The Incoherence of the Philosophers

1. Introduction

The Incoherence of the Philosophers (Tahāfut al-Falāsifa) is a polemical yet technically sophisticated treatise in which the theologian Abu Ḥāmid al-Ghazālī (d. 1111) scrutinizes central doctrines of the Islamic Peripatetic (falāsifa) tradition, above all as articulated by Ibn Sīnā (Avicenna) and, to a lesser extent, al-Fārābī. Written in Classical Arabic in the late 5th/11th century, it is structured as twenty ordered “discussions” (masā’il) that each present a philosophical thesis and then subject it to critical analysis.

Al-Ghazālī’s declared aim is not to refute philosophy in its entirety, but to challenge what he sees as unwarranted metaphysical claims that conflict with Sunni Islamic theology (especially Ashʿarism). He accepts the utility of logic and parts of natural philosophy while arguing that in areas concerning God, creation, and the afterlife, the falāsifa claim a demonstrative certainty they do not in fact possess.

The work is distinctive for combining:

• close, often accurate summaries of Avicennian arguments;
• rigorous logical critique;
• explicit attention to doctrinal implications for Islamic creed.

At several points al-Ghazālī charges the philosophers with internal inconsistency (tahāfut) and, in three cases, with outright unbelief (kufr): their doctrines of the eternity of the world, God’s knowledge only of universals, and the denial of bodily resurrection.

Later thinkers interpreted the Tahāfut in divergent ways. Some read it as a decisive theological victory over philosophy; others as an intra-philosophical critique that relies heavily on philosophical tools; still others as a key text in the broader medieval debate on reason and revelation. Its arguments on causality, divine knowledge, and eschatology became touchstones in subsequent Islamic and, indirectly, Latin scholastic thought.

This entry surveys the context, arguments, methods, and reception of the Tahāfut, focusing on how al-Ghazālī engages the falāsifa’s metaphysics and theology and how later readers have understood the significance of that engagement.

2. Historical and Intellectual Context

2.1 The Islamic World in the 5th/11th Century

Al-Ghazālī composed the Tahāfut during the Seljuq period, when Sunni institutions such as the Nizāmiyya madrasas were being consolidated. Theological debate was intense, and several currents coexisted:

Politically, patronage of both jurisprudence and rational sciences created space for philosophical and theological disputation, while also making orthodoxy a live concern for jurists and sultans.

2.2 Development of Falsafa before al-Ghazālī

From the 9th century, translations of Greek works—Aristotle, Plotinus (via the so‑called Theology of Aristotle), and others—enabled the rise of falsafa. By al-Ghazālī’s time, a relatively systematic Islamic Peripatetic tradition existed:

• al-Kindī initiated the philosophical project.
• al-Fārābī developed a political and cosmological synthesis.
• Ibn Sīnā constructed an elaborate metaphysical system centered on the Necessary Being, emanation, and a graded cosmos of intellects and spheres.

Al-Ghazālī engages this mature Avicennian synthesis rather than the translation movement as such.

2.3 Kalām and Philosophy

The relationship between kalām and falsafa was complex. Some theologians adopted philosophical vocabulary and logic while rejecting Avicennian metaphysics; others opposed philosophy more wholesale. Al-Ghazālī stands at a transitional point: he had mastered, systematized, and even taught philosophy in Maqāṣid al-Falāsifa before composing the Tahāfut.

Scholars differ on how antagonistic his project is. One view holds that he intended to curtail philosophical speculation decisively; another interprets him as internalizing and redirecting philosophical methods within an Ashʿarite framework.

2.4 Precedent Critiques

Earlier critiques of philosophy existed, including anti-falsafa treatises by theologians and jurists, but none matched the technical depth of the Tahāfut. Al-Ghazālī’s work emerges, therefore, at the intersection of a sophisticated Avicennian metaphysics and an equally sophisticated kalām tradition eager to engage it on its own terms.

3. Author, Composition, and Purpose

3.1 Al-Ghazālī’s Background

Abu Ḥāmid al-Ghazālī (1058–1111), a jurist, theologian, and mystic, was trained in Shāfiʿī law and Ashʿarite theology and attained prominence as a teacher at the Nizāmiyya of Baghdad. His intellectual formation included intensive study of falsafa, culminating in his own expositions of philosophical doctrine.

His broader oeuvre integrates law, theology, and Sufism. The Tahāfut belongs to his “philosophical–theological” phase, prior to or overlapping with his more overtly mystical writings such as Iḥyāʾ ʿUlūm al-Dīn.

3.2 Circumstances and Dating of Composition

Most scholars date the Tahāfut to c. 1094–1095 CE, around the end of al-Ghazālī’s Baghdad teaching career and close to his well‑known spiritual crisis and temporary withdrawal from public life. Internal evidence—its reliance on Avicennian doctrine as summarized in Maqāṣid al-Falāsifa and the maturity of its Ashʿarite positions—supports a relatively late date within his early middle period.

The work appears to have first circulated among scholars and students as a polemical treatise rather than as an official institutional text.

3.3 Declared Aims

Al-Ghazālī presents his purpose as twofold:

1. Doctrinal defense: to safeguard core Sunni beliefs from philosophical doctrines he regards as incompatible with revelation.
2. Methodological critique: to show that the falāsifa have not achieved genuine demonstration (burhān) in metaphysics and thus lack the epistemic authority they claim.

He stresses that he will first present philosophical positions “in their strongest form” before disputing them, aiming to prevent readers from being misled by the prestige of philosophical language and reasoning.

3.4 Intended Audience

The text addresses educated Muslims conversant with scholastic argumentation—jurists, theologians, and advanced students—rather than lay believers. At the same time, its polemical tone suggests an apologetic dimension: it seeks to reassure the broader scholarly community that key philosophical theses can be challenged using the very tools of logic and analysis that made them attractive.

3.5 Interpretive Debates on Purpose

Modern interpreters disagree on the deeper purpose of the Tahāfut:

The text itself provides evidence for all three readings, and no single consensus has emerged.

4. Structure and Organization of the Work

4.1 Overall Layout

The Tahāfut is organized into an introductory prologue followed by twenty thematically ordered “discussions” (masā’il), each addressing a specific philosophical doctrine. The sequence moves from cosmology and theology to psychology and eschatology, culminating in final doctrinal judgments.

4.2 The Standard Discussion Format

Most discussions follow a recognizable pattern:

1. Exposition of the philosophers’ thesis, often in Avicennian terms.
2. Presentation of their arguments, in syllogistic or quasi-syllogistic form.
3. Refutation, combining logical, metaphysical, and scriptural considerations.

This structure allows al-Ghazālī both to demonstrate his mastery of philosophical doctrine and to highlight, in his view, its internal tensions.

4.3 Thematic Progression

The arrangement is not random. It moves from:

• foundational issues of cosmic origin and divine action (Discussions 1–4),
• to more specific questions concerning attributes, knowledge, and providence (5–11),
• then to the human soul and the eschatological consequences of the philosophers’ positions (12–16, 20),
• with the cluster on causality and miracles (17–19) providing the metaphysical underpinnings for prophecy, revelation, and extraordinary events.

This progression underscores how, for al-Ghazālī, debates about the eternity of the world and divine knowledge are directly connected to the status of prophecy and the afterlife.

4.4 The Introductory Prologue

In the prologue, al-Ghazālī:

• distinguishes between acceptable and unacceptable uses of philosophy;
• delineates the categories of philosophical sciences (mathematics, logic, natural science, metaphysics, politics, ethics);
• explains why his critique will focus primarily on metaphysics (ilāhiyyāt), where he believes the greatest theological risks lie.

4.5 The Concluding Sections

The final parts of the work, especially after Discussion 20, do not add new arguments but classify philosophical doctrines according to their theological gravity. Al-Ghazālī lists beliefs he considers unbelief versus those he deems innovations or serious errors, thereby tying the argumentative structure to explicit doctrinal evaluation.

5. The Philosophers Targeted by al-Ghazali

5.1 The “Falāsifa” as a Collective

Al-Ghazālī addresses his critique to the falāsifa, a term that in his usage designates a specific stream of Islamic Peripatetic philosophy rather than all philosophers in a broad sense. He portrays them as heirs to Aristotle and the Greek tradition but working within an Islamic milieu.

He often speaks generically of “the philosophers,” although his arguments frequently presuppose Avicennian formulations.

5.2 Ibn Sīnā (Avicenna)

Most scholars agree that Ibn Sīnā (Avicenna) is the primary, though not always explicitly named, target. This is evident from:

• reliance on Avicennian concepts such as Necessary Being (wājib al-wujūd), emanation, and the hierarchy of intellects;
• engagement with Avicennian theses on the eternity of the world, God’s knowledge, and the nature of the soul.

Some discussions appear to track passages in Avicenna’s al-Shifāʾ and al-Najāt, although al-Ghazālī typically cites “the philosophers” rather than individuals.

5.3 al-Fārābī and Earlier Thinkers

Al-Ghazālī also draws upon and disputes doctrines associated with al-Fārābī, particularly regarding emanation and the structure of the celestial intellects, as well as views on prophecy and the relation of religion to philosophy. Earlier figures such as al-Kindī and the translators are less explicitly present, but form part of the intellectual background of the tradition he addresses.

5.4 Inclusion and Exclusion of Philosophical Currents

The Tahāfut targets primarily the Peripatetic-Avicennian strand. It does not systematically address:

• Ismāʿīlī esoteric philosophies,
• Illuminationist (Ishrāqī) philosophy (which largely postdates al-Ghazālī),
• mystical or Neoplatonic strands not tied to the falsafa canon.

He also distinguishes between different philosophical disciplines. Mathematics and logic, and even some aspects of physics, are not objects of wholesale condemnation; the critique is largely confined to metaphysics and certain theological claims drawn from physics (such as necessity in nature).

5.5 How Explicit Are the Targets?

Al-Ghazālī seldom names individual philosophers, a feature that has generated scholarly discussion. Some interpret this anonymity as rhetorical, allowing him to treat falsafa as a unitary position; others suggest that it reflects his focus on doctrinal content rather than on personal polemic.

Modern reconstructions typically map specific arguments to identifiable Avicennian and Fārābian sources, though there remains debate over how accurately he represents the nuances of those authors’ systems.

6. Central Arguments on Creation and the Eternity of the World

Discussions 1–4 of the Tahāfut are devoted to the question of whether the world is eternal or temporally originated (ḥādith).

6.1 Philosophers’ Doctrine of Eternity

Al-Ghazālī attributes to the falāsifa the thesis that:

• the world has no beginning in time;
• it eternally and necessarily emanates from God as its first cause;
• God’s action is not a temporal choice but an eternal, unchanging causal relation.

This view is rooted in an Avicennian adaptation of Aristotelian cosmology, where time and motion are co-eternal with the celestial spheres and God as the unmoved mover.

6.2 Al-Ghazālī’s Critique of Their Proofs (Discussion 1)

Al-Ghazālī examines several philosophical proofs for eternity—for instance, arguments based on the impossibility of a first temporal instant or on the nature of divine immutability—and contends that they fall short of demonstration (burhān). He argues that:

• the philosophers smuggle in unproven premises, such as specific assumptions about infinity and temporal succession;
• the claim that an eternal cause must have an eternal effect is not self‑evident.

He maintains that reason does not preclude a world beginning in time.

6.3 Eternal Cause and Temporal Effect (Discussion 3)

A central theme is the alleged impossibility of a temporal effect arising from an eternal, unchanging cause. Philosophers argue that if the cause is eternally complete, its effect must be co-eternal. Al-Ghazālī responds that:

• an eternal will can specify a particular moment for creation without itself changing;
• divine choice can explain why the world begins at one time rather than another.

He contends that the philosophers’ denial of such choice restricts divine freedom.

6.4 Emanation and Divine Unity (Discussions 2–4)

The falāsifa propose an emanation scheme in which a multiplicity of beings proceeds from the simple Necessary Being through a hierarchy of intellects, each producing a sphere. Al-Ghazālī challenges:

• the claim that from a purely one, simple cause only one effect can proceed;
• the coherence of deriving a complex, finite cosmos through necessary emanation.

He argues that these doctrines either undermine genuine tawḥīd (divine unity) or fail to explain multiplicity satisfactorily.

6.5 Creation in Time and Scriptural Commitments

While much of the argumentation is philosophical, al-Ghazālī does not hide that temporal creation is also a scriptural teaching. He holds that, given the alleged defects in the philosophers’ demonstrations, revelation’s assertion that the world began in time stands unrefuted. Modern interpreters disagree on whether his position ultimately subordinates reason to revelation or treats them as harmonious once philosophical overreach is curbed.

7. Divine Knowledge, Will, and Attributes

Discussions 5–11 focus on God’s attributes, particularly knowledge, will, and power, and on how these relate to the created order.

7.1 Philosophers on Divine Simplicity and Knowledge

The falāsifa affirm a radically simple, immaterial deity whose essence is identical with existence. In Avicennian fashion, they claim:

• God knows Himself perfectly;
• from this self-knowledge He knows other things, but only at the level of universals, not as changing particulars;
• God’s knowledge is timeless and unchanging, incompatible (they argue) with tracking transient details.

They also restrict divine attributes, treating them as conceptual, to avoid multiplicity in God.

7.2 Al-Ghazālī’s Defense of Attributes

Al-Ghazālī, working within Ashʿarite kalām, upholds real attributes such as knowledge, will, and power that are neither identical to the divine essence nor wholly other. He argues that the philosophers’ strict simplicity undermines:

• meaningful predication about God;
• the scriptural affirmation of multiple perfections in God.

He contends that acknowledging attributes does not entail composition in a corporeal sense and thus does not compromise transcendence.

7.3 Debate on God’s Knowledge of Particulars (Discussion 12/centre of 8–11 block)

Al-Ghazālī criticizes the thesis that God knows only universals:

• He argues that ignorance of particulars would be a defect incompatible with divine perfection.
• He claims that the philosophers’ fear of change in God’s knowledge confuses change in the object with change in the knower.

For him, God eternally knows particulars “as they are,” including their temporal succession, without His knowledge undergoing temporal alteration.

7.4 Divine Will and Freedom

The philosophers’ notion of necessary emanation suggests that God does not will in a deliberative or selective sense; the world flows from Him by necessity. Al-Ghazālī contends that:

• this undermines divine choice and omnipotence;
• it renders the world necessary rather than contingent upon God’s free act.

He defends a robust divine will that can choose between alternatives and specify contingent states of affairs, including the timing and structure of creation.

7.5 Cosmic Order and Providence

On providence, philosophers describe a universe governed by universal laws and intelligible patterns derived from the divine intellect, sometimes interpreted as minimizing particularized care. Al-Ghazālī, by contrast, insists on a God who is intimately aware of and in control of each event.

Modern scholars note that the debate here concerns not only metaphysical attributes but also views of law, regularity, and contingency in the cosmos, which will resurface in the discussions on causality and miracles.

8. Causality, Occasionalism, and Miracles

8.1 Philosophers’ Conception of Causality

The falāsifa hold that:

• natural things possess intrinsic causal powers;
• causal connections are necessary given the natures of things (e.g., fire necessarily burns cotton under suitable conditions);
• God is the ultimate cause but operates through stable secondary causes.

This yields a law-like universe in which miracles, if admitted, require special explanation.

8.2 Al-Ghazālī’s Critique of Necessary Causality (Discussion 17)

Al-Ghazālī contests the notion that there is any necessary connection between what we call cause and effect:

"

The connection between what is habitually believed to be a cause and what is habitually believed to be an effect is not necessary, according to us.

— al-Ghazālī, Tahāfut al-Falāsifa (Marmura trans.)

He argues that:

• observation shows only constant conjunction, not necessary linkage;
• positing inherent causal efficacy in creatures limits divine freedom, since God could not withhold effects without altering natures.

From this he develops an occasionalist view: created things are mere “occasions” for God’s direct creation of events.

8.3 The Fire and Cotton Example

In a celebrated passage, he imagines:

• fire approaching cotton;
• cotton’s burning ordinarily following.

He states that God could, without contradiction, cause the cotton not to burn or to turn into ashes without fire, demonstrating that what we call causation is a habit established by God, not a necessity of nature.

8.4 Miracles and the Stability of Nature (Discussions 17–19)

Discussions 18–19 extend these claims to miracles (muʿjizāt) and prophetic signs:

• If causality is only habitual, miracles are not violations of necessary laws but exceptions to customary patterns.
• This framework allows prophetic miracles and extraordinary events without, in his view, inconsistency.

Critics, both medieval and modern, have questioned whether this undermines confidence in empirical science. Some interpreters respond that al-Ghazālī preserves practical reliance on regularity by emphasizing the divine habit (ʿāda), which God ordinarily maintains.

8.5 Prophethood and Epistemic Authority

The possibility of miracles underwrites the credibility of prophets, whose signs mark divine endorsement. Al-Ghazālī argues that philosophical accounts that strictly naturalize causality struggle to accommodate such signs, whereas occasionalism makes them metaphysically straightforward. The broader debate concerns not only metaphysics but also which sources—prophets or philosophers—have ultimate authority in matters concerning the unseen.

9. Soul, Intellect, and Eschatology

Discussions 12–16 and 20 address the nature of the soul, its relation to the intellect, and the character of the afterlife.

9.1 Philosophers on the Soul and Intellect

The falāsifa typically adopt an Aristotelian-Avicennian psychology:

• The human soul is an immaterial, subsistent substance capable of intellectual cognition.
• Human understanding is completed through contact with an Active Intellect, a separate intellect that actualizes forms in the human mind.
• Ultimate human perfection lies in intellectual contemplation of separate intelligibles.

On eschatology, many philosophical accounts emphasize:

• the immortality of the rational soul;
• a primarily intellectual or spiritual afterlife;
• symbolic or pedagogical readings of scriptural depictions of bodily pleasures and pains.

9.2 Al-Ghazālī on the Soul’s Nature

Al-Ghazālī accepts that the soul is immaterial and survives bodily death, aligning in part with the philosophical tradition. However, he contests:

• overly naturalistic or deterministic accounts of the soul’s operations;
• the reduction of spiritual states to intellectual cognition alone.

He often stresses the moral and volitional dimensions of the soul, reflecting broader kalām and Sufi concerns.

9.3 Active Intellect and Prophetic Knowledge

Regarding the Active Intellect, al-Ghazālī criticizes the explanatory role philosophers assign to it:

• He questions whether it is needed to explain human knowledge, given divine omnipotence and illumination.
• He resists attempts to reduce prophecy to an exceptional relation to the Active Intellect, arguing that prophetic revelation has a sui generis status and content, including detailed law and eschatological information.

Some modern scholars read him as partially appropriating philosophical psychology while reconfiguring it within a theologically grounded theory of prophecy.

9.4 Eschatology and the Afterlife (Discussions 16 and 20)

Al-Ghazālī’s most explicit disagreement concerns the afterlife:

• Philosophers who treat Qurʾānic descriptions of Paradise and Hell as mere metaphors for intellectual joy and pain are, in his view, denying a core belief.
• He insists on bodily resurrection, involving reconstitution of the body and concrete rewards and punishments, while still allowing for spiritual dimensions.

He claims that reason cannot disprove bodily resurrection and that revelation’s clear statements take precedence where philosophical demonstration is lacking.

9.5 Classification of Philosophical Eschatology

In the conclusion, al-Ghazālī identifies the denial of bodily resurrection as one of three doctrines constituting unbelief. Other philosophical reinterpretations of eschatological imagery he treats as grave errors or innovations. This classification illustrates how for him, views on the soul and intellect have direct doctrinal consequences regarding judgment, reward, and punishment in the hereafter.

10. Key Concepts and Technical Terminology

The Tahāfut employs a shared philosophical–theological vocabulary. Some central terms include:

10.1 Shared vs. Contested Terms

Some terms are shared between falsafa and kalām but interpreted differently. For example:

• ʿIlm (knowledge): both sides affirm divine knowledge but disagree on its scope (universals vs. particulars).
• Irāda (will): philosophers often reinterpret it as necessary self‑knowledge; theologians see it as selecting among alternatives.

10.2 Conceptual Translation Between Traditions

Modern scholarship emphasizes that al-Ghazālī frequently translates Avicennian concepts into kalām categories and vice versa, creating potential shifts in meaning. Interpretive disagreements often turn on whether he preserves the technical precision of philosophical terms or adapts them to Ashʿarite usage.

11. Famous Passages and Exemplary Arguments

11.1 Fire and Cotton (Causality)

The best-known passage appears in Discussion 17, where al-Ghazālī uses the example of fire and cotton to illustrate his denial of necessary causality. He argues that observing fire burn cotton does not warrant the conclusion that burning follows from the nature of fire by necessity:

"

The agent of the burning is God… for there is no other creator than He, and what is customarily believed to be a cause is merely the occasion.

— al-Ghazālī, Tahāfut al-Falāsifa (paraphrased from Marmura trans.)

This argument is frequently cited in histories of philosophy as anticipating later debates about causation.

11.2 Critique of the Eternity of the World

In the opening discussions, al-Ghazālī offers detailed analyses of philosophical proofs for an eternal universe. A recurring argumentative strategy is to accept, for the sake of argument, certain premises and then show that they lead to contradictions or unwarranted conclusions. For example, he questions the coherence of an actual infinite past composed of temporal units, challenging the philosophers’ assumptions about infinity and time.

11.3 Divine Knowledge of Particulars

Discussion 12 (within the broader 8–11 block) contains a nuanced critique of the thesis that God knows only universals. Al-Ghazālī deploys both:

• an argument from divine perfection (ignorance of particulars would be a defect); and
• a logical analysis of the philosophers’ fear that knowing changing particulars would require change in God.

He suggests that God’s eternal knowledge encompasses temporal events without undergoing temporal modification, a position that becomes influential in later kalām.

11.4 The Three Doctrines of Unbelief

Near the close of the work, al-Ghazālī famously identifies three philosophical doctrines as constituting kufr:

1. Eternity of the world.
2. God’s knowledge restricted to universals.
3. Denial of bodily resurrection.

He distinguishes these from other, less severe errors, thereby shaping the reception of philosophical doctrines in subsequent Sunni discourse.

11.5 Exemplary Use of Philosophical Method

Throughout, al-Ghazālī’s arguments exhibit a sophisticated command of logic and Avicennian metaphysics. Scholars often highlight his systematic refutation of the principle that “from the One only one proceeds,” where he presses the philosophers on how multiplicity can emerge from a strictly simple Necessary Being. This discussion exemplifies his broader strategy of turning philosophical commitments against one another to expose what he characterizes as tahāfut.

12. Philosophical Method and Use of Demonstration

12.1 Al-Ghazālī’s Engagement with Logic

Al-Ghazālī accepts and employs Aristotelian logic, including syllogistic reasoning and the classification of arguments. He does not reject burhān as such; rather, he questions whether the falāsifa’s metaphysical arguments truly meet the standards of demonstrative proof.

He had earlier presented philosophical doctrines systematically in Maqāṣid al-Falāsifa, indicating familiarity with their methods before critiquing them.

12.2 Critique of Pseudo-Demonstration

A central methodological claim is that many of the philosophers’ arguments in metaphysics:

• rely on premises that are themselves unproven or only plausible;
• sneak in theological or cosmological assumptions about infinity, time, and necessity;
• therefore yield, at best, dialectical or persuasive conclusions, not strict demonstration.

He repeatedly invites readers to distinguish clearly between certainty and conjecture.

12.3 Scope and Limits of Reason

Al-Ghazālī maintains that:

• reason can yield demonstrative knowledge in mathematics, logic, and some aspects of natural philosophy;
• in metaphysics and matters of the unseen (e.g., detailed eschatology), reason is more limited.

He argues that when clear revelation conflicts with philosophical arguments that lack true burhān, revelation has priority. Some interpreters see this as setting principled limits to metaphysics; others view it as subordinating rational inquiry to theological commitments.

12.4 Use of Internal Critique

Methodologically, al-Ghazālī often adopts an internal critique:

• he temporarily accepts the philosophers’ premises;
• he then attempts to derive contradictions or problematic consequences.

This strategy allows him to argue that even on their own terms, philosophical systems exhibit tahāfut. Ibn Rushd later contests whether these alleged inconsistencies are genuine or the result of misrepresentation.

12.5 Comparison with Later Scholastic Methods

Modern scholars sometimes draw parallels between al-Ghazālī’s method and later scholastic disputation formats, noting:

• the structured presentation of an opponent’s view;
• the ordering of objections and replies;
• the blend of reasoned argument with appeal to authority.

Debate continues over whether al-Ghazālī’s approach represents a culmination of earlier kalām rationalism or a turning point toward greater theological restraint on philosophical speculation.

13. Theological Stakes and Accusations of Unbelief

13.1 Degrees of Error

In the closing parts of the Tahāfut, al-Ghazālī differentiates among philosophical doctrines by theological severity. He identifies:

• unbelief (kufr): doctrines that, in his view, contradict essentials of Islamic faith;
• innovation (bidʿa) or grave error: doctrines that deviate from accepted theology but do not expel one from Islam.

This gradation shapes how later theologians assess engagement with philosophy.

13.2 The Three Doctrines of Unbelief

Al-Ghazālī classifies as kufr:

He argues that these positions contradict “what is known from religion necessarily,” a juristic–theological criterion for unbelief.

13.3 Other Doctrines as Innovation

Other philosophical claims—such as aspects of the emanation scheme, reinterpretations of divine attributes, or certain psychological theories—are labeled as innovation or serious error but not outright unbelief. This more moderate classification leaves open the possibility that a philosopher could err gravely while remaining within the fold of Islam.

13.4 Doctrinal Boundaries and Community Protection

Al-Ghazālī presents his work as protecting the Muslim community from doctrines that might, in his view, erode:

• belief in a free, omnipotent God;
• trust in prophetic revelation;
• hope and fear associated with a concrete afterlife.

He is particularly concerned that philosophical prestige and technical language might lead students to adopt controversial metaphysical theses uncritically.

13.5 Later Interpretations of His Accusations

Subsequent scholars have debated:

• whether his charges of unbelief were meant primarily as juridical, social, or intellectual judgments;
• how strictly they were enforced in practice;
• whether they contributed to suspicion toward philosophy in some circles.

Others argue that his careful distinction between kufr and bidʿa shows an attempt to set precise doctrinal boundaries rather than to suppress rational inquiry wholesale.

14. Manuscript Tradition, Editions, and Translations

14.1 Manuscript Transmission

No autograph of the Tahāfut survives; the work is known through later manuscripts, the earliest of which date from the 12th century CE. The manuscript tradition is relatively rich but exhibits the usual variations in wording, marginalia, and arrangement typical of pre‑modern transmission.

Scholars note that comparison among manuscripts helped clarify:

• the ordering and numbering of discussions;
• variant readings that affect interpretive nuances, especially in technical arguments.

14.2 Critical Editions

Modern critical editions rely on collating multiple manuscripts:

These editions provide the Arabic base text for most contemporary translations and studies, though further philological work continues in some specialized projects.

14.3 Major Translations

Several translations have made the Tahāfut accessible:

In addition, Simon van den Bergh’s English translation of Ibn Rushd’s Tahāfut al-Tahāfut includes substantial quotations from al-Ghazālī, offering a comparative perspective.

14.4 Textual Issues and Debates

Textual scholars discuss questions such as:

• whether some passages represent later interpolations or glosses;
• how to resolve variant readings affecting key terms (e.g., in the causality discussion);
• the extent to which Ibn Rushd’s quotations confirm or challenge readings in surviving manuscripts.

These issues affect detailed exegesis but do not generally call into question the overall structure or authenticity of the work.

14.5 Accessibility and Modern Editions

Modern printings, often based on Dunya’s edition, circulate widely in the Muslim world, sometimes with commentary or teaching notes. Scholarly interest has also led to digital editions and online facsimiles of older manuscripts, facilitating philological comparison and cross‑cultural study.

15. Reception, Criticism, and the Averroist Response

15.1 Immediate and Medieval Reception

In the centuries following its composition, the Tahāfut became a major reference in Ashʿarite kalām and Sunni theology. Many jurists and theologians welcomed it as:

• a powerful refutation of Avicennian metaphysics;
• a justification for restricting philosophical speculation in theology.

Some contemporaries and near‑contemporaries, however, expressed reservations, suggesting that al-Ghazālī had not always represented the philosophers’ positions with full precision.

15.2 Ibn Rushd’s Tahāfut al-Tahāfut

The most celebrated direct response is Ibn Rushd (Averroes)’s Tahāfut al-Tahāfut (“The Incoherence of the Incoherence”), composed in 12th‑century al‑Andalus. It proceeds discussion by discussion, quoting al-Ghazālī and then replying.

Ibn Rushd argues that:

• al-Ghazālī confuses dialectical and demonstrative arguments;
• he attributes to the philosophers positions they did not actually hold, or ignores relevant distinctions;
• properly understood, Aristotelian-Avicennian philosophy is compatible with Islam when confined to qualified experts.

From this perspective, Ibn Rushd defends the legitimacy of philosophical inquiry and reasserts the possibility of genuine burhān in metaphysics.

15.3 Later Islamic Responses

Subsequent thinkers engaged with the Tahāfut in diverse ways:

• Fakhr al-Dīn al-Rāzī and other theologians adopted many Ghazalian themes while further refining arguments on creation, divine knowledge, and causality.
• Some philosophers, especially in eastern traditions, sought to synthesize Avicennian, kalām, and eventually Illuminationist elements, partially responding to Ghazalian critiques.
• In some circles, the work contributed to a cautious or critical stance toward falsafa, though historians debate the extent of any “decline” in philosophy.

15.4 Modern Scholarship and Criticism

Modern scholars have assessed the Tahāfut through various lenses:

There is no consensus on these issues, and recent work often emphasizes the sophistication of both al-Ghazālī and Ibn Rushd.

15.5 Latin and Cross‑Cultural Reception

Through the mediation of Ibn Rushd’s Tahāfut al-Tahāfut and related texts, elements of the Ghazālī–Averroes debate reached Latin scholasticism. While medieval Latin authors rarely read al-Ghazālī’s Tahāfut directly, discussions of:

• the eternity of the world,
• the scope of divine knowledge,
• the relation between faith and reason,

were indirectly shaped by these exchanges, contributing to broader medieval conversations about Aristotelianism and Christian doctrine.

16. Legacy and Historical Significance

16.1 Reconfiguration of Philosophy–Theology Relations

The Tahāfut played a major role in redefining the relationship between falsafa and kalām in Sunni Islam. Many later theologians:

• accepted logic and some natural philosophy as legitimate tools;
• treated Avicennian metaphysics with caution, often filtered through Ghazalian critiques.

Some historians view this as a decisive “domestication” of philosophy under theology; others see it as a creative integration that allowed philosophical methods to persist within a theological framework.

16.2 Influence on Islamic Thought

The work influenced:

• Ashʿarite occasionalism, reinforcing views of divine omnipotence and continuous creation;
• later debates on divine knowledge and attributes, with many theologians adopting or adapting Ghazalian arguments;
• Sufi metaphysics, where some authors drew on Ghazalian criticisms of strict rationalism while developing their own ontologies.

Its classifications of philosophical doctrines as unbelief or innovation shaped juristic and theological assessments of intellectual heterodoxy.

16.3 Comparative and Global Philosophy

In modern comparative philosophy, al-Ghazālī’s arguments on:

• causality and necessary connection,
• limits of metaphysical demonstration,
• the interplay of reason and revelation,

are often juxtaposed with early modern European thinkers such as Hume or occasionalists like Malebranche. Scholars differ on whether such comparisons reveal direct influence, parallel development, or merely analogous problematics.

16.4 Impact on the “Decline of Philosophy” Debate

The Tahāfut has frequently been cited in narratives about a supposed “decline” of philosophy or science in the Islamic world. Contemporary scholarship, however, tends to:

• question simplistic causal links between the work and later intellectual trends;
• highlight ongoing philosophical activity after al-Ghazālī, including Avicennian, Illuminationist, and kalām traditions.

In this view, the Tahāfut represents a transformation rather than an end of philosophical reasoning in Islamic contexts.

16.5 Modern Reassessments

Recent studies reexamine al-Ghazālī not only as a theologian but as a sophisticated philosopher of religion. The Tahāfut is read as:

• a case study in critical engagement with inherited metaphysics;
• a complex negotiation between scriptural commitments and rational inquiry;
• a pivotal text for understanding the diversity of pre‑modern Islamic intellectual life.

Its legacy thus extends beyond intra‑Islamic debates to broader questions about how religious traditions interact with philosophical systems across cultures and epochs.