The Muslim philosopher Ibn Rushd (d. 1198) or, as he is known in the West, Averroes, is unique in the history of philosophy. He represents the culmination of one philosophical tradition in an Islamic cultural context, and he may perhaps also be considered chief initiator of aniother in the Latin Christian cultural context.

Reaching back -- looking forward

In his native Islamic milieu, Averroes stands at the end of the classical rationalist philosophical tradition initiated by Alfarabi (d. 950), furthered by Avicenna (d.1037), and brought to a climax in his own works. That tradition continued in Islam the inherited Greek philosophical view that secular scientific reasoning held greater weight than popular religion.

While all three of these thinkers held for the existence of an eternal and transcendent First Principle of all reality, they did so on purely philosophical grounds. They viewed the dominant religions of their day as inferior ways to understand reality -- as ways suitable in practice for the formation of character on the part of those of lesser intellectual abilities.

This approach is found in Averroes’ methodologically important Decisive Treatise and in other works. But it reached its apogee in his Long Commentary on the Metaphysics of Aristotle where he asserts that the most noble of all worship of God consists not in religious practices but in the intellectual apprehension of God and creation in the philosophical science of metaphysics. (Tafsîr mâ ba'd at-Ṭabîcat, Bouyges, ed., 1: 10.11–16).

In the Latin Christian West, the works of Averroes and also Avicenna had a powerful impact on theological and philosophical thought. But it was Averroes who was most criticized for the non-sectarian philosophical rationalism found in his translated commentaries on the works of Aristotle. In those commentaries, thinkers of the Latin West found powerful arguments for such ideas as

  • the eternity of the world
  • the denial of the immortality of the individual human soul
  • the contention that ultimate human happiness is something had only in mortal earthly existence

and much more. These were all grounded in the understanding of rationality as functioning independently of religious revelation and sectarian theological doctrine. In this Averroes can rightly be deemed a leading instigator in the Latin West of a new and controversial tradition of secular rationalism capable of attaining truth in ways methodologically independent of religious belief and doctrine while still recognizing the practical value of religion for the formation of suitable human consciousness in relation to the divine.

The city of Cordoba, in Spain

Professional Life

Born at Cordoba ca. 1126 during the ascendancy of the Almoravids to a family devoted to Malikite jurisprudence, Abû al-Wahîd Ibn Aḥmad Ibn Muḥammad Ibn Rushd al-Ḥafîd ("the grandson") made a career in Islamic religious law (sharcîa). In this, he followed his father and his famous grandfather of the same name (d. 1126) who was a well-respected judge and also prayer leader (imâm) of the Great Mosque of Cordoba.

Not long after the death of his father, Averroes was appointed judge (qâḍî) at Seville in 1169. This appointment took place subsequent to his introduction by physician, vizier and philosopher Ibn Ṭufayl (d. 1185) to Abû Yacûb Yûsuf. Yûsuf was an Almohad ruler whose father, cAbd al-Mu’min, had vanquished the Almoravids and established a new ruling dynasty under the theological influence of al-Maḥdî Ibn Tûmart (d. ca. 1129-30).

As reported by al-Marrâkushî, when Ibn Ṭufayl brought Averroes to court, the ruler himself initiated discussion of the nature of the heavens and of their temporal beginning or eternality, much to the apparent surprise and trepidation of Averroes. Averroes had already undertaken serious study of the works of Aristotle and the philosophical tradition (reflected in his Short Commentaries on various works by Aristotle), so he was well aware of Aristotle’s impressive arguments for eternity and equally well aware of the commonly held religious view that the Qur'ân teaches the world’s temporal origination.

Yet Averroes did not know the mind of Abû Yacûb Yûsuf on the issue, and so he refrained from responding until Ibn Ṭufayl and the ruler began to speak openly and with subtle sophistication evidencing their own common erudition on the topic. As a result of the discussion that ensued, Abû Yacûb Yûsuf extended to Averroes his patronage.  He apparently commissioned Averroes with the task of preparing paraphrasing explanations of the works of Aristotle, which became Averroes’s Middle Commentaries. Averroes also went on later to write five Long Commentaries on works of Aristotle, the first of which was completed in 1186. 

In his public life, this relationship advanced his legal career and Averroes was eventually appointed high judge or grand qâḍî at Cordoba. Averroes continued to enjoy caliphal patronage under the rule of al-Manṣûr (r. 1184-1199) until 1195 when he was exiled to Lucena, not far from Cordoba, and some of his books were burned. It is possible that this may have been the result of jealousies at the Caliph’s court or of a desire to appease religious conservatives in an atmosphere of rising tensions that would eventually lead to the banning of philosophy in Andalusia. But Averroes’s teachings on religion and philosophy may also have played an important role in his condemnation.

Not long afterward, Averroes was restored to favor and eventually moved to Marrakesh where he died in 1198.  But in part as a result of the controversies late in his life, a number of important works by Averroes are available not in Arabic, but only in Hebrew or Latin translations, such as his Long Commentaries on the De anima and the Physics as well as a substantial part of his Long Commentary on the Posterior Analytics.

Religious and Philosophical Studies

While functioning as a judge, Averroes continued his philosophical writing with various treatises and commentaries on Aristotle’s works. But in the period of ca. 1179-1180 he crafted a trilogy of legal and theological works on method deeply reflective of his Aristotelian approach — not easily apparent to the philosophically uninformed and insensitive — in response to Algazel's attack on the philosophers in the Incoherence of the Philosophers.

In the Faṣl al-Maqâl, commonly called the Decisive Treatise, he set forth what may be termed a kind of fatwa or formal legal and religious opinion reasoning subtly for the priority of philosophy to revelation in the determination of truth. Averroes proceeds to respond to the issue with veiled Aristotelian analyses to determine whether in the Qur'ân philosophy and logic are permitted or condemned and, if they are permitted, whether they are recommended or required.  He makes two important identifications:  

  • The religious reflection commanded by the Qur'ân (al-naẓar) he identifies with the theoretical sciences (cilm naẓarî)
  • The traditional Islamic reasoning by analogy (qiyâs) he identifies with syllogistic logic called by the same name (qiyâs).
syllogistic logic: logic based on deductive reasoning

Averroes went on to reason that Quránic injunctions to reflect on the presence of God as Creator of the world command as required the use of the best sort of syllogistic -- namely the demonstrative scientific method of the philosophers -- by those capable of that reasoning.

syllogistic: describes an argument in which a logical conclusion is based on two statements or premises

Applied to the interpretation of the Qur'ân, this meant that demonstrated scientific truths require that the learned understand certain passages of this holy book as necessitating analogical interpretation. By contrast the unlearned masses and those only capable of dialectical or probabilistic reasoning must take those passages at face value. Insofar as truth does not contradict truth — a principle central to Averrroes’s reasoning but taken from Prior Analytics 1.32, 47a5-6, though Averroes does not disclose that he took it from Aristotle — there is no double truth at work here.  Rather, there are levels of understanding in accord with the intellectual and psychological dispositions of people: those of the highest philosophical disposition could grasp truth per se rather than per accidens.

per se: essentially
per accidens: accidentally

In his al-Kashfc an manânij (Explanation of the Sorts of Proofs in the Doctrines of Religion), Averroes criticized traditional religious argumentation.  Again, he employed subtle philosophical reasoning and Aristotelian presuppositions not easily evident on the surface of the text. And in his Ḍamîmah or Treatise on Divine Knowledge, in response to Algazel and Avicenna, Averroes argued that God’s knowledge can be neither of particulars nor of universals.  Instead, Averroes asserted that divine knowledge is of a prior and transcendent sort as causative of all forms of knowledge; this  understanding of God’s knowledge is also found in his last major philosophical work, the Long Commentary on the Metaphysics.

In the same period Averroes also wrote his Incoherence of the Incoherence, a spirited defense of philosophical teachings against the attack of Algazel in the Incoherence of the Philosophers in the form of a detailed commentary.  With these writings and their methodological principles, Averroes established in his own fashion the priority of philosophy to religion following lines of reasoning earlier set out by Alfarabi in various works.

In philosophical writings in the years immediately following, Averroes moved beyond the confines of the formats of the Short and Middle Commentaries and began to write Long Commentaries.  Like his Incoherence of the Incoherence, which contained the complete text of Algazel’s Incoherence of the Philosophers on which he commented in detail, the Long Commentaries contain the complete text of Aristotle with Averroes’s section-by-section commentary drawing on the work of key figures of the Greek and Arabic traditions. The first of the Long Commentaries completed was on the De anima and the second on the Physics. Averroes went on to write Long Commentaries for Aristotle’s On the Heavens, Posterior Analytics, and Metaphysics, perhaps in that order.

Averroes's work spreads to the Latin West

While the Long Commentary on the Posterior Analytics was translated into Latin only in Renaissance times, the other four were translated perhaps beginning around 1220, probably by Michael Scot (d. 1236).  There is evidence that the Long Commentary on the De anima was available in Paris as early as 1225. Michael Scot worked at Toledo before he took a place at the Sicilian court of Frederick II, who was his patron for the remainder of Michael’s life. (The Long Commentary on De caelo is known with certainty to have been translated by Michael.  Recent, as-yet unpublished stylistic analyses by Dag Hasse at the University of Würzburg support the view that Michael is the translator of all four of the Long Commentaries translated in the thirteenth century.) 

While the works of Avicenna made available earlier by translators in Toledo provided impressive synthetic accounts of philosophical issues raised in Aristotelian writings, the Long Commentaries of Averroes with their complete texts of Aristotle’s works more directly taught Latin theologians and students of philosophy how to read the texts of Aristotle with care and precision. All the Long Commentaries contain arguments for Aristotelian teachings unacceptable for Christian theologians of the Latin West -- such as eternality of the world without beginning and the view that happiness is naturally attainable for human beings in the present life.  However, it was the Long Commentary on the De anima with its teaching on intellect that caused the most heated controversies that repeatedly resurfaced through the time of the Renaissance.

Averroes on Intellect

Averroes struggled with the issue of the nature of the human intellect throughout his life.  He only came to what he regarded as a satisfactory account around 1186 in his Long Commentary on the De anima.  Averroes composed all three sorts of commentaries on the De anima (Short, Middle and Long), and set forth distinctively different accounts of human intellect in each. Still, like his predecessors in the Greek and Arabic traditions, he consistently held that there is one agent intellect associated with the sphere of the moon and tasked to assist human beings in achieving intellectual understanding of a scientific sort.

For Averroes and most of the thinkers of the Greek and Arabic Aristotelian traditions, the agent intellect is a separate entity. While for many of the thinkers of the traditions the agent intellect contains the forms which make human thinking possible, for Averroes the agent intellect does not provide intelligible content but rather an abstracting power by which forms apprehended through senses are transferred from particularity to immaterial intelligibility and universality.

Following sources he later identified as Alexander of Aphrodisias and Themistius, Averroes understood this separate and transcendent agent intellect in some way to be “form for us” (ṣurah fî-nâ, forma nobis).  It was required for the activity of intellectual abstraction, and so it had to be involved with the human soul in an intrinsic way. Regarding what Alexander called the material intellect, in his early Short Commentary, Averroes follows Ibn Bâjjah (Avempache) in holding that the receptive power of human understanding is nothing but a disposition of forms held in the human imagination; he apparently considered that these dispositions represented intelligible universals. 

Later in the Middle Commentary, Averroes attacks the view that the material intellect is a perishable disposition set out by Alexander, who held it to be an epiphenomenon consequent upon the composition of bodies. He further reasons that the reception of intelligibles can only come about where the recipient is an immaterial reality distinct from body and powers of body. Now following a celestial model of the relation of heavenly bodies and souls, Averroes views the material intellect as an immaterial entity disposed to receive abstracted intelligibles.  It is individuated by its relationship with its body, whose powers of perception and imagination provide the content of abstraction.

Averroes’s final position is found in the Long Commentary on the De anima.  It was presaged by critical reflections in his Epistle 1: On Conjunction. There, he reasons that

what is called ‘material intellect’ has only the nature of possibility and disposition since it is mixed neither with matter nor any sensible natures. That is why this disposition is not anything existing in a subject.

Next he asked, what stops us from thinking of this material intellect as a single separate immaterial reality, existing separately but shared by all human knowers as they understand intelligibles? Here Averroes raises for the first time what would become his controversial doctrine on the material intellect, but chooses to leave the issue aside for more profound study. That study is provided in his Long Commentary, a work which appears to have been a product of many years' composition, reflection, and revision.

While only fragments of what was perhaps an earlier version of the Arabic Long Commentary survive today, the Latin version of this work is broadly held to contain Averrroes’s final thoughts on intellect.  Here he responds to the question of Epistle 1: On Conjunction with a new and comprehensive account of:

  • the separate agent intellect
  • the separate material intellect
  • human intellectual understanding
  • the nature of intelligibles in act.

Averroes draws on principles taken from Themistius' arguments, which he understands to require a single set of intelligibles for the unity of human discourse and science and also to require the presence of the agent intellect in the soul. Averroes reasoned both that

  1. There must be one commonly shared collection of intelligibles to which different human beings refer in language and knowledge.
  2. The agent intellect must be in the soul.  Those intelligibles in act are to be found in the immaterially separate yet shared material intellect.
separate: not embodied in matter

The agent intellect acts upon images that contain intelligibles in potency from human experiences of the world through the five external senses and the four internal sense powers (common sense, imagination, cogitation and memory). These images are denuded as much as possible from accidents and materiality and abstracted and separated from particularity by the intellectual activity of the separately existing agent intellect. Those separated intelligibles — now existing as intelligibles in act — are in the same instant impressed upon the unique receptive incorporeal material intellect which functions to satisfy the requirement of intelligibles in act for an immaterial and singular subject.

Averroes expands on the notion of the agent intellect as “form for us” shared in a way that allows it to act intrinsically in the human soul so that human beings may “generate intelligibles when we wish.” He writes that human intellectual understanding requires a natural power of the human soul for “conjoining”or “uniting” with these separate intellects, such that the agent intellect and the material intellect are “in the soul.” 

For Averroes, then, the evidence of voluntary human intellectual understanding meant that human beings must have some significant control over their apprehension of intelligibles. In turn, the immaterial nature of these intelligibles in act required that the agent and material intellect must have an eternal existence separate from perishable individual human beings.  Yet they must nevertheless be present “in the soul” of every human knower somehow and have a continuing presence there after the manner of intellectual memory. What is more, since the senses supply the content of intellectual understanding for each individual human being, the intellectual understanding of each human being is limited to that individual’s experiences and abstractions. The fact that we share the unique material intellect does not entail that each human being has access to the knowledge possessed by every member of the entire human species.

Averroes' Impact on Later Philosophers

The Long Commentary on the De Anima with its insistence that the agent intellect and material intellect are “in the soul” was initially welcomed in the Latin West, perhaps as a valuable corrective to the teaching of Avicenna on the existence of a single, shared agent intellect for all human beings.

However, as early as 1238, Averroes's doctrine on the unity of the material intellect was rejected by Richard Rufus. This negative assessment was widespread after the doctrine was explicitly condemned by Robert Kilwardby and Bonaventure in 1252.

Yet the teachings and arguments of Averroes proved notably persuasive to Siger of Brabant as well as others who defended the value of human reason operating independent of religious teachings, as had the philosophers of the classical rationalist period in the Islamic tradition. Aquinas famously responded to Siger and others of Averroist leanings at the University of Paris in his De unitate intellectus contra averroistas.  But the most powerful blow to the non-sectarian account of Averroes and his Latin followers was in the condemnation of 219 philosophical and theological teachings, many of them taken from Averroes, by Bishop Stephen Tempier of Paris in 1277. 

Nevertheless, Averroes’s final attempt in the Long Commentary to complete Aristotle's discussion of the intellect had intellectual staying power.  It continued to play a powerful role in discussions through the time of the Renaissance with followers such as Jean of Jandun (d. 1328), Paul of Venice (1369/72–1429), Cajetan (1480–1547), Nicoletto Vernia (d. 1499), Alessandro Achillini (1463–1512), Pietro Pomponazzi (1462–1525), Agostino Nifo (ca. 1470–1538),  and others.

In the Arabic tradition, no school of Averroes formed. Though his writings were known, they played no prominent role in later philosophical developments. More attention was paid to the integration of religious principles and doctrines into philosophical teachings with key philosophical insights, mostly from Avicenna, coming to be integrated into theological reasoning.

In the Latin West, however, the spirit of the classical rationalist tradition of Islamic philosophy lived on, in a way, through the texts of Averroes and Avicenna in translation.  This supported various efforts by Western Christian thinkers to establish a place for secular reason’s access to truth and knowledge in a manner independent from religious presuppositions and doctrines.


Averrois Cordubensis Commentarium Magnum in Aristotelis De Anima Libros, F. Stuart Crawford (ed.). Cambridge, MA: Mediaeval Academy of America, 1953.  Translated in Averroes (Ibn Rushd) of Cordoba. Long Commentary on the De Anima of Aristotle, Richard C. Taylor, trans. & intro., Therese-Anne Druart, subeditor.  New Haven: Yale University Press, 2009

Averroës. Middle Commentary on Aristotle’s De Anima. A Critical Edition of the Arabic Text with English Translation, ed. and tr.,  Alfred L.Ivry. Provo, Utah: Brigham Young University Press, 2002.

B. Carlos Bazán. “Radical Aristotelianism in the Faculty of Arts,” in Albertus Magnus und die Anfänge der Aristoteles-Rezeption im lateinischen Mittelalter: Von Richardus Rufus bis zu Franciscus de Mayronis. Albertus Magnus and the Beginnings of the Medieval Reception of Aristotle in the Latin West: From Richardus Rufus to Franciscus 454 bibliography de Mayronis, eds. Ludger Honnefelder et al., pp. 585–629. Münster: Aschendorff Verlag, 2005.

R. Gauthier, O.P., introduction, Thomas Aquinas, Sententia libri De anima, ed.  R.-A. Gauthier in Opera Omnia, v. 45, 1, pp. 1*-294*. Rome: Commissio Leonina; Paris: Librairie Philosophique J. Vrin, 1984.

R. Taylor,  “Averroes: Religious Dialectic and Aristotelian Philosophical Thought,” in The Cambridge Companion to Arabic Philosophy, eds. Peter Adamson and Richard C. Taylor, pp.180-200. Cambridge: Cambridge University Press, 2005.