THOMAS AQUINAS AND THE RESTORATION OF REASON.

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 G.o.ds. He refused, but the emperor, reluctant to lose him, sent him away to the east to Antiochus, one of Sergius' former proteges 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 a.s.sert its ident.i.ty 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 Averroes 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 pa.s.sed 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 cla.s.sical 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 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 ma.s.sive 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 a.n.a.lysing, summarizing and commenting on the canon of authoritative texts. One of the results of the ma.s.sive 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 a.n.a.lysing, 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 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 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 Division of Nature, of Nature, he explores "nature," by which he means the totality of all that exists or does not exist, from a Neoplatonist perspective. he explores "nature," by which he means the totality of all that exists or does not exist, from a Neoplatonist perspective. The Division The Division was, in fact, too original for the church, which disapproved of his views on the ident.i.ty of G.o.d (and presumably his endors.e.m.e.nt 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. was, in fact, too original for the church, which disapproved of his views on the ident.i.ty of G.o.d (and presumably his endors.e.m.e.nt 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 (10331109) 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 a.s.sistance 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 cla.s.sical 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 a.s.serts that acc.u.mulating knowledge about the world does not necessarily threaten the supremacy of either G.o.d or the Church. So begin the compilations of summae, 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 ma.s.sive 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." 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 ma.s.sive 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 a.n.a.lysis 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. 12001280), 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 G.o.d. His was a major endors.e.m.e.nt of the significance of reason and empiricism (and eventually, in the twentieth century, earned Albert the t.i.tle 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 s.e.xual 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 G.o.d. 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 Ca.s.sino. 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 G.o.d's, were established. 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 Ca.s.sino. 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 G.o.d'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, Summa contra gentiles, a defence of Christianity against unbelievers, and began the most celebrated of all his works, the a defence of Christianity against unbelievers, and began the most celebrated of all his works, the Summa theologiae, Summa theologiae, a comprehensive synthesis of theology aimed at Dominican students. The second part of the a comprehensive synthesis of theology aimed at Dominican students. The second part of the Summa theologiae Summa theologiae was written during Aquinas' most productive period, as professor of theology in Paris between 1269 and 1272. Alongside the vast was written during Aquinas' most productive period, as professor of theology in Paris between 1269 and 1272. Alongside the vast Summa 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 (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. 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 G.o.d'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 circ.u.mstances, 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, 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 a.s.sent." (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 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 a.s.sent." (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 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 G.o.d 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 G.o.d ex ex nihilo, 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 G.o.d). "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 G.o.d).

While Aquinas accepted the articles of faith which had been revealed by G.o.d, 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 G.o.d, not a means of subverting G.o.d. 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 G.o.d's natural order. G.o.d wants man to reach towards Him and has given him the means, his rational mind, to do so; in return G.o.d 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 G.o.d's creation. "To take something away from the perfection of the creature is to abstract from the perfection of the creative power [i.e. G.o.d] 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 G.o.d-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 G.o.d, 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. 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. 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 acc.u.mulation 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 Aristotle's insistence on the importance of rational thought and the acc.u.mulation 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 Summa theologiae Aquinas virtually takes over the Aquinas virtually takes over the Nicomachean Ethics, Nicomachean Ethics, even modelling the even modelling the Summa 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 G.o.d. He also derives from the 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 G.o.d. He also derives from the Nicomachean Ethics 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, fort.i.tude 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.) 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, fort.i.tude 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 appet.i.te for the good of their nature as rational, and this is proper to them, that they should know truths about G.o.d 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). G.o.d'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 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. 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. 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 G.o.d, 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 circ.u.mscribed 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 circ.u.mstances 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 G.o.d'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 impa.s.se: "There are as many miracles as there are articles of the Summa. 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.

Epilogue.

It has never been part of the argument of this book that Christians did not attempt to use rational means of discovering theological truths. 1 1 The problem was rather that reason is only of limited use in finding such truths. Any rational argument must begin with axioms, foundations from which an argument can progress, and proceed to conclusions on which all concur. Pythagoras' theorem starts from a right-angled triangle-the important point being that any conceivable right-angle triangle can serve as the "axiom" from which the theorem is proved-and ends with a proof which is logically irrefutable at any time or in any place. This is the essence of mathematical logic. Similarly, empirical evidence serves as axioms from which inductive proofs are made, although the empirical evidence which exists will always be provisional. The problem was rather that reason is only of limited use in finding such truths. Any rational argument must begin with axioms, foundations from which an argument can progress, and proceed to conclusions on which all concur. Pythagoras' theorem starts from a right-angled triangle-the important point being that any conceivable right-angle triangle can serve as the "axiom" from which the theorem is proved-and ends with a proof which is logically irrefutable at any time or in any place. This is the essence of mathematical logic. Similarly, empirical evidence serves as axioms from which inductive proofs are made, although the empirical evidence which exists will always be provisional.

So where are the axioms from which theology can progress? Attempts by Thomas Aquinas and others to provide self-evident principles from which logical argument about the nature of G.o.d could progress collapsed as soon as it became clear (in the Enlightenment, for example) that there was no agreement about what these principles might be (as there had to be if they were "self-evident"!). One can talk of the revelation of G.o.d, but, as the Montanists showed, anyone can claim to have received a revelation from G.o.d, and there is virtually no way of a.s.sessing what is a valid or invalid revelation. In practice, revelation does not prove susceptible to reason because there is no way through which it can be a.s.sessed by reasoning minds. The result is that in the churches there was soon a battle for control over what counted as revelation, and the Montanists were among the casualties. The scriptures are often cited by theologians as the primary source of "axioms." However, when one puts together the Gospels, the letters of Paul, the Book of Revelation and the Old Testament, there is no sense of a coherent "axiomatic" basis on which to build theological truths. As any study of, say, the Arian dispute shows, the different sides to the conflict drew on different texts to "support" their argument. Again the churches had eventually to a.s.sume control of how scripture was to be interpreted, in effect so that interpretations never conflicted with what became established as orthodoxy. Even Thomas Aquinas, one of Europe's most outstanding champions of rational thought, had to suspend reason when it conflicted with orthodoxy.

So the point being made here is not that the Christians did not attempt to use reason but they could never reach agreed truths, any more than there could be, in practice, an agreed formulation of what is meant by Plato's "the Good." The evidence of Christian disputes shows conclusively that reason failed in achieving any kind of consensus, and, in fact, like other spiritual movements in the ancient world, Christianity splintered as it settled into different cultural and philosophical niches across the empire. The important question to answer is why Christianity was different from other spiritual movements in the ancient world in insisting that Christians throughout the empire should adhere to a common authority. This was the aspect of Christianity which was truly revolutionary, even if the fact is often overlooked in histories of the church. The common adherence to the message of Christ, both in his teachings and in his death and resurrection (and the need to control Christ in face of the many other spiritual movements which appropriated him), provides much of the answer, but it also seems to have been important to define the boundaries of what it meant to be Christian in a society many of whose values Paul had told Christians they must reject. Christians did not have the distinguishing physical and cultural marks of Judaism; they had to create these marks and enforce them in the highly fluid spiritual world of the Greco-Roman empire. Crucial to the establishment of authority in the early church was the emergence of the bishop and the consolidation of his position within a hierarchy of bishoprics based on the doctrine of apostolic succession. Ultimately this, and not reasoned argument, was where authority rested. Even though the hierarchy remained a loose one, authority rested here and not on the fruits of reasoned argument.

Increasingly, the history of the early church is being written in terms of diversity rather than unity of belief. Most communities were remote from each other. The varied cultural and religious traditions which shaped local theologies-now more fully recognized with the ever growing number of early Christian inscriptions being found and published- coalesced with the lack of axiomatic foundations to make doctrinal certainty impossible. When the bishops of Rome adopted Latin rather than Greek for the western church in the fourth century, they distanced themselves from the ancient centres of Christianity and destroyed any chance of a.s.serting their primacy over the Greek world. As we have seen, orthodoxy eventually had to be imposed from above.

What seems to have marked the turning point is Constantine's appreciation that the authority of the bishops could be used in support of the empire. However, he failed to appreciate how intractable the doctrinal disputes between the bishops had become, and his hope of having the church as a united body brought into the structure of the state by patronage, tax exemptions and toleration soon proved to be a fantasy. "You [the bishops] do nothing but that which encourages discord and hatred and, to speak frankly, which leads to the destruction of the human race," he fumed. Hence his initiative in calling the Council of Nicaea to define and enforce a common doctrine. The theological history of the fourth century is largely one of the emperors, under immense pressure from invaders, attempting to achieve a foundation of orthodoxy so that they could preserve a united society. The embattled Theodosius eventually enforced Nicene orthodoxy by imperial decree and then, unlike his predecessors, moved vigorously to crush those Christians and others who continued to oppose it. Here politics won over theology.

In short, the argument is first that despite attempts by Christians to use reason, it was not an appropriate way of finding theological truths. The frustrations which followed led to arguments becoming personal and bitter. The texts of a Jerome or an Athanasius are marked by invective at the expense of reasoned argument. This was not only deeply unfortunate for Christianity but became a major hindrance to a state which was hoping to use a docile church to support its authority. Hence the imposition of authority, an imposition which, backed by Christian suspicions of scientific argument, crushed all forms of reasoned thinking.

Why was the suppression of reasoned argument so important? Reason is a means of finding truths through deductive and inductive logic. These truths may be valuable in themselves in helping us understand who we are (the theory of evolution), but they have also, through medicine, for instance, transformed human life. We are free to apply the fruits of reasoned thought to some of our greatest needs, in many areas with enormous success. Yet built into a tradition of rational thought is the necessity for tolerance. It is the only way in which it can progress. Reason also provides external standards of truth, often, for instance, from empirical evidence. This helps take personal animosity out of debates in that disputes over the interpretation of external evidence are normally less abrasive than those between human beings struggling to a.s.sert or maintain their personal authority. History suggests that conflicts between religions tend to be more destructive than those between scientists! In this sense, the price to pay for the a.s.sumption that there can be doctrinal certainty has been a heavy one.

Philosophically, therefore, it becomes crucial to define the areas where certainty is possible and those where it is not. This was another of the intellectual achievements of the Greeks. Pace Pace Plato, they understood that the nature of the divine, if such spiritual force exists, cannot be grasped when there is no external evidence for it. The troubles described in this book come not from the teachings of Jesus or from the nature of Christians themselves (though arguably one can trace them to Paul), but from the determination to make "certain" statements about G.o.d. Tragically, the pressures to do so, many of them politcal and economic, were intensified by the introduction of the concept of an afterlife, in which most would be punished eternally for failure to adhere to what was eventually decided to be orthodox. If there is no external standard by which one can define G.o.d, then figures who have the authority to define him for others have to be created and this authority given ideological support. This invariably means the suppression of freedom of independent thought. It was unfortunate that Christianity became embroiled in historical circ.u.mstances which made this such a dominant issue. Plato, they understood that the nature of the divine, if such spiritual force exists, cannot be grasped when there is no external evidence for it. The troubles described in this book come not from the teachings of Jesus or from the nature of Christians themselves (though arguably one can trace them to Paul), but from the determination to make "certain" statements about G.o.d. Tragically, the pressures to do so, many of them politcal and economic, were intensified by the introduction of the concept of an afterlife, in which most would be punished eternally for failure to adhere to what was eventually decided to be orthodox. If there is no external standard by which one can define G.o.d, then figures who have the authority to define him for others have to be created and this authority given ideological support. This invariably means the suppression of freedom of independent thought. It was unfortunate that Christianity became embroiled in historical circ.u.mstances which made this such a dominant issue.

One important theme which has run through this book is the linking of belief in rational thought with a belief in free will. Because rationalism has in so many fields enriched humanity's understanding of itself and improved human life, rationalists have every right to believe in further progress. Those who have decried the possibility of rational thought or denigrated it do seem to have a much more pessimistic view of human existence. That was why I preferred to end this book with Aquinas rather than Augustine! Yet at the same time we do have a spiritual and emotional nature, and without it rational thought in itself would be arid. It is a healthy balance between the two which seems the goal.2 In conclusion, it is worth asking why the political dimension to the making of Christian doctrine has been so successfully expunged from the history of the western churches. It is virtually ignored in most histories of Christianity. (The important role of the emperors and their successors has been more readily accepted by the Orthodox churches.) It is understandable, of course, that the churches wished to claim control over their own history, but the disappearance is also a symbol of Plato's greatest triumph, the successful integration of his thought into Christian theology. Plato argued that his Forms were realities which existed eternally and independently of whether or not they were grasped by the reasoning mind at any historical moment. The context, the time or place or particular historical circ.u.mstances, in which orthodox doctrine (if it was given the same status as a Platonic Form) was formulated was immaterial. As we have seen, Eusebius a.s.sumes that doctrinal truth was known from the beginning of time and had to be protected from novelties introduced by heretics. The church councils were simply markers in the process of protecting the truth. So one could disregard the role of the emperor in calling or influencing the outcome of councils.

History still has to be rewritten in the west, but the process is complete by the time of Gregory the Great. His immediate concern was to establish his own authority over the remains of an empire in which traditional imperial authority had disintegrated. There was no one to prevent him from rewriting the history of Christian doctrine as if the emperors had never played a part in it, and so he did. Drawing on the precedents set by Ambrose, the popes were now a.s.sumed to have control over emperors, a reversal of the political realities of the fourth century. It is only recently that scholars have begun to appreciate the extent to which the emperors actually made, in the words of Hilary of Poitiers, the bishops their slaves. It is simplistic to talk of the Greek tradition of rational thought being suppressed by Christians. It makes more sense to argue that the suppression took place at the hands of a state supported by a church which it had itself politicized (and, in the process, removed from its roots in the Gospel teachings).

The history of Christianity is often presented as if it had a natural coherence. The evidence suggests that this is not true. The church of Constantine and his successors, embedded as it was in the stressed environment of the late empire, was radically different from that of earlier times. It was in this context that the suppression of rational thought took place, for reasons which I hope this book has made clear. Likewise, after the collapse of the empire, the medieval church in western Europe developed new roles and strategies to cope with a society in which a number of weaker political authorities (the early states of Europe) were emerging in compet.i.tion with each other. The battle to defeat the cla.s.sical intellectual tradition was, for the moment, a thing of the past, and the church could turn itself to new and different challenges. Gregory is the linchpin. There is no doubt that he is one of the greatest spiritual leaders the west has ever produced, not least in terms of his restoration of moderation and moral integrity to the Christian tradition after the obsessional ascetic narcissism and destructive invective of the fourth and fifth centuries.

I would reiterate the central theme of this book: that the Greek intellectual tradition was suppressed rather than simply faded away. My own feeling is that this is an important moment in European cultural history which has for all too long been neglected. Whether the explanations put forward in this book for the suppression are accepted or not, the reasons for the extinction of serious mathematical and scientific thinking in Europe for a thousand years surely deserve more attention than they have received.

Notes.

1.

1. It is now known to be of the emperor Marcus Aurelius, but the mistaken belief that it was of Constantine led to it being spared when pagan statues were being destroyed by Christians. It was later moved to the Capitoline Hill and can now be seen under cover there in the Palazzo Nuovo.

2. The information used in this chapter comes from the fine study of the fres...o...b.. G. Geiger, Filippino Lippi's Carafa Chapel: Renaissance Art in Rome Filippino Lippi's Carafa Chapel: Renaissance Art in Rome (Kirksville, Mo., 1986), chap. 5, on which my own text is based. (Kirksville, Mo., 1986), chap. 5, on which my own text is based.

3. The text itself is from Paul's first letter to the Corinthians, 1:19, where it is related back to earlier scripture. In the subsequent verses Paul goes on to place G.o.d's wisdom above human wisdom. The consequences of this condemnation of pagan philosophy are a major theme of this book, although, as will be argued later, Paul appears to have known very little of the philosophical tradition which he was attacking.

4. Filippino Lippi was the son of the Florentine Fra Filippo Lippi, an important painter of narrative scenes, and, between 1488 and 1493, a student of Botticelli. The chapel-the only commission known to have been undertaken by Filippino in Rome-was undertaken at the behest of Cardinal Oliviero Carafa (14301511), cardinal protector of the Dominicans and a staunch upholder of papal authority. Carafa was a man of action who led a crusade against the Turks in the 1470s. (The Porta Ripa Grande is probably included in the fres...o...b..cause it was from here that he embarked for the crusade.) 5. The concept of "faith" will be explored in different contexts in this book. For some of the philosophical problems involved see chap. 9, note 14. The words "all will be well" come from the writings of the Christian mystic Julian of Norwich and refer directly to the peace and serenity brought by Jesus.

2.

1. Aristotle, Metaphysics II. 1 993a3034, trans. W. D. Ross.

2. The story is told in book 5 of the Odyssey. Odyssey. A recommended translation is that by R. f.a.gles (London and New York, 1996). Examples of "heroes" consciously using rational thought to decide on a course of action can also be found in Homer's A recommended translation is that by R. f.a.gles (London and New York, 1996). Examples of "heroes" consciously using rational thought to decide on a course of action can also be found in Homer's Iliad. Iliad. In book 17, lines 10121 (trans. R. f.a.gles, Harmondsworth, 1991), Menelaus, "deeply torn, as he probed his own great heart," weighs up whether to fight Hector in single combat or to withdraw from battle. In an important article, "The Epic Cycle and the Uniqueness of Homer" ( In book 17, lines 10121 (trans. R. f.a.gles, Harmondsworth, 1991), Menelaus, "deeply torn, as he probed his own great heart," weighs up whether to fight Hector in single combat or to withdraw from battle. In an important article, "The Epic Cycle and the Uniqueness of Homer" (Journal of h.e.l.lenic Studies, vol. 97 [1977], pp. 3953), Jasper Griffin compares Homer's epics, the vol. 97 [1977], pp. 3953), Jasper Griffin compares Homer's epics, the Odyssey Odyssey and the and the Iliad, Iliad, with an epic cycle that survives from the same period. In the epic cycle heroes are immortal and there are monsters and miracles, while Homer's is a cosmos where even heroes cannot escape death and the natural world is presented as it really is. (Animals cannot change shape or form, for instance.) In Homer's world, of course, the G.o.ds still hold some power, as in the pa.s.sage here, but over the next centuries the development of rational thought was to diminish their role in the natural world. Homer can thus be seen to have made an important contribution to the transition from a world of magic and miracles to one of reason. with an epic cycle that survives from the same period. In the epic cycle heroes are immortal and there are monsters and miracles, while Homer's is a cosmos where even heroes cannot escape death and the natural world is presented as it really is. (Animals cannot change shape or form, for instance.) In Homer's world, of course, the G.o.ds still hold some power, as in the pa.s.sage here, but over the next centuries the development of rational thought was to diminish their role in the natural world. Homer can thus be seen to have made an important contribution to the transition from a world of magic and miracles to one of reason.

3. The evolution of the city state can be traced in O. Murray, Early Greece, 2nd ed. (London, 1993), and R. Osborne, Greece in the Making, 1200479 B.C. (London, 1996).

4. For an introduction to Greek religion see S. Price, Religions of the Ancient Greeks Greeks (Cambridge, 1999). (Cambridge, 1999).

5. Quoted ibid., p. 79.

6. Thucydides, The Peloponnesian War The Peloponnesian War 3:82, trans. R. Warner, Penguin Cla.s.sics. 3:82, trans. R. Warner, Penguin Cla.s.sics.

7. Homer's epics already include some appreciation of an underlying natural order. In this extract, the G.o.ds themselves act to impose it. Poseidon, the G.o.d of earthquakes, helped, significantly, by Apollo, the G.o.d of reason among other things, gets rid of the intrusive settlement made by the Greeks along the coastline outside Troy.

The earth-shaker himself, trident locked in his grip, led the way, rocking loose, sweeping up in his breakers all the bastions, strong supports of logs and stones . . .

He made all smooth along the rip of the h.e.l.lespont and piled the endless beaches deep in sand again and once he had levelled the Argives' mighty wall he turned the rivers flowing back in their beds again where their fresh clear tides had run since time began.

So in the years to come Poseidon and the G.o.d Apollo would set all things to rights once more.

Trans. R. f.a.gles, The Iliad, The Iliad, Penguin Cla.s.sics. The "Argives" are the Greeks. Penguin Cla.s.sics. The "Argives" are the Greeks.

8. Translation by O. Murray.

9. As an overview of the "scientific revolution," see C. Kahn, "The Origins of Greek Science and Philosophy," in A. Bowen, ed., Science and Philosophy in Ancient Science and Philosophy in Ancient Greece Greece (New York and London, 1993). (New York and London, 1993). The Cambridge Companion to Early Greek The Cambridge Companion to Early Greek Philosophy, Philosophy, ed. A. A. Long (Cambridge, 1999), has articles on the main pre-Socratic (that is, those practising before Socrates, late fifth century) philosophers. For a broad survey of Greek thinking in general, see J. Brunschwig and G. E. R. Lloyd, eds., ed. A. A. Long (Cambridge, 1999), has articles on the main pre-Socratic (that is, those practising before Socrates, late fifth century) philosophers. For a broad survey of Greek thinking in general, see J. Brunschwig and G. E. R. Lloyd, eds., Greek Thought: A Guide to Cla.s.sical Knowledge Greek Thought: A Guide to Cla.s.sical Knowledge (Cambridge, Ma.s.s., and London, 2000), and the chapter "Philosophy" by B. Williams, in M. I. Finley, ed., (Cambridge, Ma.s.s., and London, 2000), and the chapter "Philosophy" by B. Williams, in M. I. Finley, ed., The Legacy The Legacy of Greece: A New Appraisal of Greece: A New Appraisal (Oxford, 1984). (Oxford, 1984).

10. Lloyd's case for the relationship between politics and philosophy is argued most strongly in his Magic, Reason and Experience Magic, Reason and Experience (Cambridge, 1979). See especially chap. 4, "Greek Science and Greek Society." (Cambridge, 1979). See especially chap. 4, "Greek Science and Greek Society."

11. M. West, "Early Greek Philosophy," in J. Boardman, J. Griffin and O. Murray, eds., The Oxford History of the Cla.s.sical World The Oxford History of the Cla.s.sical World (Oxford, 1986). (Oxford, 1986).

12. For Aristotle a particularly good introduction is J. Barnes, Aristotle Aristotle (Oxford, 1982). Chap. 7, "Logic," deals with syllogisms. A more advanced survey is J. Lear, (Oxford, 1982). Chap. 7, "Logic," deals with syllogisms. A more advanced survey is J. Lear, Aristotle: The Desire to Understand Aristotle: The Desire to Understand (Cambridge, 1988). (Cambridge, 1988).

13. Quoted in P. Hoffman, The Man Who Loved Only Numbers (London, 1999), p. 113. A good introduction to Greek mathematics is to be found in M. Kline, Mathematical Thought from Ancient to Modern Times, Mathematical Thought from Ancient to Modern Times, vol. 1 (New York and Oxford, 1972). Euclid and Apollonius are given full treatment in chap. 4. vol. 1 (New York and Oxford, 1972). Euclid and Apollonius are given full treatment in chap. 4.

14. Herodotus used to be derided by commentators for his continuing use of myth and uncritical use of oral evidence, in contrast, it is argued, with the more "scientific" Thucydides. Recently, however, R. Thomas, in her Herodotus in Herodotus in Context: Ethnography, Science and the Art of Persuasion Context: Ethnography, Science and the Art of Persuasion (Cambridge, 2000), has argued that Herodotus deserves to be placed in the forefront of intellectual developments of the fifth century. (Cambridge, 2000), has argued that Herodotus deserves to be placed in the forefront of intellectual developments of the fifth century.

15. From Sacred Disease, attributed to Hippocrates, VI 352, 19L; 364, 915; 366, 56L. Trans. J. Longrigg; quoted in his Greek Medicine: From the Heroic to the h.e.l.lenistic Age. A Source Book h.e.l.lenistic Age. A Source Book (London, 1998), p. 21. (London, 1998), p. 21. Sacred Disease Sacred Disease is considered at some length by G. E. R. Lloyd, in his is considered at some length by G. E. R. Lloyd, in his Magic, Reason and Experience Magic, Reason and Experience (Cambridge, 1979), pp. 1529. (Cambridge, 1979), pp. 1529.

16. The Ionian physician Alcmaeon (Ionian, fifth century B.C.) transfers the concept of stability being achieved through the union of opposites, surely a concept taken from notions of "the ideal city," to the human body.

Alcmaeon holds that what preserves health is the equality of the powers, moist and dry, cold and hot, bitter and sweet, and the rest-and the supremacy of any one of them causes disease, for the supremacy of either is destructive. The cause of disease is an excess of heat or cold, the occasion of it surfeit or deficiency of nourishment: the location of it, marrow or the brain. Disease may come about from external causes, from the quality of water, local environment or toil or torture. Health, on the other hand, is a harmonious blending of the qualities.

Longrigg, Greek Medicine, Greek Medicine, p. 31. For Galen's attempts to find a mathematical base for scientific demonstration, see G. E. R. Lloyd, "Demonstration in Galen," in M. Frede and G. Striker, eds., p. 31. For Galen's attempts to find a mathematical base for scientific demonstration, see G. E. R. Lloyd, "Demonstration in Galen," in M. Frede and G. Striker, eds., Rationality in Greek Thought Rationality in Greek Thought (Oxford, 1996), pp. 25578. (Oxford, 1996), pp. 25578.

17. This is how Aristotle defended the spherical nature of the earth: (i) If the earth were not spherical, eclipses of the moon would not exhibit segments of the shape they do . . . (ii) Observation of the stars also shows not only that the earth is spherical but that it is of no great size . . . we do not see the same stars as we move to the North or South . . . For this reason those who imagine that the region around the Pillars of Heracles [Straits of Gibraltar] joins on to the regions of India, and that in this way the ocean is one, are not, it would seem, suggesting anything incredible.

From On the Heavens, trans. W. Guthrie, Loeb Cla.s.sical Library, 1939, 297b25298a10.

18. For introductions to Greek science, see T. E. Rihill, Greek Science Greek Science (Oxford, 1999), and G. E. R. Lloyd, (Oxford, 1999), and G. E. R. Lloyd, Early Greek Science: Thales to Aristotle Early Greek Science: Thales to Aristotle (London, 1974), and (London, 1974), and Greek Science After Aristotle Greek Science After Aristotle (London, 1973). For astronomy there is Michael Hoskin, ed., (London, 1973). For astronomy there is Michael Hoskin, ed., The Cambridge Concise History of Astronomy The Cambridge Concise History of Astronomy (Cambridge, 1999). (Cambridge, 1999).

19. Barnes, Aristotle, Aristotle, is excellent on all this. is excellent on all this.

20. These examples are taken from Aristotle's Historia Animalium Historia Animalium and and De De Partibus Animalium, Partibus Animalium, which are discussed in G. E. R. Lloyd, which are discussed in G. E. R. Lloyd, Aristotelian Explorations Aristotelian Explorations (Cambridge, 1996), chap. 3. When Aristotle was absorbed into Christianity (see chap. 20 of this book), his readiness to question was played down, and it was only fully recognized again in the twentieth century. (Cambridge, 1996), chap. 3. When Aristotle was absorbed into Christianity (see chap. 20 of this book), his readiness to question was played down, and it was only fully recognized again in the twentieth century.

21. G. E. R. Lloyd, The Revolutions of Wisdom The Revolutions of Wisdom (Berkeley and London, 1957), p. 153. (Berkeley and London, 1957), p. 153.

22. Ibid., p. 57.

23. It is easy to pick up, from Paul's letters and from Christian thought in general, the idea that rational thinking is somehow an arrogant enterprise, trespa.s.sing on what belongs to G.o.d. However, in so far as rational argument is subject to public scrutiny at every stage, the opposite is the case. A mathematician or scientist can be humiliated by his peers when his arguments are shown to be invalid. As E. R. Dodds put in in his well-known study The Greeks and the Irrational The Greeks and the Irrational (Berkeley and London, 1951): "That honest distinction between what is knowable and what is not appears again and again in fifth-century thought, and is surely one of its chief glories; it is the foundation of scientific humility [ (Berkeley and London, 1951): "That honest distinction between what is knowable and what is not appears again and again in fifth-century thought, and is surely one of its chief glories; it is the foundation of scientific humility [sic]" (p. 181). The real problem, as Dodds suggests, lies in taking rational thought in directions where it cannot go-in cases where there are no firm axioms from which the argument can begin. This is, arguably, the problem with Plato. Plato believed that the ultimate truth about everything from "the Good" to beauty and justice could be solved by the use of rational thought. The difficulties this led to will be discussed in the next chapter and at other points in this book. There was an important strand in Greek thought-known usually as Pyrrhonist Skepticism, after its supposed founder, Pyrrhon (c. 365275 B.C.)-that used rational argument to delineate the problems in making rational argument. The Greeks were also aware of how the value of materials or concepts may be relative to their context. Herac.l.i.tus, inventive as ever, noted, "Sea: purest and most polluted water, for fish drinkable and life-sustaining, for people undrinkable