Islamic natural philosophy and medicine reached their peaks with the work of Abu ‘Ali al-Husain Ibn Sina (ca. 980–1037), known to the West as Avicenna, the ‘Prince of Physicians’.
According to his autobiography, which he dictated to his disciple Abu-‘Ubayd al-Juzjani, Ibn Sina was born and educated near Bukhara, in present-day Uzbekistan. He writes that ‘when I reached the age of ten I had mastered the Qur’an and a good deal of literature to such an extent that I evoked great amazement’, after which he notes that his father ‘sent me for a while to a greengrocer who used Indian arithmetic and I would thus learn from him’.
His father then hired Abu ‘Abdallah al-Natili, ‘who claimed to be a philosopher’, and under his tutelage Ibn Sina studied Aristotle’s Organon, Euclid’s Elements and Ptolemy’s Almagest. He says that he soon outstripped his tutor, who ‘took leave of me’, and ‘I occupied myself on my own with Determining the Validity of books, both original texts on Physics and Metaphysics, and the gates of the Philosophical Sciences began opening before me.’ Then, as he writes, he embarked on a study of medicine.
Next I desired [to learn] medicine and I read the books that have been written on this subject. Medicine is not one of the difficult sciences, and therefore I excelled in it in a very short time, to the point where distinguished physicians began to read medicine with me. I cared for the sick, and there opened up to me indescribable possibilities of therapy which can only be acquired through experience. At the same time I was also occupied with jurisprudence and would engage in legal disputations, being now sixteen years of age.
He goes on to say that during ‘The next year and a half I devoted myself entirely to reading Philosophy...So I continued until all the Philosophical Sciences became deeply rooted in me and I understood them as much as is humanly possible...Having mastered Logic, Physics and Mathematics, I had now reached Theology.’ Then he read Plotinus’ Enneads ‘but did not understand what it contained ...’, despite rereading it forty times. He was at his wit’s end until he read a copy of al-Farabi’s On the Purposes of the Metaphysics, and immediately everything in Aristotle’s book became clear to him. ‘I rejoiced at this and the next day I gave much in alms to the poor in gratitude to God Exalted.’
By the time he was seventeen Ibn Sina was such a renowned physician that he was summoned to Bukhara by Sultan Nuh ibn Mansur (r. 976–97), who was suffering from an illness that his own doctors could not cure. Ibn Sina says he collaborated with the court physicians and cured the sultan, who in gratitude gave him free use of the royal library. He says that the library contained books by the ancients that he had never even heard of before, which he soon devoured. ‘So that by the time I reached my eighteenth year I had completed my study in all the Philosophical Sciences. At that time my retention of Knowledge was better, but today my grasp of it is more mature; otherwise the Knowledge is the same, nothing new having come to me since.’
Ibn Sina’s first work, written at the age of seventeen, was a short treatise entitled Compendium on the Soul, dedicated to Sultan Nuh ibn Mansur. Ibn Sina describes this work in his last treatise, On the Rational Soul, written forty years later: ‘As a matter of fact, I happened to write at the beginning of my career forty years ago a summary treatise setting forth the knowledge about the soul and related matters by following the method of those who engage in philosophy through research; whoever wishes to find out about the soul should study this thesis because it is appropriate for students who do research.’
The eighth chapter of the Compendium deals with ‘The Stages of the Human Soul from Inception to Perfection’. Ibn Sina writes that the species of rational beings possesses a faculty called the rational soul, ‘by means of which it is able to conceptualise the intelligibles’. He says that ‘This faculty...does not in itself possess any intelligible forms, but these rather come about within it in one of two ways’. One of these ways is ‘divine inspiration...as in the case with...our belief that the whole is greater than the part’. The other way is to acquire these forms ‘through syllogisms and Discover [them] through demonstration’. As examples of the second way he presents Logic, Physics, Mathematics and Metaphysics, which includes Universal Science and Theology. He goes on to say that some inspired and sanctified people can acquire knowledge without recourse to the second way. ‘None shall gain the enjoyment of this rank except prophets and messengers of God, peace and prayers be upon them.’
Three years later Ibn Sina completed three works commissioned by two learned neighbours in Bukhara. The first of these, The Compilation, or Philosophy for ‘Arudi, was written for Abu ‘l-Hasan ‘Arudji, a neighbour of his in Bukhara. This was an attempt to write a comprehensive work on ‘all the sciences except mathematics’, i.e., the whole of the Aristotelian canon. The other two were The Available and the Valid, a multivolume work on philosophy, and a two-volume treatise on ethics called Piety and Sin. Ibn Sina says in his autobiography that these works were written for another neighbour of his named Abu Bakr al-Baraqi, who ‘asked me to comment on the books on Philosophy and so I composed The Available and the Valid for him in about twenty volumes, and I also composed a book for him on Ethics which I called Piety and Sin. These two books exist only in his possession because he never lent them to anybody to copy from.’
Ibn Sina’s life changed after the death of his father, when he became involved in a career in the service of a succession of princes that kept him on the move for the rest of his days, as he notes in his autobiography.
Then my father died. Independent now, I took over one of the administrative posts of the Sultan. However, necessity led me to abandon Bukhara and move to Gurganj, where Abu-l-Husayn al-Suhayli, a lover of the Philosophical Sciences, was a minister. I was introduced to the Prince there, ‘Ali ibn Ma’mun; at the time I was in lawyer’s garb,... They fixed me for a monthly salary which provided enough for someone like me. Then necessity forced me to move to Nasa, and from there to Baward, and then to Tus, then to Samanqan, then to Jajarm, and then to Jurjan. I was planning to go to Prince Qabus, but it happened meanwhile that he was taken and imprisoned in a fortress where he died. Then I departed for Dihistan, where I fell very ill. I returned to Jurjan, and there I became associated with Abu ‘Ubayd al-Juzjani.
Ibn Sina was thirty-two when he met al-Juzjani, who became his devoted disciple, and to whom he dictated his autobiography up to the time of their meeting. Al-Juzjani then took up the story from that time on, noting that ‘From this point I mention these episodes of the Master’s life of which I myself was a witness during my association with him, up to the time of his death.’
According to al-Juzjani, shortly after Ibn Sina arrived in Jurjan, ca. 1013, he wrote a treatise called The Provenance and Destination for his patron Abu Muhammad as-Shirazi, an ‘amateur of these sciences’. The treatise was divided into three parts, the first two of which deal with the first principle and the being that emanates from it, while the third treats the survival of the human soul.
At this time Ibn Sina began writing his major medical text, al-Qanun fi’l-tibb, the Canon of Medicine, an encyclopedic work that took him more than a decade to complete. While in Jurjan he also wrote a book on logic called The Middle Summary and a treatise on astronomy entitled Summary of the Almagest, in which he said that ‘he introduced ten new figures into the observations’ and claimed that ‘he had things that had never been discovered before’.
The following year Ibn Sina and al-Juzjani moved on to Rayy, ‘one of the glories of the land of Islam’, the birthplace of Harun al-Rashid. Ibn Sina joined the court of the Buyid emir Majd al-Dawlah, whom he successfully treated for melancholia. While he was in Rayy Ibn Sina composed a treatise called The State of the Human Soul, in which he developed more fully the ideas he had presented in the third part of The Provenance and Destination. In the introduction he says that book ‘contains the marrow [of the theory] about the state of the human soul arrived at through demonstrative proofs’.
Ibn Sina, accompanied by al-Juzjani, moved from Rayy to Qazwin and then to Hamadan, where he entered the service of the emir Shams al-Dawlah brother of Majd al-Dawlah, whom he successfully treated for colic. Ibn Sina says that when he left his grateful patient’s presence he was ‘loaded with many costly robes...having passed forty days and nights at the palace and become one of the Emir’s intimates’.
Ibn Sina accompanied Shams al-Dawlah as his personal physician in a war against the Kurds, and on his return he was raised to the rank of vizier. But the army for some reason would not accept this, ‘fearing for themselves on this account’, and Ibn Sina says that ‘they surrounded his house, hauled him off to prison, pillaged his belongings...They even demanded that he should be put to death; but this the Emir refused, though he was agreeable to banishing him from the State, being anxious to conciliate them.’ Ibn Sina was forced to hide in a friend’s house for forty days, but then Shams al-Dawlah suffered another attack of colic and brought him back to the palace, reinstating him as vizier.
Al-Juzjani writes that at this time he suggested that his master write a commentary on the philosophy of Aristotle. Ibn Sina replied that he had little spare time to do so, because during the day he was in attendance on Shams al-Dawlah and in the evening was working on his Qanun, but ‘if you agree that I should compose a book setting forth these parts of the sciences that I believe to be sound, not disputing therein with any opponents nor troubling to reply to their arguments, I will do so.’
Ibn Sina thus began writing the Kitab al-Shifa, the longest of his extant works, a compendium of Aristotelian philosophy known in English as the Book of Healing, also called The Cure and sometimes The Cure of Ignorance. According to Dimitri Gutas, Ibn Sina’s choice of the title was influenced by the sixth-century scholar Paul the Persian, who described ‘Aristotle’s oeuvre as a “course of treatment” (Shifa) that cures “the diseases of ignorance”’. Ibn Sina’s prologue to the Shifa’ states that his compendium of Aristotelian thought ‘will help remove the veils of fanciful notions’ from philosophy.
Ibn Sina spent his evenings with his disciples listening to them read from his works, convivial gatherings that recalled the symposia of Plato’s Athens. As al-Juzjani writes: ‘I would read the Shifa’ and another in turn the Qanun. When we had each finished our allotted portion, musicians of all sorts would be called in and cups brought out for drinking, and in this manner we spent the rest of the time. Studying was done by night because during the day attendance upon the Emir left him no spare time.’
Shams al-Dawlah died in 1021 and was succeeded by his son Saman al-Dawlah, who reappointed Ibn Sina as vizier. Ibn Sina was unsure of the stability of his new patron’s regime, and to hedge his bet he went into hiding in the house of a friend and entered into secret correspondence with a rival ruler, ‘Ala’ al-Dawlah, emir of Isfahan. His secret correspondence was discovered by Saman al-Dawlah’s vizier Taj al-Mulk, who found Ibn Sina’s hiding place and had him imprisoned in a castle at Fardjan, fifty-five miles from Hamadan. As Ibn Sina wrote at the time of his imprisonment: ‘That I go in you see, so that’s without doubt./ What’s uncertain is whether I ever come out.’
Al-Juzjani, in his account of these events in the year 1022, tells of how Ibn Sina, at his request, made an effort to complete the Shifa’ while he was in hiding, ‘without having any book at hand or source to consult, accomplishing the work entirely from memory’.
Each day he wrote fifty leaves, until he had completed the natural sciences and metaphysics save for the books of zoology and botany. He commenced work on the logic, and wrote one part of this; but then Taj al-Mulk suspected him of corresponding with ‘Ala’ al-Dawlah, and disapproving of this instituted a search for him. The master’s whereabouts were betrayed by an enemy, and he was committed to a fortress called Fardjan, where he remained for four months.
During the four months that Ibn Sina remained in Fardjan he completed three works, one of which was a medical treatise called Colic, a subject on which he had become expert through his treatment of Shams al-Dawlah. The second of the three works was al-Hidaya, or The Guidance, which had a full section on the Metaphysics of the Rational Soul.
The third was Risalat Hayy ibn Yaqzan, an allegory of the human intellect, also known as Treatise of the Living the Son of the Wakeful. This was the first of a cycle of what are termed Ibn Sina’s ‘Visionary Recitals’, three in number, the others being The Bird and Salman and Absal. Hayy ibn Yaqzan inspired the Andalusian Muslim philosopher Ibn Tufayl to write a book with the same theme and title. Ibn Sina’s allegory was translated into Hebrew by the Spanish Jewish poet, philosopher and scholar, Abraham ben Ezra, who used it to write a poetic work called Hay ben Meqitz. Aaron W. Hughes writes of the allegories of Ibn Sina, Ibn Tufayl and Abraham ben Ezra in The Texture of the Divine: ‘All three are highly literate accounts that offer elaborate descriptions of the structure of the universe and the changing role of the individual within it. All three texts poetically describe the protagonist’s intellectual and mystical ascent, and all culminate in the protagonist’s imaginative apprehension of the divine.’
‘Ala’ al-Dawlah captured Hamadan in 1023, forcing Saman al-Dawlah and Taj al-Mulk to flee to Fardjan, joining Ibn Sina. When ‘Ala’ al-Dawlah withdrew Sama’ al-Dawlah and his vizier returned to Hamadan, along with Ibn Sina, who went to live there with an old friend to whom he dedicated a treatise on Cardiac Therapies that he wrote soon after his return.
While Ibn Sina was at Hamadan he completed the Qanun, his major work on medicine, which comes to about a million words, divided into five books. Book I, ‘Generalities’, is devoted to a discussion of medical theories such as that of the four humours (blood, bile, black bile and phlegm), the causes and symptoms of disease, hygiene, modes of therapy, treatment by regimes and diet, the use of drugs, and the procedures involved in cupping, blood-letting, cautery, evacuation and general surgery. Book II, ‘Materia Medica’, is a survey of the properties and uses of some 760 drugs, as well as the application to medicine of his scientific method, in which he favoured empirical methods over abstraction and formalism. Book III, ‘Head to Toe Diseases’, discusses diseases of organs or systems, twenty-one in all, including the brain, nerves, eyes, ears, joints and even the nails of the fingers and toes. Book IV, ‘Diseases That are not Specific to Organs’, begins with a treatise on fevers, their types and symptoms; it then goes on to teach minor surgery and the treatment of wounds, sprains, dislocations, poisons, bites by insects, snakes and animals, and skin diseases. Book V, ‘Compound Drugs’, is a manual of pharmacology as an integral part of medical practice.
Ibn Sina codified Greek medical knowledge translated into Arabic in his Qanun, basing, for example, his description of anatomy and physiology principally on Galen and his Materia Medica on Dioscorides. His Qanun remained the most popular medical textbook for six centuries, not only in the Muslim world but also in Christian Europe. It was first translated into Latin as the Canon Medicinae between 1150 and 1187 by Gerard of Cremona, and in the last three decades of the fifteenth century it was published in fifteen printed editions along with one in Hebrew. Another twenty editions of the Canon were printed in the sixteenth century and several more in the seventeenth century along with one in Arabic issued in Rome in 1593.
Da Monte, in his commentary on the Canon published in 1554, said that Avicenna, as he was known in Latin, had written his text ‘because he saw that neither the Greeks nor the Arabs had any book that could teach the art of medicine as an integrated and connected subject’. It was still used as a textbook in the medical school at Montpellier as late as 1650. Although Ibn Sina’s adoption of the ancient theory of the four humours makes the theoretical basis of the Canon seem preposterous today, as does his cures for ailments such as werewolfism. But as an encyclopedia of medicine as a teaching discipline, divided into practical and theoretical medicine the Canon remained unsurpassed up until the beginning of the twentieth century, at least according to the opinion of Professor John Urquhart. Writing in the British Medical Journal in 2006, Urquhart said: ‘If the year were 1900 and you were marooned and in need of a guide for practical medicine, which book would you want by your side? My choice was Ibn Sina.’
Meanwhile Ibn Sina resumed his secret correspondence with ‘Ala’ al-Dawlah, who promised to give him refuge. Al-Juzjani describes how he and Ibn Sina fled from Hamadan disguised as dervishes and made their way to the emir’s court in Isfahan, where he received a royal welcome. ‘At court he was received with the respect and consideration he so richly merited. ‘Ala’ al-Dawlah appointed every Friday night a meeting for learned discussion before him, to be attended by all the scholars according to their various degrees, the Master Abu Ali among them; in these gatherings he proved himself quite supreme and unrivalled in every branch of learning.’
‘Ala’ al-Dawlah made Ibn Sina a vizier, a rank that he held for the rest of his days, often accompanying the emir on campaign. The Muslim scholar Bayhaqi (d. 1174) writes of Ibn Sina’s attractive appearance and manner when he paid court to ‘Ala’ al-Dawlah: ‘He used to sit very close to the Emir, whose face became radiant with delight as he marveled at his good looks, and accomplishment and wit. And when he spoke all those present listened attentively, none uttering a word.’
On one of these campaigns, when ‘Ala’ al-Dawlah defeated the Kurds in 1027, Ibn Sina completed the Shifa’, which he had been working on for more than seven years. According to al-Juzjani, he also worked on the Kitab al-Najah while on that campaign: ‘So he finished the Shifa’, all but the botany and zoology, which he composed in the year when ‘Ala’ al-Dawlah marched to Sabur-Khwast; these parts he wrote en route, as well as the Kitab al-Najah.’
The organisation of the Shifa’ follows the Aristotelian tradition for the classification of the sciences, which Ibn Sina had presented in the Compendium on the Soul, the Compilation, and undoubtedly also in The Available and the Valid. Ibn Sina’s prologue outlines the contents of his work, noting that it dealt with Aristotle’s logic and physics, Euclid’s geometry, Ptolemy’s astronomy, and the Introduction to Arithmetic by Nicomachus, after which he says ‘I then concluded the discipline of the mathematicians with an abridgment of the science of Music...Finally, I concluded the book with the science that belongs to Metaphysics in accord with its parts and aspects, while referring in it [only] to the essential elements of Ethics and Politics.’
The first sections of the Shifa’ to appear in Latin were the commentaries on Aristotle’s logic, on De anima, and on the Physica, which in the second half of the twelfth century were translated as the Sufficientia Physicorum by Domenicus Gundissalinus, the archdeacon of Segovia, working in collaboration with a converted Spanish Jew named Abraham ben Daud.
Around 1200 the English scholar Albert of Sareschal translated part of the Mineralogy section of the Shifa’ into Latin under the title De Mineralibus. Ibn Sina’s ideas about the formation of stones, mountains and fossils given there in the geological sections are remarkably accurate. He writes of how mountains became ‘petrified in the course of ages, the limits of which history has not preserved’. He goes on to say that it is because mountains are formed from earth that was formerly beneath the sea ‘that in many places, when they are broken, are found parts of aquatic animals such as shells, etc’.
Ibn Sina’s observations on the formation of stones, mountains and fossils were picked up by Albertus Magnus in the thirteenth century in his commentary on De Mineralibus, from which they were passed on to Leonardo da Vinci and other European scholars in the sixteenth and seventeenth centuries.
After completing the Shifa’ he began writing a treatise called an-Najat, or The Salvation, which he completed that same year, using mostly material from works he had previously written. He says that he composed this in response to a request from friends, who had asked him to write a book that contained the absolute minimum of philosophical and scientific knowledge that an educated person should have ‘to attain salvation from drowning in a sea of errors’.
He also composed a work in Persian called Daneshname-ye ‘Ala’i for ‘Ala’ al-Dawlah, who had asked him for a digest of logic, physics, metaphysics, astronomy and music, of which he wrote only the first three. Here he acknowledges his debt to Aristotle, ‘the leader of the wise and the guide and teacher of philosophers’.
Al-Juzjani added sections on astronomy and music as well as on arithmetic and geometry, thus completing the mathematical quadrivium.
Ibn Sina’s last work of philosophical summation is his Pointers and Reminders, written sometime between 1030 and 1034. It consists of two parts, the first on Logic, the second on Physics and Metaphysics, each divided into ten chapters. He describes the book in the prologue to the first part: ‘O you who are anxious to Ascertain the Truth: I have exposed to you in these Pointers and Reminders, Fundamental Principles and essential elements of philosophy; if sagacity takes hold of your hand it will become easy for you to Derive Corollary Principles from the former and work out the details of the latter.’
The two collections of writings known as Appendices: Notes and Discussions were probably completed in 1037, the year that Ibn Sina died. The Notes is a collection of writings in logic, physics and metaphysics, while the Discussions comprises philosophical questions and Ibn Sina’s answers. Ibn Sina refers to the Appendices in the prologue to the Shifa’, which he wrote long after the work itself was completed: ‘Then I thought it appropriate that I should write another book to follow this one. I have called it Appendices, and it will end with my life, finding its termination in whatever will have been completed every year. It is like a commentary to this book, Providing Corollaries to its Fundamental Principles and elaborating upon its briefly expressed concepts.’
When ‘Ala’ al-Dawlah went off to make war on the Ghaznavids in 1037 Ibn Sina accompanied him throughout the campaign, though he suffered a severe attack of colic, which he tried to treat himself. Al-Juzjani tells of how Ibn Sina, despite his illness, continued to serve the emir to the end, passing away in June 1037 after a march from Isfahan to Hamadan.
He once more attended the court of ‘Ala’ al-Dawlah; however, he was incautious and indulged his sexual appetite too far, so that he was never wholly cured, suffering repeated relapses...He therefore gave up treating himself, and took to saying, ‘The manager who used to manage me is incapable of managing me any more; so it is no use trying to cure my sickness. So he continued some days, and was then transported to the Presence of his Lord. He was buried at Hamadhan, being 58 years old.
Ibn Sina’s medical writings were translated into Latin and used as basic texts in Europe’s medical schools until the seventeenth century. His Canon of Medicine was far ahead of its times in dealing with such matters as cancer treatment, the influence of the environment, the beneficial effects of physical exercise, and the need for psychotherapy, where he recognised the connection between emotional and physical states, including the heartache of unrequited love.
Ibn Sina wrote on light and the theory of vision in a number of his works, including the Shifa’, Najat, Qanun and Danishnama. He defended the Aristotelian intromission theory of vision, in which the visual rays proceed from the luminous object to the eye.
Ibn Sina was the first Muslim scientist to revive the impetus theory of John Philoponus, an attempt to explain why a projectile continues to move after it is fired. He described this impetus as ‘a quality by which the body pushes that which prevents it moving itself in any direction’. He also calls it an ‘impressed force’, and describes it as a ‘borrowed power’ given to the projectile by the source of motion, ‘just as heat is given to water by a fire’. The fourteenth-century French physicist Jean Buridan used the term ‘impetus impressus’, defined as weight times velocity, revived by Galileo under the names ‘impeto’ and ‘momento’, which is proportional to the modern ‘momentum’, or mass times velocity. Newton’s second law of motion, the basis of the new dynamics that he introduced in his Principia, published in 1687, says that the force acting on a body is proportional to the time rate of change of momentum.
One of Ibn Sina’s most influential followers was Sayyid Zayn al-Din al-Juzjani (d. ca. 1070), who came from the Central Asian region of Khwarazm. His principal work is the Treasury Dedicated to the King of Khwarazm, a medical encyclopedia based on Ibn Sina’s Canon, written in Persian, which contributed to the establishment of the scientific terminology for medicine, including pharmacology. Al-Juzjani’s other writings include his Medical Memoranda and The Aims of Medicine, which, along with his Treasury, were the principal sources for the perpetuation of the medical teachings of Ibn Sina and his predecessors.
Al-Juzjani is remembered principally because of his association with Ibn Sina, whose tomb can still be seen in Hamadan. Ibn Sina had immense influence on the subsequent development of philosophy and medicine, both in the Islamic world and in Latin Europe. His ideas, which combined Platonic and Aristotelian concepts, had a profound effect on western thought in the thirteenth century.
Ibn Sina’s accomplishments led A. C. Crombie to say ‘I think we can agree with Roger Bacon’s judgment that in its natural branches, Avicenna was “the man who completed philosophy as far as it was possible for him to do so”.’ Ibn Sina was also a gifted poet, as is evident from the verses of his Poem on the Soul quoted by A. J. Arberry, who ranks them ‘among the sublimest composed in any language’.
Out of her lofty home she hath come down
Upon thee, this white dove in all the pride
Of her reluctant beauty; veiled is she
From every eye eager to know her, though
In loveliness unshrouded radiant....
And if the tangled net impeded her,
The narrow cage denied her wings to soar
Freely in heaven’s high ranges, after all
She was a lightning-flash that brightly glowed
Momentarily o’er the tents, and then was hid
As though its gleam was never glimpsed below.