Among the many martyrs of the persecutions of the early years of the fourth century was Sergius, a high-ranking army officer and a friend of the emperor (probably Maximinus, Augustus in the east from 310 to 313). He was also a Christian. His Christianity had never interfered with his military duties, but when he was denounced by rivals the emperor insisted that he sacrifice to the Roman gods. He refused, but the emperor, reluctant to lose him, sent him away to the east to Antiochus, one of Sergius’ former protégés who had become the governor of a remote frontier province. Antiochus also did his best to persuade Sergius to sacrifice—unsuccessfully—and finally Antiochus ordered Sergius’ execution by the sword. The site of the martyrdom was the fortress city of Rusafa on the Syrian steppes, thirty miles from the Euphrates. It was a remote area, constantly disputed between the Romans and the Persians and known to the Greeks as “the Barbarian Plain.”
In the middle of the fifth century a local bishop gave 300 pounds of gold so that a basilica could be erected over Sergius’ remains. Rusafa became a place of pilgrimage and the city grew wealthy. Then, in the seventh century, Arabs overran the area. Rusafa was now no longer a frontier town but lay well within the territories of the Ummayads, Syria’s rulers between 661 and 750; one of these rulers, the caliph Hisham, made Rusafa the site of his summer palace. The basilica still stood, but Hisham did nothing to disturb it directly. Rather, in the courtyard of the building he erected a mosque, and there is evidence that Sergius was adopted as an Islamic holy man. (“An old Christian saint at Damascus, now of Islam,” as the Victorian traveller Charles Doughty was to put it.) The presence of Islam was affirmed, but so was the continuation of Christian worship. As the patriarch of the Nestorian Christians, who had themselves been cast out as heretics by their fellow Christians, put it in 649, “These Arabs fight not against our Christian religion; nay, rather they defend our faith, they revere our priests and saints, and they make gifts to our churches and monasteries.” In 1150 an Arab source referred to the inhabitants of Rusafa as “mostly Christians,” occupied in the caravan trade. In 1982 some silver vessels, two of them chalices dating from the mid thirteenth century, were found. The chalices came from northern Europe, perhaps even from England, and appear to have been buried just before the Mongol invasions. Rusafa continued as a centre of Christian pilgrimage for 600 years after the Arab conquest.1
The story of the basilica at Rusafa shows that it was possible for a monotheistic faith to assert its identity without necessitating the destruction of other faiths. They could even be shown continuing respect and “a holy man” might be honoured for his piety rather than his specific religious allegiance. Arab toleration extended also to the Greek intellectual tradition, which the Arabs had encountered in the course of their conquests and which they both preserved and built on. The ninth-century scholar Abu al-Hasan Tabith paid fulsome tribute to the achievements of “the heathen,” by whom he meant the Greeks.
And we are the heirs and transmitters to our heirs, of heathenism, which is honoured gloriously in this world . . . Who made the world to be inhabited and flooded it with cities except the good men and kings of heathenism? Who has constructed harbours and conserved the rivers? Who has made manifest the hidden sciences . . . and it is they who have also made to arise the medicine for bodies. And they have filled the world with the correctness of modes of life and with the wisdom which is the head of excellence. Without these products of heathenism the world would be an empty and a needy place and it would have been enveloped in sheer want and misery.2
Reflecting this readiness to accept the best of Greek thought, not only were Plato’s “the Good,” Aristotle’s “unmoved mover” and Plotinus ’ “the One” appropriated to provide insights into the nature of Allah, but also in the ninth and tenth centuries most of the great Greek thinkers—Aristotle, Plato, Hippocrates, Galen, Euclid and Ptolemy among them—were carefully translated by teams of scholars into Arabic.
What proved crucial for its survival in this new context was the fact that Greek thought did not have to be doctored for the Islamic world. As the philosopher Averroës argued, religion and philosophy reached the same truths but by different routes and thus could exist alongside each other. Nor was original thinking stifled by the adoption of Greek thought. Avicenna, for instance, compiled a major textbook of medicine based on Greek sources but added to it the results and conclusions of his own researches and observations. Al-Razi, a Persian who studied at Baghdad before returning to Persia, deliberately set out, in the best tradition of Greek thinking, to expose his forebears to rational criticism, in Al-Razi’s case even including Aristotle. Reason should come first; it is “the ultimate authority which should govern and not be governed; should control and be not controlled; should lead and not be led.” While Al-Razi declared that he was a disciple of Galen, he also wrote books criticizing some of Galen’s precepts; he was the first to distinguish between smallpox and measles. Ibn al-Nafis also directly criticized Galen, noting how the blood passed through the lungs, not between the cavities of the heart as Galen had claimed. By contrast, Galen’s works were at this time being treated as sacred texts in Christian Europe and no attempt was being made to progress from them. In short, the Arabs sustained the Greek tradition by valuing the intellectual achievements of the past without being overawed by them and in using empirical evidence and reason to carry the understanding further. All this was possible without threatening Islam itself.3
So the classical tradition survived and in time it was once again to filter through to Europe. While fifth-century Christianity defined itself, in a defensive tradition inherited from Paul, largely in terms of its enemies—Judaism, paganism and other heretical Christians (as Augustine was to put it: “heretics, Jews and pagans; they have formed a unity against our Unity”) 4—even by the time of Gregory there is a sense of a lessening of insecurity and a relaxation of tension. As Christianity spread inexorably through western Europe, it gained confidence in itself, though this confidence was for some time expressed solely in spiritual rather than intellectual terms.5 One of the results of the massive shifts of perspective consequent on the “triumph” of Christianity was an intense concentration on the other world at the expense of this one. For centuries there was virtually no sign of any renaissance of independent thought, and most scholarly work focused on analysing, summarizing and commenting on the canon of authoritative texts.
The only western Christian philosopher of note in the 500 years between Boethius (whose Consolation of Philosophy of c. 524 became a medieval best-seller) and Anselm in the eleventh century was the ninth-century Irishman Erigena, who was remarkable for his time in knowing Greek. It was through him that the works of Pseudo-Dionysius entered the west, and so he played an important role in founding western mysticism. Erigena is intriguing in that he seems to come from nowhere; he has no links to an existing tradition or centre of learning. In his Division of Nature, he explores “nature,” by which he means the totality of all that exists or does not exist, from a Neoplatonist perspective. The Division was, in fact, too original for the church, which disapproved of his views on the identity of God (and presumably his endorsement of Origen’s view that ultimately everyone would be saved), and all Erigena’s works were declared heretical in the thirteenth century. He was removed so effectively from the western tradition that he still does not appear in many standard introductions to medieval thought, and it is only recently that his importance has been recognized.
In the eleventh century, Anselm of Canterbury (1033–1109) raised the possibility that reason could again play a part in orthodox Christian thought. He argued that certain tenets of faith—for instance, the impossibility of salvation without divine assistance in the shape of an incarnated Jesus—could be proved by reason. However, it was not until the twelfth century that a newly emerging investigative spirit in the west (usually referred to as Scholasticism) began to rediscover the classical tradition as it had been preserved in the writings of the Islamic east. Early stirrings of this spirit can be seen in the work of the Augustinian canon Hugh of Saint-Victor in Paris early in the century. Hugh asserts that accumulating knowledge about the world does not necessarily threaten the supremacy of either God or the Church. So begin the compilations of summae, encyclopaedic works synthesizing what was known to the medieval world, and also the foundation of the first universities (Paris, for instance, in 1170, Oxford at about the same time), in which secular learning could be taught so long as it was not seen to subvert the authority of the Church. Instruction in scientific method was inevitably sought in the works of Aristotle, which, along with the massive commentaries of the Arab philosophers, now began to be translated into Latin. With them came a fuller knowledge of the work of Ptolemy—his great astronomical treatise is still known by its Arab name, the Almagest, the “greatest.”6
Yet Aristotle offered an obvious challenge to Christianity: he was a pagan philosopher (whose “unmoved mover” did not even relate to the created world), and he extolled reason not only through the use of formal logic (the syllogism), but also as a means of understanding the natural world through the analysis of empirical evidence. As we have seen, his works had long since been discredited; suspicions still lingered. In 1215 the Faculty of Arts of the University of Paris forbade the use of his works as a basis for discussion. For Christians to accept Aristotle, his work had somehow to be made compatible with Christian doctrine, which in turn made it necessary for Christianity to allow reason and the study of the natural world a new role. A German Dominican, Albert the Great (c. 1200–1280), was the first to present Aristotle in full to Christian Europe. To Albert the scientific exploration of the world was of value in itself, and he claimed that its findings could never conflict with those arrived at through faith. Aristotle was not to be feared, and, as the philosophers of Islam had already argued, reason and faith would eventually reach a harmony in the knowledge of God. His was a major endorsement of the significance of reason and empiricism (and eventually, in the twentieth century, earned Albert the title of “patron saint” of the natural sciences). Yet this was just a beginning; in 1248, Albert acquired a new student, a young Dominican who already shared his enthusiasm for “the Philosopher,” as Aristotle was known, called Thomas Aquinas. Aquinas was to incorporate Aristotle into the Christian, above all Roman Catholic, tradition with such intellectual power and coherence that in some areas of thought Aristotelianism and Catholicism became virtually indistinguishable. As one commentator has put it, Aquinas converted Aristotle to Christianity and carried out the baptism himself! In view of Aquinas’s heavy dependence on Aristotle, it might rather be said that Aquinas was converted to Aristotelianism.
A prodigious worker, Aquinas wrote several million words of lucid, albeit technical, medieval Latin prose. He avoids rhetoric and exposes little of his personality in the relentless logic and thoroughness with which his great works unfold. Unlike Augustine, he does not offer insights into his own character—there is none of Augustine’s struggle with sexual temptation and a difficult mother to appeal to the modern reader. Adopted into the Catholic tradition as the great teacher, above all in the nineteenth and early twentieth centuries, he remains a major figure in Catholic theology. Outside Catholicism, philosophers of religion still have to tackle his five “proofs” of the existence of God. He is little read today, but it is arguable that Thomas Aquinas revived the Aristotelian approach to knowing things so successfully that he unwittingly laid the foundations of the scientific revolution that was to transform western thought.7
Aquinas was born near Naples in southern Italy almost certainly in 1225.8 His background was aristocratic, but as a seventh son he was expected to join a religious order, probably the Benedictines—at the age of five he was sent off to the celebrated Benedictine abbey of Monte Cassino. His university studies were in Naples, where he was introduced to secular learning and the works of both Jewish and Arab philosophers; it was here he had his first acquaintance with Aristotle. He was also drawn to the Dominican order, in some ways a surprising choice for one of his background. Compared to the wealthier and more established religious orders, the Dominicans were new (Dominic, their founder, had died only five years before Aquinas’ birth) and relied on begging as a means of support. However, they had already established a reputation for learning and teaching, and this may have attracted the somewhat reserved Aquinas. Shocked by Thomas’ choice of this low-status order, his brothers kidnapped him and removed him to a family estate. He escaped to the Dominicans’ teaching house at Paris, where his extraordinary intellect was soon recognized, and he was then sent to Cologne to study with Albert, the academic star of the order, before returning to Paris, the most celebrated of Europe’s universities, for seven intensive years of study. He was already writing, and even at this early stage the contours of his philosophy, with its emphasis on the use of reason to explore all that can be explored within a creation that was wholly God’s, were established.
Having been licensed to teach theology, Aquinas spent the next ten years in Italy, moving from one Dominican house to another, and even spending time at the papal court at Orvieto. Here he caught up with his old mentor, Albert, but also met another Dominican, William of Moerbeke, who was able to translate Aristotle for him directly from the original Greek. Some previous versions of Aristotle’s works had made their way from Greek to Syriac to Arabic to Spanish to Latin, losing much of their original meaning in the process. It was in these years that he produced his first great work, Summa contra gentiles, a defence of Christianity against unbelievers, and began the most celebrated of all his works, the Summa theologiae, a comprehensive synthesis of theology aimed at Dominican students. The second part of the Summa theologiae was written during Aquinas’ most productive period, as professor of theology in Paris between 1269 and 1272. Alongside the vast Summa (the second part alone comprises a million words) he wrote commentaries on most of Aristotle’s surviving works. He subsequently returned to Italy, to his old university, Naples, where he became head of a Dominican teaching house and continued work on the Summa.
Here, in December 1273, Aquinas appears to have had some form of breakdown. This has been variously explained in terms of a mystical experience, complete exhaustion or as a possible moment of realization that reason was breaking the bounds of orthodoxy. He had always had his enemies, among traditionalists who resented the Dominicans and Aquinas in particular for his stress on rationalism, and among enthusiastic Aristotelians who disapproved of his integration of Aristotle and Christianity. In the year of his breakdown he was strongly criticized in Paris for his insistence on a natural underlying order of things (which appeared to deny God’s power of miraculous intervention) and his respect for the body as the sustainer of the soul. In 1274 Aquinas was summoned by the pope to a council at Lyons, where it is possible that he would have been confronted with these criticisms, but he fell ill on the way, in unknown circumstances, and died. Three years later, several of his theses were formally condemned, first in Paris and then in Oxford; the Paris condemnation lasted fifty years, and there is no record that the Oxford condemnation has ever been revoked.
Aquinas avoided the abusive and aggressive language of the more combative theologians, believing that reason could convince on its merits. In his Summa contra gentiles, a missionary tract for those working with Muslims and pagans, he even avoids drawing on the scriptures on the grounds that his readers did not know them. “Hence we must have recourse to natural reason, to which all men are forced to assent.” (Aquinas has here reached a point where Christianity seems to have become largely divorced from the scriptures.) It is not until the fourth and final book of the Summa that he introduces those Christian doctrines sustainable only by faith, among which he includes the doctrine of the Trinity, the Incarnation and the creation of the world by God ex nihilo, “out of nothing” (the alternative view, held by both Aristotle and Plato, which Aquinas accepted he could not disprove, being that matter had existed eternally alongside God).
While Aquinas accepted the articles of faith which had been revealed by God, he did not denigrate reason in the way many of his fellow Christians had done. Challenging the pessimism of Augustine and his followers, he presents reason as a gift of God, not a means of subverting God. A deeper understanding of the natural world leads only to greater conviction of the greatness of its creator. Rather than ignore what is to be seen in the sky, as Plato had argued, we should observe it in the confidence that it would help explain God’s natural order. God wants man to reach towards Him and has given him the means, his rational mind, to do so; in return God will reveal, as articles of faith, those things that remain impossible for the human mind to grasp. To denigrate humanity as corrupted by sin is to make nonsense of God’s creation. “To take something away from the perfection of the creature is to abstract from the perfection of the creative power [i.e. God] itself,” as Thomas himself put it. Furthermore, man’s possession of a rational mind with, inherent in its rationality, the possibility of choice ensures free will: “that man acts from free judgement follows necessarily from the fact that he is rational.” The contrast with Augustine’s view of man as trapped in self-loathing and engulfed in his sinfulness is striking. It is a contrast as much of temperament as of theology (arguably, one fed into the other). Augustine expects human beings to fail; inspired by Aristotle, Aquinas is naturally optimistic that they will use their God-given reason to find spiritual and personal fulfillment.9
If we are to value empirical knowledge, we must also value the means by which it is obtained, the senses. In contrast to the Platonic Christian view that envisaged the human body as pulling the soul away from God, Aquinas argues, following Aristotle, that the soul and body are inexorably joined. “Plato said that the soul is in the body ‘as a sailor in a ship.’ Thus the union of soul and body would only be by contact of power. But this doctrine seems not to fit the facts,” as Aquinas boldly writes in the Summa contra gentiles. The essence of being human lies in having an ensouled body, and it is no more possible to distinguish between body and soul than between a piece of wax and the impression a stamp has made on it. Since the rational mind can only act on what it learns from the senses, the body itself should not be despised.10
Aristotle’s contribution in every respect was immense: one scholar has gone so far as to say, “In so far as Thomas ‘had’ a philosophy it was simply Aristotle’s . . . in so far as he thought philosophically, his thought moved in Aristotelian grooves.”11 Aristotle’s insistence on the importance of rational thought and the accumulation of empirical evidence was, of course, crucial, but even more so was his work on the nature of man. In the second part of the Summa theologiae Aquinas virtually takes over the Nicomachean Ethics, even modelling the Summa on the structure of Aristotle’s work. It is the natural instinct of man, Aristotle had argued, to develop into his final and most complete form, that of a flourishing human being capable of using rational thought at the highest level; it was this optimistic approach that Aquinas absorbed into Christianity. The end result, for Aquinas, would be a full appreciation of the nature and love of God. He also derives from the Nicomachean Ethics a belief in the importance of using reason to make moral choices; in so doing he argues, as had Aristotle, for the necessity for achieving control over the emotions without, however, denying their importance. Temperance and prudence, fortitude and justice are important virtues and should be deliberately cultivated. This realistic approach comes as somewhat of a relief after the tortured struggles that Paul, Jerome and Augustine believed intrinsic to man’s time on earth. (Aquinas’ writings may be dull, but in contrast to those of some of the more excitable Church Fathers they radiate good sense, optimism and down-to-earth practicality.)
Aristotle had argued that it was the natural impulse of human beings to desire “the good.” Aquinas goes further. The combination of this impulse towards “the good” with the power of rational thought allows human beings to reach an understanding of what is morally right.
There is in people an appetite for the good of their nature as rational, and this is proper to them, that they should know truths about God and about living in society. Correspondingly whatever this involves is a matter of natural law, for instance that people should shun ignorance, not offend others with whom they ought to live in civility, and other such related requirements.12
The concept of natural law was one of Aquinas’ most influential contributions to western thought (although there are precedents in Plato, Aristotle and in Roman law). God’s law is eternal, made up of absolute precepts, and it is possible to grasp it by means of reason. Here, ironically for someone so steeped in Aristotle, Aquinas drew on Platonism; the concept of natural law, or moral law—as it is sometimes termed— has raised the same philosophical challenges that Platonism did. Is it possible to be sure of the moral absolutes or to define with any clarity the ways in which they should determine our behaviour? Though Aquinas made a distinction between universal and absolute values and those that are relative to time, place and cultures, where is the line to be drawn? Aquinas’ concept of natural law remains influential: the 1968 papal encyclical Humanae Vitae forbade artificial contraception for Catholics partly on the grounds that it was against “natural law,” here as defined by Pope Paul VI on behalf of the Catholic Church.13 Less controversially, natural law has been used as a means of defining inviolable human rights and crimes against humanity. Aquinas’ formulation of the concept of “the just war” remains crucial to modern debates.14
Aquinas restored the relationship between reason and faith; to him, the one sustained the other. Thus Thomas could argue that articles of faith, which were by definition true as the revealed word of God, could act as the axioms from which rational thought could progress. Aquinas had, of course, no reason to foresee how much they would come into conflict after his death. To him “faith” included belief in the teachings of the Church and of scripture. So it was an article of faith to believe that “the earth was fixed on its foundation, not to be moved for ever” (Psalm 103), yet by the sixteenth century observation and reason (by Copernicus and then Galileo) suggested that it moved around the sun. The famous clash between Galileo and the Catholic Church was the result. This was the inherent flaw in Aquinas’ legacy. Empirical evidence could challenge the authority of the scriptures, but, more than this, Aquinas, perhaps unwittingly, had exposed the potential clash between reason and faith. It was impossible to allow orthodox Christian doctrine, much of which depended on faith or revelation, to be undermined by reason, and this meant that the uses of reason in the Christian tradition had to be circumscribed so as not to subvert orthodoxy. This was certainly alien to the Aristotelian tradition, where, as we have seen, empirical evidence was seen as superior to “theory.” In the event the power of orthodox theology was such that Aristotle became integrated into Christianity as Plato, Ptolemy and Galen had been, and the sheer innovatory power of Aquinas’ achievement was forgotten. It is ironic to find the seventeenth-century rationalists using “reason” as a weapon with which to attack the Christianized version of Aristotle!15
The contrasting approaches of Aquinas and Augustine to the nature of man and the use of reason reflect the earlier contrast between Aristotle and Plato. It is perhaps a measure of the Greek achievement that both were eventually absorbed into Christianity. If there are arguably two historical Christianities, that of the early church (and even here the Gospel evidence needs to be distinguished from the theologies of Paul) and that of the imperial church, there are also two philosophical Christianities, one resting on the Platonic tradition and the other on the Aristotelian. Any study of Christianity needs to recognize these different strands of thought and aim to disentangle them from the specific historical circumstances that shaped them. In short, while traditionally theologians have presented Christian doctrine as having an inner philosophical coherence independent of events, historians, both Christian and non-Christian, are increasingly coming to recognise that it is impossible to divorce the making of doctrine from the society in which it evolved.
Despite the condemnations of his work soon after his death, Thomas’ brilliance was soon recognized; by 1316, when his works were still banned in Paris, the process of canonization began. Normally two miracles were required as evidence of God’s power working through a potential saint. Those produced for Thomas were scarcely convincing. On his deathbed it was said he had asked for herrings, unknown in the Italian seas, and sure enough in the next load of fish produced by the local fishmonger there were indeed herrings. As it transpired that the witnesses had never seen herrings before and could not be sure what they had seen, the case faltered. It was left to the pope, John XXII, to break the impasse: “There are as many miracles as there are articles of the Summa.” Thomas was duly acknowledged as a saint in July 1323. Thus the power of words and independent thinking were once again given a status that they had almost lost.