Avicenna (AKA Ibn Sina or Ibn Seena or, in full, Abu Ali al-Hussain Ibn Abdallah Ibn Sina) (980 – 1037) was a Persian philosopher, physician and polymath in the Medieval period (Islam’s Golden Age).
He was one of the most learned men of his time in a wide variety of subjects, and is often considered one of the greatest thinkers and scholars in history. In particular, he is regarded by many as the father of early modern medicine.
As a philosopher and a devout Muslim, he tried to reconcile the rational philosophy of Aristotelianism and Neo-Platonism with Islamic theology. He also developed his own system of Logic, known as Avicennian Logic, and founded the philosophical school of Avicennism, which was highly influential among Muslim and Western European Scholastic thinkers alike.
Avicenna (the Latinized distortion of the actual Arab name Ibn Sina) was born around 980 in his mother’s home town of Afshana, near Bukhara (then part of the extensive Persian empire, now in modern-day Uzbekistan, Central Asia). His father was a respected Ismaili scholar fom Balkh (in modern-day Afghanistan, but then also part of the Persian empire), a high official of the Samanid administration and, at the time of his son’s birth, the governor of a village in one of the estates of the Samanid emir, Nuh ibn Mansur.
We have details of much of Avicenna’s early life from his own autobiography. In his early years, he was educated by his father, and he had a remarkable memory and an ability to learn which amazed the scholars who met in his father’s home. By the age of ten he had memorised the Qur’an and most of the Persian and Arabic poetry which he had read; he learned jurisprudence at an early age from the Hanafi scholar Ismail al-Zahid; at thirteen he began to study medicine, and he had mastered that subject by the age of sixteen, when he began to treat patients (often without taking payment) and to discover new methods of treatment; by eighteen, he had achieved full status as a qualified physician. He also studied Logic and Metaphysics, partly on his own (he prided himself on being self-taught) but also receiving instruction from some of the best teachers of his day, including the famous mathematician Abu ‘Abdallah al-Natili among others.
Due to his reputation as a physician in that area, the Samanid dynasty ruler Nuh ibn Mansur came to hear of him, and as a reward for curing the emir of an illness in 997, Avicenna was granted the use the Royal Library of the Samanids, which proved important for his further development in the whole range of scholarship.
In 1002, Avicenna’s father died and then, soon after, the Samanids were deposed by the Turkish Qarakhanids. Avicenna declined the offers of new ruler Mahmud of Ghazni and, without the support of a patron or his father, he began a life of wandering around the towns of Nishapur, Merv and Khorasan. He acted as a physician and administrator by day, while every evening he gathered studentsround him for philosophical and scientific discussion. For a period he was court physician and vizier at Hamadan (west-central Iran), despite threats of banishment by the emir, and at one point he was forced into hiding and even spent some time as a political prisoner. He began his two most important medical works (“The Book of Healing” and “The Canon of Medicine”) during his time at Hamadan.
In 1022, on the death of the Buwayhid prince Shams al-Daula who he was serving in Hamadan and the ensuing political chaos, Avicenna dramatically escaped out of the city in the dress of a Sufi ascetic. After ten years of constantly moving from place to place, amidst political turmoil and uncertainty, he finally settled in Isfahan in central Iran, at the court of the local prince Abu Ja’far ‘Ala Addaula, whom he accompanied as physician and general literary and scientific adviser. During a fifteen year period of relative calm and peace, he completed his major works begun at Hamadan, and also wrote many other works on philosophy, medicine and the Arabic language.
While accompanying his patron on one of his many military campaigns (as his duties required), Avicenna was seized with a severe colic, which he was unable to check with his own remedies. He managed to reach Hamadan, where he finally resigned himself to his fate, gave away his goods on the poor, freed his slaves, and finally died in June of 1037.
Avicenna wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived (150 of these concentrate on philosophy and 40 on medicine). Almost half of his works are versified, his poems appearing in both Arabic and Persian. His most famous works are “The Book of Healing” (a vast philosophical and scientific encyclopedia) and “The Canon of Medicine” (a standard medical text at many Islamic and European universities up until the early 19th Century).
Avicenna wrote extensively on early Islamic philosophy, including two treatises named “Logic” and “Metaphysics”. His commentaries on the works of Aristotle often “corrected” the philosopher, encouraging a lively debate in the spirit of ijtihad(a term used in Islamic law describing independent interpretation of the sources). Due to the success of Avicenna’s reconciliation of Aristotelianism and Neo-Platonism with Islamic Kalam, Avicennism became the leading school of Islamic philosophy by the 12th Century. His philosophy was also influential in medieval Europe: even if it was proscribed in 1210, it nevertheless had a great impact on leading Scholastics such as William of Auvergne (1190 – 1249), Albertus Magnus and St. Thomas Aquinas.
Avicenna’s Metaphysics owes much to his 10th Century Persian predecessor al-Farabi (particularly as regards the thorny issue of essence and existence), but also to Aristotle. His early work “Compendium on the Soul” was dedicated to establishing that the rational soul or intellect is incorporeal and indestructible, without resorting to Neo-Platonic insistence on its pre-existence (i.e. “essence precedes existence”).
According to Avicenna, the universe consists of a chain of actual beings, each giving existence to, and responsible for, the rest of the chain below (angels, souls and all of creation). He argued that, as an infinite chain is impossible, the chain as a whole must terminate in a being that is wholly simple, self-sufficient and one, whose essence is its very existence (i.e. God). This is a combination of the Ontological Argumentand Cosmological Argument for the existence of God (see the section on Philosophy of Religion), and a very early use of the method of a priori proof, utilizing intuition and reason alone.
Avicenna developed his own system of Logic, known as Avicennian Logic, as an alternative to Aristotelian Logic, and by the 12th Century it had replaced Aristotelian Logic as the dominant system in the Islamic world. Avicennian Logic had an influence on early medieval European logicians such as Albertus Magnus, although Aristotelian Logic later became more popular in Europe with the strong influence of Averroës. Avicenna developed an early theory of the hypothetical syllogism as well as propositional calculus, an area of Logic not covered in the Aristotelianism tradition. He also contributed inventively to the development of inductive logic, mainly through his medical writings.
In Epistemology, Avicenna developed the concept of the tabula rasa (the idea that individual human beings are born with no innate or built-in mental content), which strongly influenced later Empiricists like John Locke, and the nature versus nurture debate in modern philosophy and psychology. He developed a theory of knowledge based on four faculties: sense perception, retention, imagination and estimation. He was also the first to describe the methods of agreement, difference and concomitant variation which are critical to inductive logic and the scientific method, which was essential to later scientific methodology.
While he was imprisoned near Hamadan, Avicenna formulated his famous “Floating Man” thought experiment to demonstrate human self-awareness and the substantiality of the soul. He asked his readers to imagine themselves suspended in the air, isolated from all sensations, even sensory contact with their own bodies. He argued that one would still have self-consciousness, and so the self is not logically dependent on any physical thing, and the soul is therefore a primary or given substance.
Avicenna developed a medical system that combined his own personal experience with that of Islamic medicine, the medical system of the Greek physicians Hippocrates (460 – 370 B.C.) and Galen (129 – 200 A.D.), and ancient Persian, Mesopotamian and Indian medicine. In particular, he is credited with: the introduction of systematic experimentation and quantification into the study of physiology; the discovery of the contagious nature of infectious diseasesand the introduction of quarantine to limit the spread of contagious diseases; the introduction of experimental medicine and the establishment of rules and principles for testing the effectiveness of new drugs and medications (which still form the basis of clinical pharmacology and modern clinical trials); the discovery of the concept of syndromes; the identification of the importance of dietetics and the influence of climate and environment on health; the pioneering of aromatherapy treatment; the anticipation of the existence of micro-organisms; and early work on psychology, neuropsychiatry, psychophysiology and psychosomatic medicine (he first described numerous neuropsychiatric conditions such as hallucination, insomnia, mania, nightmare, melancholia, dementia, epilepsy, paralysis, stroke, vertigo and tremor).
In the physical sciencs, he is considered the father of the fundamental concept of momentum (part of his elaborate theory of motion), and was the first to employ an air thermometer to measure air temperature in scientific experiments. He was the first to successfully classify simple machines (lever, pulley, screw, wedge and windlass) and their combinations. He reasoned that the speed of light is finite, on the grounds that the perception of light is due to the emission of some sort of particles, a very prescient notion. In earth sciences, his hypotheses on the geological causes of mountains came very close to the truth many centuries before it was proven.
As a strict believer in Empiricism, he refuted the study of astrology as being conjectural rather than empirical (and anyway conflicting with orthodox Islam). He also refuted alchemy and discredited the theory of the transmutation of substances commonly believed by the alchemists of the day.