Medieval Philosophy

Between the ninth and twelfth centuries, while the Latin West knew only fragments of Aristotle, the Islamic world was the great guardian and continuator of Greek philosophy. Falsafa — the Arabic transliteration of the Greek philosophía — names the tradition that received, commented upon, and transformed the legacy of Aristotle and of Neoplatonism, facing the decisive problem of articulating Greek philosophical reason with Qur’anic revelation. Without it there would have been no rediscovery of Aristotle in the West and, to a large extent, no Scholasticism of Thomas Aquinas. This article traces its protagonists — Al-Kindi, Al-Farabi, Avicenna, Al-Ghazali, and Averroes — and the debate that runs through them. ...

When the Goths of Alaric sacked Rome in 410 — the city that for eight centuries had thought itself eternal — the ancient world felt the ground give way beneath its feet. It was in that climate of disorientation that a bishop from North Africa undertook, between intimate meditation and a theology of history, the work that would make him the greatest intellectual figure of late antiquity. Aurelius Augustinus of Hippo (354–430) lived on the frontier between two ages: trained in classical Greco-Roman rhetoric, he converted to Christianity and transformed the legacy of Plato and Plotinus into the philosophical idiom of the medieval West. In him, the search for truth ceased to be merely contemplation of the cosmos and became exploration of the inner life of the soul. ...

If medieval philosophy had to be represented by a single name, that name would be Thomas Aquinas (1225–1274). Dominican friar, theologian, and philosopher, Aquinas undertook the most ambitious intellectual synthesis of the Middle Ages: harmonizing the philosophy of Aristotle — newly rediscovered in the Latin West through Arabic and Greek translations — with Christian theology. The result was two monumental Summae and dozens of commentaries, disputed questions, and opuscula that shaped Catholic theology, natural law theory, political ethics, and Western metaphysics for centuries. ...

In the heart of the twelfth century, amid Andalusian mosques, North African synagogues, and Egyptian Islamic courts, a rabbi, physician, and philosopher undertook one of the most daring intellectual syntheses of the Middle Ages: to show that philosophical reason and biblical revelation do not contradict each other but are, in fact, complementary. His name was Moses ben Maimon — in Hebrew, Rambam; to the Latin West, Maimonides. No other medieval Jewish thinker exerted so deep and lasting an influence — within Judaism and far beyond it, shaping Christian and Islamic thought in ways that still resonate today. ...

No twelfth-century philosopher provoked as much turbulence — intellectual and personal — as Peter Abelard (c. 1079–1142). An unmatched master of dialectic, tragic lover of Héloïse, twice condemned by the Church, he reshaped the landscape of medieval thought by subordinating authority to reason, offering an original solution to the problem of universals, and founding an ethics centered on individual conscience. His life reads like a classical tragedy; his philosophy anticipates problems that would occupy the scholastics for centuries. ...

What is the structure of reality? What truly exists — and what is illusion, appearance, or a construction of our minds? This is the oldest, most persistent, and most vertiginous question in all of philosophy. From Thales of Miletus, who in the sixth century BC declared that everything is water, to quantum physicists who now debate whether the universe is made of vibrating strings in eleven dimensions, humanity has never stopped asking: what is this thing we call reality? ...

Abelardo (Peter Abelard) The most brilliant and controversial intellectual of the 12th century. Also famous for his tragic love affair with Heloise (castrated by order of her uncle). He proposed conceptualism in the dispute over universals and introduced dialectical reason into theology. “I understand in order to believe” — reason must examine before accepting by faith (an inversion of Anselm of Canterbury). Born in Brittany into a family of the minor nobility, Abelard renounced his military inheritance to devote himself to the liberal arts, becoming an itinerant master who drew crowds of students to the schools of Paris. His career spans the decisive moment when teaching ceased to be a monopoly of the monasteries and migrated to the urban schools, foreshadowing the medieval university. A tireless polemicist, he challenged his own teacher William of Champeaux over the universals and later found himself in open conflict with the monastic authority embodied by Bernard of Clairvaux, who saw in his confidence in reason a danger to faith. This tension between dialectic and the contemplative tradition marks his entire body of work and helps explain the condemnations he suffered at ecclesiastical councils. ...

Al-Farabi Abū Naṣr Muḥammad ibn Muḥammad al-Fārābī (c. 872–c. 950) was one of the greatest philosophers of the medieval Islamic world, called by the tradition “the Second Teacher” (al-Muʿallim al-Thānī) — the first being Aristotle. Born in the region of Farab (present-day Kazakhstan/Uzbekistan), he worked principally in Baghdad and Aleppo under the patronage of the Hamdanid court. His work spans logic, political philosophy, metaphysics, philosophy of music, and theory of the sciences. ...

Albertus Magnus (Albert the Great) Dominican friar, Bishop of Regensburg, and Doctor Universalis. He was the teacher of Thomas Aquinas and the principal figure responsible for the systematic introduction of Aristotle into the medieval Latin world. Unlike other scholastics, Albert had a genuine interest in the natural sciences — botany, zoology, mineralogy, alchemy — combining empirical observation with philosophical reflection. Canonized and declared Doctor of the Church in 1931, he is the patron saint of natural scientists. ...

Anselm of Canterbury Born in Aosta, in the Alps, in 1033, Anselm entered the famous Benedictine monastery of Bec, in Normandy, where he became an admired master, and later became Archbishop of Canterbury, amid harsh conflicts with the English kings over the authority of the Church. He is called “the father of Scholasticism” for having inaugurated the systematic effort to use reason to penetrate the contents of faith. His motto sums up the whole medieval program: “fides quaerens intellectum” — faith seeking understanding. In the Proslogion he radicalizes it: “I do not seek to understand in order to believe, but I believe in order to understand” — a formula that gathers up the “crede ut intelligas” of Saint Augustine. ...

Averroes (Ibn Rushd) Abu al-Walid Muhammad Ibn Rushd, Latinized as Averroes, was born in Córdoba in 1126, at the height of the Islamic civilization of Al-Andalus. A judge (qadi), physician, and philosopher in the service of the Almohad caliphs, he became known in medieval Europe simply as “the Commentator”: his meticulous commentaries on the work of Aristotle were, for centuries, the principal gateway to Aristotelian thought for Latins and Jews. He fell from favor at the end of his life, when his works were condemned, and died in Marrakesh in 1198. ...

Avicenna (Ibn Sīnā) Born in 980 near Bukhara, in Persian-speaking Central Asia, Abu Ali Ibn Sīnā — Latinized as Avicenna — was a prodigy: it is said that by the age of eighteen he had already mastered the medicine of his time. He led a turbulent life, amid courts, imprisonments, and posts as vizier, yet left more than two hundred works. His Canon of Medicine was the principal medical textbook in the West for centuries, and his Book of Healing is a vast philosophical encyclopedia. He is the greatest philosopher of the medieval Islamic world, and his name is bound to a distinction that would transform Western metaphysics. ...

Boethius “The last Roman and the first Scholastic.” He translated and commented on the Logic of Aristotle into Latin, transmitting it to the Middle Ages. The Isagoge of Porphyry — which Boethius translated and commented on — (introduction to the Categories) launched the debate of universals that will dominate Scholasticism. Imprisoned and condemned to death by Theodoric, he wrote The Consolation of Philosophy in prison — one of the most widely read works of the Middle Ages. ...

Bonaventure Giovanni di Fidanza, known as Bonaventure of Bagnoregio. Franciscan theologian and philosopher; cardinal and Minister-General of the Franciscan Order. Contemporary and cordial adversary of Thomas Aquinas. Called the Doctor Seraphicus. Bonaventure trained at the University of Paris, then the great center of Latin scholasticism, where he studied the liberal arts and afterward theology under the Franciscan master Alexander of Hales. There he taught at the same time as Thomas Aquinas, in a period when the massive arrival of the works of Aristotle — many of them mediated by the Arabic commentaries of Averroes — was forcing Christian theologians to decide how much of the new natural philosophy they could absorb without compromising the faith. Bonaventure embodies the Augustinian and Franciscan response to that challenge: rather than fully naturalizing reason as Aquinas did, he upheld the primacy of divine illumination and inner experience, refusing to treat philosophy as an autonomous knowledge severed from the wisdom that leads to God. ...

Duns Scotus Born around 1266 in Duns, Scotland, John Duns Scotus entered the Franciscan order and taught at Oxford, Paris, and Cologne, where he died prematurely in 1308. The subtlety and rigor of his distinctions earned him the title of “Subtle Doctor.” Alongside Thomas Aquinas and William of Ockham, he is one of the great names of high Scholasticism — and the principal Franciscan counterpoint to Thomism. His most characteristic metaphysical thesis is the univocity of being. Against Thomas Aquinas, who held that “being” is attributed to God and creatures only by analogy, Scotus maintains that the concept of being has a univocal sense, the same for the Creator and the creature — without which, he argues, no knowledge of God from the world would be possible. It is the most universal and indeterminate concept of all. ...

Maimonides Moses ben Maimon — known by the acronym Rambam and, in the Latin West, as Maimonides — was born in Córdoba, in Al-Andalus, around 1138, and is the greatest Jewish philosopher of the Middle Ages. Fleeing Almohad persecution, his family wandered through North Africa before settling in Egypt, where Maimonides became a court physician and the spiritual leader of the Jewish community of Cairo. He was at once a jurist, a Talmudist, a physician, and a philosopher, and died in 1204. ...

Saint Augustine Aurelius Augustine was born in 354 in Thagaste, in Roman North Africa, the son of a Christian mother (Monica) and a pagan father. A teacher of rhetoric in Carthage, Rome, and Milan, he traveled a long intellectual and spiritual road: he was kindled to philosophy by reading Cicero, adhered for years to Manichaeism, passed through skepticism, and found in the Neoplatonism of Plotinus the instrument that would lead him back toward Christianity. His conversion in Milan (386) — the famous “tolle, lege” (“take up and read”) scene narrated in the Confessions — was a turning point. He became bishop of Hippo and, until his death in 430, during the Vandal siege, was the greatest thinker of the Patristic age and one of the most influential figures in the whole history of the West. ...

Thomas Aquinas Born around 1225 in Roccasecca, near Aquino, in southern Italy, Thomas belonged to the high nobility, which firmly opposed his entry into the mendicant order of the Dominicans — even confining him for about a year. He studied under Albert the Great in Paris and Cologne and became a master of theology at the University of Paris. Despite the nickname “the dumb ox,” he proved to be the greatest genius of Scholasticism. After an intense experience in 1273, he ceased writing, saying that all he had produced seemed to him like “straw”; he died the following year, on his way to the Council of Lyon. Canonized in 1323, he is “the Angelic Doctor,” and Thomism remains the official reference of Catholic philosophy. ...

William of Ockham Born around 1287 in the English village of Ockham, in Surrey, William entered the Franciscan order and studied at Oxford. Accused of heresy, he was summoned to the papal court at Avignon; caught up in the dispute between the Franciscans and Pope John XXII over evangelical poverty, he ended up fleeing to the court of Emperor Louis of Bavaria, under whose protection he lived until his death, around 1347. His work marks the end of classical Scholasticism and opens the way to Modernity. ...