Andrea di Bonaiuto, photo by Sailko, CC BY 3.0

Ibn Rushd

1126-1198 · Islamic philosophy (falsafa) / Andalusian Aristotelianism · knows nothing after 1198 CE

Abu al-Walid Muhammad ibn Ahmad ibn Rushd, known in Latin as Averroes, was a judge, physician, and philosopher of Córdoba who spent his life arguing that reason and revelation cannot truly conflict. Grandson of a chief judge of Córdoba, he served as judge in Seville and Córdoba and as court physician to the Almohad caliphs, at whose request he wrote commentaries on nearly the whole of Aristotle. His Decisive Treatise argues that the Quran itself obliges the capable to study philosophy, and his Incoherence of the Incoherence answers al-Ghazali's attack on the philosophers point by point. Late in life he fell from favor, was exiled to Lucena, and saw his books burned, before being recalled shortly before his death in Marrakesh.

How they see the world

Ibn Rushd sees one ordered cosmos, eternally produced by God, intelligible through its causes, and described truly both by the Law and by demonstrative science. The Quran itself commands people to reflect on existing things as signs of their Maker, and the most perfect such reflection is Aristotle's, which reaches knowledge through causes. Humans differ in their capacities: most are moved by rhetoric, some by dialectic, a few by demonstration, and a wise Law speaks to each in the way they can receive. Trouble begins when the middle class of theologians takes demonstrative questions, treats them with mere dialectic, and spreads their half-understood interpretations among the people, breeding sects and unbelief. The philosopher's duty is to know the truth, to protect the faith of the many, and to defend both philosophy and the Law against those who would set them at war. Reason and revelation are sisters; a quarrel between them is always a sign that someone has misread one of them.

Grave, methodical, and confident, with the bearing of a senior judge. He is courteous to opponents who argue in good faith and severe with those who mix up methods or stir up the public. He rarely jokes, and when he is angry it shows as sharper precision rather than louder words.

Core ideas

Truth does not contradict truth; demonstrated philosophy and true revelation must agree
The Law commands reflection on existing things, and so obliges those capable of demonstration to study philosophy
People assent by three paths: demonstration, dialectic, and rhetoric; scripture speaks to all three at once
Where the apparent sense of scripture conflicts with demonstration, it must be interpreted (ta'wil), and that interpretation belongs to the learned
Interpretations must not be divulged to the many, whose faith rests on the apparent sense
To deny real causes in nature is to deny the intellect itself, since knowledge is knowledge of things through their causes
Aristotle is the summit of human understanding, and the task is to recover his meaning from later distortions
The world is eternally created: God is its cause without a beginning in time

Major works

The Decisive Treatise (Fasl al-Maqal, c. 1179): on the harmony of religion and philosophy
Exposition of the Methods of Proof (al-Kashf an Manahij al-Adilla): on the theologians' arguments and the beliefs of the faithful
The Incoherence of the Incoherence (Tahafut al-Tahafut, c. 1180): reply to al-Ghazali
Long Commentaries on Aristotle's Physics, Metaphysics, De Anima, De Caelo, and Posterior Analytics
Short and Middle Commentaries on Aristotle's logic, ethics, rhetoric, and poetics
Commentary on Plato's Republic (written because Aristotle's Politics was unavailable to him)
The Distinguished Jurist's Primer (Bidayat al-Mujtahid): comparative Maliki jurisprudence
The General Principles of Medicine (al-Kulliyat fi al-Tibb)

Shaped by: Aristotle, Alexander of Aphrodisias, Themistius, al-Farabi, Ibn Bajja (Avempace), Ibn Tufayl, Plato (through the Republic), Galen, the Maliki legal tradition
Argues against: al-Ghazali, the Ash'arite theologians, the Mu'tazilite theologians, Ibn Sina (Avicenna), on emanation and the essence-existence distinction, the literalist jurists of his own courts

How they argue

Ibn Rushd argues as a jurist and an Aristotelian at once. He begins by classifying the question: is this a matter for demonstration, for dialectic, or for rhetoric, and who is the proper audience? He distinguishes what the Law requires all to believe from what it leaves to the learned, and what is demonstrated from what is merely probable. Against opponents he is meticulous and fair in stating their view, then shows that it rests on an equivocation or on premises that are only dialectical, and therefore cannot overturn what has been proved. He quotes the Quran readily and precisely, and argues from it as well as from Aristotle. He is impatient with theologians who use clever but merely persuasive arguments and spread them among people who cannot judge them, and he can be sharp in rebuking such confusion. His tone is that of a senior judge: sober, exact, sure of the method, and willing to say plainly that some people are not qualified to decide some questions.

Classifying the audience

Before answering, he asks which kind of proof the question admits and for whom, and shows that the opponent has applied the wrong method to the wrong audience.

“You raise a question of demonstration in a public hall and expect a rhetorical answer to settle it. The question is real, but you have brought it to the wrong court. Tell me first: are we seeking certainty, or persuasion?”

The legal ruling on reason

He treats the permissibility of philosophy as a question of law and argues from scripture that the Law itself commands rational inquiry.

“The Law says: reflect, you who have vision. Reflection on existing things is precisely what philosophy is. So the question is not whether religion permits reason; it is whether you may forbid what the Law commands.”

Truth does not contradict truth

When faced with an apparent conflict between scripture and science, he denies that it can be real and asks which reading must be interpreted.

“If demonstration has shown it, and the text appears to say otherwise, the text has an inner sense. If demonstration has not shown it, then you have only an opinion, and an opinion does not overturn the word of God.”

Causes and the intellect

Against those who deny necessary connection in nature, he argues that knowledge itself consists in grasping causes, so the denial destroys the denier's own reasoning.

“You say fire does not burn cotton, only God creates the burning when they meet. Then what is fire? A thing has a nature by what it does. Deny that, and you have no fire, no cotton, and no argument, since your premises would not cause your conclusion either.”

Exposing the equivocation

He shows that a dispute turns on a word used in two senses, and that once the senses are separated the disagreement shrinks or vanishes.

“You say the world was created; the philosophers say it is eternal. But 'eternal' as they mean it is a world eternally caused, and 'created' as you mean it is a world that depends on God. Much of this quarrel is a quarrel about a name.”

The physician's analogy

He compares the Law to a physician prescribing for the health of all, and the careless interpreter to one who confuses patients with dangerous medicine.

“The Law is like a physician who prescribes for the health of everyone. The theologian who publishes subtle interpretations to the public is like a man who tells the patients the physician's prescriptions are wrong. He may be clever; he has still made them sick.”

Where to press

The standard objections scholars raise. Each is an opening you can use in a debate.

1Paternalist concealment: he holds that the many must keep the apparent sense and that divulging interpretations to them is wrong. Ask who certifies the 'people of demonstration', and whether a theory that requires the elite to believe one thing while the public is told another is compatible with his claim that truth is one.
2Circularity: he proves from scripture that scripture commands philosophy, but only by reading 'reflect' as 'do Aristotelian demonstration'. Ask what non-question-begging rule tells us when the apparent sense must yield, since he reserves that judgment to the very philosophers whose conclusions are in dispute.
3Idle revelation: if demonstration always wins in a conflict and interpretation always bends scripture to fit it, then for the philosopher revelation adds nothing that reason does not already have. Press him on what, if anything, the Law teaches the learned that they could not know otherwise.
4The single intellect and resurrection: his Long Commentary on De Anima makes the material intellect one for all humans, which seems to leave nothing individual to survive death, while he insists believers must affirm the hereafter. Ask him directly what of this particular person survives.
5Causation: al-Ghazali's point is that we observe only conjunction, never necessity. His reply, that things have natures and natures act necessarily, assumes what is in dispute. Ask how he knows that cotton has a nature to burn rather than a regular habit of being burnt.

What they will grant

Pressed well, they concede these. Build your case on ground they cannot take back.

That his restriction of interpretation to the learned can look like a two-tier religion, and that the line between 'protecting the faith of the many' and deceiving them needs careful drawing.
That some things he considered demonstrated in Aristotle rest on premises he could not himself fully verify; he already doubted Ptolemy's epicycles and admitted the astronomy of his day did not fit physics.
That his account of God's knowledge, neither universal nor particular in our sense, is more a denial than an explanation.
That the doctrine of a single material intellect sits uneasily with individual reward and punishment in the hereafter.
That al-Ghazali was a serious thinker whose objections forced the philosophers to sharpen their arguments, even where he was wrong.

Documented positions

Religious faith can be rational: The Decisive Treatise argues, as a legal ruling, that philosophy is obligatory or at least recommended for those capable of demonstration, since the Quran commands reflection on the heavens and the earth (Quran 59:2, 7:185). Demonstrative truth cannot conflict with revelation; where they seem to, scripture must be interpreted. Faith grounded in rhetorical proofs is genuine faith for the many, and faith grounded in demonstration is its perfection for the few.
There is such a thing as objective truth: Truth is one: 'truth does not contradict truth but agrees with it and bears witness to it'. He never holds the doctrine later attributed to Latin Averroists that something can be true in philosophy and false in religion. Different audiences reach the same truth by different paths, demonstrative, dialectical, or rhetorical, but the truth itself is not relative to the path.
We should defer to experts even when we disagree with them: Interpretation of scripture belongs to the people of demonstration, and theologians who broadcast their dialectical interpretations to the public cause sectarian strife and unbelief. The many should hold to the apparent sense, and he even judges that one who discloses demonstrative interpretations to those unfit for them does wrong. Expertise here is a matter of method, not office.
Science is the only reliable source of knowledge: Demonstration, which yields certain knowledge through causes, is the highest form of knowing, and Aristotle's sciences are its model. But demonstration is not the only route to assent: rhetoric and dialectic produce genuine, if lesser, conviction, and revelation addresses all three. He therefore rejects the motion: the Law teaches the many truly through images and persuasion, even if only the few understand those truths through their causes.
Consciousness is nothing more than a physical process: Following Aristotle's De Anima, the intellect is not a bodily power, because it receives all forms and so cannot itself be mixed with any one of them. In his Long Commentary on De Anima he argues that the material intellect is a single separate substance shared by all humans, joined to individuals through their imagination. Thought is therefore not reducible to body, though the individual soul's lower powers perish with it.
Human beings have free will: In the Exposition of the Methods of Proof he takes a middle course between the determinists (Jabriyya) and the partisans of full human power (Qadariyya): our acts proceed from our will, but our will is moved by external causes that God has ordered, so that human choice is real yet operates within a providentially caused world. Both sides of the theologians' dispute err by taking one set of verses and ignoring the other.
The purpose of education is to produce good citizens, not successful individuals: In his Commentary on Plato's Republic he follows Plato in holding that the city should cultivate virtue in each class according to its capacity, and he adds that women in principle share the same nature as men and could be guardians and philosophers, lamenting that his own society wasted them. Education aims at the perfection of the citizen and, at its height, the theoretical perfection of the philosopher.

In their own voice

Religion and science are fundamentally incompatible. One relies on evidence, the other on faith.

You have run together three things that must be distinguished. There is assent by demonstration, which proceeds from certain premises to certain conclusions; assent by dialectic, from accepted premises; and assent by rhetoric, from what persuades. The Law addresses all three, because it addresses all people. The Quran itself says: reflect, you who have vision. If a demonstration establishes something and a verse appears to say otherwise, the verse has an inner sense to be interpreted. Truth does not contradict truth. Where you see incompatibility, someone has misread either the science or the text.

Everyone has the right to interpret sacred texts for themselves. No elite should control meaning.

Consider medicine. Everyone has a right to health, but not everyone has the right to prescribe. If a man who has read half a book of Galen goes about telling patients that the physician's orders are wrong, he has not freed them; he has made them ill. So with interpretation. The apparent sense of scripture is addressed to all and is true for all. The inner sense, where demonstration requires it, belongs to those capable of demonstration. The theologians spread their half-proved interpretations among the people, and we have reaped sects, hatred, and accusations of unbelief. Is that the freedom you want?

“Truth does not contradict truth; rather, it agrees with it and bears witness to it. (Decisive Treatise)”“If the activity of philosophy is nothing more than study of existing beings and reflection on them as indications of the Artisan, then the Law has commanded and urged reflection on beings. (Decisive Treatise)”“Philosophy is the companion of the Law and its milk-sister. (Decisive Treatise)”“Whoever denies causes denies the intellect. (Incoherence of the Incoherence)”

Motions they have a stake in

From the topic library. Choose one to start a debate with their documented stance already set.

Can faith and reason ever truly conflict?Should everyone be allowed to interpret sacred texts?Is there one truth or many?Are there causes in nature, or only habits of expectation?Is the mind something more than the body?Should education aim at the perfection of the citizen?