Averroes

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In Cordoba the office of chief judge ran in a family before it ran in a man. The grandfather, Ibn Rushd al-Jadd, was qadi of the city and a Maliki jurist of the first rank; the father held the post after him. The grandson, born there in 1126, was raised to inherit the law — and did, sitting as judge in Seville and then as chief qadi of Cordoba — but he carried into the courtroom a second vocation that the law had no name for. He read Aristotle as no one in Arabic had read him: line by line, against the accreted layers of later interpretation, trying to recover what the Greek had actually meant. The Latin West, receiving the result two generations after his death, gave him a title it reserved for him alone. Aristotle was the Philosopher. Ibn Rushd was the Commentator.

The judge of Cordoba

Abu al-Walid Muhammad ibn Ahmad ibn Rushd — Averroes to the Latins, who mangled the name through Hebrew and Spanish intermediaries — belonged to the last great generation of Andalusian falsafa, the Arabic philosophical tradition built on the Greek inheritance. He came of age under the Almohads, the Berber dynasty that had taken al-Andalus and the Maghreb, and his career was bound to their court. Around 1169 the philosopher and royal physician Ibn Tufayl, author of the philosophical romance Hayy ibn Yaqzan, brought him before the caliph Abu Yaqub Yusuf. The caliph, by the account that has come down, complained of the difficulty of Aristotle’s prose and wished for someone to make it plain. Ibn Tufayl was old; he proposed the younger man. Out of that audience came the labor of a lifetime.

Judging and medicine ran alongside the commentaries. As chief qadi he produced the Bidayat al-Mujtahid wa-Nihayat al-Muqtasid, a manual of Maliki jurisprudence remarkable less for partisanship than for its method: it lays out, point by point, where the schools of law — Maliki, Hanafi, Shafi’i, Hanbali, Zahiri — diverge, and traces each divergence to the interpretive principle that produced it. It is a work of comparative reasoning about disagreement, and it has remained in use. As court physician he wrote al-Kulliyat fi al-Tibb — the Latins called it the Colliget — a systematic survey of medicine completed in the 1160s, in which he set down a theory of stroke, noted the role of the retina, and described tremor of the kind later medicine would name for Parkinson. The jurist, the physician, and the philosopher were one man, and he saw no seam between them.

The three commentaries

The commentaries were built in three sizes for three kinds of reader. The short commentary, or jami, an epitome, compressed a treatise into its working conclusions for the beginner. The middle commentary, talkhis, paraphrased the whole, smoothing the argument into continuous exposition. The long commentary, tafsir, set Aristotle’s text in segments and worked through it phrase by phrase — the form of the advanced reader, and the form in which Ibn Rushd did his most original thinking. Across the corpus he wrote at one level or another on nearly the whole of Aristotle available to him: the logic, the Physics, On the Soul, On the Heavens, the Metaphysics, the ethics, the Rhetoric and Poetics. The Politics he never had, and so commented instead on Plato’s Republic.

The project had a polemical edge that is easy to miss under its patience. The Aristotle who had reached the Arabic world arrived wrapped in Neoplatonism — most consequentially through the Theology of Aristotle, a paraphrase of Plotinus circulated under Aristotle’s name, which had shaped the emanationist systems of al-Farabi and above all Avicenna. Ibn Rushd set himself against that inheritance. Where Avicenna had made existence an accident superadded to essence and strung the cosmos on a chain of emanating intelligences, Ibn Rushd wanted the genuine Aristotle: a world of substances actual in their own right, a first mover that moves as the object of desire rather than as a font from which being overflows. The recovery of Aristotle was, for him, the correction of Neoplatonism’s long contamination of the record.

The incoherence of the incoherence

The defining contest of his life was with a man a century dead. Al-Ghazali, the great theologian and Sufi of the East, had written the Tahafut al-Falasifa — The Incoherence of the Philosophers — a forensic dismantling of falsafa that singled out twenty doctrines and pronounced three of them not merely mistaken but unbelief: that the world is eternal, that God knows only universals and not particulars, and that there is no bodily resurrection. The book had done lasting damage to the standing of philosophy in Islam. Around 1180 Ibn Rushd answered it sentence by sentence in the Tahafut al-Tahafut — The Incoherence of the Incoherence — quoting al-Ghazali, then quoting the philosophers al-Ghazali was attacking, then entering his own verdict. The structure follows al-Ghazali’s twenty discussions, the first sixteen on metaphysics and theology, the last four on natural philosophy.

The work is no blanket apology for the philosophers; Ibn Rushd is as hard on Avicenna’s formulations as on al-Ghazali’s attack on them. On the eternity of the world he holds that the question turns on equivocation — that creation in time and the dependence of the world on its cause are not the same problem, and that an eternal world can still be wholly an effect. On divine knowledge he rejects Avicenna’s compromise, the claim that God knows particulars only in a universal manner, and refuses as well the kalam picture of God knowing as a human knows; the manner of the divine knowing, he holds, is unlike any creaturely knowing and at bottom beyond the reach of the human mind. The argument is not that al-Ghazali has won and the philosophers must retreat, nor that al-Ghazali is simply wrong, but that the theologian has fought the philosophers with weapons borrowed from a worse philosophy. Behind the duel lies a conviction that organized the whole of Ibn Rushd’s thought: that reason and revelation, rightly understood, cannot collide.

The decisive treatise

That conviction received its formal statement in two short works, the Fasl al-Maqal — usually rendered The Decisive Treatise — and its companion al-Kashf an Manahij al-Adilla. Their argument is framed as a juridical ruling, fitting for a qadi: does the revealed Law command, permit, or forbid the study of philosophy? The verdict is that it commands it. The Qur’an repeatedly enjoins reflection on creation; demonstrative reasoning is the most exact form of such reflection; therefore the Law obliges those capable of it to philosophize. And since truth does not contradict truth, no conclusion validly demonstrated can stand against the Law correctly understood.

The reconciliation runs through a stratified account of human minds. People assent to truth in three ways — by rhetoric, by dialectic, and by demonstration — and scripture is composed to reach all three at once. Where the literal sense of a verse conflicts with a demonstrated conclusion, the demonstrative reader is licensed, even required, to read that verse allegorically, by ta’wil; but the same license is withheld from those who cannot follow a demonstration, for whom the surface meaning is the saving truth and tampering with it is corrosion. Philosophy is thus not the enemy of the Law but its inner sense, available to the few; the surface is not falsehood but the Law’s deliberate accommodation to the many. The doctrine is at once a defense of philosophy and a defense of keeping it within bounds — an esotericism written into the structure of revelation itself. A near-contemporary across the confessional line, Maimonides of Cordoba and Cairo, would build a parallel architecture for the Hebrew scriptures, reading the secrets of the Torah as physics and metaphysics reserved for the qualified mind.

One mind for all

The doctrine that made his name and his notoriety concerns the intellect, and it grew out of the hardest passage in Aristotle — the few dense lines of On the Soul on the intellect that becomes all things and the intellect that makes all things. Greek and Arabic commentators had quarreled for a millennium over how many intellects these were, and whose. Ibn Rushd’s mature answer, set out in the Long Commentary on De Anima, is the one the Latins would call the unicity of the intellect, or monopsychism: the material intellect — the receptive capacity by which a human being comes to understand — is not a faculty multiplied in each person but a single immaterial substance, numerically one, shared by all of humanity. Above it stands a single separate Active Intellect, also one for all, which illuminates the intelligible forms. The individual human contributes the images drawn from sense; the shared intellect supplies understanding; thought happens at their conjunction.

The doctrine solves a genuine problem. If understanding grasps universals, and universals are one and the same for every knower, then the faculty that holds them must itself be one — otherwise the geometry in one mind and the geometry in another would be two different things, and the two could not be said to think the same truth. But the solution exacts a price that his readers saw at once. If the intellect is one and separate, then what is individual in a person — the body, the senses, the imagination — is precisely what perishes; nothing personal carries over. The shared intellect is immortal because it never began; the individual is not. Whether anything of the single human being survives death, on this account, became the question fixed to his name, and within the Islamic tradition it was contested at once, set against the resurrection that the Law plainly teaches.

The fall and the books

Favor at the Almohad court did not hold. Under Abu Yusuf Yaqub al-Mansur, around 1195, Ibn Rushd fell — whether through the maneuvering of jurists hostile to philosophy, the politics of a caliph rallying religious opinion for a campaign in Spain, or some personal offense the sources do not preserve. He was banished to Lucena, a town southeast of Cordoba, and his philosophical books were ordered burned. The disgrace was not final; he was recalled to Marrakesh and rehabilitated shortly before he died there in 1198. His remains were later carried back across the strait to Cordoba. The episode is the standing emblem of the precariousness of falsafa in its own house — tolerated under a sympathetic patron, abandoned when the politics turned.

The Latin afterlife

What dimmed in al-Andalus blazed up in Latin Christendom. Within a generation of his death his long commentaries were crossing into Latin, the work above all of Michael Scot, who rendered the great expositions of On the Soul, On the Heavens, and the Metaphysics; Hermannus Alemannus added the Middle Commentary on the Nicomachean Ethics in 1240. They reached the new universities at the moment when the whole of Aristotle was arriving with them, and Aristotle now came inseparable from his interpreter. To study the Philosopher in the arts faculty at Paris was to study him through the Commentator.

Some masters of arts followed the readings where the text led. Siger of Brabant and his circle taught, as the strict sense of Aristotle seemed to demand, that the world is eternal and that the intellect is one shared mind in which all participate — conclusions that struck at the doctrine of creation and at the immortal individual soul. The reaction was institutional and swift. In 1270 the bishop of Paris, Etienne Tempier, condemned thirteen propositions of this kind; in 1277 he issued a sweeping list of two hundred and nineteen, the eternity of the world and the unicity of the intellect among them. Thomas Aquinas, who had labored to wed Aristotle to Christian doctrine while insisting against the Commentator that each person possesses an intellect of his own, wrote a treatise expressly to break the monopsychist reading — De Unitate Intellectus contra Averroistas — arguing that Averroes had misread Aristotle and that an intellect not the individual’s own could not make a single human being the one who thinks. Out of these quarrels the West coined the labels: Averroism, the Averroists, and the charge of a double truth, that something might be true in philosophy and false in theology at once. The charge distorted what Ibn Rushd had held — for him there was one truth, reached by two roads, not two truths at war — but it stuck, and through it the scholastic world remembered him as reason pressed past its license.

He did not vanish when the condemnations cooled. His commentaries passed into Hebrew, where Jewish philosophers wrote supercommentaries on them for centuries, and from Hebrew back into Latin during the Renaissance, when the Aristotelians of Padua — and Jewish Averroists in their orbit, among them Elia del Medigo, who taught Pico della Mirandola — kept his reading of the Philosopher alive into the age of print. The great Venetian editions gathered Aristotle and Averroes side by side on the page. In the Islamic East, by contrast, his influence thinned; there the currents that prevailed ran through al-Ghazali and through the Avicennan and Illuminationist traditions, and the Commentator who governed the Latin schools became, in the world that produced him, a figure more honored than read.

Texts and scholarship

The Arabic corpus survives unevenly — some long commentaries exist now only in their Hebrew or Latin translations, the original lost — and recovering it has been a long collaborative labor. The Tahafut al-Tahafut was made fully available to English readers by Simon van den Bergh in his annotated two-volume translation, Averroes’ Tahafut al-Tahafut (The Incoherence of the Incoherence) (London: Luzac, for the E. J. W. Gibb Memorial, 1954), still the standard rendering. The Fasl al-Maqal is best approached through Charles E. Butterworth’s facing-page edition, Averroës: Decisive Treatise and Epistle Dedicatory (Provo: Brigham Young University Press, 2001), in the Islamic Translation Series. The legal masterwork appears in English as Imran Ahsan Khan Nyazee’s translation of the Bidayat al-Mujtahid under the title The Distinguished Jurist’s Primer (Reading: Garnet, 1994–96).

On the philosophy of intellect, Richard C. Taylor’s translation and study of the Long Commentary on the De Anima of Aristotle (New Haven: Yale University Press, 2009) is the essential entry into the monopsychism debate, and Stephen R. Ogden’s Averroes on Intellect: From Aristotelian Origins to Aquinas’ Critique (Oxford: Oxford University Press, 2022) reconstructs the argument and its scholastic reception. For the life and the shape of the whole project, Peter Adamson’s Philosophy in the Islamic World (Oxford: Oxford University Press, 2016) sets Ibn Rushd within the falsafa tradition he closed, and the Stanford Encyclopedia of Philosophy entry Ibn Rushd surveys the works and the controversies with full bibliography. The transmission into Latin and Hebrew, and the rivalry with al-Ghazali that framed his defense of philosophy, are mapped in the standard histories of medieval philosophy and of the Arabic-to-Latin translation movement.

In the courtroom and at the bedside Ibn Rushd had ruled on disagreement for a living, tracing each conflict back to the principle that bred it. He spent the rest of his hours doing the same for a more dangerous quarrel — between the reasoning of the Greeks and the word of the Law — and ruled, against the temper of his age and his place, that the two could not finally contradict. His own century in al-Andalus burned the books that said so. The schools of Paris and the presses of Venice made the verdict permanent.

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