Al-Ghazali (1058–1111)

Abu Hamid Muhammad ibn Muhammad al-Ghazali was one of the most influential Muslim theologians, jurists, mystics, and philosophers of the Islamic Golden Age. Widely honored as Hujjat al-Islam (“The Proof of Islam”), he shaped Islamic theology, Sufism, and philosophy in ways that echoed for centuries across the Muslim world and even into Christian and Jewish thought. His writings reflect both deep rational inquiry and profound spiritual insight, bridging law, philosophy, and mysticism into a unified vision of faith and practice.

1. Background

Origin – Born in Tus, in the Persian region of Khorasan (modern-day Iran).

Career – Al-Ghazali rose to prominence as a leading scholar at the prestigious Nizamiyya Madrasa in Baghdad, where he taught theology, law, and philosophy. At the height of his career, he underwent a spiritual crisis that led him to abandon his teaching post and withdraw from public life. He spent years traveling, studying, and engaging in Sufi practice, later returning to Tus to write and teach until his death.

2. Education and Influences

Teachers

• His most important teacher was Imam al-Juwayni (al-Imam al-Haramayn), a leading Ash‘ari theologian and jurist in Nishapur. Under him, al-Ghazali mastered jurisprudence, kalam (theology), and logic.

Influences

• Ash‘ari Theology: Al-Juwayni passed on the Ash‘ari emphasis on divine omnipotence, occasionalism, and theological moderation between reason and revelation.

• Greek Philosophy: Studied Aristotle and Neoplatonism, particularly as mediated by Ibn Sina and al-Farabi.

• Sufism: Later in life, he was influenced by Sufi thinkers like al-Muhasibi and Junayd of Baghdad, which transformed his outlook.

• Islamic Jurisprudence: He was trained in the Shafi‘i school of law.

3. Main Themes of His Philosophical Thought

Critique of Philosophy

• In Tahafut al-Falasifa, al-Ghazali launched a rigorous critique of the metaphysical claims of Islamic Neoplatonists, especially Avicenna and Farabi.

• He argued that philosophers went astray in key theological areas:

  • The eternity of the world

  • Denial of bodily resurrection

  • Limiting God’s knowledge to universals

• He used logical and philosophical tools to expose contradictions in their arguments but did not reject philosophy entirely—only metaphysics where it clashed with Islamic beliefs.

Defense of Sunni Orthodoxy

• Al-Ghazali affirmed Ash‘ari theology, emphasizing divine omnipotence, occasionalism (that God is the direct cause of all events), and the limits of human reason in understanding God.

• He wrote Ihya’ ‘Ulum al-Din (“Revival of the Religious Sciences”), a monumental work integrating Shari‘a, theology, and Sufi spirituality, emphasizing the purification of the soul and sincerity of worship.

Integration of Sufism and Law

• After a spiritual crisis, al-Ghazali left his prestigious position in Baghdad and embraced a life of asceticism and Sufi discipline.

• He saw inner spiritual transformation as essential for true religiosity, and he reconciled Sufism with orthodox Islam, making mystical practice a legitimate path within Sunni Islam.

Epistemology and Certainty

• In his spiritual autobiography al-Munqidh min al-Dalal (“Deliverance from Error”), he described his quest for certain knowledge, which led him to doubt theological speculation and legal formalism.

• He concluded that certainty (yaqin) arises not just from rational proof, but from spiritual experience and divine illumination.

Ethics and Psychology

• Al-Ghazali taught that the human soul needs discipline through worship, reflection, and ethical conduct.

• He offered a holistic psychology, where the heart, ego (nafs), intellect (‘aql), and soul (ruh) must be harmonized through spiritual training.

4. Influence on His Generation and Beyond

In His Own Time

• Al-Ghazali became the most revered Sunni scholar of his time. His integration of rationalism and mysticism helped revive Islamic orthodoxy at a time when philosophical influence was rising.

• He taught at Nizamiyya College in Baghdad, a leading center of Islamic learning.

On Later Generations

• His work discredited Neoplatonic metaphysics in much of the Islamic world, although philosophers like Ibn Rushd later responded to him in Tahafut al-Tahafut (“Incoherence of the Incoherence”).

• His Ihya’ ‘Ulum al-Din became a cornerstone of Islamic spirituality, widely read across the Muslim world.

• He laid the foundation for later Sunni theologians and mystics, including Fakhr al-Din al-Razi, Imam Nawawi, and Ibn Qudama.

• His influence extended even to Christian Europe, where his logical methods and spiritual philosophy were noted by thinkers such as Thomas Aquinas.

5. Major Works

• Tahafut al-Falasifa (The Incoherence of the Philosophers) – A famous critique of philosophical doctrines in the Islamic world.

• Ihya Ulum al-Din (The Revival of the Religious Sciences) – His magnum opus, integrating law, ethics, and Sufism.

• al-Munqidh min al-Dalal (Deliverance from Error) – An autobiographical account of his intellectual and spiritual journey.

• al-Maqasid al-Falasifa (The Aims of the Philosophers) – A summary of philosophical thought, written before his critique, showing his mastery of philosophy.

• al-Iqtisad fi al-I‘tiqad (Moderation in Belief) – A balanced theological treatise defending Ash‘ari orthodoxy.