Averroes's Decisive Treatise: A Defense of Philosophical Inquiry

Suppose a religious text appears to say something that a carefully established argument rules out. Is the argument mistaken, is the text being misunderstood, or must one kind of authority defeat the other? Averroes's Decisive Treatise approaches that problem by first asking a legal question: what status does religious law give to philosophical inquiry?

His answer changes the terms of the dispute. For a suitably qualified person, he argues, investigating existing things is part of what the law requires. Philosophy therefore needs to be understood within the religious life. The task is to explain how inquiry, interpretation, and the education of a whole community can belong together.

The argument offers a defense of demanding intellectual work. It also imposes restrictions on who should receive certain interpretations. Understanding the treatise means taking both commitments seriously. Its protection of philosophy and its limits on public teaching grow from the same account of how people come to accept what is true.

The opening of the Decisive Treatise asks whether the study of philosophy and logic is permitted, prohibited, recommended, or obligatory according to the law. Those are categories of religious legal assessment. Averroes does not begin by asking the religious community to withdraw from the question. He proposes to reason from commitments that he takes that community to possess.

He defines philosophy, for the purpose of this argument, as reflection on existing things insofar as they indicate their maker. The more completely someone understands the workmanship, the more completely that person can know the artisan. Scriptural commands to consider creation can therefore support the activity he has identified as philosophy.

A reader need not accept this conception of the world to follow its argumentative role. Averroes is not offering a religiously neutral demonstration that every possible philosophical project is obligatory. He is connecting a particular conception of inquiry to the scriptural demand for reflection. The premises matter as much as the conclusion.

His argument concerns qualified practitioners. In section 10 of the Butterworth translation, he specifies intellectual aptitude together with religious justice and moral virtue. Philosophy is not presented as an activity for anyone under any conditions. The restrictions are part of the defense from the beginning, rather than qualifications added after a general declaration of unrestricted freedom.

Reflecting carefully on what exists requires a method for reaching what is unknown from what is known. Averroes identifies syllogistic reasoning as the relevant instrument and demonstration as its most complete form. A syllogism connects premises to a conclusion through an organized inference. Demonstration adds demanding conditions concerning the knowledge those premises and inferences provide.

The argument then moves from an end to its necessary means. If a person is obliged to pursue a kind of knowledge, and that knowledge requires logical tools, acquiring those tools belongs to the obligation. Before undertaking demonstrations, the inquirer must learn what distinguishes them from other arguments and how their premises work.

He supports this move through an analogy with jurisprudence. A jurist needs training in legal reasoning to carry out the law's requirements. Someone pursuing intellectual reflection likewise needs training in intellectual reasoning. The analogy establishes a parallel between disciplines. It does not identify philosophy with jurisprudence or suggest that studying nature is simply another procedure for issuing legal rulings.

This distinction helps us assess the argument. A command to reflect does not immediately prove that one particular account of logic is the only suitable instrument. Averroes supplies a conception of the best kind of reflection and reasons from it. A critic can question that conception while recognizing why the training requirement follows within his framework.

He also answers the objection that this logical study was absent in the earliest period of Islam. Legal syllogistic reasoning was itself developed after that period, he observes. If that development is not rejected merely because it came later, the same objection cannot automatically disqualify intellectual syllogistic reasoning. The reply concerns the consistency of the proposed prohibition.

The next part of the argument concerns intellectual inheritance. A single person cannot begin every science again. Averroes points to the cumulative character of fields such as geometry and astronomy. Philosophical investigation likewise requires making use of predecessors rather than treating all earlier work as though it had never happened.

That requirement includes predecessors who did not share the inquirer's religion. In section 6, Averroes compares a valid intellectual instrument to a tool used in a valid sacrifice. The relevant question is whether the instrument meets its conditions, rather than the religious identity of its owner. The analogy supports using a sound method without first demanding religious agreement from its discoverer.

His acceptance is conditional. In sections 7 and 9, he calls for accepting what is true and identifying what is mistaken in earlier writings. Studying the ancients is therefore not the same as accepting every ancient conclusion. The distinction protects the inquiry from replacing religious conformity with uncritical philosophical conformity.

There are consequently two errors to avoid within his account. Rejecting a sound argument because of its origin obstructs inquiry. Accepting an unsound argument because of its origin obstructs it too. The required assessment concerns the argument itself, including the premises that its earlier readers may have taken for granted.

Consider a hypothetical reader who distrusts a proof because its author belonged to another religious community. Averroes's argument asks the reader to examine whether the proof works. Conversely, the author's prestige does not turn an error into knowledge. This illustration states the implication of his argument; it is not an episode reported in the treatise.

He then distinguishes essential benefit from incidental harm. Some people become confused through study because of poor preparation, disordered reasoning, passions, or lack of a teacher. That does not, he argues, justify preventing a suitable student from studying. His comparison is with denying water to the thirsty because someone has choked while drinking it.

The comparison does not establish that every philosophical course is beneficial. It identifies what a prohibition would have to show. An example of harm is insufficient if the harm depends on conditions that appropriate education can address. A reader can ask whether the proposed distinction actually fits the kinds of philosophical disagreement at issue.

Averroes holds that the law addresses people through different methods because their capacities for assent differ. To assent is to accept a proposition as true. His three principal methods are demonstration, dialectic, and rhetoric. The distinction concerns how acceptance is produced and justified within his account.

Demonstration aims at certainty through the appropriate premises and reasoning. Dialectic works with accepted opinions. Rhetoric persuades through forms of argument accessible to a wider audience. These descriptions concern methods; the treatise also associates them with differences among people. It would soften his position too much to treat the hierarchy as merely a preference among teaching styles.

The law's address to a whole community must accommodate those differences. An argument that convinces someone trained in demonstration might be inaccessible to another person. The absence of that training does not, for Averroes, exclude the person from religious life. The law contains ways of establishing assent appropriate to different capacities.

Section 12 states the principle that connects this account to interpretation: truth cannot oppose truth. Given the truth of the law and the truth established by an actual demonstration, their conclusions cannot genuinely contradict one another. The principle is conditional on the philosophical result actually being demonstrated. Confidence, fashion, and the prestige of a philosopher cannot substitute for that condition.

This is why attributing two incompatible truths to Averroes would misrepresent the argument here. He does not authorize someone to affirm a proposition as philosophically true and its denial as religiously true in the same respect. The problem is an apparent conflict between a demonstrated result and an apparent meaning. Interpretation is supposed to disclose their compatibility.

Section 13 distinguishes several cases. The law might be silent about the matter established by demonstration. Its apparent meaning might agree with the result. Or its apparent meaning might conflict. Only the third case creates the need for the interpretive move under discussion.

Interpretation, or ta'wil, draws a figurative meaning from an expression while respecting the conventions of Arabic speech. Averroes lists familiar relationships through which language can work figuratively, including resemblance, cause, and consequence. He is not giving an interpreter permission to assign any convenient meaning to any sentence.

The interpretive claim has two constraints. There must be a demonstrated result that warrants departing from the apparent sense. The proposed reading must also be possible within the language of the text. In section 14, Averroes adds that examining scripture as a whole will reveal apparent passages supporting, or approaching support for, the interpretation.

An everyday illustration can help isolate the linguistic point. In a hypothetical sentence, a person might call a ruler “the shield of the city.” Understanding the ruler as literally made of metal would miss a familiar figurative use. The possibility of figurative speech does not allow us to turn “shield” into any meaning we prefer. This is our illustration of linguistic constraint, not Averroes's own scriptural example.

The more difficult question remains philosophical: who has really demonstrated the disputed conclusion? A figurative reading cannot rescue a weak argument by calling it certain. Nor does the mere presence of metaphor in a language prove that a particular passage should be read metaphorically. The two sides of the proposed reconciliation require separate scrutiny.

Averroes next considers a possible obstacle. What if a proposed interpretation contradicts an established consensus about what a religious text means? In section 15, he distinguishes consensus known with certainty from consensus established only conjecturally. The distinction matters because not every reported agreement possesses the same authority.

Establishing consensus about a theoretical question would require knowing the relevant scholars and their positions. It would also require accounting for the possibility that some held interpretations they did not disclose publicly. If learned people regard certain interpretations as appropriate only for prepared readers, silence cannot automatically be counted as agreement with the apparent reading.

This argument does not mean that Averroes rejects consensus everywhere. He distinguishes theoretical questions from practical matters and argues that the evidence needed to establish agreement differs. His conclusion challenges the certainty of a particular kind of consensus claim, rather than erasing religious authority by definition.

The controversy with al-Ghazali enters here. Averroes questions the condemnation of philosophers over the world's eternity, divine knowledge, and the afterlife. He also contests whether al-Ghazali has represented their account of divine knowledge accurately. These are disagreements within the argument, not conclusions a reader should settle simply by choosing a favored author.

On divine knowledge, Averroes insists that God's knowing cannot be assimilated to ours. In the account he defends, human knowledge is an effect of existing things, whereas divine knowledge is their cause. The vocabulary of universal and particular knowledge must therefore be handled carefully. He does not want the alleged restriction on God's knowledge to be treated as a straightforward description of philosophical teaching.

His discussion of the world's origin likewise examines whether familiar labels conceal more complicated agreements and disagreements. A reader should resist reducing the treatise to a slogan that religion says “created” while philosophy says “eternal.” The meaning of dependence, temporal beginning, and the world's relationship to God needs to be specified before the opposition can be judged.

The treatise's account of education places limits on communicating interpretations. Averroes argues that giving an interpretation to someone unable to understand its proof can remove an existing basis for assent without supplying a replacement. The result may be a loss of belief rather than increased understanding. He treats this as a religious danger.

For him, the interpretation may be required for one person and inappropriate for another. The difference follows from the recipient's capacity to understand it. This is a stronger position than the familiar advice to explain difficult material patiently. It can support withholding conclusions, rather than merely presenting them in simpler words.

The argument also bears on the kinds of books in which interpretations should appear. Averroes objects to exposing certain matters in writings that reach people who cannot follow the demonstration. His concern joins the truth of what is said to the conditions under which it can be understood. Correct content alone is not sufficient, on his view, to make its publication appropriate.

A contemporary reader can recognize a limited educational concern here without accepting the restriction. A learner can lose confidence in a simple explanation before acquiring a better one. That observation does not by itself authorize an intellectual authority to decide permanently what the learner may know. The move from a teaching difficulty to a rule of nondisclosure requires an additional argument.

This is one of the treatise's hardest questions. Who judges capacity, and how can that judgment be challenged? Averroes gives requirements concerning aptitude, virtue, and preparation. Whether they justify the boundaries he draws remains open to criticism. A defense of his position should confront that question directly rather than redescribe the restrictions as modern educational equality.

The project depends on more than the slogan that truth agrees with truth. A reader has to assess the conception of demonstration, the interpretation of scriptural commands, the linguistic constraints on figurative reading, and the classification of audiences. Each component does work. Accepting one does not automatically establish the others.

The argument's internal form is nevertheless clear. An activity commanded by the law needs its appropriate instruments. Knowledge can be inherited across religious boundaries while remaining subject to criticism. A true conclusion cannot conflict with a true revelation, though it can conflict with an apparent reading. Teaching must then consider how its audience can understand and assent.

The principle can be tested through the hypothetical conflict with which we began. First establish whether the philosophical argument warrants its conclusion. Then ask whether the apparent scriptural meaning is required by the language and context. Finally examine the proposed interpretation and the conditions of communicating it. Moving through those questions prevents a declaration of harmony from replacing the work of reconciliation.

Averroes offers qualified philosophical inquiry a place inside religious obligation. He also asks that inquiry to accept obligations concerning its readers. The resulting tension is part of the book's substance: a defense of the philosopher's work can coexist with restrictions that many readers will reject. Reading the treatise well means being able to explain both the defense and the cost.

• Averroes, The Book of the Decisive Treatise Determining the Connection between the Law and Wisdom, Charles E. Butterworth translation, available in this online transcription and a Yale-hosted PDF. Section numbers here follow that translation.
• Read sections 1–10 for the legal question, logic, intellectual inheritance, and qualifications for study.
• Read sections 11–15 for methods of assent, the compatibility principle, interpretation, and consensus; continue into the discussion of al-Ghazali's condemnations for the disputed doctrines.
• Read the later discussion of interpretation and its audiences alongside the defense of inquiry. The restrictions are necessary to understanding the position being defended.