings of the Sufis and of al-Ghazālī. He viewed Islam not so much as the antithesis of Christianity but rather Christianity as the fulfilment of Islam, with Islam as a kind of preparation for Christianity. Zwemer, by contrast, adopted a more confrontational approach, seeing Christianity as the final revelation and thus the Christian task as simply to preach the gospel to Muslims. There could be no compromise with Islam, therefore, since it was fundamentally the antithesis of Christianity. While Zwemer could thus be said to have sympathy with Muslims, he had no sympathy with Islam; his approach was thus more of a dialectical one than that of Gairdner, stressing contrast rather than continuity between the two traditions.

The titles of some of their books illustrate the differences between their approaches quite clearly. Gairdner is best known for his The Reproach of Islam, first published in 1909 and in later editions entitled The Rebuke of Islam. These titles clearly indicate the element of self-criticism in his approach, suggesting that the mere existence of Islam is, in a sense, a reproach, or judgment, of past Christian failings. The titles of some of Zwemer’s books, such as The Disintegration of Islam (1915) or The Cross above the Crescent (1941), seem to strike a rather more triumphalistic note. The prognosis of The Disintegration of Islam has very definitely not been borne out by subsequent history. With regard to their subsequent influence, Gairdner’s ideas and approach have tended to enjoy more influence in denominational Christian missionary societies, while Zwemer has enjoyed more influence in evangelical circles (Werff 1977).

4.3 Summary

The period since 1500 has thus seen both continuity and change in Christian thinking about Islam. In Christian-majority societies, the Enlightenment stimulated new perceptions of Islam which then became influential among theologians. In other parts of the world, particularly Muslim-majority places, missionaries sought to engage with Islam in different ways, for example through various kinds of debate and through Bible-translation. However, it should not be assumed that these two trends did not engage with or interact with each other. To give just one example, one of the first comprehensive English-language studies of Shī‘ī Islam, The Shi‘ite Religion: a History in Persia and Irak (1933), was written by Dwight M. Donaldson, who was a missionary of the American Presbyterian Church in Iran. Twenty years later, he also produced a pioneering study of Muslim ethics, having relocated to India (Donaldson 1953).

5.1 Inclusivism

Inclusivism provides an apt place to begin, because this is the point of view represented by what is probably the most important Christian statement about Islam in the whole of Christian history – given that it comes from an official Council of the world’s largest church rather than any individual theologian. Among the many statements on different topics which came from the Second Vatican Council (Vatican II) in the 1960s was this one, on Islam, published in 1965 as paragraph 3 of the decree Nostra Aetate (In Our Time):

The Church also regards with esteem the Muslims who worship the one, subsistent, merciful and almighty God, the Creator of heaven and earth, who has spoken to man. Islam willingly traces its descent back to Abraham, and just as he submitted himself to God, the Muslims endeavour to submit themselves to his mysterious decrees. They venerate Jesus as a prophet, without, however, recognizing him as God, and they pay honour to his virgin mother Mary and sometimes also invoke her with devotion. Further, they expect a day of judgment when God will raise all men from the dead and reward them. For this reason they attach importance to the moral life and worship God, mainly by prayer, alms-giving and fasting.

If in the course of the centuries there has arisen not infrequent discussion and hostility between Christian and Muslim, this sacred Council now urges everyone to forget the past, to make sincere efforts at mutual understanding and to work together in protecting and promoting for the good and benefit of all men, social justice, good morals as well as peace and freedom. (Hick 2001: 41)

This statement did not come from nowhere but was rather the end-result of a long process of gestation and deliberation, in which a key role was played by the important French Islamicist Louis Massignon (1883–1962), whose biography is a very interesting one. Having lost the Christian faith into which he had been baptized in his teens, Massignon recovered it as a result of the care which he received from a Muslim family in Iraq in 1908 while he was suffering from malaria. He went on to a very distinguished academic career in France, during which he published many books on Sufism, and on the tenth-century figure of al-Ḥallāj (d. 922) in particular. Al-Ḥallāj was crucified in Baghdad as a punishment for proclaiming ‘I am the truth’, and Massignon saw this and the events leading up to it as a kind of re-enactment of the life and death of Christ. He was convinced that the Holy Spirit was active in Islam, and that Islam should be described as an Abrahamic religion. He also expressed the hope that al-Ḥallāj might one day be recognized by the church as a martyr. Massignon was ordained as a priest of the Greek Catholic Church in 1950; many of his ideas are reflected in the carefully-worded statement of Vatican II, with its insistence on both the common ground and the difference between the two traditions, and its recognition, in the second paragraph, of the errors that have been made in the past, and its expression of a determination to do better in future (Gude 1996; Krokus 2017).

Although this was a Roman Catholic document, the broadly inclusivist view which it manifested with regard to Islam had also been established in other Christian churches. Thus, ten years earlier, the Anglican writer Kenneth Cragg (1913–2012) had produced his Call of the Minaret, first published in 1956. After outlining the contemporary situation in the world of Islam, particularly the achievement of political independence from former colonial masters in many countries, Cragg went on to outline the main elements of the faith and practice of Muslims. His main contribution here was to ensure that these topics were studied not only on the basis of classical texts but also through the everyday lives of contemporary Muslims. The existential dimension of Islam was thus given proper attention, and Cragg in his survey of these themes also ranged across the whole extent of the world of Islam, so that not just Egypt but also Pakistan and the wider Islamic world figure largely in the discussion. Part three of the book is the most original, in which Cragg outlines his view of the meaning of Islam for Christians. The call from the mosque, he suggests, is one which Christians should also heed, and although there are long traditions of mutual alienation there are also elements which point to openness and concern – so that Christians should seek to understand, to serve, to retrieve (in an echo of the earlier ideas of Temple Gairdner), to interpret, and to be patient.

The book attracted wide attention and significant reviews, with new editions being prepared in 1985 and 2000, and the comment by Lamin Sanneh that the book ‘marks a watershed in Christian-Muslim relations’ is fully deserved (from Sanneh’s commendation on the back cover of the book’s third edition in 2000; Cragg 1956; Lamb 2014; Goddard 2003). Cragg went on to produce over forty further books on Islam and Christian views of Islam, with his volumes on the Qur’an (Cragg 1971; 1973), and Muhammad (Cragg 1984) being of particular ongoing significance.

Among Orthodox Christians, a significant thinker who might also be described as an inclusivist is Georges Khodr, the Orthodox Metropolitan of Mount Lebanon. In an important article published in 1971, Khodr suggested that there is an urgent need for Christians to develop a fuller appreciation of the activities of the Holy Spirit in thinking about other religious traditions. The background to this idea is the dispute between Eastern and Western Christians concerning the ‘procession’ of the Holy Spirit. If, as Eastern Christians believe, the Spirit proceeds only from the Father and not the Son, it may be easier to perceive the activity of the Holy Spirit even where the Son is not named. Western Christians, with their view that the Spirit proceeds from the Father and the Son, may find it more difficult to recognize the Spirit’s activity if Jesus is not specifically named (Khodr 1971). In some of his other writings, Khodr has developed this argument very suggestively with regard to Islam (Sharp 2012: 67–73, 99–103).

5.2 Exclusivism

In the twentieth century, a towering influence in the theology of religions – as in almost every other aspect of Christian theology – has been Karl Barth. Barth devoted only a modest amount of attention to Islam, though this is significant because of the comparison which he drew between National Socialism and Islam (Ralston 2020: 203–208). A figure who was considerably influenced by him, and who did address a considerable amount of attention to Islam, was the Dutch thinker Hendrik Kraemer (1888–1965). Kraemer studied Oriental Studies in Leiden and then worked for the Dutch Bible Society in Indonesia from 1922 to 1928, then again from 1930 to 1936. On returning to Europe, he took up the position of Professor of the History and Phenomenology of Religions at Leiden. There he published The Christian Message in a Non-Christian World (1938), a work which, on the one hand, reflected the clear influence of Barth in terms of an emphasis on the discontinuity between the gospel and religion, and on the other drew on his very considerable experience of Islam in Indonesia. His tone was very different from that of earlier figures such as Muir and Zwemer, but his conclusions concerning Islam were nevertheless quite damning, characterizing it as unoriginal, superficial, simple, ruthless, stubborn, and possessing something of a superiority complex. Islam, he suggested, has almost no questions and no answers (Kraemer 1938: 216–217). This work was published shortly before the outbreak of World War II, and there is some indication that Kraemer moderated his views to some extent later in life – for example, in his Why Christianity of All Religions? , originally a series of radio talks in the Netherlands. There, Islam is still described as a legalistic religion, and although there is recognition of close kinship between Islam and the prophetic proclamation of God in the Bible, it is ultimately asserted that it is not possible to equate Allah with the God and Father of Jesus Christ (Kraemer 1962).

Exclusivism remains a widely held attitude in many, though by no means all, evangelical circles, and three particular groups seem to demonstrate a particular animosity towards Islam. Firstly, in dispensationalist circles – with their view that the end times are near, and that the state of Israel occupies a key role in demonstrating this – Islam is often portrayed quite negatively. Christian Zionism, widely influential as it is in the United States, is thus a factor in perpetuating harsh judgements on Islam (Kidd 2009). Secondly, in those parts of the world where Christians and Muslims are roughly equal in number, with the result that they are sometimes in competition for political power, negative judgements of Islam sometimes exert broad influence. These views can often be found in Africa, where the publication of the book Who is this Allah? under the pseudonym G. J. O. Moshay in Nigeria in 1990, became widely influential (Gifford 1991). Finally, in Europe, far right groups often make use of Christian language to point to what they see as the Islamic threat to Europe and the need to resist the Islamification of the continent. A significant proponent of this view was Anders Breivik, who killed seventy-seven people and injured over three hundred in attacks in Norway in 2011. A number of more recent public Qur’an burnings also demonstrate what can genuinely be described as Islamophobia, an irrational fear of Islam (Bangstad 2014).

5.3 Pluralism

A good example of a Christian thinker who adopts a pluralist attitude towards Islam, recognizing that it can be one among several ways to salvation, is the Canadian scholar Wilfred Cantwell Smith (1916–2000). Smith worked as a missionary in India between 1941 and 1945, the period which led up to Indian independence from Britain. The communal tensions between Hindus and Muslims, which eventually led to the death of perhaps half a million people in massacres associated with the creation of India and Pakistan, gave him a particular sensitivity to the communal aspect of religion. It was on this basis that, in his The Meaning and End of Religion (1962), Smith drew what was to him the crucial distinction between what he called ‘the cumulative tradition’ (Smith 1962: 154–169), the outward manifestations of religion in terms of rituals, beliefs, communities, and institutions, and ‘faith’, the attitude of trust which is the core of all religious experience. With regard to Islam, Smith suggested that not only Aquinas, Calvin, and Søren Kierkegaard but also Muslim writers, such as al-Ghazālī and al-Rāzī, wrote valuably about God, so that the writings of all of them could be vehicles whereby humans might come to the true knowledge of God. None of them, either Christian or Muslim, could enable human beings to know God fully, but Smith records how he met some Muslims who seemed to know God more fully than certain of his fellow Christians. Final judgment between the two traditions, he therefore insisted, should be left to God (Smith 1991: 22–23; Cracknell 2001).

Another example of a pluralist approach can be found in the writings of Kenneth Cracknell, in a pamphlet which he produced for the British Council of Churches under the title Considering Dialogue (1981). Here, he suggested that Christians and Muslims should see each other as fellow pilgrims to the truth that none has yet grasped in its immensity (Cracknell 1981). The third volume of Hans Küng’s massive trilogy on the three Abrahamic religions, entitled simply Islam, also fits most naturally into the pluralist category (Küng 2007).

5.4 Summary: the range of Christian thinking

The discussion of Christian thinking about Islam over the past few decades has made clear the range of opinion among Christians about the Islamic tradition. Other ways of presenting the material would have been possible, with Jacques Waardenburg employing the more established pattern of looking at Roman Catholic, Protestant, and Orthodox opinion (reviewed respectively by C. W. Troll, J.-C. Basset, and A. Argyriou) in his survey of the mutual opinions of Christians and Muslims in the second half of the twentieth century (Waardenburg 1998). Orthodox opinion is also usefully surveyed by Andrew Sharp, who focuses especially on Ecumenical Patriarch Bartholomew, Metropolitan of Mount Lebanon Georges Khodr, Archbishop Anastasios Yannoulatos of Tirana (Albania), and Dr Tarek Mitri of the World Council of Churches (Sharp 2012).

Another possible way of approaching the topic would be to look at regional approaches, giving full space to geographical and cultural as well as theological factors (O’Mahony 2008). Yet another method is to adopt the biographical approach used by Christian Troll and Chris Hewer, who give twenty-eight significant recent Christian thinkers about Islam the opportunity to share stories of how their interest in Islam, and their theological thinking about it, developed (Troll 2012). To select a few illustrative examples from this collection, the journeys of Christian Troll from Bonn to India, of Christiaan van Nispen tot Sevenaer from the Netherlands to Cairo, and of David Burrell and Tom Michel from the United States to Jerusalem and Cairo, and to Indonesia and Turkey, respectively, are particularly interesting.

There is thus no shortage of material, and plenty of interest, in developments within Christian thinking about Islam over the past few decades. A helpful review of over twenty publications which appeared between 2016 and 2021, across the whole spectrum of Christian opinion, can be found in The Ecumenical Review (Marshall 2021). The journal Islamochristiana, produced annually by PISAI, the Pontifical Institute for Arabic and Islamic Studies in Rome since 1975, is an invaluable source of information about developing Christian thinking about Islam, as well as about Christian-Muslim relations more widely.