Islamic Philosophy: Falsafa from al-Kindi to Mulla Sadra

Islamic philosophy, known in Arabic as falsafa (from the Greek philosophia), is the tradition of rational inquiry that Muslim, and also Christian and Jewish, thinkers developed in the Islamic world after Greek philosophy was translated into Arabic from the eighth century onward. Its great figures, al-Kindi, al-Farabi, Avicenna and Averroes, combined Aristotle and Neoplatonism with reflection on God, prophecy and the soul, and their works shaped both later Islamic thought and medieval European scholasticism.

The Translation Movement and the Arabic Aristotle§

Between the mid-eighth and the tenth centuries, Abbasid caliphs, courtiers and scholars in Baghdad paid for the translation of Greek works of philosophy, medicine, astronomy and mathematics into Arabic, often through Syriac versions made earlier by Christian scholars. The most famous translator, Hunayn ibn Ishaq (d. 873), a Nestorian Christian physician, and his circle rendered much of Galen and Aristotle. The caliph al-Ma'mun's "House of Wisdom" (Bayt al-Ḥikma) is often credited with organising this work, though historians such as Dimitri Gutas have argued that its role has been exaggerated and that the movement had wide social and political roots.

The result was an Arabic Aristotle, read through the late Greek commentators, together with Neoplatonic material that circulated under misleading names: the so-called Theology of Aristotle was in fact a paraphrase of parts of Plotinus' Enneads, and the Book of Causes (Liber de causis) drew on Proclus. Arabic philosophy therefore combined Aristotle's logic and natural science with the Neoplatonic picture of a cosmos emanating from the One, discussed further in Neoplatonism and Theurgy.

Al-Kindi and al-Farabi: The First Philosophers§

Abu Yusuf Ya'qub al-Kindi (d. c. 870), called "the philosopher of the Arabs", worked in Baghdad under the caliphs al-Ma'mun and al-Mu'tasim. He wrote on metaphysics, optics, music, astrology and medicine, and argued that philosophy and revelation lead to the same truth; unlike later philosophers he defended the creation of the world in time. His treatise On the Rays, which explains the influence of stars, words and images through radiation, later circulated in Latin as a theoretical basis for astral magic.

Abu Nasr al-Farabi (d. 950), called "the Second Teacher" after Aristotle, set Arabic logic on a firm footing and developed a cosmology in which a series of celestial intellects emanates from the First Cause, the lowest being the Active Intellect, which illuminates human minds. In The Virtuous City he describes an ideal state ruled by a philosopher-prophet whose intellect is joined with the Active Intellect and whose imagination renders philosophical truths as symbols for the many. Prophecy, on this view, is the highest perfection of the human intellect and imagination, a theory that both attracted and alarmed later readers.

Avicenna: Being, the Soul and the Visionary Recitals§

Abu 'Ali al-Husayn ibn Sina (980–1037), known in Latin as Avicenna, was born near Bukhara and served as physician and minister at several Persian courts. His Canon of Medicine (al-Qānūn) remained a standard medical textbook in Europe for centuries, and his philosophical encyclopaedia The Cure (al-Shifāʾ) covered logic, natural science, mathematics and metaphysics.

Avicenna distinguished between the essence of a thing (what it is) and its existence (that it is). Everything in the world is "possible in itself" and owes its existence to a cause; the chain of causes must end in a "Necessary Existent", which is God. In his famous "flying man" thought experiment, a person created suspended in the air, without sensation of body, would still be aware of his own existence, which Avicenna took to show that the soul is distinct from the body. He also wrote short allegorical "visionary recitals", among them Ḥayy ibn Yaqẓān, in which the soul is guided by an angelic figure; the French scholar Henry Corbin read these as evidence of an "oriental" or mystical side to his thought, an interpretation others have questioned.

Al-Ghazali's Critique and Averroes' Reply§

The jurist and theologian Abu Hamid al-Ghazali (1058–1111), after a careful study of the philosophers, wrote The Incoherence of the Philosophers (Tahāfut al-falāsifa), completed around 1095. He accepted logic and mathematics but argued that the philosophers had failed to prove their metaphysical claims. He judged three doctrines incompatible with Islam: that the world is eternal, that God knows particulars only in a universal way, and that the resurrection is of souls alone. He also challenged the necessity of causal connection, arguing that God directly creates the burning when fire touches cotton. Al-Ghazali later turned to Sufism, as he relates in Deliverance from Error.

In al-Andalus, the Cordoban judge and philosopher Abu'l-Walid ibn Rushd (1126–1198), Averroes in Latin, answered with The Incoherence of the Incoherence (Tahāfut al-tahāfut). In his Decisive Treatise he argued that the Qur'an commands reflection on creation, that demonstrative philosophy is the highest form of such reflection, and that where scripture's apparent sense conflicts with demonstration, the learned may interpret it allegorically. His long commentaries on Aristotle made him, for Latin scholastics, simply "the Commentator". His Andalusian predecessor Ibn Tufayl (d. 1185) wrote a philosophical novel, also called Ḥayy ibn Yaqẓān, about a child raised alone on an island who reaches knowledge of God by reason alone.

Translated in Toledo and elsewhere in the twelfth and thirteenth centuries, Avicenna and Averroes became essential to Thomas Aquinas, Albertus Magnus and the universities of Paris and Oxford, while "Latin Averroism" provoked condemnations in Paris in 1270 and 1277.

Illumination and Later Islamic Philosophy§

The older Western story that Islamic philosophy died with Averroes is now rejected. In the east, Shihab al-Din Yahya Suhrawardi (1154–1191), executed in Aleppo, founded the "philosophy of illumination" (ḥikmat al-ishrāq). He described reality as degrees of light flowing from the "Light of Lights", gave a place to knowledge by presence and vision beside discursive proof, and claimed to revive the wisdom of ancient sages, including Hermes, Plato and the kings of ancient Persia. Fakhr al-Din al-Razi and Nasir al-Din al-Tusi (d. 1274), who also directed the observatory at Maragha, continued to engage with Avicenna.

In Safavid Iran the "School of Isfahan" culminated in Mulla Sadra (Sadr al-Din Shirazi, d. 1640), who combined Avicenna, Suhrawardi, Ibn Arabi's mysticism and Shi'i theology. He taught the primacy and gradation of existence and "substantial motion", the idea that things change in their very substance. His "transcendent wisdom" (al-ḥikma al-mutaʿāliya) is still studied in the seminaries of Qom. Meanwhile the North African historian Ibn Khaldun (1332–1406) wrote in his Muqaddimah a philosophical analysis of history and society, together with a critical survey of the sciences of his time, including the occult ones.

The Brethren of Purity, Hermes and the Esoteric Current§

Alongside formal philosophy ran a current that historians of esotericism find especially important. The Epistles of the Brethren of Purity (Rasāʾil Ikhwān al-Ṣafāʾ), fifty-two treatises composed in Basra probably in the tenth century by an anonymous group, present a complete encyclopaedia of knowledge from mathematics and music to magic, built on Pythagorean number symbolism, Neoplatonic emanation and astrology; their links with Ismailism are debated. Arabic authors also knew Hermes Trismegistus, often identified with the Qur'anic prophet Idris, as the founder of the sciences, and attributed to him or to "Balinas" (Apollonius of Tyana) texts on alchemy and talismans, among them the Emerald Tablet. These traditions, explored in What Is Hermeticism? and Islamic Occult Sciences, passed with Arabic philosophy into Latin Europe.

Frequently asked questions§

Who was the greatest Islamic philosopher?§

Avicenna is generally considered the most influential, since his system shaped philosophy and theology across the Islamic world for centuries. In Europe Averroes was more famous as an interpreter of Aristotle, and in Iran Mulla Sadra is regarded as the culmination of the tradition.

Did al-Ghazali end philosophy in Islam?§

No. His critique changed the terms of debate, and theologians after him absorbed much of Avicenna's logic and metaphysics. Philosophy continued to flourish, especially in Iran, Central Asia and the Ottoman world.

What is the difference between falsafa and kalam?§

Falsafa was the tradition rooted in Greek philosophy that began from demonstrative reasoning; kalām was the theologians' science of defending religious beliefs by argument. Over time the two converged, and later theologians wrote in a largely philosophical vocabulary.

Sources and further reading§

• Greek Thought, Arabic Culture — Dimitri Gutas, 1998
• A History of Islamic Philosophy — Majid Fakhry, 1970
• History of Islamic Philosophy — Henry Corbin, 1964
• The Cambridge Companion to Arabic Philosophy — Peter Adamson & Richard C. Taylor (eds.), 2005
• Philosophy in the Islamic World — Peter Adamson, 2016
• The Incoherence of the Philosophers — al-Ghazali, trans. Michael E. Marmura, 1997
• Ibn Tufayl's Hayy Ibn Yaqzan: A Philosophical Tale — Lenn Evan Goodman, 1972