Al-Ghazali (1058-1111)

In a few dates

Tus, childhood and formation

Al-Ghazali was born around 1058 in Tus, a small town in Khorasan near present-day Mashhad, into a modest family: his father, a wool-carder (ghazzal, whence the family name), died while he and his younger brother Ahmad — later himself a renowned Sufi preacher — were still children. The two boys were entrusted to a Sufi friend of their father, who provided their first instruction before directing them to a Qur'anic school when he could no longer support them^[18]. This modest origin, combined with an early education marked by Sufism rather than by law or learned theology alone, already helps explain the later synthesis between doctrinal rigor and interior life.

His scholarly formation continued in Nishapur, where he became the student of Abu al-Ma'ali al-Juwayni, known as Imam al-Haramayn ("the imam of the two holy places"), the most respected Ash'arite theologian of his day and a teacher at the Nizamiyya madrasa. Al-Juwayni transmitted to him Ash'arite dialectical theology (kalam), Shafi'i law and a solid logical formation^[19] — the same school whose foundation and doctrine Ignispedia presents in the article on Al-Ash'ari, and of which al-Ghazali would become, one generation later, the most accomplished representative.

Nizam al-Mulk and the Baghdad chair (1091)

After al-Juwayni's death in 1085, al-Ghazali joined the court of the great Seljuk vizier Nizam al-Mulk, the real architect of the Seljuk state and founder of the Nizamiyya madrasa network, intended to form a Sunni religious elite loyal to the ruling power. Recognizing his talent, Nizam al-Mulk appointed him in 1091 to the most prestigious chair in the eastern Sunni world: the Nizamiyya of Baghdad^[20]. Al-Ghazali was then only in his thirties; he taught before large audiences and became one of the most listened-to theological voices of the Abbasid caliphate — a position made all the more sensitive by the rise of Nizari Isma'ilism, the movement later associated with the Assassins of Hasan-i Sabbah, which had just assassinated Nizam al-Mulk himself in 1092. In this climate of intense political and religious tension — an assassinated vizier, a militant Isma'ili sect in expansion, a weakened Abbasid caliphate — Caliph al-Mustazhir commissioned al-Ghazali, in 1094-1095, to write the systematic refutation of Batini doctrine that became the Fada'ih al-batiniyya wa fada'il al-Mustazhiriyya ("The Infamies of the Batinites and the Virtues of the Supporters of al-Mustazhir"), better known as the Kitab al-Mustazhiri^[21].

The crisis of 1095: a paralysis not merely intellectual

It was at the height of this glory that the crisis occurred. In the Munqidh, al-Ghazali says that he was seized by a gnawing doubt about his own motives: was he teaching for God, or for his own glory? This initially moral question became a psychosomatic crisis of extraordinary violence for a professor in full possession of his intellectual powers: he literally lost the use of speech, could no longer lecture, and the physicians consulted diagnosed an illness that touched the "heart" rather than the body^[22]. In 1095 he left everything behind — chair and income — leaving his family provided with resources in Baghdad, for some ten years of retreat, voluntary poverty and Sufi asceticism, visiting Damascus, where he withdrew for a time in the minaret of the Umayyad Mosque, then Jerusalem, Hebron, and finally Mecca and Medina for the pilgrimage^[23].

In the Munqidh, he presents his healing not as the result of a demonstration, but as the effect of a divine light cast into his breast (paraphrase of the account summarized by the IEP after the 1980 McCarthy translation)^[24].

Return and death (1106-1111)

After these ten or so years of retired life, al-Ghazali resumed teaching in 1106, this time in Nishapur and on terms he set himself — Sunni tradition honours him with the title of "renewer" (mujaddid, the one who renews the faith of his century)^[25]. He then withdrew definitively to his private school and Sufi lodge in Tus, his native town, where he died on December 19, 1111 (14 Jumada II 505 AH), surrounded by his last disciples^[26]. Local tradition places his burial in Tus, today absorbed into the Mashhad metropolitan area, near the mausoleum of the great Persian poet Ferdowsi^[27]. Among his recognized students was the Andalusian jurist Abu Bakr ibn al-'Arabi of Seville, who studied under him at the Nizamiyya of Baghdad — not to be confused with the later Andalusian mystic Muhyi al-Din Ibn 'Arabi (1165-1240), treated by Ignispedia in a separate article^[28].

The four paths examined

The work that best reveals al-Ghazali's inner trajectory is his late spiritual autobiography, written after his return to teaching: Al-Munqidh min al-dalal ("Deliverance from Error"). There he describes a search for certainty that led him to examine four categories of "seekers of truth" in his time: the dialectical theologians (mutakallimun), the Hellenizing philosophers (falasifa), the Batini Isma'ilis who claimed access to hidden truth through the teaching of an infallible imam, and finally the Sufis^[29]. Each path, he argues, contains a share of truth but fails, by itself, to ground complete certainty: dialectical theology argues well against heretics but does not produce in the one who practices it the inward evidence it defends; philosophy reaches an impressive logical rigor but, on decisive points, ends in conclusions incompatible with revealed faith; Batini Isma'ilism, by making all certainty rest on the authority of a hidden imam, closes itself into an unverifiable circle of authority; only Sufism, he concludes, gives access to a lived and tasted knowledge (dhawq) that surpasses discursive reasoning alone.

Radical skepticism before resolution

Before even sorting these four paths, al-Ghazali says that he underwent a methodological doubt of rare radicality in medieval literature: wondering whether his belief resulted simply from the conditioning of his education rather than from objective grounds, he came to question the reliability of the senses themselves — the sun appears as small as a coin although it is immense, proving that the senses deceive — and then the reliability of elementary rational truths, before this paralyzing doubt was lifted, he writes, not by a new demonstration but by a received grace^[30]. Several Islamologists have compared this pattern — methodical doubt pushed to its limits, then resolution through an experience beyond pure argument — to the spiritual trajectory of Saint Augustine's Confessions, without implying direct influence: the two authors share a narrative structure (crisis, conversion, appeasement) common in ancient and medieval religious autobiography, but nothing indicates that al-Ghazali knew the work of the doctor of Hippo. This autobiography remains, for academic research, one of the most precious documents on the inner life of a great medieval religious mind, whether Christian, Jewish or Muslim.

Twenty theses examined, three charges of unbelief

The Tahafut al-falasifa ("The Incoherence of the Philosophers") is the work in which al-Ghazali directly attacks the Hellenizing philosophical tradition of Islam, represented in his eyes by al-Farabi and especially by Avicenna (Ibn Sina). He reviews twenty characteristic positions of these philosophers and seeks to show that none of them is demonstrated with the rigor (burhan) that the philosophers themselves claim as the criterion of truth: he fights them, he says, with their own logical weapons, not by mere dogmatic rejection. On three of these twenty points, however, al-Ghazali does not merely denounce demonstrative weakness: he classifies them as pure unbelief (kufr), incompatible with Islam — the eternity of the world (against creation ex nihilo), the claim that divine knowledge concerns only universals and not concrete particulars, and the denial of the bodily resurrection of souls in recreated bodies^[31].

Causality: occasionalism or second causes?

The point most discussed by contemporary philosophers in the Tahafut concerns causal necessity. Al-Ghazali argues that the link between an observed cause and effect — fire and the burning of cotton, for example — is not a necessary connection but a habit God establishes in creation; nothing in pure reason requires that fire necessarily burn cotton, apart from the free and permanent will of God. On this question he presents two explanations that he regards as equally admissible, without deciding definitively between them: either God directly creates each event without any true intermediary between the apparent cause and the effect (occasionalism: the idea that God alone acts directly at every instant, without any real action of creatures — a thesis later fully developed by the Ash'arite school), or God uses genuinely effective second causes that he himself has instituted^[32]. This deliberate hesitation — he treats the two options as "compossible" rather than choosing sharply — has fueled a vast scholarly debate over the exact reach of his occasionalism.

On this precise point, Catholic theology, as Saint Thomas Aquinas would formulate it, clearly favors the third column: God, the First Cause, does not deprive his creatures of real second causality, a dignity the Catechism recalls when it teaches that "he is the first cause who operates in and through secondary causes"^[33]. This doctrinal contrast is developed more fully in the Ignispedia article on Al-Ash'ari and Ash'arite occasionalism.

Averroes' response and the later debate

This trial of philosophy did not go unanswered. A century later, the great Andalusian commentator Averroes (Ibn Rushd) wrote a systematic refutation of the Tahafut, titled by antiphrasis Tahafut al-tahafut ("The Incoherence of the Incoherence"), defending step by step the legitimacy of Aristotelian philosophy against al-Ghazali's objections. This intellectual duel, spread across two generations and two ends of the Islamic world — Baghdad and al-Andalus — still structures the way historiography narrates the relationship between philosophy and theology in classical Islam.

The great ethical and spiritual summa

Al-Ghazali's largest and most enduringly read work, written for the most part during his years of retreat, is the Ihya' 'ulum al-din ("The Revival of the Religious Sciences"). This monument, organized into four major parts (rub') of ten books each, covers the whole of Muslim religious life: acts of worship (rub' al-'ibadat), the norms of social and daily life (rub' al-'adat), the vices that lead to perdition (rub' al-muhlikat) and the virtues that lead to salvation (rub' al-munjiyat)^[34]. The project is ambitious: to reconcile, within one coherent doctrinal edifice, the rigor of law and dialectical theology with the depth of Sufi interior life, then viewed with strong suspicion by many literalist jurists, who saw in it the risk of antinomianism or even heresy.

A middle path between rigorist jurists and antinomian mystics

Al-Ghazali does not legitimize a Sufism without limits: he condemns both the excesses of mystics who claim to free themselves from revealed Law (shari'a) in the name of inner experience, and the dry formalism of jurists who reduce religion to external observance without transformation of the heart. His position — rigorous practice of the commandments as condition, not substitute, for interior purification (riyadat al-nafs, the "discipline of the soul") — would become, after him, the balanced position received by the immense majority of later Sunni Sufi currents, including later figures whom Ignispedia presents elsewhere, such as Ibn 'Arabi or Jalal ad-Din Rumi^[35]. It is largely thanks to al-Ghazali's intellectual authority that Sufism, long merely tolerated at best and marginal at worst, became a fully integrated and respected component of classical Sunni Islam.

The Fada'ih al-batiniyya and the caliphal commission

At the very moment when his reputation as a theologian was at its height, al-Ghazali was mobilized by Abbasid power on a more directly political terrain: the fight against Nizari Isma'ilism, a Batini movement claiming that ultimate religious truth is hidden (batin) and accessible only through the infallible teaching of an imam, in open rupture with the authority of the Sunni Abbasid caliph. Caliph al-Mustazhir, newly enthroned in a climate made explosive by the assassination of Nizam al-Mulk (1092) and by the expansion of Hasan-i Sabbah's fortified sect at Alamut, commissioned al-Ghazali, around 1094-1095, to write a complete doctrinal refutation: the Fada'ih al-batiniyya wa fada'il al-Mustazhiriyya ("The Infamies of the Batinites and the Virtues of the Supporters of al-Mustazhir"), also known by the shorter title Kitab al-Mustazhiri^[36]. In it al-Ghazali methodically dismantles the Batini argument based on the need for an infallible teacher, and he goes so far as to classify some of their doctrinal positions as unbelief (kufr).

Hujjat al-Islam: the "Proof of Islam"

It is especially from this role as doctrinal champion of Sunni orthodoxy against dissident currents — Batinites, but also rationalist philosophers — that al-Ghazali received the honorific title by which posterity would almost exclusively designate him: Hujjat al-Islam, "the Proof of Islam," to which Sunni tradition adds the epithets Zayn al-Din ("Ornament of the Faith") and Mujaddid ("renewer", the one who renews the faith of his century)^[37]. Few Muslim scholars, before or after him, have received an honorific title of such theological scope.

Triumph within Sunni Islam

In the Sunni world, the Ghazalian synthesis between Ash'arite theology, Shafi'i law and measured Sufism became a durable reference point, received by almost all later theologians — in particular his hermeneutical rule that when a certain rational demonstration contradicts the literal sense of a revealed text, the text should be interpreted allegorically rather than the demonstration denied: a principle "accepted by almost all later Muslim theologians"^[38]. It is this immense intellectual authority that leads W. Montgomery Watt to judge that al-Ghazali "has been acclaimed as the greatest Muslim after Muhammad"^[39] — a judgment that, from the Catholic viewpoint, must be situated for what it is: homage to the intelligence and coherence of a man, not recognition of any additional prophetic mediation after Revelation is closed in Christ, a question already treated in the Ignispedia article on Muhammad.

Algazel in the Latin West: the misunderstood source of Albert the Great and Saint Thomas

Less known to the general public, but well documented by historians of medieval philosophy, is al-Ghazali's indirect and partly misunderstood influence on Latin Christian scholasticism. His purely expository — non-polemical — account of the philosophers' theses, Maqasid al-falasifa ("The Aims of the Philosophers"), written as pedagogical preparation before his own critique in the Tahafut, was translated into Latin in the 12th century at Toledo, especially by Dominicus Gundissalinus and a certain "Magister Iohannes," under the Latinized name Algazel. This text became one of the principal sources through which Albert the Great and then Saint Thomas Aquinas encountered the teaching of the Arabic philosophers^[40]. The irony of this reception is notable: because the Latin translators did not have the critical Tahafut that normally accompanied this exposition, they long believed Algazel to be a disciple of Avicenna sharing his theses, whereas the text was in fact the neutral exposition of a determined opponent of that philosophy, prior to its refutation^[41]. Al-Ghazali also left a more discreet trace in medieval Jewish thought: more than seventy-five Hebrew manuscripts of the Maqasid al-falasifa have been identified, evidence of the interest shown by Jewish readers between the 14th and 16th centuries who were seeking an alternative to Averroes^[42].

A Catholic can recognize, without embarrassment, the real intellectual and spiritual greatness of al-Ghazali. His itinerary — the ambition of a brilliant scholarly life, the discovery that intellectual and social success cannot satisfy the heart, a crisis so radical that it becomes physical, then a conversion toward poverty, asceticism and the search for God — speaks to every sincere religious soul, Christian or not; in it one recognizes, with all necessary distinctions and without forced assimilation, the structure of an authentic mystical purification. His struggle against a philosophical rationalism that claimed to close all ultimate questions by demonstrative reason alone, leaving no room for Revelation or grace, also meets a deeply Catholic concern: classical theology, from Saint Augustine to Saint Thomas Aquinas, has always refused to let autonomous and self-sufficient reason dictate the content of faith, while also refusing — unlike al-Ghazali on this precise point — to set reason and faith too sharply against each other.

It is precisely here that the clearest limit appears. By hesitating between pure occasionalism — where God alone acts and creatures have, strictly speaking, no real causality — and the recognition of true second causes, al-Ghazali touches a question on which the Church has clearly chosen the second option: God, the transcendent First Cause, does not deprive his creatures of an authentic causality that he himself has given them in creating them — "he is the first cause who operates in and through secondary causes"^[43]. A God who recreates everything at every instant without allowing creatures a consistency and causality of their own risks, at the limit, dissolving the dignity of creation itself; whereas the Christian God, precisely because he is all-powerful and perfectly free, can grant his creatures a true participation in his own causality without losing his sovereignty.

More radically still, what al-Ghazali's system, however refined, can neither contain nor anticipate is the Incarnation: a God who does not merely send an inner light to the one who seeks him sincerely, but who became flesh, suffered, died and rose again for man. The Second Vatican Council, in the declaration Nostra Aetate, recalls how the Catholic Church regards believers of the religious tradition of which al-Ghazali remains one of the greatest doctors:

"The Church regards with esteem also the Moslems. They adore the one God, living and subsisting in Himself; merciful and all-powerful, the Creator of heaven and earth, who has spoken to men." — Second Vatican Council, declaration Nostra Aetate on the relation of the Church to non-Christian religions, October 28, 1965, § 3^[44]

It is in this spirit that a Catholic reader can approach Abu Hamid al-Ghazali: not as an adversary to be dismissed, nor as a mere anonymous precursor of truths Christianity alone would possess, but as one of the greatest religious minds of classical Islam, whose journey — from intellectual pride to the humility of the search for God — retains, across doctrinal boundaries, a real exemplary value, without ever removing the need to recognize what, in the Revelation received in Jesus Christ, absolutely surpasses everything his system, coherent though it is, could conceive.

• W. Montgomery Watt, Muslim Intellectual: A Study of al-Ghazali, Edinburgh University Press, 1963 — the major academic biography in English.
• Al-Ghazali, Al-Munqidh min al-dalal (Deliverance from Error), trans. Farid Jabre, Beirut, Lebanese Commission for the Translation of Masterpieces, 1959.
• Al-Ghazali, Ihya' 'ulum al-din (The Revival of the Religious Sciences), available in several partial translations.
• Frank Griffel, Al-Ghazali's Philosophical Theology, Oxford University Press, 2009 — a major academic study of the Tahafut and the theory of causality.
• Kenneth Garden, "al-Ghazali," Stanford Encyclopedia of Philosophy, plato.stanford.edu/entries/al-ghazali/.
• Farouk Mitha, Al-Ghazali and the Ismailis: A Debate on Reason and Authority in Medieval Islam, London, I.B. Tauris, 2001.
• See also, in Ignispedia, Al-Ash'ari, Avicenna, Averroes, Ibn 'Arabi, Muhammad, Maimonides and What Does the Church Say About Islam?, each of which develops a specific aspect of his work and context.