The Incoherence of the Philosophers: Al-Ghazali’s Intellectual Challenge to Medieval Islamic Thought

Al-Ghazali’s “Tahafut al-Falasifa” (The Incoherence of the Philosophers) is a landmark work in medieval Islamic intellectual and religious history. It highlights the conflict between Islamic speculative theology (kalam) and philosophy (falsafa) by refuting twenty philosophical doctrines. Seventeen of these doctrines are deemed heretical innovations, while three are seen as entirely opposed to Islamic belief, branding their supporters as infidels.

Despite this condemnation, the philosophers were not atheists. Their system affirmed God’s existence, with all other beings emanating from God as a necessary consequence of the divine essence. Al-Ghazali argued that this view implied God created the world out of necessity, like the sun produces light, which he saw as denying God’s attributes of life, will, power, and knowledge. Thus, the God of the philosophers differed from the God of the Qur’an.

The “Tahafut” significantly challenged Islamic philosophy, but it also unintentionally made philosophical ideas more known in the Islamic world. By refuting the philosophers, al-Ghazali explained their ideas clearly, making them accessible to non-philosophers and setting a new tradition in kalam. After al-Ghazali, Islamic theologians engaged deeply with the philosophical theories he criticized, intertwining kalam and falsafa as never before.

“The Tahafut” is a high point in medieval Arabic thought due to its intellectual rigor. Though motivated by religious and theological concerns, its arguments are deeply philosophical. It offers a logical critique, particularly of the emanative metaphysics, causal theory, and psychology of Avicenna (Ibn Sina, d. 1037), and is incisive and thorough.

While theological criticism of philosophy existed before al-Ghazali, none matched the comprehensive, sustained critique found in “The Tahafut,” a work entirely dedicated to refuting the philosophers. Despite some flaws, highlighted by Averroes (Ibn Rushd, d. 1198) in his response “Tahafut al-Tahafut” (The Incoherence of the Incoherence), it remains a brilliant, incisive critique.

To truly understand the importance of examining the incoherence of the philosophers, it is essential to delve into the life journey of al-Ghazali , his background and the intellectual landscape of medieval Islam.

Abu Hamid Muhammad ibn Muhammad al-Tusi al-Ghazali, one of medieval Islam’s most renowned religious intellectuals, was trained as an Islamic lawyer (faqih) and theologian (mutakallim), and later became a noted Islamic mystic (sufi). Born in 1058 in Tus, northeast Persia, he studied in madrasas, religious colleges focused on Islamic law. His education began in Tus, continued briefly in Jurjan by the Caspian Sea, and then in 1077 at a major madrasa in Nishapur. There, he was taught by Imam al-Haramayn al-Juwayni, a leading lawyer of the Shafi’i school and the foremost theologian of the Ash’ari school.

By the eleventh century, Ash’arism was becoming the dominant school of kalam. It proposed a metaphysics of transient atoms and accidents, considering all temporal existents as God’s direct creation, determined by His eternal will and enacted by His power. Human perceptions of natural cause and effect are, in reality, events decreed by divine will with no inherent causal connection. God is the sole cause, and all events are His creation, allowing for the possibility of miracles without contradiction. Al-Ghazali fervently defended this atomist-occasionalist doctrine on logical and epistemological grounds in his works of kalam.

After al-Juwayni’s death, al-Ghazali spent about six years at the court of Nizam al-Mulk, the vizier of the Seljuk sultans, and also taught in Nishapur. He gained fame as a scholar and author of Islamic law. In 1091, Nizam al-Mulk invited him to teach law at the Nizamiyya in Baghdad, the most prestigious of several madrasas founded by Nizam al-Mulk to promote Shafi’i Islamic law and counter the Fatimid caliphs’ influence from Egypt. The Islamic world at the time was divided between the Sunni Abbasid caliphate in Baghdad and the Shia Fatimid caliphate in Cairo.

 

Al-Ghazali’s appointment at the Nizamiyya integrated him into the Abbasid-Seljuk establishment. During this period, he wrote “Fada’ih al-Batiniyya” (Scandals of the Esoterics), criticizing Ismaili Fatimid doctrine, at the request of the Abbasid caliph al-Mustazhir.

Between 1091 and 1095, al-Ghazali wrote “Tahafut al-Falasifa” (The Incoherence of the Philosophers) and three related works. The first, “Maqasid al-Falasifa” (The Aims of the Philosophers), explains Avicenna’s philosophies as a prelude to refuting them in the “Tahafut,” though it is never mentioned in “Tahafut.” The second, “Miyar al-Ilm” (The Standard for Knowledge), is a comprehensive exposition of Avicennan logic, which al-Ghazali saw as a neutral tool for knowledge and encouraged theologians and lawyers to adopt. The third, “Al-Iqtisad fi al-I’tiqad” (Moderation in Belief), is an exposition of Ash’arite theology, building and affirming true doctrine, as opposed to the refutations in “Tahafut.”

Around the time al-Ghazali moved to Baghdad, he experienced a period of skepticism. In his autobiography, written shortly before his death, he recounted examining the various sciences he had studied but found they did not provide certainty. He distrusted the senses, as they could deceive, such as seeing a star as small when it is actually larger than the earth. This distrust extended to reason, leading him to doubt the self-evident truths of logic. He remained in this state for two months until God restored his faith in reason.

In 1095, al-Ghazali faced another spiritual crisis, losing his ability to speak for a time. He realized his career pursuits were motivated by worldly glory rather than genuine religious impulse. He became dissatisfied with purely doctrinal and intellectual approaches to religion, believing they bypassed the heart of the matter, which is the direct experiential aspect of religion, called “dhawq” in Sufi terms. Convinced that the path of the Sufis led to true knowledge, he decided to abandon his career and follow their path.

After making arrangements for his family, al-Ghazali left Baghdad, seeking seclusion in the great mosque of Damascus, then the Dome of the Rock in Jerusalem, and later traveling to Hebron, Medina, and Mecca. He lived as an ascetic for about eleven years, pursuing the mystic’s way. During this period, he wrote his major work, “Ihya’ Ulum al-Din” (The Revival of the Religious Sciences), aiming to reconcile traditional Islamic beliefs with Sufi teachings. He reinterpreted the Sufi concept of “annihilation” (al-fana) in the divine essence, suggesting that it meant seeing the unity of all things and losing the sense of self, rather than violating the Islamic concept of divine transcendence. He also proposed a synthesis of Islamic theological principles, the Aristotelian doctrine of the mean, and Sufi virtues, with the highest virtue being the love of God.

In 1106, al-Ghazali returned to teaching in Nishapur and then Tus until his death in 1111. His later writings included theological and mystical works, his autobiography, and a significant book on Islamic law, “Al-Mustasfa min Usul al-Din” (The Choice Essentials of the Principles of Religion). While his later works are crucial for understanding his religious views, his most pivotal work from a philosophical standpoint remains his detailed critique of Islamic philosophers in “Tahafut al-Falasifa” (The Incoherence of the Philosophers).

In “Tahafut al-Falasifa” (The Incoherence of the Philosophers), al-Ghazali critiques Al-Farabi (d. 950) and Avicenna (d. 1037) as the foremost Islamic proponents of Aristotle’s philosophy. While both were Aristotelian, they were also Neoplatonists with distinct emanative schemes. Despite differences in their ideas on emanation, the soul, epistemology, and eschatology, there are overlaps, leading many of al-Ghazali’s criticisms to apply to both. Al-Ghazali’s primary focus is on Avicenna’s philosophy.

In “Tahafut al-Falasifa” (The Incoherence of the Philosophers), al-Ghazali criticizes specific aspects of Avicenna’s philosophy, such as his triadic emanative scheme, his theory that God knows only universals or particulars in a universal way, and his concept of an immaterial soul that denies bodily resurrection. These criticisms are distinct from the ideas of al-Farabi, another philosopher he critiques.

The book is divided into two parts: the first deals with metaphysical questions, while the second covers natural sciences. In the metaphysical section, al-Ghazali condemns the theories of a pre-eternal world and God’s limited knowledge to universal characteristics of particulars. In the natural sciences section, he specifically critiques Avicenna’s psychology and also discusses causality.

The longest debate in the book is about the theory of the world’s pre-eternity, which touches on the nature of divine causality. Philosophers argue that the world is the necessitated effect of an eternally necessitating cause and therefore must be eternal. Al-Ghazali counters by emphasizing that this denies the divine attribute of will, asserting instead that the world and time were created together at a finite moment in the past through the choice of the eternal divine will.

In the thirteenth discussion of the “Tahafut al-Falasifa” (The Incoherence of the Philosophers), al-Ghazali critiques Avicenna’s theory that God knows particulars only “in a universal way.” Avicenna distinguishes between celestial and terrestrial particulars, with celestial particulars being unique members of their species, like the sun. However, al-Ghazali focuses on terrestrial particulars, such as individual humans and their actions, arguing that Avicenna’s system cannot account for God knowing these particulars individually, which contradicts Qur’anic teachings on divine omniscience.

 

Similarly, regarding Avicenna’s denial of bodily resurrection based on the immateriality of the soul, al-Ghazali argues that even if one accepts the soul as immaterial, bodily resurrection is still possible. He asserts that the Qur’anic language affirming bodily resurrection must be taken literally unless shown to be impossible. Al-Ghazali’s argument throughout the “Tahafut” is based on the criterion that scriptural assertions must be accepted literally unless they are proven impossible, a principle that underpins his entire critique.

Al-Ghazali provides a religious preface and four short introductions in the “Tahafut” to explain its purpose. He criticizes pseudo-intellectuals of his time who, impressed by names like Socrates and Aristotle, imitate these philosophers without understanding their ideas. These individuals use philosophy to justify their disregard for religious obligations, leading to unbelief. Al-Ghazali aims to show the incoherence and contradictions in philosophers’ beliefs, emphasizing that all significant thinkers, past and present, believe in God and the last day.

While he initially downplays his differences with philosophers as minor, he condemns three of their doctrines as irreligious, stating that their supporters should be punished by death. This highlights the fundamental disagreements he has with these philosophers, contrary to what some might believe.

In his introductions, Al-Ghazali makes a few key points. He argues not against all of the philosophers’ ideas, but only those that go against religion. He’s not trying to defend any specific religious belief but is using arguments from various Islamic theological schools to refute the philosophers. He aims to show that the philosophers haven’t proven their theories that contradict religious principles. Al-Ghazali clarifies that his book, “The Incoherence of the Philosophers,” is solely about refuting, not defending, any particular doctrine. He plans to write another book, “The Principles of Belief,” to affirm the true doctrine, once he completes this one.

In his response to al-Ghazali, Averroes often labels al-Ghazali’s arguments as Ash’arite, which is a theological approach. Al-Ghazali indeed often argues from this perspective, aiming to refute philosophical ideas. However, he doesn’t construct a full theological system in his work “The Incoherence of the Philosophers.” Al-Ghazali also defends non-Ash’arite positions in this work, mainly for the purpose of argumentation against philosophers.

Al-Ghazali planned a sequel to “The Incoherence,” called “The Principles of Belief.” Although this title is typically associated with Ash’arite works, another of his works, “The Just Balance in Belief and Practice,” aligns more closely with the themes of “The Incoherence.” This work directly references “The Incoherence” and delves deeper into its topics.

In “The Just Balance,” al-Ghazali focuses on the principles of belief, affirming his stance, unlike in “The Incoherence,” where he primarily aimed to refute. Al-Ghazali clarifies that while he won’t extensively argue for the temporal origin of the world in “The Principles of Belief,” he plans to do so in another book. The discussion of the world’s origin is more detailed in “The Just Balance,” making it the true sequel to “The Incoherence.”

Al-Ghazali’s defense of non-Ash’arite positions is evident in his discussions on causality and the immateriality of the soul. In the Tahafut, he generally supports the Ash’arite view that all causal action is from God. However, in the seventeenth discussion, he presents two different causal theories. He first defends the Ash’arite view, stating that the connection between a cause and its effect is not necessary but rather a result of God’s decree. He argues that observation only shows concomitance, not necessary causation.

In response to objections raised against this view, particularly regarding the possibility of miracles, al-Ghazali proposes another causal theory. He suggests that God has ordained a regular natural pattern, which is not necessary but inevitable due to God’s decree. Humans perceive this pattern as uniform and expect it to continue unless interrupted by a miracle, also decreed by God. Al-Ghazali dismisses the objections against denying causal necessity as baseless, suggesting that they are mere attempts to vilify his position.

To avoid such vilification, al-Ghazali presents a second causal theory that accommodates the possibility of miracles, which the philosophers reject as impossible.

Al-Ghazali presents a modified Aristotelian theory as a second possible causal explanation, allowing for the possibility of miracles. In this theory, created things possess causal efficacy, but divine intervention can alter the natural order to produce miracles. However, in his later work “The Just Balance,” he unequivocally affirms the Ash’arite view that divine power is the direct cause of all existence and events, denying any inherent causal power in created things. This refutes the modified Aristotelian theory proposed in “The Incoherence,” indicating that it was introduced for argumentative purposes rather than as a belief he held.

Regarding the immateriality of the human soul, al-Ghazali refutes Avicenna’s proofs for its immateriality in “The Incoherence,” yet in “The Just Balance,” he defends the Ash’arite doctrine of a material soul. He acknowledges in “The Just Balance” that his defense of an immaterial soul in “The Incoherence” was for argumentative purposes, aiming to refute Avicenna’s position. This illustrates al-Ghazali’s strategy of defending positions he does not personally hold in order to counter philosophical arguments.

In both cases, al-Ghazali’s primary aim remains refutation, consistent with his declaration that “The Incoherence” is intended primarily as a critique of philosophical ideas rather than an exposition of his own beliefs.

In essence, in “The Incoherence of the Philosophers,” we have witnessed al-Ghazali’s meticulous dismantling of the philosophical doctrines of his time, particularly those of Al-Farabi and Avicenna. Through his incisive critique, al-Ghazali not only challenges the philosophical underpinnings of his era but also offers profound insights into the intricate interplay between reason and revelation in Islamic thought.

 

References:

 

• Al-Ghazali, A. H. M. (2000). The Incoherence of the Philosophers (M. E. Marmura, Trans.). Brigham Young University Press.
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