al-Kindi, Abu Yusuf Ya‘qub ibn Ishaq (d. c.866–73)

Practically unknown in the Western world, al-Kindi has an honoured place in the Islamic world as the ‘philosopher of the Arabs’. Today he might be viewed as a bridge between Greek philosophers and Islamic philosophy. Part of the brilliant ninth-century ‘Abbasid court at Baghdad, composed of literati of all types, he served as tutor for the caliph’s son. He gained insights into the thought of Greek philosophers, especially Aristotle, through the translation movement; although he did not make translations himself, he corrected them and used them advantageously in his own thought.

Al-Kindi is notable for his work on philosophical terminology and for developing a vocabulary for philosophical thought in Arabic, although his ideas were superseded by Ibn Sina in the eleventh century. The debate about the allowability of philosophy in terms of orthodox Islam also began with al-Kindi, a battle that is usually considered to have been won for religion by al-Ghazali. Like other innovators, his ideas may no longer appear revolutionary, but in his own day, to push for the supremacy of reason and for the importance of a ‘foreign science’ – philosophy – as opposed to an ‘Arab science’ – grammar, Qur’anic studies – was quite astonishing. When the Khalif al-Mutawwakil came to power and sought to restore traditionalism, al-Kindi suffered a reversal of fortunes.

Logic and translation

Abu Yusuf Ya‘qub ibn Ishaq al-Kindi was an ethnic Arab (died in Baghdad between AH 252–60/AD 866–73), with an illustrious lineage going back to such near-mythic Arabian families as Qays. Al-Kindi was known as ‘the philosopher of the Arabs’ in contrast to the later Islamic philosophers who, though Muslim, were not Arabs and often learned Arabic as a second language. The early bio-bibliographers gave his ancestry and a long list of works, many of which are no longer extant, but his personal life remains unknown. Although he is remembered for introducing philosophy to the ‘Abbasid court, his skills covered many fields including medicine, mathematics, music, astrology and optics. He also served as tutor to the son of the Khalif al-Mu‘tasim. Al-Qifti, one of the medieval Islamic bio-bibliographers, pointedly asserted that al-Kindi was skilled in the arts of the Greeks, the Persians and the Hindus.

Al-Kindi used early, Arabic-language translations of Greek philosophy, which enabled him to add part of the Hellenistic tradition to his programme. The founding of the bayt al-hikma (house of wisdom), for the large-scale translation of documents from Greek, in the early ninth century meant both that the ‘foreign sciences’ were available wholesale to Arabophone scholars and that there was serious interest in the knowledge they contained. Al-Kindi was occasionally credited (in the title inscription) with correcting the translation, but it is generally accepted that he did not read Greek himself. The pursuit of ‘foreign sciences’ was also politically acceptable at this juncture, which ceased to be the case later. A study of his terminology shows that al-Kindi was aware of particular terms used in Hellenistic philosophy, and of which Arabic word best expressed the same idea.

Al-Kindi may be thought of as a stage-setter for philosophy in the Islamic world, laying out terms qua terms and redirecting the metaphysical concerns suggested by the mutakallimun (theologians) from the realm of religion to that of philosophy. His lack of interest in religious argument can be seen in the topics on which he wrote. These topics were ontological, but he generally refrained from eschatological discussions on topics such as the resurrection, the last day and the last judgment. Even in his ethical treatise he dealt with the disciplined life in which a person might find interior serenity in their current life, rather than an emphasis on reward in the hereafter. Scholars have sometimes thought of al-Kindi as a Mu‘tazili sympathizer, but this has not been proved; he appears rather to coexist with the worldview of orthodox Islam.

Al-Kindi’s work on definition is Fi Hudud al-Ashya’ Wa-Rusumiha (On the Definitions of Things and their Descriptions). Through the terms he chose to define – finitude, creation, the first cause – we can see where the constructs of Islamic philosophy diverged from their Greek predecessors. In the eleventh century the Kitab al-hudud (Book of Definitions) of Ibn Sina replaced al-Kindi’s work; this was considerably more advanced, both in its definitions and in its organization of the world into a concise ontological schema.



Al-Kindi’s best known treatise is the metaphysical study, Fi al-Falsafa al-Ula (On First Philosophy). Aristotelian influence can be seen in certain elements, such as the four causes. However he is Aristotelian only up to a point. The point of divergence is reached over the question of the origin of the world. Aristotle teaches the eternity of the world; Al-Kindi propounds creation ex nihilo. The later philosophers, such as al-Farabi, are usually considered to understand Aristotle more accurately; they had the advantage of better translations and a greater number of works. In Fi al-Falsafa al-Ula, al-Kindi described the first philosophy, which is also the most noble and highest philosophy, as the knowledge of the first truth, including the cause of every truth (the first cause). The first cause is prior in time because it is the cause of time. By the study of philosophy, people will learn the knowledge of things in reality, and through this the knowledge of the divinity of God and his unity. They will also learn human virtue. Throughout many of his treatises, al-Kindi emphasizes the importance of the intellect (‘aql) and contrasts it with matter.

He also discusses the One Truth, which is another name for God, and states that it does not have any attributes, predicates or characteristics. This view is consonant with the Mu‘tazili declaration of the unity of God as being strictly without attributes, and consequently al-Kindi has sometimes been deemed to be a Mu‘tazili by scholars.

Other aspects of his position include emphasis on the absolute unity of God, his power – particularly as creator – and creation ex nihilo. The Eternal, that is God, is not due to another; he has no cause and has neither genus nor species. There is no ‘before’ for the Eternal. The Eternal is unchanging, immutable and imperishable. In human terms, death is the soul’s taking leave of the body, which it employed during life. For al-Kindi, the intellect continues. Perhaps the soul is primarily the locus of the intellect. He reiterated in his ethical treatise the idea that humans must choose the world of the intellect over the material world (see §3).

Al-Kindi differs from the Hellenistic philosophical tradition primarily in espousing the belief that the world was created ex nihilo. In Aristotelian metaphysics the Prime Mover set the world in motion, but in the Hellenistic tradition, time and motion are intrinsically linked. Matter set in motion is eternally existing, since it exists before motion (and therefore before time). In this system, time is defined as the extension of the series of movements. Thus time begins with movement. In al-Kindi’s system, matter, time and movement are all finite, with a beginning and a cessation at some future point. Other subjects that concern al-Kindi can be seen from his titles, including Fi wahdaniya Allah wa tunahiy jirm al-‘alam (On the Unity of God and the Limitation of the Body of the World), and Fi kammiya kutub Aristutalis wa ma yahtaj ilahi fi tahsil al-falsafa (The Quantity of the Books of Aristotle and What is Required for the Acquisition of Philosophy).

In his philosophical writings, al-Kindi does not so much direct arguments to the concerns of religion as avoid them altogether, instead describing a parallel universe of philosophy. He consistently tries to show that the pursuit of philosophy is compatible with orthodox Islam. The mutakallimun had previously speculated on questions about matter, atoms and substance, which he also considers. Another reason for the claim that he was a Mu‘tazili was his persecution by the Khalif al-Mutawwakil, who instigated a reactionary policy against the Mu‘tazili and a return to traditionalism (see Ash‘ariyya and Mu‘tazila). Al-Kindi was caught in the general net of the Khalif’s anti-intellectualism; the Kindian emphasis is always on rationalism, an attitude which the orthodox establishment of a revealed religion is bound to find inimical.


Al-Kindi’s ethics and practical philosophy are most discussed in a treatise Fi al-hila li-daf‘ al-ahzan (On the Art of Averting Sorrows), of questionable authenticity. Fehmi Jadaane (1968) argues that al-Kindi was strongly influenced by the Stoic tradition, particularly the thought of Epictetus, which was known throughout the Islamic world at the time through contact with Syriac Christian scholars, if not through specific texts. Epictetus emphasized the importance of freedom from the world and human beings’ status as agents, who through their ultimate independence were responsible for their own happiness and independent of others. His last logical step, however, was that suicide was permissible if life was no longer worth living. This last idea is not repeated in al-Kindi.

Like the writings of the Stoics, al-Kindi’s treatise, which is of the ‘consolation of philosophy’ type, exhorts readers to concentrate on the life of the mind and the soul, not of the body (see Stoicism). Al-Kindi says that human beings are what they truly are in the soul, not in the body. Again, on the futility of looking for eternities in the visible world, he says that whoever wishes for what is not in nature wishes for what does not exist. The reader is admonished that unhappiness follows such an attitude. In this treatise, al-Kindi advocates maintaining an internal balance through the mechanism of the individual’s interior autonomy. If worldly property becomes a concern and is then lost or damaged, this will upset an individual’s mental equilibrium. Stoic ideas about the ephemeral nature of earthly goods are recalled; al-Kindi warns against attachment to favourite worldly goods, using an example from Plutarch’s On Moral Virtue. In that story, Nero receives a gift of a gorgeous, elaborate crystal tent, with which he is obviously smitten. A philosopher who is present in the crowd advises him that he has already been impoverished through his keen attachment to this object. If Nero were to lose it, the philosopher says, he will suffer because it is irreplaceable. Later when the rare object is lost at sea during transport, Nero is devastated. Scholars have argued that this treatise appears to be a mélange of wisdom literature from various Hellenistic sources, with no ideas that sound Kindian. Ibn Miskawayh refers to the ideas of al-Kindi in his treatise on ethics, Tahdib al-akhlaq.

Some ethical remarks are contained in other treatises. The virtues discussed in the treatise on definitions are wisdom, courage and temperance. A reflection of each virtue which exists in the soul is seen in the body. Virtue exists as a focal point between two extremes. Bravery, for example, is both mental and physical; it is midway between rashness and timidity.

Some reverberations of al-Kindi’s thought also continued in the twelfth-century Christian Latin West, as certain of his treatises were translated into Latin by the Scholastics, notably De intellectu (On the Intellect). In the thirteenth century Giles of Rome criticized ‘Alkindus’ with other philosophers in his work Errores philosophorum (Errors of the Philosophers). Only a portion of al-Kindi’s work survives, so judgment of him must necessarily be imperfect. However, al-Kindi’s influence endured longer in the Western Islamic tradition than in the Eastern, as reflected in the writings of the twelfth-century mystic Ibn al-‘Arabi. With al-Kindi, who pursued reason against the background of revealed religion, begins the Islamic philosophical tradition which continues with the works of Ibn Sina and Ibn Rushd.



List of works

  1. al-Kindi (before 873) Rasa’il al-Kindi al-falsafiya (Philosophical Treatises of al-Kindi), ed. M.A. Abu Ridah, 2 vols in 1, Cairo, 1953. (The standard collection of al-Kindi’s treatises, with introductory notes in Arabic.
  2. al-Kindi (before 873) Fi al-falsafa al-ula (On First Philosophy), ed. and trans. A. L. Ivry, Al-Kindi’s Metaphysics: A translation of Ya‘qub ibn Ishaq al-Kindi’s Treatise ‘On First Philosophy’, Albany, NY: State University of New York Press, 1974. (A clear account of al-Kindi’s metaphysics with English translation.)
  3. al-Kindi (before 873) Risalah fi al-hilah li-daf‘ al-ahzan (On the Art of Averting Sorrows), ed. and trans. H. Ritter and R. Walzer, ‘Uno scritto morale inedito di al-Kindi’, Memorie della Reale Accademia nazionale dei Lincei, Rome, Series VI, 8 (1), 1938, 47–62. (Text and Italian translation.)
  4. al-Kindi (before 873) Fi hudud al-ashya’ wa-rusumiha (On the Definitions of Things and their Descriptions), ed. M. A. Abu Ridah in Rasa’il al-Kindi al-falsafiya, Cairo, 1953; trans. D. Gimaret in Cinq épîtres, Paris: Centre National de la Recherche Scientifique, 1976. (Al-Kindi’s treatise on definitions.)
  5. al-Kindi (before 873) Fi wahdaniya allah wa tunahiy jirm al-‘alam (On the Unity of God and the Limitation of the Body of the World), ed. M. A. Abu Ridah in Rasa’il al-Kindi al-falsafiya, Cairo, 1953. (Al-Kindi on the nature of God.)
  6. al-Kindi (before 873) Fi kammiya kutub Aristutalis wa ma yahtaj ilahi fi tahsil al-falsafa (The Quantity of the Books of Aristotle and What is Required for the Acquisition of Philosophy), ed. M. A. Abu Ridah in Rasa’il al-Kindi al-falsafiya, Cairo, 1953. (Writings on Aristotle.)


References and further reading

  1. Gimaret, D. (1976) Cinq Épîtres (Five Treatises), Paris: Centre National de la Recherche Scientifique. (An excellent French translation with commentary of five treatises by al-Kindi. There are unfortunately very few English translations of al-Kindi’s works.)
  2. Jadaane, F. (1968) L’Influence du stoïcisme sur la pensée musulmane (The Influence of Stoicism on Muslim Thought), Beirut: Dar el-Machreq. (An interesting argument for Stoic, rather than merely Aristotelian and Neoplatonic influence, on the Islamic philosophers.)
  3. Jolivet, J. (1971) L’Intellect selon Kindi, Leiden: Brill. (A classic work: extensive commentary and French translation of al-Kindi’s treatise on the intellect.)
  4. Klein-Franke, F. (1996) ‘Al-Kindi’, in S. H. Nasr and O. Leaman (eds) History of Islamic Philosophy, London: Routledge, ch. 11, 165–77. (Account of the role of al-Kindi as the first Muslim philosopher, and in particular the links between his philosophy and contemporary theology and understanding of Greek thought.)
  5. Moosa, M. (1967) ‘Al-Kindi’s Role in the Transmission of Greek Knowledge to the Arabs’, Journal of the Pakistan Historical Society 15 (1): 3–18. (Good discussion of ‘The Quantity of the Books of Aristotle’.)
  6. Rosenthal, F. (1940) Review article of ‘Uno scritto morale’, Orientalia IX: 182–91. (An interesting review of the Ritter–Walzer treatise, still important despite its age.)
  7. Stern, S. M. (1959) ‘Notes on al-Kindi’s Treatise on Definitions’, Journal of the Royal Asiatic Society parts 1 and 2: 32–43. (Considered a classic.)

Source: Routledge Encyclopedia of Philosophy site sampler/teaser.


1.   What was so radical about Al-Kindi's views?
2.   How does Al-Kindi differ from Aristotle on metaphysical issues?
3.   How does Al Kindi characterize bravery?


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