Among the early Islamic philosophers, Ibn Sina stands out as a thinker of exceptional power and versatility. The whole of his philosophy stems from his conception of God as a necessary being whose essence is to exist and from whom the universe necessarily flows. His thought is not highly original but it is marvellously systematic, fluent and lucid. It exhibits a blend of Platonism, Aristotelianism and Neo-Platonism that is characteristic of Muslim philosophy of the time. He adopted and developed many of the ideas of his predecessor al-Farabi, imparting to them a spirituality that reflected an aspect of his own personality. When his work was translated into Latin it came to exert a powerful influence on the thirteenth-century scholastic philosophy of the western world. The hundred or so of his works that survive include books on science, logic, psychology, astronomy, language, literature and religion as well as his famous treatise The Canons of Medicine (al-Qanun fi al-Tibb). His major philosophical work is Kitab al Shifa (the Book of Healing), which he abridged as Kitab al Najat (the Book of Salvation). Ibn Sina’s intellectual capability was remarkable. When he was only 16 he qualified as a practising physician. He was a brilliant logician and his writings include detailed commentaries on Aristotle. He became vizier to several sultans, travelled extensively in Persia and was frequently close to or involved in fighting with the Turks. At the age of 57, shortly before his death, he freed his slaves.
There is considerable knowledge of Ibn Sina’s life because, unusually for a Muslim, he left an autobiography which he dictated to a pupil. He was born in northern Persia in the village of Afshanah, near Bukhara. His family then moved to Bukhara where he was given a private education and became acquainted with the Ismaili1 doctrine of Islam. In his autobiography he is outspoken about his educational achievements and leaves the reader in no doubt that he excelled in his studies. By the age of 10 he had made a complete study of the Koran and a major part of Arab letters and was able to display a detailed understanding of numerous areas of knowledge. ‘So much so’, he recounts, ‘that people wondered at my attainments.’2 He outstripped his logic teacher when he was in his early teens and then turned of his own accord to physics, medicine, mathematics and, eventually, metaphysics. He relates that he read Aristotle’s Metaphysics forty times without any real comprehension but then came across a copy of al-Farabi’s Intentions of Aristotle’s Metaphysics which succeeded in making Aristotle’s ideas clear to him. Ibn Sina’s life was a restless one. He rarely settled for long in one place but moved between the courts of the sultans to whom he was medical adviser. His health became much impaired by his over-indulgences and when he died at the age of 58 it was because he had been unable to cure himself of a severe and prolonged attack of colic.
The foundations of Ibn Sina’s thought are firmly Aristotelian but its development and superstructure are imbued with Neo-Platonism. He held that God is a necessary being and that he is the eternal, unmoved First Mover. His argument for the existence of God derives from the notion of causality. He says, first, that anything that exists must do so in virtue of being caused to exist; second, that causes cannot be linked either in an infinite series or in a circle; and third, as the conclusion of those premisses, that the series of causes must have their source in a necessary being that is not dependent on anything else for existence and who is God. God’s essence is to exist and he cannot not exist. Since he exists eternally, the creation which he necessarily causes is also eternal.
Like al-Farabi, Ibn Sina expounds an emanationist theory of the cosmos that derives from the Neo-Platonist philosophy of Plotinus.3 But, as already mentioned, whereas al-Farabi held that the cosmos comes into being by God’s acts, Ibn Sina argued that it is a necessary consequence of God’s nature. He holds that although necessarily caused by God, each created entity is contingent in that, unlike God, it does not exist in virtue of its own essence: it is not Cause of Itself as God is. Thus Ibn Sina does not regard creation as a temporal event or as occurring ‘out of nothing’; for him it is co-eternal with God. In this he is in agreement with Aristotle but not with Islamic theology which asserted a temporal act of creation and a limited existence for the cosmos.
Ibn Sina describes God as wholly good and without multiplicity. He therefore has to account for the evident multiplicity of the cosmos and it is here that the theory of emanation serves him well. The theory states that the world emanates from God as the consequence of God’s knowledge of himself. Emanation begins because God’s selfknowledge logically entails the existence of a pure Intellect. This Intellect, or Intelligence, is necessarily brought into existence by God but is in itself not a necessary but a contingent being, since its essence is not identical with its existence. It is known as the First Intelligence, and is aware of three things: of God as Necessary Being; of its own existence as necessarily produced by God; and of its own status as a possible being, dependent on God, rather than as a necessary being able to exist in itself. When the First Intelligence reflects on God it generates a Second Intelligence; when it reflects on itself as a possible or contingent being it generates the body of the first celestial sphere; and when it reflects on the necessity of its emanation from God it generates the soul of that first sphere. This triadic process continues. The Second Intelligence generates a Third Intelligence and a second celestial sphere, and so on until, with the Tenth Intelligence and the ninth celestial sphere, the sublunar world is produced. The Tenth Intelligence is known as Agent or Active Intelligence. It provides the forms that are received by matter, producing thereby the earthly realm of which humanity is a part. Ibn Sina’s cosmology broadly follows the Ptolemaic system of the universe,4 much as al-Farabi’s does, but he does not lay down that there must be ten Intelligences for he was aware that new astronomical discoveries might be made. What he does stipulate is that there could not be fewer Intelligences than celestial spheres.
The Aristotelian notions of potentiality and actuality feature prominently in almost every aspect of Ibn Sina’s thought. They are especially important in his theory of knowledge and his account of the soul. His teaching concerning the soul is very close to Aristotle’s. He regards soul as an emanation from Active Intelligence and says that it may be vegetative, animal, or rational. The soul is the animation of the body that comes into being with the body; it is not something that exists prior to the body. Only the human soul is capable of rationality and it should, accordingly, be able to control the body and its passions. At death the soul separates from the body. If it has triumphed by realizing its rational potential it is able eternally to contemplate higher principles in a state of rapture. If it has failed it endures eternal torment as it searches to regain the body through which it might once have perfected itself.
According to Ibn Sina the soul is a potential being that is able to come to actuality by being moved by the senses and by receiving direct emanation from a higher realm. Knowledge begins with sense-experience which imparts a degree of actuality to the soul. This actuality increases and a higher understanding is achieved when the soul generalizes by reflecting on senseexperience; but it is only when Active Intelligence illuminates the sensible images to reveal their intellectual reality that the individual soul is able to participate in a universal kind of knowledge. Thought at this level is described as the Actual or Acquired Intellect. It operates by abstracting forms from the images of particular objects so that the individuating particularities fall away leaving the purity of the object’s form or essence. It is in this activity that the human soul reaches up to the divine. Its success in so doing represents a peak of human attainment and is surpassed only by a direct insight into the divine, an achievement which is within the capacity of only a few holy mortals. All souls aspire to what is above them, and so to God, and in the successive triads of Intelligence, sphere and soul, already described, it is a soul’s desire for intellectual enlightenment that moves its sphere. Unlike God and the Intelligences, whose knowledge is of universals, souls have aspects which can connect materially with and so influence particular entities in the sublunar world. Souls are the mode of communication between the divine and the earthly.
The concept of prophecy is a vitally significant one in Muslim philosophy and Ibn Sina considers it in some detail. His treatment of it is consistent with his general emphasis on the intellect as the supreme form of spirituality. Both he and al-Farabi regard prophecy as the highest of human abilities but whereas al-Farabi sees it as essentially an imaginative capacity, Ibn Sina analyses it as the rare intellectual ability to achieve a swift, intuitive kind of apprehension, an insight inspired by a direct communion with Active Intelligence. But prophethood, he maintains, is not simply a matter of experiencing an occasional intuitive understanding of something piecemeal or partial. It requires a comprehensive and sustained vision. Moreover, its visionary insights must translate into a conception of things that not only appeals to the mass of people but also satisfies more critical demands for an intelligible world-view and a coherent future prospect. The prophet is a messenger from and a link with a higher reality, a person whose conviction concerning his prophecies must be unshakeable so that his delivery of his message compels and inspires. It is characteristic of prophetic vision that its insights are so vivid that the prophet has to speak of ‘seeing’ divine beings, of ‘hearing’ their voices; and his understanding of bliss and agony becomes objectified as heaven and hell.
Ibn Sina’s conception of the cosmos as existing eternally rather than as the result of an act of creation was not palatable to orthodox Islamic thought. Nevertheless his view of the cosmos as a contingent being, unable to exist without the Necessary Being who is God, served as a strong argument both against an atheistic doctrine which maintained that the physical universe had existed eternally without need of God, and against a religious pantheism, equally repugnant to Muslim tenets, that identified God with the cosmos.
Ibn Sina’s works were translated into Latin in Spain in the mid-twelfth century CE. They exerted a profound influence not only on the thought of St Thomas Aquinas, who came to know them through his teacher, Albert the Great, but on medieval philosophy in general. Half a century after his death, Ibn Sina’s carefully reasoned synthesis of the dogmatic theology of Islam with traditional Greek thought was confronted by the remarkable challenge embodied in the views of his successor, al-Ghazali.
1 The Ismaili constitute a sub-sect of the Islamic Shi‘ite sect. The Shi‘a are distinguished from mainstream Sunni Islam by their devotion to the family of Muhammad the Prophet, and by a special doctrinal emphasis on individual decision-making. The Ismaili subsect maintains a belief in a line of Islamic leaders, descended from Muhammad’s family, and continuing to the present day.
2 See Soheil M. Afnan, Avicenna: His Life and Works, London, Allen & Unwin, 1958, pp. 57–75.
3 See the essay on al-Farabi in this book, pp. 19–22. There is an account of Plotinus’ philosophy in Diané Collinson, Fifty Major Philosophers, London, Routledge, 1991, pp. 26–28.
4 Ptolemy’s planetary system (second century CE) is an earth-centred one in which each planet moves in a small circular orbit which in turn travels around a larger circle. The Ptolemaic system was superseded by the Copernican system (sixteenth century CE) in which the sun is central, with the planets, including the earth, moving round it.
Over one hundred of Ibn Sina’s works have survived, most of which are in Arabic but some in Persian. There is no collected edition of his works. In 1951, the University of Tehran published a series of his works to celebrate his millenary. Some translations are as follows:
Arberry, A.J. (trans.), Avicenna on Theology, London, Murray, 1951
Gruner, O.C. (trans.), A Treatise on the Canons of Medicine, London, Luzac, 1930
Rahman, Fazlur, Avicenna’s Psychology, London, Oxford University Press, 1952
Muhammad, al-Kindi, al-Farabi, al-Ghazali, Ibn Rushd, Muhammad Iqbal
Fakhry, M., A History of Islamic Philosophy, New York, Columbia University Press, 1970
Sharif, M.M. (ed.), A History of Muslim Philosophy, 2 vols, Wiesbaden, Harrassowitz, 1963–1966
Walzer, R., Greek Into Arabic, Oxford, Bruno Cassirer, 1962
Wickens, G.M. (ed.), Avicenna: Scientist and Philosopher: A Millenary Symposium, London, Luzak, 1952