It is by veiling itself a little that the sun can be the better contemplated. When, on the contrary, the heliophany sheds all the violence of its brightness, the sun is denied to the eyes, and that is why its light is the veil of its light. In truth, the King manifests His beauty on the horizon of those who are His. Towards them He is not niggardly of His vision. Those who are deprived of contemplating Him are so because of the wretched state of their faculties. . . . Whoever perceives a trace of His beauty fixes his contemplation upon it forever; never again, even for the twinkling of an eye, does he let himself be distracted from it.
 Sometimes certain solitaries amongst men emigrate towards Him. So much sweetness does He give them to experience that they bow under the weight of His graces. He makes them conscious of the wretchedness of your terrestrial clime. And when they return from His palace, they return laden with mystical gifts.

Risalah Hayy ibn Yaqzan
Ibn Sina

 The history of philosophy, the visible surface of the luminous core of spiritual insight that constitutes the vital source of religious traditions and social structures, could be seen as the convergence of similar elements in differing patterns. Christianity tended to discard the traditions out of which it arose even whilst drawing from them. Islam preferred to absorb traditions as it encountered them, fusing and transmuting their power into a new way of thought and life. Revelation, reason, mystical experience and empirical observation were important in both movements, and yet their esprit and élan diverged sufficiently to becloud mutual understanding more completely with each passing century. Without presuming to assess classes of souls and the destinies of peoples, it is possible to discern one fundamental difference between them. Almost from the first, Christianity was centered around a church, a hierarchy of individuals with authoritative powers of interpretation. As self-appointed custodians of the primal revelation, they used and arrested reason, restricted the value of observation and were troubled by the mystic experiences of individuals, all of which could undermine church authority. In Islam the imam and jurist alike became protectors of shari'a, the great highway of the law, but there was no strict hierarchy of authority. Thus, in the vivid imagery of the Qur'an, Allah remained as close to each individual as his jugular vein.

 Insights of logicians, visions of mystics and observations of experimental scientists might unsettle the umma, the community of the faithful, and even outrage some imams, but no hierarchy could muster its powers to eradicate offensive views. Since what disturbs one generation may be accepted as obvious by the next, evolving Islam embraced change and rejuvenation with confidence in the certitude of the Prophet and the Book. The ferment of social change and intellectual expansion provided the environment into which Avicenna was born. He combined the empirical observations of medicine and astronomy, Aristotelian logic, neo-Platonic emanative cosmogony and mystical understanding with an originality and brilliance that amazed the eastern Islamic world and influenced Christian Europe for seven centuries.

 Unlike most of his predecessors, Avicenna (as Ibn Sina came to be known in Europe) dictated a sketchy autobiography to his chief disciple, Abu 'Ubayd al-Juzjani, who added his own recollections. Avicenna's father, a native of Balkh, settled near Bukhara, where he became governor of a small town, Kharmaythan. Before long he married Sitara of Afshanah, and in AD. 980 she gave birth to Abu 'Ali al-Husain ibn 'Abdallah ibn Sina. His natal horoscope suggested a man of great intellect, understanding and facility in expression. The ascendant was Cancer in the degree of exaltation of Jupiter; Sun, moon and Venus were all in their degrees of exaltation, whilst both the Pars Fortuna and the Lot of the Unseen were in Cancer, the latter with Canopus and Sirius. When Ibn Sina was five years old, his family moved to Bukhara, then the capital and centre of learning for the Samanid dynasty, which ruled eastern Persia, Khurasan and Transoxiana. Ibn Sina's father belonged to the Isma'iliyyah sect of Shi'a Islam, a movement advocating a dual interpretation of the Qur'an, exoteric and esoteric, and requiring initiation into the Truth through a series of graded levels. The Isma'ilis believe that the son of the seventh Shi'a imam will return at the end of the world as the mahdi, the divinely guided one. Whilst Ibn Sina came to reject his father's belief, he learnt to place himself above the growing Sunni-Shi'a split and to avoid sectarian entanglements, and he profited from his father's concern to provide him with the best possible education.

 By the age of ten, Ibn Sina had mastered grammar, literature, the whole of the Qur'an, geometry and "Indian calculation", as well as some treatises of the Ikhwan as-Safa, the Brethren of Purity. When the famous mathematician, Abu 'Abdallah al-Natili, came to Bukhara, Ibn Sina's father offered him his own home so that he might teach his son. Ibn Sina studied Ptolemy's Almagest, Euclid's Elements and Porphyry's Isagoge under al-Natili, but he soon surpassed his teacher in understanding. When al-Natili left Bukhara, Ibn Sina turned his attention to metaphysics, medicine and jurisprudence.

Medicine is not one of the difficult sciences and therefore I excelled in it in a very short time, to the point that distinguished physicians began to read the science of medicine under me. I cared for the sick and there opened to me some of the doors of medical treatment that are indescribable and can be learnt only from practice.

 Given the sophistication of Islamic medicine at this time, Ibn Sina's statement is remarkable. Whilst studying medicine he relaxed by engaging in legal disputations. Having thoroughly acquainted himself with the sciences, he returned to philosophy and logic. "During this time I did not sleep completely through a single night nor devote myself to anything else by day." Whenever a logical problem resisted his attempts at solution, he would retire into meditative worship at the local mosque, where al-khaliq, the All-Creating, would illumine his understanding. "And whenever sleep seized me, I would see those very problems in my dream; and many questions became clear to me in my sleep."

 Nevertheless, the essence of Aristotle's Metaphysics eluded Ibn Sina. He read the work forty times and memorized difficult passages, yet he could not understand its import. One day he strolled in despair through the booksellers' quarter and was offered an old volume. At first rejecting it, he bought it when told that the owner needed money. When he opened the volume, he discovered that it was al-Farabi's commentary on the Metaphysics. Within one night Ibn Sina's mind was cleared and his education complete. The next day he gave alms to the poor in gratitude. Shortly thereafter, in 997, he was called to the court of Bukhara to assist in the healing of the ruler Nuh ibn Mansur al-Samani, whose illness had baffled the court physicians. There he obtained entrance to the vast royal library and saturated himself so thoroughly in its treasures that he later remarked to al-Juzjani: "I now know the same amount as they, but more maturely and deeply; otherwise the truth of learning and knowledge is the same."

 By the time he was twenty-one in 1001, he began to write books on mathematics, science and ethics. Though his books have been lost in war and pillage, two hundred and fifty works have survived the capriciousness of history. In the next year his father died and life at court had become dangerous. Various dynasties in Persia and beyond became embroiled in a long and often indecisive struggle for dominance. For the remainder of his life Ibn Sina travelled from court to court as physician and scholar, usually ahead of dynastic collapse, internecine conflict and conquest. In Jurjaniyah at the court of the Khwarazmshah, he found a true patron in the wazir al-Suhaili and wrote works on astronomy for him. Later he travelled to Jurjan, where he met his lifetime companion, al-Juzjani, who followed him for the rest of his life.

 Sometime around 1015 he cured the wife and son of the fakhr of Rai and then pushed on to Hamadan, where he treated the Buwaihid ruler, Shams al-Dawlah. The cure made him a court favourite, but his appointment as wazir burdened him with court duties and nurtured jealousy and envy amongst some courtiers. He continued to write, but when the ruler died in 1021, he declined the offer to continue as wazir, for he wanted to go to the court of 'Ala al-Dawlah in Ispahan. Old enemies took advantage of the situation and imprisoned him in Fardjan castle near Hamadan, where he languished for four months. Whilst shut off from the world, he wrote several treatises, including the famous mystical allegory, Risalah Hayy ibn Yaqzan. Suddenly, 'Ala al-Dawlah attacked Hamadan and Ibn Sina was able to escape with al-Juzjani to Ispahan. Here he found fifteen years of peaceful study in a great centre of culture and learning. He continued to write in Arabic, but out of gratitude for his patron's generous support he composed treatises in Persian as well.

 Whilst in the service of 'Ala al-Dawlah, he invented several astronomical instruments which allowed him to correct inaccurate ephemerides, and he finished the al-Qanun, the canon of medicine which remained a standard textbook in Europe until the seventeenth century. Unfortunately, the Ghanza dynasty, whose conquest had forced him to begin his wanderings from Bukhara, now attacked Ispahan. He retreated south with 'Ala al-Dawlah and soon fell ill. He insisted upon caring for himself but had to be carried back to Ispahan. Once he could walk, he returned to the full activities of the court, and when 'Ala al-Dawlah marched on Hamadan, Ibn Sina accompanied him. By the time they reached the city, Ibn Sina knew that his health had failed. He refused to treat himself further, saying, "The governor who used to govern my body is now incapable of governing, and so treatment is no longer of any use." He died in Hamadan in 1037, having lived for fifty-eight lunar years, or fifty-seven years in the solar calendar.

 Whilst Aristotle's general scheme of the universe was acceptable to Ibn Sina, Aristotle began with natural philosophy (physics) and moved to metaphysics, believing that sensible knowledge precedes intellectual understanding. Ibn Sina reversed the order, proceeding from metaphysics to mathematics to natural science. Knowledge of the visible world depends upon the architectonics of the invisible world, which is consonant with the root categories of developed consciousness. Particular entities do not give rise to the idea of Being; rather, Being itself, prior to the universe, is the source of particulars. "If it be said that the central element of Platonic metaphysics is the theory of Ideas, and that of the Aristotelian is the doctrine of potentiality and actuality," S.M. Afnan wrote, "that of the Avicennian metaphysics is the study of being as being." Christian Europe came to see in this approach a deductive logic that satisfied the highest aspirations of reason. Ibn Sina, however, believed that such an approach to the Philosophia Perennis provided a conceptual map for a journey that begins in Aristotelian logic and ends in the mystical realization of tawhid, unity of Being. Being is beyond all distinctions and yet their cause, in that the essential natures of things are only limitations of being. Accidental properties are dependent on contingent beings, which in turn depend upon necessary beings, and these are dependent upon Being beyond distinctions. Thus, Being is necessary in essence and in existence, which are one in It. For Ibn Sina this reasoning comes as close as possible to proving the existence of Deity (Being without qualities) from the fact of the universe.

 Like al-Farabi, Ibn Sina taught that Deity contemplating Itself gave rise to the first intelligence, and that when the first intelligence contemplated Deity, the second intelligence arose. When the first intelligence saw itself as necessary because of its cause, it produced thereby the soul of its sphere, and when it thought of itself as possible, it generated the body of its sphere. This process of emanation continued until ten intelligences emerged, the last being associated with the moon and functioning as the Agent Intellect, whose ideation provides the sublunary world with its archetypes and the human mind with knowledge. Because each celestial sphere is also an angelic intelligence, the structure of the empyrean is not just celestial architecture, but a Jacob's ladder for the ascent of the soul.

 The human mind which actualizes its potential for understanding Being becomes immortal. Thus, immortality is at once individual and rooted in supreme Unity, the mystery of consciousness which is solved only by realization. From this standpoint the universe constitutes a dialectical symbology by which human consciousness rises to participate in the primordial and timeless act of self-reflection. Ibn Sina's philosophy is based upon the ultimate unity of Being and consciousness, and he tries to demonstrate that unity with the analogy of the flying man. Imagine a human being suspended in space such that he can touch nothing, not even himself, and imagine that his eyes are covered. Even if he had been deprived of all sensory experience, he would nonetheless know that he exists. Thus, knowledge of being and awareness of self arise simultaneously. Some philosophers believe that this idea found its way to Descartes, who echoes it in his Cogito, ergo sum.

 Whilst Being transcends the universe, the universe is fayd, an effusion, of Being. Ontology gives its architectonic structure and natural science deals with all that moves. For Ibn Sina natural philosophy can be divided into seven broad branches – medicine, astrology, physiology, oneiromancy, natural magic, theurgy and alchemy. Another seven sciences, geometric astronomy, geography, geodesy, mechanics, statics, optics and hydraulics are, for Ibn Sina, branches of mathematics. Natural philosophy cannot prove that Nature, Tabi'ah, is the power of motion, for "one cannot prove the principles of a science by that science itself", but metaphysics can. Nature in its most universal aspect is the power of the first heavenly sphere. It belongs to the intelligible hierarchy represented by angelic ideation and is the source of the evolving material order.

 Nature is regulatory, and for it motion and rest are relative, since the power of Nature is involved in keeping a body at rest just as much as impelling a body to move. Matter, on the other hand, is passive, the medium upon which the forces of Nature and the angelic hierarchy work. Form is the raison d'ître of matter. Without form, matter could not be said to exist. The sublunary realm is distinguished from the celestial spheres in that on earth, form must be accompanied by matter and matter cannot exist without form. This urge towards embodiment manifests as the ceaseless exchange of forms in matter.

 On the basis of these broad principles, Ibn Sina examined all the sciences. He distinguished types of rocks and concluded that sedimentary layers of earth at the bottoms of lakes and seas were the result of erosion of the surrounding mountains. Sediments in turn became rocks of one kind. Fossils found in mountains are due to successive inundations which gave shape to the land. He believed that with adequate instrumentation one could distinguish a series of floods from the records of the rocks. He understood the nature of comets and meteorites and grasped the respiratory cycle of the earth. Whilst he doubted the possibility of literal transmutation of lead into gold, and criticized conventional astrology on the ground that it imposed purely terrestrial elements upon the celestial vault, he held that a purely spiritual astrology is the key to the nature of the universe. Ibn Sina premised his medical doctrines on the view that in man, body and soul form a unity, and thus in man the whole of creation returns to the Source. The cosmos exhibits a principle of universal life which attains its full potency in human consciousness. Medicine errs in treating forms as the source of life; life is the source of forms. All life yearns for the highest Truth, and just as Nature intends the enhancement of goodness and perfection unless blocked, so life tends towards regularity and perfection except when inhibited. Medicine is the science of removing inhibitions. Since growth and decay are rooted in human temperament, medicine includes psychology.

 For Ibn Sina the process of healing is analogous to striving for immortality. In both, breath is central.

Allah the Most High created the left side of the heart and made it hollow in order that it should serve both as a storehouse of the breath and the seat of manufacture of the breath. He also created the breath to enable the faculties of the soul to be conveyed into the corresponding members. In the first place, the breath was to be the rallying-point for the faculties of the soul, and in the second place it was to be an emanation into the various members and tissues of the body. . . . The beginning of the breath is as a divine emanation from potentiality to actuality proceeding without intermission or stint until the form is completed and perfected. . . . The breath, then, is that which emerges from a mixture of first principles and approaches towards the likeness of celestial beings. It is a luminous substance. It is a ray of light.

 The perfection of breath is the purification of the human being as soul and as body. This is accomplished by inward contemplation and ethical conduct, the twin manifestations of authentic love, which are essentially love for the Source of all existence. Given this conception, in which the manifest universe is seen as a vast emblem comprising at every point symbols of spiritual possibilities, it is not surprising that Ibn Sina, unexcelled in rational philosophy, should compose three mystical visions of the soul's journey to God and immortality.

 This journey through the universe of symbols is depicted as a movement from the extreme Occident (pure matter) through the Occident (the terrestrial world) to the Orient, the pole of pure light. The journey begins when the traveller, salik, meets the spiritual master, pir, Hayy ibn Yaqzan, 'living son of the awake', who shows the path to be travelled. No sooner does the ordinary man become salik than the universe becomes the cosmic crypt which imprisons him. His journey is from the realm of death, however alive it may seem to the unaware, to the region of true life, indistinguishable from Deity. The salik must learn 'ilm al-khawass, the science of the élite, the right interpretations of things. He will have to pass through the realms of pure matter, the material body, the four mental kingdoms, which include the imagination, the world of the intelligibles, and finally the angelic world. He may get caught and deluded at any point along the way. He will pass through the four elements and the nine heavenly spheres. He must become like a bird through dispassion, so that he can fly above each region and see it for what it is. He will fly beyond the cosmos only when he has integrated it within his own being. When he has done so, he soars from the "roof of the cosmos" out of the crypt into the Divine Presence.

 The traveller's journey is the ultimate sojourn of Everyman. The salik's journey ends in a spiritual death which is the return of the soul to its Divine Source and the indrawing of the cosmos to its Origin. Ibn Sina's thought showed the majesty and luminosity of this supreme pilgrimage. In the West he influenced a host of thinkers, from Albertus Magnus and Thomas Aquinas to Robert Grosseteste and Roger Bacon, all of whom were concerned with light. In the East he overbrooded a school of mystical philosophy, the Ishraqi or illuminationist tradition. Ibn Sina exemplified to some degree the gnostic sojourn depicted by Seyyed Hossein Nasr:

The gnostic who has journeyed beyond the cosmos becomes the norm of the Universe and the channel through which all of Nature receives Divine grace. In his union with God, the whole Universe becomes once again integrated into its Transcendent Principle, as his life is the life of the cosmos and his prayers before the Divine throne, the prayer of all of Nature before the Divine artisan.