Chapter 2
A map of earlier medieval philosophy
Late antiquity and its Platonic schools
Broadly speaking, medieval philosophy in its different traditions had its origins in the philosophy of ancient Greece, principally the thinking of Aristotle and Plato, as understood and elaborated in late antiquity (c. ad 200–500), especially in the Platonic schools.
From the time of Plotinus (d. 270) onwards, a revived Platonism drove the philosophical schools which had been popular for the preceding five centuries (Epicureanism, Scepticism, and, especially, Stoicism) into obscurity. Plotinus claimed just to be interpreting Plato, but he went far further in mapping out of the intelligible world: the realm of true being which is grasped, not through our senses, but by thought. Plato had argued that the world as it appears to our senses is merely a copy of immaterial, eternal Forms or Ideas, which alone truly exist. For Plotinus, the Ideas constitute the second level of reality (or ‘hypostasis’), Intellect: this hypostasis comes from the One, by emanation, a type of derivation which brings no change to that from which the derivation takes place. Similarly, from Intellect emanates the third hypostasis, Soul, which is responsible for all that makes up the life of the universe, from the workings of the elements to human reasoning.
Plotinus’ successors kept and elaborated this three-layered metaphysical structure, but it was his pupil, Porphyry (c.232–305) who gave the late ancient tradition its distinctive character. Whereas Plotinus had regarded Aristotle with reserve, Porphyry accepted his thinking as well as Plato’s, contending that Plato wrote about the intelligible world and Aristotle about the everyday world perceptible through the senses, so that the two spoke in harmony, despite their apparent disagreements.
Porphyry therefore made Aristotle’s works, including his logic, part of the Platonic curriculum, and the two great Platonic schools, at Athens and Alexandria, followed his lead. Although Plato’s dialogues (and some mystical, pagan religious texts) were officially the culmination of the course, there was room for philosophers, such as Ammonius of Alexandria (d. 517–26), who concentrated on expounding Aristotle. The School of Athens flourished in the 5th century, an unreservedly pagan institution in an increasingly monolithically Christian Empire. Only in 529 did the Christian Emperor, Justinian, close it down.
Five originators of the medieval traditions
Five thinkers, each with strong links to late ancient Platonism and (except for one) to the Platonic schools, were founding figures for the medieval traditions.
Augustine (354–430), son of a Christian mother and pagan father, who became a bishop in Roman North Africa and the most influential of all Latin Christian writers, grew up in a world where the relationship between pagan philosophy and Christianity was conflicted. He was schooled in the Latin literary classics in preparation for a lucrative career as a rhetorician, but his encounter with Latin translations of Plotinus and Porphyry set him on the path to conversion, vividly recorded in his Confessions. His thinking continued to reflect this Platonism, yet, as it matured, it stressed the gulf between Christianity and Roman civilization, and the corrupt, fallen state of humankind. Although his writings are unsystematic and often linked to questions of Christian doctrine or take the form of Biblical commentary, Augustine reflected deeply and originally about many philosophical themes, such as time, scepticism, the will, evil, and human freedom.
Unlike Augustine, Boethius (c.475/7–c.525/6) was trained in Greek as well as Latin and had access to material from the Platonic schools. Like Ammonius, he had a special interest in logic: he translated almost all Aristotle’s logical works, and he wrote commentaries on them and logical textbooks, making this late ancient scholastic tradition available to Latin readers. A set of short theological works showed how these logical ideas and techniques could be applied to thinking about Christian doctrine. But, above all, Boethius became famous for his last work, the Consolation of Philosophy, written in prison under sentence of death on a trumped-up charge of treason. Drawing on Stoic and Platonic themes, the Consolation aims to provide a purely philosophical, reasoned vindication of divine providence, even in the face of the apparent injustice its author is suffering. It also develops an influential solution to the problem of reconciling God’s foreknowledge with human freedom (see Chapter 8).
‘Pseudo-Dionysius’ (late 5th century), as he is called, was someone, probably a Syrian monk, who issued a set of writings under the name of Dionysius, the learned Athenian converted by St Paul (Acts 17:16–34). They were widely read for the next millennium, both in Byzantium and in Latin translation. They are based on Proclus. In Proclus’ system, Plotinus’ three hypostases are themselves divided and subdivided into groups of three, and the pagan gods are placed in this elaborate hierarchy. Pseudo-Dionysius took over the system, simplifying and Christianizing it, replacing gods with angels and the ecclesiastical hierarchy.
John Philoponus (c.490–570s) was another Syrian Christian. He studied under Ammonius at the School of Alexandria, but in his later years he used his Aristotelian training against Aristotle, in a series of works in Greek and Syriac, rejecting central aspects of his physical theory. For example, he used Aristotle’s argument that it is impossible to traverse an infinite number of things as an argument against Aristotle’s fundamental view, unacceptable to Christians, that the world has no beginning: if so, he objected, then there must have been an infinite number of changes before this fire which is burning now could come into existence—and that is impossible, according to Aristotle himself. Philoponus, who wrote in Greek and Syriac, was not read in the Byzantine tradition (where his branch of Christianity was considered heretical) nor, directly, in the Latin tradition, but he was an important figure, known as ‘John the Grammarian’, in Arabic philosophy.
Sergius of Resh‘aynā (d. 536), also a Syriac Christian, knew Ammonius’ logical teaching through Philoponus’ versions of the lectures. He is regarded as the founder of the Syriac logical tradition which, through the work of Syriac Christian teachers and translators (from Greek to Syriac and Arabic), stands at the beginning of Greek-based philosophy in Arabic. Sergius also contributed to the Platonic side of the Syriac tradition, as the translator into Syriac of pseudo-Dionysius.
Philosophy in the continuity and collapse of the Roman Empire
These five figures all lived in what was still, culturally, the ancient world, though a Christianized one. In the east the Roman Empire, with its capital at Byzantium, continued; the people we call ‘Byzantines’ thought of themselves as Romans. There the most powerful philosopher of the 7th century, Maximus the Confessor (580–662), continued the tradition of pseudo-Dionysius. Following Proclus, pseudo-Dionysius had stressed how God himself is unknowable and can be described only negatively. Taking this idea further, Maximus argues that God is not a thing at all, and that it is only by allowing things to participate in him that he creates himself.
Although familiar with logic and deeply influenced by Platonic themes, Maximus held the pagan tradition of philosophy in low esteem. His two successors in the Greek tradition, John of Damascus (d. before 754), and Photius, Patriarch of Constantinople (820–91), who also developed philosophically informed theological systems, took a different view. John prefaced his summa of theology with (a rather elementary) introduction. Photius assembled a vast Bibliotheca, a collection of extracts from ancient authors, including philosophers, and elsewhere he discussed logical problems, with a view to putting logic to use in theology.
By contrast, in the west, Roman political control and institutions were already crumbling in the 6th century. North Africa had been lost to the Vandals shortly after Augustine’s death, and Boethius’ Italy was under the rule of the Goths. Further barbarian invasions followed, and it was not until the late 8th century, with the peace, stability, and cultural revival brought by Charlemagne, crowned Emperor on Christmas Day 800, that the Latin tradition of philosophy began to be revived. The English scholar, Alcuin (d. 804), Charlemagne’s protégé, compiled the first medieval Latin logical handbook, and students in his circle dabbled with philosophical themes and arguments they found in Augustine, Boethius, and the Timaeus, the one work of Plato’s available in (an incomplete) Latin translation.
John Scottus Eriugena (fl. c.850–70), who worked at the court of Charlemagne’s grandson, Charles the Bald, was a vastly more original and ambitious philosopher. Eriugena’s special admiration was for the tradition of Greek Christian thought. He learned Greek and translated the whole pseudo-Dionysian corpus, works by Maximus the Confessor, and one by an earlier, philosophically minded Church Father of the 4th century, Gregory of Nyssa. In his masterpiece, the Periphyseon, Eriugena systematized and greatly extended Maximus’ thinking, helped by his study of Aristotelian logic and often in dialogue with Augustine, whose work he had also read carefully. Eriugena’s God, utterly unknowable and indefinable, is both uncreated and creating—constituting himself as an object of knowledge through the universe which is, ultimately, just an appearance of Him—and also uncreated and uncreating, when seen as the end to which all things return (see Figure 2).
In the 10th and 11th centuries, philosophy continued to be studied in the Latin West on the basis of a small number of ancient and late ancient texts: a few works of Aristotelian logic, Roman popularizations of Platonism, the Timaeus, and Boethius—his commentaries, textbooks, theological treatises, and the Consolation. The most remarkable thinker of the period, Anselm (1033–1109), spent much of his life in a Norman monastery, before he became Archbishop of Canterbury. Unlike most medieval writers, he rarely cites authorities. He learned from Aristotle, Augustine, and Boethius, but—a finer philosophical mind than any of them except, perhaps, Aristotle—he rarely accepts their positions uncritically. His writings, often in the form of dialogues, though concerned with Christian doctrine, explore some of the most difficult issues in moral psychology, the philosophy of action and the philosophy of religion. His famous argument for God’s existence is part of an extended exercise in a discipline he himself invented: perfect-being theology—the attempt to deduce rationally what God’s attributes must be given that he is omniperfect.
The beginning of Arabic philosophy
The greatest of all the geopolitical changes at the end of antiquity was the rise of Islam. By 700 Muslim armies had conquered Syria, Iraq, and Egypt (territories which had belonged to Byzantium), the Persian Empire, much of North Africa, and what had been the Christian Visigothic Kingdom of Spain.
2. Illumination in a 12th-century manuscript of Honorius Augustodunensis’ Clavis Physicae, an abbreviation of John Scottus Eriugena’s Periphyseon, which depicts Eriugena’s conception of the universe.
For philosophy, however, the result was not a break with the ancient tradition, but the very opposite. The School of Alexandria had survived, along with its books, until the town fell to the Muslims in 641. Between the late 8th and early 10th century, in the first of the great translation movements which gave shape to medieval philosophy, almost all these philosophical and scientific texts were put into Arabic. Some of the most important translators were Syriac-speaking Christians. The philosophical works translated included almost the whole of Aristotle and many commentaries on him from the Platonic schools and late ancient Aristotelians, such as Alexander of Aphrodisias (active c. ad 200), as well as work extracted from Plotinus (confusingly called the Theology of Aristotle) and from the 5th-century Platonist Proclus (The Book of the Pure Good). Plato himself was known through translations of epitomes.
From the early 9th century some scholars in Islam consciously set out to continue this Greek tradition of what they called falsafa. But they were not the only, nor the first, philosophers in Islam. From the early 700s Muslim scholars began to engage in kalām, a type of philosophical discussion based on Quranic problems and questions, but probably also influenced by some knowledge of ancient Greek ideas (though not by study of the texts) and the need to defend Islam against the philosophically trained Syriac Christians.
Both those who attached themselves to the Greek tradition and the earliest dominant school of kalām, the Mu‘tazilites, were seeking, in different ways, a rational understanding of their world and their religion, and both groups were fostered by the new ‘Abbāsid dynasty (established 750). The Mu‘tazilites placed great emphasis on the power of human reason to understand divine justice, and they emphasized God’s absolute unity. Mostly they were atomists, and they seem consciously to have rejected the Aristotelian picture of a stable world made of substances belonging to certain, fixed natural kinds (such as humans, dogs, roses, and stones) for one in which, under God’s aegis, atoms are bound together as things by accidents.
The first of the great exponents of falsafa, al-Kindī (c.801–66) seems deliberately to have presented his Greek-inspired thinking as an alternative to kalām—a different and better way of solving the same, ultimately theological problems, within the framework of Islam. Al-Kindī was especially influenced by the more Platonic translations, such as the Theology of Aristotle. It would be wrong, though, to describe him as a Platonist. Rather, he was a polymath, who ranged over mathematics, music, and all the sciences, fascinated by the riches of a library he and his contemporaries had yet to absorb.
By contrast, al-Fārābī (c.870–950/1) was a determined follower of the ancient, Aristotelian tradition, and he traced his own intellectual genealogy, teacher by teacher, back to Aristotle himself. Not only did he comment on Aristotle and, combining Aristotelian and Platonic metaphysics with Ptolemaic cosmology, develop a theory of emanation which strongly influenced medieval thinking about intellectual knowledge (see Figure 3, and Chapter 7). He also developed a Platonically tinged model of the perfect city (see Chapter 9), and an audacious theory of the relationship between Aristotelian demonstrative science and religion, which he believed sets out the same truths as science, but in a metaphorical form capable of being grasped by non-philosophers. Islam offers the best metaphorical representation, but only Aristotelian science gives the naked truth. Al-Fārābī was the central figure of a whole school of ‘Baghdad Peripatetics’, who concentrated, though not exclusively, on expounding and discussing Aristotle.
Al-Fārābī’s Baghdad circle included Christians as well as Muslims. Jews too became fully assimilated into the culture of Islam, following its intellectual trends and writing in Arabic. Isaac Israeli (b. 850), for example, was, like al-Kindī, inspired mainly by Platonic works from late antiquity, while Saadia (882–942), head of the ancient Talmudic academy of Babylon, produced a type of Jewish kalām.
Ibn Sīnā (Avicenna; before 980–1037) admired al-Fārābī, but, born near Bukhara on the eastern extremity of Islam, he distinguished his approach sharply from that of the Baghdad Peripatetics. Where they aimed to paraphrase or interpret Aristotle, paragraph by paragraph, with the help of the ancient commentaries, Avicenna set out to systematize the thought of Aristotle and his commentators, rearranging the elements and very often rethinking them. Unlike al-Fārābī, Avicenna does not try to trace a philosophical lineage back to the ancients. Rather than rely on a teacher, he could use his own ḥads, his power to form arguments, to seize on the truth in what he read, changing whatever was necessary. His favoured form of writing was, accordingly, the philosophical encyclopaedia, covering the whole Aristotelian curriculum according to his own reading of it. The longest of these works was called The Cure; the latest, and most influential in Islam, Pointers and Reminders, epitomized his teaching for initiates. Avicenna innovated in almost every field, from modal logic to the theory of universals (see Chapter 6) and of body and mind. His most far-reaching development was his distinction—among things which, being eternal, are necessary (in Aristotle’s sense)—between those things that are necessary through another, because they require a cause for their existence, and God, who alone is necessary in himself: the mere fact of what he is explains that he exists.
3. The Aristotelian–Ptolemaic universe, in an engraving from Peter Apian’s Cosmographia, 1524.
While falsafa flourished, kalām continued to develop. Al-‘Asharī (d. 935/6) began his career as a Mu‘tazilite, but abandoned some of the school’s characteristic doctrines, while retaining its atomism and using it to emphasize God’s complete power over everything—even (against the Mu‘tazilites) human volition and action. The idea that God is the sole creator of everything, including human acts, was emphasized by al-Juwaynī (1028–85). But Juwaynī was also a reader of Avicenna, who introduced his notions of necessity and possibility into his theological discussion.
Juwaynī’s outstanding pupil was al-Ghazālī (1058–1111), still revered as one of Islam’s greatest religious thinkers. His studies and interests included not only Asharite kalām, but law, Sufism, and falsafa. His attitude to philosophy in the Greek tradition, and its leading exponent, Avicenna, was two-sided. He compiled a summary of Avicennian thought—the Intentions of the Philosophers—but only to attack it, thesis by thesis, in the Incoherence of the Philosophers; and he judged three of Avicenna’s Aristotelian views, that the world is eternal, that God has no knowledge of particulars, and that there is no bodily resurrection, to be not merely wrong, but heretical. Yet he borrowed heavily from Avicenna’s system, to the extent that some consider his metaphysical framework to be entirely Avicenna’s, except that for al-Ghazālī the existent which is necessary of itself, God, acts, not out of necessity, but voluntarily.
Latin philosophy in the 12th century
In the Latin world, Paris, where the cathedral authorities allowed competing schools, became the outstanding intellectual centre in the early 12th century, with masters and their followers in constant debate. The curriculum was much the same as that of the previous century and a half, with logic more important than ever; the few Aristotelian writings known, along with Boethius’ commentaries and textbooks, were now thoroughly scrutinized. Theology, in a form highly influenced by the Masters’ logical training, also came to be studied in the Paris schools. The result was a special, characteristically 12th-century way of thinking, based on logical and linguistic analysis, perhaps closer to contemporary analytic philosophy than the more fully Aristotelian philosophy which would replace it.
Peter Abelard (1079–1142), the most famous 12th-century Parisian teacher, made his name as a logician. He also advanced a controversial theory of universals (see Chapter 6), and he went on to develop a wide-ranging ethico-theological system, in which God cannot choose between alternatives, because he must always do whatever is best, but humans are free and will be judged according to their intentions in following divine law, revealed or as naturally known to everyone. A different, but equally sophisticated and highly distinctive approach to language, logic, metaphysics, and their relations to God was taken by Gilbert of Poitiers (c.1085/90–1154). In the second half of the century, the followers of Abelard, Gilbert, and other important early 12th-century Masters formed rival schools, each with its own proclaimed logical and metaphysical principles.
In theology, the main contention involved two parties. There were those who based their method broadly on Gilbert of Poitiers, who himself was influenced by Boethius (his most important work is a commentary on Boethius’ theological treatises). A different approach to theology, however, had been pioneered in Laon at the turn of the century, and developed by Abelard. The collections of views or ‘Sentences’ written by these theologians looked at contentious points of doctrine and tried, often through conceptual analysis, to reconcile apparently conflicting authoritative texts about them. It was this second approach which was adopted in 13th-century theology, and the Sentences, written by Peter the Lombard, Bishop of Paris, in the 1150s—based on Augustine, but influenced by contemporaries including Abelard—became the textbook for university theology.
Some thinkers had different interests. William of Conches (d. after 1155), who probably worked outside Paris, concentrated on expounding texts such as Boethius’ Consolation and Plato’s Timaeus. He was particularly concerned with physical science, and saw Plato, rightly interpreted, as an authority in this field. Bernardus Silvestris dramatized the Timaeus in a work written in prose and verse; Adelard of Bath and Hermann of Carinthia looked towards Arabic culture for new scientific and mathematical knowledge; and, in writings associated with Thierry of Chartres, Boethius’ Platonism was given a numerological, and sometimes even mystical, twist.
Muslim and Jewish philosophy in the Islamic West
In the late eleventh and twelfth centuries, the Islamic West—North Africa and Spain—developed its own philosophical culture. While Ibn Ṭufayl (before 1110–85) looked to Avicenna (see Chapter 9), Ibn Bājja (d. 1139) and Ibn Rushd (Averroes; c.1126–98) continued the Baghdad tradition of Aristotelianism. Averroes was, indeed, the most thorough of all the Arabic exegetes of Aristotle, commenting on the whole range of his known works—usually more than once and employing a variety of approaches, ranging from epitome to the ‘great’ commentaries (on five texts, including the Metaphysics and On the Soul), in which he examines Aristotle’s text minutely, paragraph by paragraph.
Averroes was also the most determined to return to an authentic understanding of Aristotle, stripping him of Platonic accretions, and asserting that Muslims who were intellectually capable of it were duty-bound to study Aristotelian science. He counter-attacked al-Ghazālī by questioning the value of kalām in his Incoherence of the Incoherence, and at the same time distanced himself from al-Ghazālī’s own target, Avicenna, in the name of authentic Aristotelianism—and yet this very desire to grasp Aristotle’s real meaning led him to an idiosyncratic and controversial reading of On the Soul (see Chapter 7). Averroes had almost no readers in later Islam, but many among Jews and Christians, and much of his work is preserved only in Hebrew or Latin.
The outstanding achievements of Jewish philosophy written in Arabic were products of this distinctive West Islamic culture. Solomon ibn Gabirol (1021/2–57/8), who spent most of his life in Saragossa, was a Hebrew poet, but wrote his only-surviving philosophical work, the Fountain of Life, in Arabic. Although heavily influenced by Platonism, Solomon did not conceive of things as emanating necessarily from the One, but as being produced by God’s will; and he insisted on the presence of matter, which was made by God, at every level of the created universe. The first Jewish thinker to adopt a more Aristotelian approach, looking back to al-Fārābī, was Ibn Daud, in the mid-12th century. He was eclipsed by his contemporary Moses ben Maimon (Maimonides; Rambam, 1138–1204). Like the other two, Maimonides was a product of Andalusian Islamic culture, but he had to flee, eventually to Egypt, when the Almohad rulers began to persecute non-Muslims.
In his two great rabbinical works, the commentary on the Mishna (in Arabic) and the Mishneh Torah (‘Second Law’), in Hebrew, Maimonides puts forward Aristotelianism as adapted by al-Fārābī and takes a view similar to his about the relationship between religion, for him Judaism, and Aristotelian science. The truths expressed openly by Aristotle were known, he contended, in the scriptural and rabbinic traditions, but expressed in metaphorical form. By the time he wrote the Guide of the Perplexed, however, his view had become more complicated. He now recognized that there were fundamental differences between an Aristotelian view of God as a being acting necessarily in an eternal universe and the Jewish conception of a creator God, acting voluntarily. Although some themes in the Guide are clear—such as the strict negative theology and the attack on kalām arguments, the solution to this central problem is open to different interpretations. Did Maimonides give up important elements in Aristotelianism, or did he merely appear to do so and, through a subtle system of hints and self-contradictions, reject, though not openly, the literal truth of cherished aspects of Jewish belief?
Philosophy and kalām in the Islamic East after Avicenna
The distinctive philosophical culture of the Islamic West disappeared when, in the early 13th century, the Christians reconquered almost all of Muslim Spain. In the Islamic East, philosophy developed differently, partly at least because of the strong influence of al-Ghazālī. By choosing Avicenna as the object of his attack on philosophy, he helped to canonize him as the philosophical authority (rather than Aristotle); by labelling three of the philosophers’ doctrines as ‘unbelief’ he paradoxically gave Muslims licence to adopt any of the philosophers’ other views; and through his own adoption of Avicennian metaphysics, he set a fashion for future kalām theologians.
The philosophical tradition was, then, dominated by Avicenna, through imitation or by reaction, until the end of the 12th century. Avicenna’s pupil, Bahmanyār (d. 1067), and his pupil, Al-Lawkarī (d. 1123/4), wrote philosophical encyclopaedias based on his work. By contrast with these Avicennians, in his Book of Evidence Abū-l-Barakāt al-Baghdādī (b. c.1077) attacked not only a number of Aristotelian physical principles, but, by subjecting each of them to doubt, many of Avicenna’s positions.
Al-Baghdādī influenced another critic of Avicenna in the following century, Suhrawardī, executed on Saladin’s orders in 1191, when he was not yet forty. Suhrawardī had already written prolifically, and in the following centuries his ‘philosophy of illumination’ became an important strand in Islamic thinking, with an extensive commentary tradition of its own. Suhrawardī challenged the Aristotelian tradition, by claiming to incorporate ideas from ancient Chinese, Indian, Egyptian, and Persian philosophy, and through his central idea of a special sort of direct knowledge by presence, which makes possible a grasp of reality distinct from the imperfect knowledge achievable by discursive reasoning. He began as a follower of Avicenna, and he is an acute critic, from a Platonic perspective, of certain questionable aspects of his system, such as the distinction between essence and existence and the Aristotelian confidence in our ability to provide definitions.