Avicenna - Father of modern Medicine
Abu Ali Sina or, more commonly, Ibn Sina, and commonly known in English by his Latinized name Avicenna (c. 980 - 1037) was a Persian polymath and the foremost physician and philosopher of his time. He was also an astronomer, chemist, geologist, logician, paleontologist, mathematician, physicist, poet, psychologist, scientist and teacher.
Ibn Sina studied medicine under a physician named Koushyar. He wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived. In particular, 150 of his surviving treatises concentrate on philosophy and 40 of them concentrate on medicine. His most famous works are The Book of Healing, a vast philosophical and scientific encyclopaedia, and The Canon of Medicine, which was a standard medical text at many medieval universities. The Canon of Medicine was used as a text-book in the universities of Montpellier and Louvain as late as 1650.
Ibn Sina developed a medical system that combined his own personal experience with that of Islamic medicine, the medical system of the Greek physician Galen, Aristotelian metaphysics (Avicenna was one of the main interpreters of Aristotle), and ancient Persian, Mesopotamian and Indian medicine. Ibn Sina is considered a father of modern medicine, and clinical pharmacology particularly for his introduction of systematic experimentation and quantification into the study of physiology, his discovery of the contagious nature of infectious diseases, the introduction of quarantine to limit the spread of contagious diseases, the introduction of experimental medicine, evidence-based medicine, clinical trials, randomized controlled trials, efficacy tests, clinical pharmacology,[25] neuropsychiatry, risk factor analysis, the idea of the syndrome, and the importance of dietetics and the influence of climate and environment on health.
He was also the founder of Avicennian logic and the philosophical school of Avicennism, which were influential among both Muslim and Scholastic thinkers. He is also considered the father of the fundamental concept of momentum in physics, and regarded as a pioneer of aromatherapy for his invention of steam distillation and extraction of essential oils. He also developed the concept of uniformitarianism and law of superposition in geology, for which he is considered to be the 'father of geology'.
Avicenna created an extensive corpus of works during what is commonly known as Islam's Golden Age, in which the translations of Graeco-Roman, Neo- and Mid-Platonic, and Aristotelian texts by the Kindi schools were commented, redacted and developed substantially by Islamic intellectuals, as well as building upon Persian and Indian mathematical systems, astronomy, algebra, trigonometry, and medicine. The Samanid dynasty in Greater Khorasan and central Asia as well as Buwayhid in the western part of Persia and Iraq could provide a thriving atmosphere for scholarly and cultural development. Under the Samanids, Bukhara rivalled Baghdad as a cultural capital of Islam.
The study of Quran and Hadith thrived in such a scholarly atmosphere. Philosophy Fiqh and theology kalam were further developed, most noticeably by Avicenna and his opponents. al-Razi and Al-Farabi had provided methodology and knowledge in medicine and philosophy. Avicenna could use the great libraries of Balkh, Khwarezm, Gorgan, Rey, Isfahan and Hamedan. As various texts, such as the 'Ahd with Bahmanyar show, he debated philosophical points with the greatest scholars of the time. As Aruzi Samarqandi describes in his four articles before Avicenna left Khwarezm he had met Abu Rayhan Biruni (a noted scientist and astronomer), Abu Nasr Iraqi (a renowned mathematician), Abu Sahl Masihi (a respected philosopher) and Abu al-Khayr Khammar (a great physician).
Medicine and pharmacology
Though the threads which comprise Unani healing can be traced all the way back to Claudius Galenus of Pergamum, who lived in the second century of the Christian Era, the basic knowledge of Unani medicine as a healing system was developed by Hakim Ibn Sina in his medical encyclopedia The Canon of Medicine. The time of origin is thus dated at circa 1025 AD, when Avicenna wrote The Canon of Medicine in Persia. While he was primarily influenced by Greek and Islamic medicine, he was also influenced by the Indian medical teachings of Sushruta and Charaka.
The Canon of Medicine
About 100 treatises were ascribed to Ibn Sina. Some of them are tracts of a few pages, others are works extending through several volumes. The best-known amongst them, and that to which Ibn Sina owed his European reputation, is his 14-volume The Canon of Medicine, which was a standard medical text in Europe and the Islamic world up until the 18th century. The book is known for its introduction of systematic experimentation and quantification into the study of physiology, the discovery of contagious diseases and sexually transmitted diseases, the introduction of quarantine to limit the spread of infectious diseases, the introduction of experimental medicine, clinical trials, neuropsychiatry, risk factor analysis, and the idea of a syndrome in the diagnosis of specific diseases,[28] and hypothesized the existence of microrganisms. It classifies and describes diseases, and outlines their assumed causes. Hygiene, simple and complex medicines, and functions of parts of the body are also covered. In this, Ibn Sina is credited as being the first to correctly document the anatomy of the human eye, along with descriptions of eye afflictions such as cataracts. It asserts that tuberculosis was contagious, which was later disputed by Europeans, but turned out to be true. It also describes the symptoms and complications of diabetes. Both forms of facial paralysis were described in-depth. In addition, the workings of the heart as a valve are described.
The Canon of Medicine was the first book dealing with experimental medicine, evidence-based medicine, randomized controlled trials, and efficacy tests, and it laid out the following 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 drug must be free from any extraneous accidental quality.
- It must be used on a simple, not a composite, disease.
- The drug must be tested with two contrary types of diseases, because sometimes a drug cures one disease by Its essential qualities and another by its accidental ones.
- The quality of the drug must correspond to the strength of the disease. For example, there are some drugs whose heat is less than the coldness of certain diseases, so that they would have no effect on them.
- The time of action must be observed, so that essence and accident are not confused.
- The effect of the drug must be seen to occur constantly or in many cases, for if this did not happen, it was an accidental effect.
- The experimentation must be done with the human body, for testing a drug on a lion or a horse might not prove anything about its effect on man.
- An Arabic edition of the Canon appeared at Rome in 1593, and a Hebrew version at Naples in 1491. Of the Latin version there were about thirty editions, founded on the original translation by Gerard de Sabloneta. In the 15th century a commentary on the text of the Canon was composed. Other medical works translated into Latin are the Medicamenta Cordialia, Canticum de Medicina, and the Tractatus de Syrupo Acetoso.
It was mainly accident which determined that from the 12th to the 18th century, Ibn Sina should be the guide of medical study in European universities, and eclipse the names of Rhazes, Ali ibn al-Abbas and Averroes. His work is not essentially different from that of his predecessor Rhazes, because he presented the doctrine of Galen, and through Galen the doctrine of Hippocrates, modified by the system of Aristotle, as well as the Indian doctrines of Sushruta and Charaka.But the Canon of Ibn Sina is distinguished from the Al-Hawi (Continens) or Summary of Rhazes by its greater method, due perhaps to the logical studies of the former. Avicenna extended the theory of temperaments in The Canon of Medicine to encompass "emotional aspects, mental capacity, moral attitudes, self-awareness, movements and dreams."
The work has been variously appreciated in subsequent ages, some regarding it as a treasury of wisdom, and others, like Averroes, holding it useful only as waste paper. In modern times it has been mainly of historic interest as most of its tenets have been disproved or expanded upon by scientific medicine. The vice of the book is excessive classification of bodily faculties, and over-subtlety in the discrimination of diseases. It includes five books; of which the first and second discuss physiology, pathology and hygiene, the third and fourth deal with the methods of treating disease, and the fifth describes the composition and preparation of remedies. This last part contains some personal observations.
He is ample in the enumeration of symptoms, and is said to be inferior in practical medicine and surgery. He introduced into medical theory the four causes of the Peripatetic system. Of natural history and botany he pretended to no special knowledge. Up to the year 1650, or thereabouts, the Canon was still used as a textbook in the universities of Leuven and Montpellier.
In the museum at Bukhara, there are displays showing many of his writings, surgical instruments from the period and paintings of patients undergoing treatment. Ibn Sina was interested in the effect of the mind on the body, and wrote a great deal on psychology, likely influencing Ibn Tufayl and Ibn Bajjah. He also introduced medical herbs.
Avicennian psychology
In Muslim psychology and the neurosciences, Avicenna was a pioneer of neuropsychiatry. He first described numerous neuropsychiatric conditions, including hallucination, insomnia, mania, nightmare, melancholia, dementia, epilepsy, paralysis, stroke, vertigo and tremor.
Avicenna was also a pioneer in psychophysiology and psychosomatic medicine. He recognized 'physiological psychology' in the treatment of illnesses involving emotions, and developed a system for associating changes in the pulse rate with inner feelings, which is seen as an anticipation of the word association test attributed to Carl Jung. Avicenna is reported to have treated a very ill patient by "feeling the patient's pulse and reciting aloud to him the names of provinces, districts, towns, streets, and people." He noticed how the patient's pulse increased when certain names were mentioned, from which Avicenna deduced that the patient was in love with a girl whose home Avicenna was "able to locate by the digital examination." Avicenna advised the patient to marry the girl he is in love with, and the patient soon recovered from his illness after his marriage.
Avicenna's legacy in classical psychology is primarily embodied in the Kitab al-nafs parts of his Kitab al-shifa' (The Book of Healing) and Kitab al-najat (The Book of Deliverance). These were known in Latin under the title De Anima (treatises "on the soul"). The main thesis of these tracts is represented in his so-called "flying man" argument, which resonates with what was centuries later entailed by Descartes's cogito argument (or what phenomenology designates as a form of an "epoche").
In the The Canon of Medicine, Avicenna dealt with neuropsychiatry and described a number of neuropsychiatric conditions, including melancholia. He described melancholia as a depressive type of mood disorder in which the person may become suspicious and develop certain types of phobias.
Astronomy and astrology
The study of astrology was refuted by Avicenna. His reasons were both due to the methods used by astrologers being conjectural rather than empirical and also due to the views of astrologers conflicting with orthodox Islam. He also cited passages from the Qur'an in order to justify his refutation of astrology on both scientific and religious grounds.
In astronomy, he criticized Aristotle's view of the stars receiving their light from the Sun. Ibn Sina stated that the stars are self-luminous, and believed that the planets are also self-luminous. On May 24, 1032, he observed the transit of Venus. Soon after, he wrote the Compendium of the Almagest, a commentary on Ptolemy's Almagest. Avicenna concluded that Venus is closer to the Earth than the Sun. In 1070, Abu Ubayd al-Juzjani, a pupil of Ibn Sina, claimed that his teacher Ibn Sina had solved the equant problem in the Ptolemaic model.
Chemistry
In chemistry, the chemical process of steam distillation was first described by Ibn Sina. The technique was used to produce alcohol and essential oils; the latter was fundamental to aromatherapy. He also invented the refrigerated coil, which condenses the aromatic vapours. This was a breakthrough in distillation technology and he made use of it in his steam distillation process, which requires refrigerated tubing, to produce essential oils.
As a chemist, Avicenna was one of the first to write refutations on alchemy, after al-Kindi. Four of his works on the refutation of alchemy were translated into Latin as:
Liber Aboali Abincine de Anima in arte Alchemiae
Declaratio Lapis physici Avicennae filio sui Aboali
Avicennae de congelatione et conglutinatione lapifum
Avicennae ad Hasan Regem epistola de Re recta
In one of these works, Ibn Sina discredited the theory of the transmutation of substances commonly believed by alchemists:
Those of the chemical craft know well that no change can be effected in the different species of substances, though they can produce the appearance of such change.
Among his works refuting alchemy, Liber Aboali Abincine de Anima in arte Alchemiae was the most influential, having influenced later medieval chemists and alchemists such as Vincent of Beauvais.
In another work, translated into Latin as De congelatione et conglutinatione lapidum, Ibn Sina proposed a four-part classification of inorganic bodies, which was a significant improvement over the two-part classification of Aristotle (into orycta and metals) and three-part classification of Galen (into terrae, lapides and metals). The four parts of Ibn Sina's classification were: lapides, sulfur, salts and metals.
Earth sciences
Ibn Sina wrote on Earth sciences such as geology in The Book of Healing, in which he developed the concept of uniformitarianism and law of superposition in geology.While discussing the formation of mountains, he explained:
Either they are the effects of upheavals of the crust of the earth, such as might occur during a violent earthquake, or they are the effect of water, which, cutting itself a new route, has denuded the valleys, the strata being of different kinds, some soft, some hard... It would require a long period of time for all such changes to be accomplished, during which the mountains themselves might be somewhat diminished in size.
Due to his fundamental contributions to the development of geology, particularly regarding the origins of mountains, Avicenna has been called the 'Father of Geology'.
Physics
In physics, Ibn Sina was the first to employ an air thermometer to measure air temperature in his scientific experiments.In 1253, a Latin text entitled Speculum Tripartitum stated the following regarding Avicenna's theory on heat:
Avicenna says in his book of heaven and earth, that heat is generated from motion in external things.
In mechanics, Ibn Sina developed an elaborate theory of motion, in which he made a distinction between the inclination (tendency to motion) and force of a projectile, and concluded that motion was a result of an inclination (mayl) transferred to the projectile by the thrower, and that projectile motion in a vacuum would not cease. He viewed inclination as a permanent force whose effect is dissipated by external forces such as air resistance.
His theory of motion was thus consistent with the concept of inertia in Newton's first law of motion.[65] Ibn Sina also referred to mayl to as being proportional to weight times velocity, a precursor to the concept of momentum in Newton's second law of motion. Ibn Sina's theory of mayl was further developed by Jean Buridan in his theory of impetus.
In optics, Ibn Sina "observed that if the perception of light is due to the emission of some sort of particles by a luminous source, the speed of light must be finite."He also provided a wrong explanation of the rainbow phenomenon. Carl Benjamin Boyer described Avicenna's ("Ibn Sina") theory on the rainbow as follows:
Independent observation had demonstrated to him that the bow is not formed in the dark cloud but rather in the very thin mist lying between the cloud and the sun or observer. The cloud, he thought, serves simply as the background of this thin substance, much as a quicksilver lining is placed upon the rear surface of the glass in a mirror. Ibn Sina would change the place not only of the bow, but also of the color formation, holding the iridescence to be merely a subjective sensation in the eye.
Ibn Sina wrote extensively on early Islamic philosophy, especially the subjects logic, ethics, and metaphysics, including treatises named Logic and Metaphysics. Most of his works were written in Arabic - which was the de facto scientific language of that time, and some were written in the Persian language. Of linguistic significance even to this day are a few books that he wrote in nearly pure Persian language (particularly the Danishnamah-yi 'Ala', Philosophy for Ala' ad-Dawla'). Ibn Sina's commentaries on Aristotle often corrected the philosopher, encouraging a lively debate in the spirit of ijtihad.
In the medieval Islamic world, due to Avicenna's successful reconciliation between Aristotelianism and Neoplatonism along with Kalam, Avicennism eventually became the leading school of Islamic philosophy by the 12th century, with Avicenna becoming a central authority on philosophy.
Avicennism was also influential in medieval Europe, particular his doctrines on the nature of the soul and his existence-essence distinction, along with the debates and censure that they raised in scholastic Europe. This was particularly the case in Paris, where Avicennism was later proscribed in 1210. Nevertheless, his psychology and theory of knowledge influenced William of Auvergne and Albertus Magnus, while his metaphysics had an impact on the thought of Thomas Aquinas.
Metaphysical doctrine
Early Islamic philosophy, imbued as it is with Islamic theology, distinguishes more clearly than Aristotelianism the difference between essence and existence. Whereas existence is the domain of the contingent and the accidental, essence endures within a being beyond the accidental. The philosophy of Ibn Sina, particularly that part relating to metaphysics, owes much to al-Farabi. The search for a truly definitive Islamic philosophy can be seen in what is left to us of his work.
Following al-Farabi's lead, Avicenna initiated a full-fledged inquiry into the question of being, in which he distinguished between essence (Mahiat) and existence (Wujud). He argued that the fact of existence can not be inferred from or accounted for by the essence of existing things and that form and matter by themselves cannot interact and originate the movement of the universe or the progressive actualization of existing things. Existence must, therefore, be due to an agent-cause that necessitates, imparts, gives, or adds existence to an essence. To do so, the cause must be an existing thing and coexist with its effect.
Avicenna’s consideration of the essence-attributes question may be elucidated in terms of his ontological analysis of the modalities of being; namely impossibility, contingency, and necessity. Avicenna argued that the impossible being is that which cannot exist, while the contingent in itself (mumkin bi-dhatihi) has the potentiality to be or not to be without entailing a contradiction. When actualized, the contingent becomes a ‘necessary existent due to what is other than itself’ (wajib al-wujud bi-ghayrihi). Thus, contingency-in-itself is potential beingness that could eventually be actualized by an external cause other than itself. The metaphysical structures of necessity and contingency are different. Necessary being due to itself (wajib al-wujud bi-dhatihi) is true in itself, while the contingent being is ‘false in itself’ and ‘true due to something else other than itself’. The necessary is the source of its own being without borrowed existence. It is what always exists. The Necessary exists ‘due-to-Its-Self’, and has no quiddity/essence (mahiyya) other than existence (wujud). Furthermore, It is ‘One’ (wahid ahad) since there cannot be more than one ‘Necessary-Existent-due-to-Itself’ without differentia (fasl) to distinguish them from each other. Yet, to require differentia entails that they exist ‘due-to-themselves’ as well as ‘due to what is other than themselves’; and this is contradictory. However, if no differentia distinguishes them from each other, then there is no sense in which these ‘Existents’ are not one and the same. Avicenna adds that the ‘Necessary-Existent-due-to-Itself’ has no genus (jins), nor a definition (hadd), nor a counterpart (nadd), nor an opposite (did), and is detached (bari’) from matter (madda), quality (kayf), quantity (kam), place (ayn), situation (wad’), and time (waqt).
Avicennian logic
Avicenna discussed the topic of logic in Islamic philosophy extensively in his works, and developed his own system of logic known as "Avicennian logic" as an alternative to Aristotelian logic. By the 12th century, Avicennian logic had replaced Aristotelian logic as the dominant system of logic in the Islamic world.[80] After the Latin translations of the 12th century, Avicennian logic was also influential in Europe.
Ibn Sina developed an early theory on hypothetical syllogism, which formed the basis of his early risk factor analysis. He also developed an early theory on propositional calculus, which was an area of logic not covered in the Aristotelian tradition. The first criticisms of Aristotelian logic were also written by Ibn Sina, who developed an original theory on temporal modal syllogism. Ibn Sina also contributed inventively to the development of inductive logic, being the first to describe the methods of agreement, difference and concomitant variation which are critical to inductive logic and the scientific method.
Natural philosophy
Ibn Sina and Abu Rayhan al-Biruni engaged in a written debate, with Abu Rayhan Biruni mostly criticizing Aristotelian natural philosophy and the Peripatetic school, while Avicenna and his student Ahmad ibn 'Ali al-Ma'sumi respond to Biruni's criticisms in writing. Abu Rayhan began by asking Avicenna eighteen questions, ten of which were criticisms of Aristotle's On the Heavens.
Philosophy of science
Further information: Avicennism, The Book of Healing, and The Canon of Medicine
In the Al-Burhan (On Demonstration) section of The Book of Healing, Avicenna discussed the philosophy of science and described an early scientific method of inquiry. He discusses Aristotle's Posterior Analytics and significantly diverged from it on several points. Avicenna discussed the issue of a proper methodology for scientific inquiry and the question of "How does one acquire the first principles of a science?" He asked how a scientist would arrive at "the initial axioms or hypotheses of a deductive science without inferring them from some more basic premises?" He explains that the ideal situation is when one grasps that a "relation holds between the terms, which would allow for absolute, universal certainty." Avicenna then adds two further methods for arriving at the first principles: the ancient Aristotelian method of induction (istiqra), and the method of examination and experimentation (tajriba). Avicenna criticized Aristotelian induction, arguing that "it does not lead to the absolute, universal, and certain premises that it purports to provide." In its place, he develops a "method of experimentation as a means for scientific inquiry."
Theology
Ibn Sina was a devout Muslim and sought to reconcile rational philosophy with Islamic theology. His aim was to prove the existence of God and his creation of the world scientifically and through reason and logic. Avicenna wrote a number of treatises dealing with Islamic theology. These included treatises on the Islamic prophets, whom he viewed as "inspired philosophers", and on various scientific and philosophical interpretations of the Qur'an, such as how Quranic cosmology corresponds to his own philosophical system.
Ibn Sina memorized the Qur'an by the age of seven, and as an adult, he wrote five treatises commenting on suras from the Qur'an. One of these texts included the Proof of Prophecies, in which he comments on several Quranic verses and holds the Qur'an in high esteem. Avicenna argued that the Islamic prophets should be considered higher than philosophers.
Thought experiments
While he was imprisoned in the castle of Fardajan near Hamadhan, Avicenna wrote his famous "Floating Man" thought experiment to demonstrate human self-awareness and the substantiality of the soul. He referred to the living human intelligence, particularly the active intellect, which he believed to be the hypostasis by which God communicates truth to the human mind and imparts order and intelligibility to nature. His "Floating Man" thought experiment tells its readers to imagine themselves suspended in the air, isolated from all sensations, which includes no sensory contact with even their own bodies. He argues that, in this scenario, one would still have self-consciousness. He thus concludes that the idea of the self is not logically dependent on any physical thing, and that the soul should not be seen in relative terms, but as a primary given, a substance.
Engineering
In the chapters on mechanics and engineering in his encyclopedia Mi'yar al-'aql (The Measure of the Mind), Avicenna writes an analysis on the ilm al-hiyal (science of ingenious devices) and makes the first successful attempt to classify simple machines and their combinations. He first describes and illustrates the five constituent simple machines: the lever, pulley, screw, wedge, and windlass. He then analyzes all the combinations of these simple machines, such as the windlass-screw, windlass-pulley and windlass-lever for example. He is also the first to describe a mechanism which is essentially a combination of all of these simple machines (except for the wedge).
Poetry
Almost half of Ibn Sina's works are versified. His poems appear in both Arabic and Persian. As an example, Edward Granville Browne claims that the following Persian verses are incorrectly attributed to Omar Khayyám, and were originally written by Ibn Sina:
Up from Earth's Centre through the Seventh Gate,
I rose, and on the Throne of Saturn sate,
And many Knots unravel'd by the Road,
But not the Master-Knot of Human Fate.
When some of his opponents blame him for blasphemy, he says.
The blasphemy of somebody like me is not easy and exorbitant,
There isn't any stronger faith than my faith,
If there is just one person like me in the world and that one is impious,
So there are no Muslims in the whole world.
Ibn Sina studied medicine under a physician named Koushyar. He wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived. In particular, 150 of his surviving treatises concentrate on philosophy and 40 of them concentrate on medicine. His most famous works are The Book of Healing, a vast philosophical and scientific encyclopaedia, and The Canon of Medicine, which was a standard medical text at many medieval universities. The Canon of Medicine was used as a text-book in the universities of Montpellier and Louvain as late as 1650.
Ibn Sina developed a medical system that combined his own personal experience with that of Islamic medicine, the medical system of the Greek physician Galen, Aristotelian metaphysics (Avicenna was one of the main interpreters of Aristotle), and ancient Persian, Mesopotamian and Indian medicine. Ibn Sina is considered a father of modern medicine, and clinical pharmacology particularly for his introduction of systematic experimentation and quantification into the study of physiology, his discovery of the contagious nature of infectious diseases, the introduction of quarantine to limit the spread of contagious diseases, the introduction of experimental medicine, evidence-based medicine, clinical trials, randomized controlled trials, efficacy tests, clinical pharmacology,[25] neuropsychiatry, risk factor analysis, the idea of the syndrome, and the importance of dietetics and the influence of climate and environment on health.
He was also the founder of Avicennian logic and the philosophical school of Avicennism, which were influential among both Muslim and Scholastic thinkers. He is also considered the father of the fundamental concept of momentum in physics, and regarded as a pioneer of aromatherapy for his invention of steam distillation and extraction of essential oils. He also developed the concept of uniformitarianism and law of superposition in geology, for which he is considered to be the 'father of geology'.
Avicenna created an extensive corpus of works during what is commonly known as Islam's Golden Age, in which the translations of Graeco-Roman, Neo- and Mid-Platonic, and Aristotelian texts by the Kindi schools were commented, redacted and developed substantially by Islamic intellectuals, as well as building upon Persian and Indian mathematical systems, astronomy, algebra, trigonometry, and medicine. The Samanid dynasty in Greater Khorasan and central Asia as well as Buwayhid in the western part of Persia and Iraq could provide a thriving atmosphere for scholarly and cultural development. Under the Samanids, Bukhara rivalled Baghdad as a cultural capital of Islam.
The study of Quran and Hadith thrived in such a scholarly atmosphere. Philosophy Fiqh and theology kalam were further developed, most noticeably by Avicenna and his opponents. al-Razi and Al-Farabi had provided methodology and knowledge in medicine and philosophy. Avicenna could use the great libraries of Balkh, Khwarezm, Gorgan, Rey, Isfahan and Hamedan. As various texts, such as the 'Ahd with Bahmanyar show, he debated philosophical points with the greatest scholars of the time. As Aruzi Samarqandi describes in his four articles before Avicenna left Khwarezm he had met Abu Rayhan Biruni (a noted scientist and astronomer), Abu Nasr Iraqi (a renowned mathematician), Abu Sahl Masihi (a respected philosopher) and Abu al-Khayr Khammar (a great physician).
Medicine and pharmacology
Though the threads which comprise Unani healing can be traced all the way back to Claudius Galenus of Pergamum, who lived in the second century of the Christian Era, the basic knowledge of Unani medicine as a healing system was developed by Hakim Ibn Sina in his medical encyclopedia The Canon of Medicine. The time of origin is thus dated at circa 1025 AD, when Avicenna wrote The Canon of Medicine in Persia. While he was primarily influenced by Greek and Islamic medicine, he was also influenced by the Indian medical teachings of Sushruta and Charaka.
The Canon of Medicine
About 100 treatises were ascribed to Ibn Sina. Some of them are tracts of a few pages, others are works extending through several volumes. The best-known amongst them, and that to which Ibn Sina owed his European reputation, is his 14-volume The Canon of Medicine, which was a standard medical text in Europe and the Islamic world up until the 18th century. The book is known for its introduction of systematic experimentation and quantification into the study of physiology, the discovery of contagious diseases and sexually transmitted diseases, the introduction of quarantine to limit the spread of infectious diseases, the introduction of experimental medicine, clinical trials, neuropsychiatry, risk factor analysis, and the idea of a syndrome in the diagnosis of specific diseases,[28] and hypothesized the existence of microrganisms. It classifies and describes diseases, and outlines their assumed causes. Hygiene, simple and complex medicines, and functions of parts of the body are also covered. In this, Ibn Sina is credited as being the first to correctly document the anatomy of the human eye, along with descriptions of eye afflictions such as cataracts. It asserts that tuberculosis was contagious, which was later disputed by Europeans, but turned out to be true. It also describes the symptoms and complications of diabetes. Both forms of facial paralysis were described in-depth. In addition, the workings of the heart as a valve are described.
The Canon of Medicine was the first book dealing with experimental medicine, evidence-based medicine, randomized controlled trials, and efficacy tests, and it laid out the following 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 drug must be free from any extraneous accidental quality.
- It must be used on a simple, not a composite, disease.
- The drug must be tested with two contrary types of diseases, because sometimes a drug cures one disease by Its essential qualities and another by its accidental ones.
- The quality of the drug must correspond to the strength of the disease. For example, there are some drugs whose heat is less than the coldness of certain diseases, so that they would have no effect on them.
- The time of action must be observed, so that essence and accident are not confused.
- The effect of the drug must be seen to occur constantly or in many cases, for if this did not happen, it was an accidental effect.
- The experimentation must be done with the human body, for testing a drug on a lion or a horse might not prove anything about its effect on man.
- An Arabic edition of the Canon appeared at Rome in 1593, and a Hebrew version at Naples in 1491. Of the Latin version there were about thirty editions, founded on the original translation by Gerard de Sabloneta. In the 15th century a commentary on the text of the Canon was composed. Other medical works translated into Latin are the Medicamenta Cordialia, Canticum de Medicina, and the Tractatus de Syrupo Acetoso.
It was mainly accident which determined that from the 12th to the 18th century, Ibn Sina should be the guide of medical study in European universities, and eclipse the names of Rhazes, Ali ibn al-Abbas and Averroes. His work is not essentially different from that of his predecessor Rhazes, because he presented the doctrine of Galen, and through Galen the doctrine of Hippocrates, modified by the system of Aristotle, as well as the Indian doctrines of Sushruta and Charaka.But the Canon of Ibn Sina is distinguished from the Al-Hawi (Continens) or Summary of Rhazes by its greater method, due perhaps to the logical studies of the former. Avicenna extended the theory of temperaments in The Canon of Medicine to encompass "emotional aspects, mental capacity, moral attitudes, self-awareness, movements and dreams."
The work has been variously appreciated in subsequent ages, some regarding it as a treasury of wisdom, and others, like Averroes, holding it useful only as waste paper. In modern times it has been mainly of historic interest as most of its tenets have been disproved or expanded upon by scientific medicine. The vice of the book is excessive classification of bodily faculties, and over-subtlety in the discrimination of diseases. It includes five books; of which the first and second discuss physiology, pathology and hygiene, the third and fourth deal with the methods of treating disease, and the fifth describes the composition and preparation of remedies. This last part contains some personal observations.
He is ample in the enumeration of symptoms, and is said to be inferior in practical medicine and surgery. He introduced into medical theory the four causes of the Peripatetic system. Of natural history and botany he pretended to no special knowledge. Up to the year 1650, or thereabouts, the Canon was still used as a textbook in the universities of Leuven and Montpellier.
In the museum at Bukhara, there are displays showing many of his writings, surgical instruments from the period and paintings of patients undergoing treatment. Ibn Sina was interested in the effect of the mind on the body, and wrote a great deal on psychology, likely influencing Ibn Tufayl and Ibn Bajjah. He also introduced medical herbs.
Avicennian psychology
In Muslim psychology and the neurosciences, Avicenna was a pioneer of neuropsychiatry. He first described numerous neuropsychiatric conditions, including hallucination, insomnia, mania, nightmare, melancholia, dementia, epilepsy, paralysis, stroke, vertigo and tremor.
Avicenna was also a pioneer in psychophysiology and psychosomatic medicine. He recognized 'physiological psychology' in the treatment of illnesses involving emotions, and developed a system for associating changes in the pulse rate with inner feelings, which is seen as an anticipation of the word association test attributed to Carl Jung. Avicenna is reported to have treated a very ill patient by "feeling the patient's pulse and reciting aloud to him the names of provinces, districts, towns, streets, and people." He noticed how the patient's pulse increased when certain names were mentioned, from which Avicenna deduced that the patient was in love with a girl whose home Avicenna was "able to locate by the digital examination." Avicenna advised the patient to marry the girl he is in love with, and the patient soon recovered from his illness after his marriage.
Avicenna's legacy in classical psychology is primarily embodied in the Kitab al-nafs parts of his Kitab al-shifa' (The Book of Healing) and Kitab al-najat (The Book of Deliverance). These were known in Latin under the title De Anima (treatises "on the soul"). The main thesis of these tracts is represented in his so-called "flying man" argument, which resonates with what was centuries later entailed by Descartes's cogito argument (or what phenomenology designates as a form of an "epoche").
In the The Canon of Medicine, Avicenna dealt with neuropsychiatry and described a number of neuropsychiatric conditions, including melancholia. He described melancholia as a depressive type of mood disorder in which the person may become suspicious and develop certain types of phobias.
Astronomy and astrology
The study of astrology was refuted by Avicenna. His reasons were both due to the methods used by astrologers being conjectural rather than empirical and also due to the views of astrologers conflicting with orthodox Islam. He also cited passages from the Qur'an in order to justify his refutation of astrology on both scientific and religious grounds.
In astronomy, he criticized Aristotle's view of the stars receiving their light from the Sun. Ibn Sina stated that the stars are self-luminous, and believed that the planets are also self-luminous. On May 24, 1032, he observed the transit of Venus. Soon after, he wrote the Compendium of the Almagest, a commentary on Ptolemy's Almagest. Avicenna concluded that Venus is closer to the Earth than the Sun. In 1070, Abu Ubayd al-Juzjani, a pupil of Ibn Sina, claimed that his teacher Ibn Sina had solved the equant problem in the Ptolemaic model.
Chemistry
In chemistry, the chemical process of steam distillation was first described by Ibn Sina. The technique was used to produce alcohol and essential oils; the latter was fundamental to aromatherapy. He also invented the refrigerated coil, which condenses the aromatic vapours. This was a breakthrough in distillation technology and he made use of it in his steam distillation process, which requires refrigerated tubing, to produce essential oils.
As a chemist, Avicenna was one of the first to write refutations on alchemy, after al-Kindi. Four of his works on the refutation of alchemy were translated into Latin as:
Liber Aboali Abincine de Anima in arte Alchemiae
Declaratio Lapis physici Avicennae filio sui Aboali
Avicennae de congelatione et conglutinatione lapifum
Avicennae ad Hasan Regem epistola de Re recta
In one of these works, Ibn Sina discredited the theory of the transmutation of substances commonly believed by alchemists:
Those of the chemical craft know well that no change can be effected in the different species of substances, though they can produce the appearance of such change.
Among his works refuting alchemy, Liber Aboali Abincine de Anima in arte Alchemiae was the most influential, having influenced later medieval chemists and alchemists such as Vincent of Beauvais.
In another work, translated into Latin as De congelatione et conglutinatione lapidum, Ibn Sina proposed a four-part classification of inorganic bodies, which was a significant improvement over the two-part classification of Aristotle (into orycta and metals) and three-part classification of Galen (into terrae, lapides and metals). The four parts of Ibn Sina's classification were: lapides, sulfur, salts and metals.
Earth sciences
Ibn Sina wrote on Earth sciences such as geology in The Book of Healing, in which he developed the concept of uniformitarianism and law of superposition in geology.While discussing the formation of mountains, he explained:
Either they are the effects of upheavals of the crust of the earth, such as might occur during a violent earthquake, or they are the effect of water, which, cutting itself a new route, has denuded the valleys, the strata being of different kinds, some soft, some hard... It would require a long period of time for all such changes to be accomplished, during which the mountains themselves might be somewhat diminished in size.
Due to his fundamental contributions to the development of geology, particularly regarding the origins of mountains, Avicenna has been called the 'Father of Geology'.
Physics
In physics, Ibn Sina was the first to employ an air thermometer to measure air temperature in his scientific experiments.In 1253, a Latin text entitled Speculum Tripartitum stated the following regarding Avicenna's theory on heat:
Avicenna says in his book of heaven and earth, that heat is generated from motion in external things.
In mechanics, Ibn Sina developed an elaborate theory of motion, in which he made a distinction between the inclination (tendency to motion) and force of a projectile, and concluded that motion was a result of an inclination (mayl) transferred to the projectile by the thrower, and that projectile motion in a vacuum would not cease. He viewed inclination as a permanent force whose effect is dissipated by external forces such as air resistance.
His theory of motion was thus consistent with the concept of inertia in Newton's first law of motion.[65] Ibn Sina also referred to mayl to as being proportional to weight times velocity, a precursor to the concept of momentum in Newton's second law of motion. Ibn Sina's theory of mayl was further developed by Jean Buridan in his theory of impetus.
In optics, Ibn Sina "observed that if the perception of light is due to the emission of some sort of particles by a luminous source, the speed of light must be finite."He also provided a wrong explanation of the rainbow phenomenon. Carl Benjamin Boyer described Avicenna's ("Ibn Sina") theory on the rainbow as follows:
Independent observation had demonstrated to him that the bow is not formed in the dark cloud but rather in the very thin mist lying between the cloud and the sun or observer. The cloud, he thought, serves simply as the background of this thin substance, much as a quicksilver lining is placed upon the rear surface of the glass in a mirror. Ibn Sina would change the place not only of the bow, but also of the color formation, holding the iridescence to be merely a subjective sensation in the eye.
Ibn Sina wrote extensively on early Islamic philosophy, especially the subjects logic, ethics, and metaphysics, including treatises named Logic and Metaphysics. Most of his works were written in Arabic - which was the de facto scientific language of that time, and some were written in the Persian language. Of linguistic significance even to this day are a few books that he wrote in nearly pure Persian language (particularly the Danishnamah-yi 'Ala', Philosophy for Ala' ad-Dawla'). Ibn Sina's commentaries on Aristotle often corrected the philosopher, encouraging a lively debate in the spirit of ijtihad.
In the medieval Islamic world, due to Avicenna's successful reconciliation between Aristotelianism and Neoplatonism along with Kalam, Avicennism eventually became the leading school of Islamic philosophy by the 12th century, with Avicenna becoming a central authority on philosophy.
Avicennism was also influential in medieval Europe, particular his doctrines on the nature of the soul and his existence-essence distinction, along with the debates and censure that they raised in scholastic Europe. This was particularly the case in Paris, where Avicennism was later proscribed in 1210. Nevertheless, his psychology and theory of knowledge influenced William of Auvergne and Albertus Magnus, while his metaphysics had an impact on the thought of Thomas Aquinas.
Metaphysical doctrine
Early Islamic philosophy, imbued as it is with Islamic theology, distinguishes more clearly than Aristotelianism the difference between essence and existence. Whereas existence is the domain of the contingent and the accidental, essence endures within a being beyond the accidental. The philosophy of Ibn Sina, particularly that part relating to metaphysics, owes much to al-Farabi. The search for a truly definitive Islamic philosophy can be seen in what is left to us of his work.
Following al-Farabi's lead, Avicenna initiated a full-fledged inquiry into the question of being, in which he distinguished between essence (Mahiat) and existence (Wujud). He argued that the fact of existence can not be inferred from or accounted for by the essence of existing things and that form and matter by themselves cannot interact and originate the movement of the universe or the progressive actualization of existing things. Existence must, therefore, be due to an agent-cause that necessitates, imparts, gives, or adds existence to an essence. To do so, the cause must be an existing thing and coexist with its effect.
Avicenna’s consideration of the essence-attributes question may be elucidated in terms of his ontological analysis of the modalities of being; namely impossibility, contingency, and necessity. Avicenna argued that the impossible being is that which cannot exist, while the contingent in itself (mumkin bi-dhatihi) has the potentiality to be or not to be without entailing a contradiction. When actualized, the contingent becomes a ‘necessary existent due to what is other than itself’ (wajib al-wujud bi-ghayrihi). Thus, contingency-in-itself is potential beingness that could eventually be actualized by an external cause other than itself. The metaphysical structures of necessity and contingency are different. Necessary being due to itself (wajib al-wujud bi-dhatihi) is true in itself, while the contingent being is ‘false in itself’ and ‘true due to something else other than itself’. The necessary is the source of its own being without borrowed existence. It is what always exists. The Necessary exists ‘due-to-Its-Self’, and has no quiddity/essence (mahiyya) other than existence (wujud). Furthermore, It is ‘One’ (wahid ahad) since there cannot be more than one ‘Necessary-Existent-due-to-Itself’ without differentia (fasl) to distinguish them from each other. Yet, to require differentia entails that they exist ‘due-to-themselves’ as well as ‘due to what is other than themselves’; and this is contradictory. However, if no differentia distinguishes them from each other, then there is no sense in which these ‘Existents’ are not one and the same. Avicenna adds that the ‘Necessary-Existent-due-to-Itself’ has no genus (jins), nor a definition (hadd), nor a counterpart (nadd), nor an opposite (did), and is detached (bari’) from matter (madda), quality (kayf), quantity (kam), place (ayn), situation (wad’), and time (waqt).
Avicennian logic
Avicenna discussed the topic of logic in Islamic philosophy extensively in his works, and developed his own system of logic known as "Avicennian logic" as an alternative to Aristotelian logic. By the 12th century, Avicennian logic had replaced Aristotelian logic as the dominant system of logic in the Islamic world.[80] After the Latin translations of the 12th century, Avicennian logic was also influential in Europe.
Ibn Sina developed an early theory on hypothetical syllogism, which formed the basis of his early risk factor analysis. He also developed an early theory on propositional calculus, which was an area of logic not covered in the Aristotelian tradition. The first criticisms of Aristotelian logic were also written by Ibn Sina, who developed an original theory on temporal modal syllogism. Ibn Sina also contributed inventively to the development of inductive logic, being the first to describe the methods of agreement, difference and concomitant variation which are critical to inductive logic and the scientific method.
Natural philosophy
Ibn Sina and Abu Rayhan al-Biruni engaged in a written debate, with Abu Rayhan Biruni mostly criticizing Aristotelian natural philosophy and the Peripatetic school, while Avicenna and his student Ahmad ibn 'Ali al-Ma'sumi respond to Biruni's criticisms in writing. Abu Rayhan began by asking Avicenna eighteen questions, ten of which were criticisms of Aristotle's On the Heavens.
Philosophy of science
Further information: Avicennism, The Book of Healing, and The Canon of Medicine
In the Al-Burhan (On Demonstration) section of The Book of Healing, Avicenna discussed the philosophy of science and described an early scientific method of inquiry. He discusses Aristotle's Posterior Analytics and significantly diverged from it on several points. Avicenna discussed the issue of a proper methodology for scientific inquiry and the question of "How does one acquire the first principles of a science?" He asked how a scientist would arrive at "the initial axioms or hypotheses of a deductive science without inferring them from some more basic premises?" He explains that the ideal situation is when one grasps that a "relation holds between the terms, which would allow for absolute, universal certainty." Avicenna then adds two further methods for arriving at the first principles: the ancient Aristotelian method of induction (istiqra), and the method of examination and experimentation (tajriba). Avicenna criticized Aristotelian induction, arguing that "it does not lead to the absolute, universal, and certain premises that it purports to provide." In its place, he develops a "method of experimentation as a means for scientific inquiry."
Theology
Ibn Sina was a devout Muslim and sought to reconcile rational philosophy with Islamic theology. His aim was to prove the existence of God and his creation of the world scientifically and through reason and logic. Avicenna wrote a number of treatises dealing with Islamic theology. These included treatises on the Islamic prophets, whom he viewed as "inspired philosophers", and on various scientific and philosophical interpretations of the Qur'an, such as how Quranic cosmology corresponds to his own philosophical system.
Ibn Sina memorized the Qur'an by the age of seven, and as an adult, he wrote five treatises commenting on suras from the Qur'an. One of these texts included the Proof of Prophecies, in which he comments on several Quranic verses and holds the Qur'an in high esteem. Avicenna argued that the Islamic prophets should be considered higher than philosophers.
Thought experiments
While he was imprisoned in the castle of Fardajan near Hamadhan, Avicenna wrote his famous "Floating Man" thought experiment to demonstrate human self-awareness and the substantiality of the soul. He referred to the living human intelligence, particularly the active intellect, which he believed to be the hypostasis by which God communicates truth to the human mind and imparts order and intelligibility to nature. His "Floating Man" thought experiment tells its readers to imagine themselves suspended in the air, isolated from all sensations, which includes no sensory contact with even their own bodies. He argues that, in this scenario, one would still have self-consciousness. He thus concludes that the idea of the self is not logically dependent on any physical thing, and that the soul should not be seen in relative terms, but as a primary given, a substance.
Engineering
In the chapters on mechanics and engineering in his encyclopedia Mi'yar al-'aql (The Measure of the Mind), Avicenna writes an analysis on the ilm al-hiyal (science of ingenious devices) and makes the first successful attempt to classify simple machines and their combinations. He first describes and illustrates the five constituent simple machines: the lever, pulley, screw, wedge, and windlass. He then analyzes all the combinations of these simple machines, such as the windlass-screw, windlass-pulley and windlass-lever for example. He is also the first to describe a mechanism which is essentially a combination of all of these simple machines (except for the wedge).
Poetry
Almost half of Ibn Sina's works are versified. His poems appear in both Arabic and Persian. As an example, Edward Granville Browne claims that the following Persian verses are incorrectly attributed to Omar Khayyám, and were originally written by Ibn Sina:
Up from Earth's Centre through the Seventh Gate,
I rose, and on the Throne of Saturn sate,
And many Knots unravel'd by the Road,
But not the Master-Knot of Human Fate.
When some of his opponents blame him for blasphemy, he says.
The blasphemy of somebody like me is not easy and exorbitant,
There isn't any stronger faith than my faith,
If there is just one person like me in the world and that one is impious,
So there are no Muslims in the whole world.
