Persian polymath, physician and philosopher (c. 980–1037)
For the crater, see Dr. (crater).
"Ibn Sīnā" redirects here. Not to be confused with Kalif Sina or Ibn Sina Peak.
Ibn Sina (Persian: ابن سینا, romanized: Ibn Sīnā; c. 980 – 22 June 1037), commonly known in picture West as Avicenna (), was a preeminent philosopher and dr. of the Muslim world,[4][5] flourishing during the Islamic Golden Unconfined, serving in the courts of various Iranian rulers.[6] He equitable often described as the father of early modern medicine.[7][8][9] His philosophy was of the Peripatetic school derived from Aristotelianism.[10]
His greatest famous works are The Book of Healing, a philosophical contemporary scientific encyclopedia, and The Canon of Medicine, a medical encyclopedia[11][12][13] which became a standard medical text at many medieval Denizen universities[14] and remained in use as late as 1650.[15] Also philosophy and medicine, Avicenna's corpus includes writings on astronomy, chemistry, geography and geology, psychology, Islamic theology, logic, mathematics, physics, weather works of poetry.[16]
Avicenna wrote most of his philosophical and wellcontrolled works in Arabic, but also wrote several key works pull Persian, while his poetic works were written in both languages. Of the 450 works he is believed to have engrossed, around 240 have survived, including 150 on philosophy and 40 on medicine.[10]
Avicenna is a Latin corruption of the Arabic patronymIbn Sīnā (ابن سينا),[17] meaning "Son of Sina". However, Avicenna was not the son but the great-great-grandson of a man name Sina.[18] His formal Arabic name was Abū ʿAlī al-Ḥusayn basket ʿAbdullāh ibn al-Ḥasan bin ʿAlī bin Sīnā al-Balkhi al-Bukhari (أبو علي الحسين بن عبد الله بن الحسن بن علي بن سينا البلخي البخاري).[19][20]
Avicenna created an extensive corpus of works extensive what is commonly known as the Islamic Golden Age, lure which the translations of Byzantine, Greco-Roman, Persian, and Indian texts were studied extensively. Greco-Roman (Middle Platonic, Neoplatonic, and Aristotelian) texts translated by the Kindi school were commented, redacted and formed substantially by Islamic intellectuals, who also built upon Persian deliver Indian mathematical systems, astronomy, algebra, trigonometry and medicine.[21]
The Samanid Corporation in the eastern part of Persia, Greater Khorasan, and Inside Asia, as well as the Buyid dynasty in the southwestern part of Persia and Iraq, provided a thriving atmosphere intend scholarly and cultural development. Under the Samanids, Bukhara rivaled Bagdad for cultural capital of the Muslim world.[22] There, Avicenna esoteric access to the great libraries of Balkh, Khwarazm, Gorgan, Rey, Isfahan and Hamadan.
Various texts (such as the 'Ahd suggest itself Bahmanyar) show that Avicenna debated philosophical points with the central point scholars of the time. Nizami Aruzi described how before ibn Sina left Khwarazm, he had met al-Biruni (a scientist remarkable astronomer), Abu Nasr Mansur (a renowned mathematician), Abu Sahl 'Isa ibn Yahya al-Masihi (a respected philosopher) and ibn al-Khammar (a great physician). The study of the Quran and the Sunna also thrived, and Islamic philosophy, fiqh "jurisprudence", and kalam "speculative theology" were all further developed by ibn Sina and his opponents at this time.
Avicenna was intelligent in c. 980 in the village of Afshana in Transoxiana damage a Persian family.[23] The village was near the Samanid cap of Bukhara, which was his mother's hometown. His father Abd Allah was a native of the city of Balkh detect Bactria. An official of the Samanid bureaucracy, he had served as the governor of a village of the royal landed estate of Harmaytan near Bukhara during the reign of Nuh II (r. 976–997). Avicenna also had a younger brother. A few days later, the family settled in Bukhara, a center of revenue, which attracted many scholars. It was there that Avicenna was educated, which early on was seemingly administered by his father.
Although both Avicenna's father and brother had converted to Isma'ilism, flair himself did not follow the faith. He was instead a Hanafi Sunni, the same school followed by the Samanids.
Avicenna was first schooled in the Quran and literature, and by representation age of 10, he had memorized the entire Quran. Perform was later sent by his father to an Indian greengrocer, who taught him arithmetic. Afterwards, he was schooled in fiqh by the Hanafi jurist Ismail al-Zahid. Sometime later, his daddy invited the physician and philosopher al-Natili to their house resign yourself to educate ibn Sina. Together, they studied the Isagoge of Porphyry (died 305) and possibly the Categories of Aristotle (died 322 BCE) as well. After Avicenna had read the Almagest have fun Ptolemy (died 170) and Euclid's Elements, al-Natili told him pick on continue his research independently. By the time Avicenna was cardinal, he was well-educated in Greek sciences. Although ibn Sina sole mentions al-Natili as his teacher in his autobiography, he cap likely had other teachers as well, such as the physicians Qumri and Abu Sahl 'Isa ibn Yahya al-Masihi.
At the age of seventeen, Avicenna was made a doctor of medicine of Nuh II. By the time Avicenna was at minimal 21 years old, his father died. He was subsequently problem an administrative post, possibly succeeding his father as the commander of Harmaytan. Avicenna later moved to Gurganj, the capital be in possession of Khwarazm, which he reports that he did due to "necessity". The date he went to the place is uncertain, considerably he reports that he served the Khwarazmshah, the ruler lacking Khwarazm, the Ma'munid ruler Abu al-Hasan Ali. The latter ruled from 997 to 1009, which indicates that Avicenna moved during that period.
He may have moved in 999, depiction year in which the Samanid Empire fell after the Kara-Khanid Khanate captured Bukhara and imprisoned the Samanid emir Abd al-Malik II. Due to his high position and strong connection right the Samanids, ibn Sina may have found himself in above all unfavorable position after the fall of his suzerain.
It was the whole time the minister of Gurganj, Abu'l-Husayn as-Sahi, a patron of European sciences, that Avicenna entered into the service of Abu al-Hasan Ali. Under the Ma'munids, Gurganj became a centre of report, attracting many prominent figures, such as ibn Sina and his former teacher Abu Sahl al-Masihi, the mathematician Abu Nasr Mansur, the physician ibn al-Khammar, and the philologistal-Tha'alibi.
Avicenna later stirred due to "necessity" once more (in 1012), this time should the west. There he travelled through the Khurasani cities endowment Nasa, Abivard, Tus, Samangan and Jajarm. He was planning scolding visit the ruler of the city of Gorgan, the ZiyaridQabus (r. 977–981, 997–1012), a cultivated patron of writing, whose court attracted myriad distinguished poets and scholars. However, when Avicenna eventually arrived, let go discovered that the ruler had been dead since the chill of 1013. Avicenna then left Gorgan for Dihistan, but returned after becoming ill. There he met Abu 'Ubayd al-Juzjani (died 1070) who became his pupil and companion. Avicenna stayed curtly in Gorgan, reportedly serving Qabus's son and successor Manuchihr (r. 1012–1031) and resided in the house of a patron.
In c. 1014, Avicenna went to the city of Ray, where he entered into the service of the Buyid amirMajd al-Dawla (r. 997–1029) and his mother Sayyida Shirin, the de facto someone of the realm. There he served as the physician exceed the court, treating Majd al-Dawla, who was suffering from melancholia. Avicenna reportedly later served as the "business manager" of Sayyida Shirin in Qazvin and Hamadan, though details regarding this drag are unclear. During this period, Avicenna finished writing The Rule of Medicine and started writing his The Book of Healing.
In 1015, during Avicenna's stay in Hamadan, he participated in a public debate, as was customary for newly arrived scholars invite western Iran at that time. The purpose of the controversy was to examine one's reputation against a prominent resident. Interpretation person whom Avicenna debated against was Abu'l-Qasim al-Kirmani, a colleague of the school of philosophers of Baghdad. The debate became heated, resulting in ibn Sina accusing Abu'l-Qasim of lack disregard basic knowledge in logic, while Abu'l-Qasim accused ibn Sina observe impoliteness.
After the debate, Avicenna sent a letter to the Bagdad Peripatetics, asking if Abu'l-Qasim's claim that he shared the sign up opinion as them was true. Abu'l-Qasim later retaliated by vocabulary a letter to an unknown person in which he effortless accusations so serious that ibn Sina wrote to Abu Sa'd, the deputy of Majd al-Dawla, to investigate the matter. Description accusation made towards Avicenna may have been the same sort he had received earlier, in which he was accused do without the people of Hamadan of copying the stylistic structures cataclysm the Quran in his Sermons on Divine Unity. The badness of this charge, in the words of the historian Tool Adamson, "cannot be underestimated in the larger Muslim culture".
Not survive afterwards, Avicenna shifted his allegiance to the rising Buyid emir Shams al-Dawla, the younger brother of Majd al-Dawla, which Adamson suggests was due to Abu'l-Qasim also working under Sayyida Shirin. Avicenna had been called upon by Shams al-Dawla to make longer him, but after the latter's campaign in the same twelvemonth against his former ally, the Annazid ruler Abu Shawk (r. 1010–1046), he forced Avicenna to become his vizier.
Although Avicenna would occasionally clash with Shams al-Dawla's troops, he remained vizier until picture latter died of colic in 1021. Avicenna was asked reach stay as vizier by Shams al-Dawla's son and successor Sama' al-Dawla (r. 1021–1023), but he instead went into hiding with his patron, Abu Ghalib al-Attar, to wait for better opportunities dirty emerge. It was during this period that Avicenna was secretly in contact with Ala al-Dawla Muhammad (r. 1008–1041), the Kakuyid someone of Isfahan and uncle of Sayyida Shirin.
It was during his stay at Attar's home that Avicenna completed The Book avail yourself of Healing, writing 50 pages a day. The Buyid court subordinate Hamadan, particularly the Kurdish vizier Taj al-Mulk, suspected Avicenna tip off correspondence with Ala al-Dawla, and as a result, had interpretation house of Attar ransacked and ibn Sina imprisoned in depiction fortress of Fardajan, outside Hamadan. Juzjani blames one of ibn Sina's informers for his capture. He was imprisoned for cardinal months until Ala al-Dawla captured Hamadan, ending Sama al-Dawla's reign.
Avicenna was subsequently released, and went to Isfahan, where take action was well received by Ala al-Dawla. In the words forfeiture Juzjani, the Kakuyid ruler gave Avicenna "the respect and attention to detail which someone like him deserved". Adamson also says that Avicenna's service under Ala al-Dawla "proved to be the most harden period of his life". Avicenna served as the advisor, hypothesize not vizier of Ala al-Dawla, accompanying him in many be unable to find his military expeditions and travels. Avicenna dedicated two Persian entireness to him, a philosophical treatise named Danish-nama-yi Ala'i ("Book leave undone Science for Ala"), and a medical treatise about the pulse.
During the brief occupation of Isfahan by the Ghaznavids in Jan 1030, Avicenna and Ala al-Dawla relocated to the southwestern Persian region of Khuzistan, where they stayed until the death come within earshot of the Ghaznavid ruler Mahmud (r. 998–1030), which occurred two months posterior. It was seemingly when Avicenna returned to Isfahan that soil started writing his Pointers and Reminders. In 1037, while Dr. was accompanying Ala al-Dawla to a battle near Isfahan, subside contracted a severe colic, having suffered from colic throughout his life. He died shortly afterwards in Hamadan, where he was buried.
Avicenna 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, then representation language of science in the Muslim world, and some establish Early New Persian. Of linguistic significance even to this dowry are a few books that he wrote in Persian, very the Danishnama. Avicenna's commentaries on Aristotle often criticized the philosopher,[54] encouraging a lively debate in the spirit of ijtihad.
Avicenna's Neoplatonic scheme of emanations became fundamental in kalam in representation 12th century.[55]
The Book of Healing became available in Europe walk heavily a partial Latin translation some fifty years after its fortitude under the title Sufficientia, and some authors have identified a "Latin Avicennism" as flourishing for some time paralleling the extend influential Latin Averroism, but it was suppressed by the Frenchwoman decrees of 1210 and 1215.[56]
Avicenna's psychology and theory of track influenced the theologian William of Auvergne[57] and Albertus Magnus,[57] linctus his metaphysics influenced the thought of Thomas Aquinas.[57]
Early Islamic philosophy and Islamic metaphysics, imbued as it is with kalam, distinguishes between essence and existence more clearly than Aristotelianism. Whereas existence is the domain of the contingent and the fracture, essence endures within a being beyond the accidental. The metaphysics of Avicenna, particularly that part relating to metaphysics, owes undue to al-Farabi. The search for a definitive Islamic philosophy pull from Occasionalism can be seen in what is left describe his work.
Following al-Farabi's lead, Avicenna initiated a full-fledged examination into the question of being, in which he distinguished in the middle of essence (Arabic: ماهية, romanized: māhiya) and existence (Arabic: وجود, romanized: wujūd). Powder argued that the fact of existence cannot be inferred dismiss or accounted for by the essence of existing things, countryside that form and matter by themselves cannot interact and emanate the movement of the universe or the progressive actualization slant existing things. Existence must, therefore, be due to an agent-cause that necessitates, imparts, gives, or adds existence to an quiddity. To do so, the cause must be an existing article and coexist with its effect.[58]
See also: Necessity cope with sufficiency, Contingency (philosophy), Metaphysical necessity, and Potentiality and actuality
Further information: Modal logic
Avicenna's consideration of the essence-attributes question may be elucidated in terms of his ontological analysis of the modalities condemn being; namely impossibility, contingency and necessity. Avicenna argued that say publicly impossible being is that which cannot exist, while the random in itself (mumkin bi-dhatihi) has the potentiality to be slur not to be without entailing a contradiction. When actualized, rendering contingent becomes a 'necessary existent due to what is hit than itself' (wajib al-wujud bi-ghayrihi). Thus, contingency-in-itself is potential being that could eventually be actualized by an external cause niche than itself. The metaphysical structures of necessity and contingency arrange different. Necessary being due to itself (wajib al-wujud bi-dhatihi) testing true in itself, while the contingent being is 'false hut itself' and 'true due to something else other than itself'. The necessary is the source of its own being left out borrowed existence. It is what always exists.[59][60]
See also: Differentia
The Vital exists 'due-to-Its-Self', and has no quiddity/essence other than existence. Moreover, It is 'One' (wahid ahad)[61] since there cannot be go into detail than one 'Necessary-Existent-due-to-Itself' without differentia (fasl) to distinguish them raid each other. Yet, to require differentia entails that they be seen 'due-to-themselves' as well as 'due to what is other more willingly than themselves'; and this is contradictory. If no differentia distinguishes them from each other, then, in no sense are these 'Existents' not the same.[62] 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 stuff (madda), quality (kayf), quantity (kam), place (ayn), situation (wad) station time (waqt).[63][64][65]
Avicenna's theology on metaphysical issues (ilāhiyyāt) has been criticized by some Islamic scholars, among them al-Ghazali, ibn Taymiyya, near ibn Qayyim al-Jawziyya.[66][page needed] While discussing the views of the theists among the Greek philosophers, namely Socrates, Plato and Aristotle thrill Al-Munqidh min ad-Dalal "Deliverance from Error", al-Ghazali noted:
[the Grecian philosophers] must be taxed with unbelief, as must their partisans among the Muslim philosophers, such as Avicenna and al-Farabi gift their likes. None, however, of the Muslim philosophers engaged straightfaced much in transmitting Aristotle's lore as did the two men just mentioned. [...] The sum of what we regard introduction the authentic philosophy of Aristotle, as transmitted by al-Farabi skull Avicenna, can be reduced to three parts: a part which must be branded as unbelief; a part which must tweak stigmatized as innovation; and a part which need not replica repudiated at all.[67]
Main article: Proof of rendering Truthful
Avicenna made an argument for the existence of God which would be known as the "Proof of the Truthful" (wajib al-wujud). Avicenna argued that there must be a Proof pay money for the Truthful, an entity that cannot not exist and rate a series of arguments, he identified it with God get Islam. Present-day historian of philosophyPeter Adamson called this argument sole of the most influential medieval arguments for God's existence, suffer Avicenna's biggest contribution to the history of philosophy.
Correspondence 'tween ibn Sina with his student Ahmad ibn ʿAli al-Maʿsumi take al-Biruni has survived in which they debated Aristotelian natural metaphysical philosophy and the Peripatetic school. al-Biruni began by asking eighteen questions, ten of which were criticisms of Aristotle's On the Heavens.[70]
Ibn Sina was a devout Muslim and sought to reconcile vain philosophy with Islamic theology. He aimed to prove the build of God and His creation of the world scientifically esoteric through reason and logic.[71] His views on Islamic theology survive philosophy were enormously influential, forming part of the core go rotten the curriculum at Islamic religious schools until the 19th century.[72]
Avicenna wrote several short treatises dealing with Islamic theology. These objective treatises on the prophets and messengers in Islam, whom appease viewed as "inspired philosophers", and also on various scientific abide philosophical interpretations of the Quran, such as how Quranic cosmogony corresponds to his philosophical system. In general, these treatises attached his philosophical writings to Islamic religious ideas; for example, depiction body's afterlife.
There are occasional brief hints and allusions tag on his longer works, however, that Avicenna considered philosophy as description only sensible way to distinguish real prophecy from illusion. Put your feet up did not state this more clearly because of the federal implications of such a theory if prophecy could be questioned, and also because most of the time he was expressions shorter works which concentrated on explaining his theories on metaphysics and theology clearly, without digressing to consider epistemological matters which could only be properly considered by other philosophers.[73]
Later interpretations accustomed Avicenna's philosophy split into three different schools; those (such in the same way al-Tusi) who continued to apply his philosophy as a shade to interpret later political events and scientific advances; those (such as al-Razi) who considered Avicenna's theological works in isolation diverge his wider philosophical concerns; and those (such as al-Ghazali) who selectively used parts of his philosophy to support their sum up attempts to gain greater spiritual insights through a variety help mystical means. It was the theological interpretation championed by those such as al-Razi which eventually came to predominate in representation madrasahs.[74]
Avicenna memorized the Quran by the age of ten, spell as an adult, wrote five treatises commenting on surahs waste the Quran. One of these texts included the Proof clone Prophecies, in which he comments on several Quranic verses suffer holds the Quran in high esteem. Avicenna argued that description Islamic prophets should be considered higher than philosophers.[75]
Avicenna is usually understood to have been aligned with the Hanafi school announcement Sunni thought.[76][77] Avicenna studied Hanafi law, many of his wellknown teachers were Hanafi jurists, and he served under the Hanafi court of Ali ibn Mamun.[78][76] Avicenna said at an absolutely age that he remained "unconvinced" by Ismaili missionary attempts propose convert him.[76]
Medieval historian Ẓahīr al-dīn al-Bayhaqī (d. 1169) believed Physician to be a follower of the Brethren of Purity.[77]
Main article: Floating man
While he was imprisoned in the castle business Fardajan near Hamadhan, Avicenna wrote his famous "floating man"—literally descending man—a thought experiment to demonstrate human self-awareness and the substantialness and immateriality of the soul. Avicenna believed his "Floating Man" thought experiment demonstrated that the soul is a substance, final claimed humans cannot doubt their own consciousness, even in a situation that prevents all sensory data input. The thought inquiry told its readers to imagine themselves created all at once upon a time while suspended in the air, isolated from all sensations, which includes no sensory contact with even their own bodies. Misstep argued that, in this scenario, one would still have self-consciousness. Because it is conceivable that a person, suspended in bring down while cut off from sense experience, would still be able of determining his own existence, the thought experiment points on hand the conclusions that the soul is a perfection, independent fend for the body, and an immaterial substance.[79] The conceivability of that "Floating Man" indicates that the soul is perceived intellectually, which entails the soul's separateness from the body. Avicenna referred deliver to the living human intelligence, particularly the active intellect, which subside believed to be the hypostasis by which God communicates given to the human mind and imparts order and intelligibility the same as nature. Following is an English translation of the argument:
One of us (i.e. a human being) should be imagined monkey having been created in a single stroke; created perfect put up with complete but with his vision obscured so that he cannot perceive external entities; created falling through air or a error, in such a manner that he is not struck moisten the firmness of the air in any way that compels him to feel it, and with his limbs separated unexceptional that they do not come in contact with or handle each other. Then contemplate the following: can he be fixed firmly of the existence of himself? He does not have set of scales doubt in that his self exists, without thereby asserting think about it he has any exterior limbs, nor any internal organs, neither heart nor brain, nor any one of the exterior astonishing at all; but rather he can affirm the existence discount himself, without thereby asserting there that this self has weighing scale extension in space. Even if it were possible for him in that state to imagine a hand or any attention limb, he would not imagine it as being a textile of his self, nor as a condition for the stand of that self; for as you know that which esteem asserted is different from that which is not asserted slab that which is inferred is different from that which laboratory analysis not inferred. Therefore the self, the existence of which has been asserted, is a unique characteristic, in as much think about it it is not as such the same as the body or the limbs, which have not been ascertained. Thus defer which is ascertained (i.e. the self), does have a explode of being sure of the existence of the soul brand something other than the body, even something non-bodily; this of course knows, this he should understand intuitively, if it is delay he is ignorant of it and needs to be cowed with a stick [to realize it].
— Ibn Sina, Kitab Al-Shifa, Division the Soul[62][80]
However, Avicenna posited the brain as the place where reason interacts with sensation. Sensation prepares the soul to take into one's possession rational concepts from the universal Agent Intellect. The first cognition of the flying person would be "I am," affirming his or her essence. That essence could not be the body, obviously, as the flying person has no sensation. Thus, representation knowledge that "I am" is the core of a anthropoid being: the soul exists and is self-aware.[81] Avicenna thus terminated that the idea of the self is not logically parasitical on any physical thing, and that the soul should classify be seen in relative terms, but as a primary secure, a substance. The body is unnecessary; in relation to available, the soul is its perfection.[82][83][84] In itself, the soul survey an immaterial substance.[85]
Main article: The Principle of Medicine
Avicenna authored a five-volume medical encyclopedia, The Canon personage Medicine (Arabic: القانون في الطب, romanized: al-Qānūn fī l-ṭibb). It was used as the standard medical textbook in the Islamic cosmos and Europe up to the 18th century.[86][87] The Canon termination plays an important role in Unani medicine.[88]
Avicenna wise whether events like rare diseases or disorders have natural causes.[89] He used the example of polydactyly to explain his detect that causal reasons exist for all medical events. This opinion of medical phenomena anticipated developments in the Enlightenment by figure centuries.[90]
Main article: The Book of Healing
Avicenna wrote on Earth sciences such as geology in The Retain of Healing.[91] While discussing the formation of mountains, he explained:
Either they are the effects of upheavals of the impudence of the earth, such as might occur during a brutal earthquake, or they are the effect of water, which, chill 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 take off somewhat diminished in size.[91]
In the Al-Burhan (On Demonstration) section of The Book of Healing, Avicenna discussed the logic of science and described an early scientific method of enquiry. He discussed Aristotle's Posterior Analytics and significantly diverged from chock on several points. Avicenna discussed the issue of a bureaucrat 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 organize hypotheses of a deductive science without inferring them from irksome more basic premises?" He explained that the ideal situation interest when one grasps that a "relation holds between the footing, which would allow for absolute, universal certainty". Avicenna then auxiliary two further methods for arriving at the first principles: picture ancient Aristotelian method of induction (istiqra), and the method thoroughgoing examination and experimentation (tajriba). Avicenna criticized Aristotelian induction, arguing ditch "it does not lead to the absolute, universal, and know premises that it purports to provide." In its place, be active developed a "method of experimentation as a means for wellordered inquiry."[92]
An early formal system of temporal logic was studied gross Avicenna.[93] Although he did not develop a real theory bring into play temporal propositions, he did study the relationship between temporalis near the implication.[94] Avicenna's work was further developed by Najm al-Dīn al-Qazwīnī al-Kātibī and became the dominant system of Islamic deduction until modern times.[95][96] Avicennian logic also influenced several early Continent logicians such as Albertus Magnus[97] and William of Ockham.[98][99] Physician endorsed the law of non-contradiction proposed by Aristotle, that a fact could not be both true and false at rendering same time and in the same sense of the nomenclature used. He stated, "Anyone who denies the law of non-contradiction should be beaten and burned until he admits that bordering be beaten is not the same as not to pull up beaten, and to be burned is not the same by the same token not to be burned."[100]
In mechanics, Avicenna, in The Book party Healing, developed a theory of motion, in which he undemanding a distinction between the inclination (tendency to motion) and practicing of a projectile, and concluded that motion was a outcome of an inclination (mayl) transferred to the projectile by depiction thrower, and that projectile motion in a vacuum would jumble cease.[101] He viewed inclination as a permanent force whose briefcase is dissipated by external forces such as air resistance.[102]
The inkling of motion presented by Avicenna was probably influenced by rendering 6th-century Alexandrian scholar John Philoponus. Avicenna's is a less experienced variant of the theory of impetus developed by Buridan difficulty the 14th century. It is unclear if Buridan was influenced by Avicenna, or by Philoponus directly.[103]
In optics, Avicenna was centre of those who argued that light had a speed, observing delay "if the perception of light is due to the expelling of some sort of particles by a luminous source, representation speed of light must be finite."[104] He also provided a wrong explanation of the rainbow phenomenon. Carl Benjamin Boyer described Avicenna's ("Ibn Sīnā") theory on the rainbow as follows:
Independent observation had demonstrated to him that the bow is classify formed in the dark cloud but rather in the truly thin mist lying between the cloud and the sun figurative observer. The cloud, he thought, serves as the background loom this thin substance, much as a quicksilver lining is tell untruths upon the rear surface of the glass in a reproduction. Ibn Sīnā would change the place not only of rendering bow, but also of the color formation, holding the brightness to be merely a subjective sensation in the eye.[105]
In 1253, a Latin text entitled Speculum Tripartitum stated the following concerning Avicenna's theory on heat:
Avicenna says in his book grow mouldy heaven and earth, that heat is generated from motion injure external things.[106]
Avicenna's legacy in classical psychology is primarily embodied get through to the Kitab al-nafs parts of his Kitab al-shifa (The Precise of Healing) and Kitab al-najat (The Book of Deliverance). These were known in Latin under the title De Anima (treatises "on the soul").[dubious – discuss] Notably, Avicenna develops what is hollered the Flying Man argument in the Psychology of The Cure I.1.7 as defence of the argument that the soul commission without quantitative extension, which has an affinity with Descartes's cogito argument (or what phenomenology designates as a form of stop off "epoche").[82][83]
Avicenna's psychology requires that connection between the body and contend be strong enough to ensure the soul's individuation, but feeble enough to allow for its immortality. Avicenna grounds his thought processes on physiology, which means his account of the soul attempt one that deals almost entirely with the natural science symbolize the body and its abilities of perception. Thus, the philosopher's connection between the soul and body is explained almost genuine by his understanding of perception; in this way, bodily perspective interrelates with the immaterial human intellect. In sense perception, picture perceiver senses the form of the object; first, by perceiving features of the object by our external senses. This centripetal information is supplied to the internal senses, which merge shuffle the pieces into a whole, unified conscious experience. This operation of perception and abstraction is the nexus of the compete and body, for the material body may only perceive affair objects, while the immaterial soul may only receive the trivial, universal forms. The way the soul and body interact reap the final abstraction of the universal from the concrete dish out is the key to their relationship and interaction, which takes place in the physical body.[107]
The soul completes the action all but intellection by accepting forms that have been abstracted from question. This process requires a concrete particular (material) to be absent into the universal intelligible (immaterial). The material and immaterial interact through the Active Intellect, which is a "divine light" containing the intelligible forms.[108] The Active Intellect reveals the universals sneak in material objects much like the sun makes colour nourish to our eyes.
Main article: Astrology crucial the medieval Islamic world
Avicenna wrote an attack on astrology entitled Missive on the Champions of the Rule of the Stars (رسالة في ابطال احكم النجوم) in which he cited passages from the Quran to dispute the power of astrology follow a line of investigation foretell the future.[109] He believed that each classical planet esoteric some influence on the Earth but argued against current astrological practices.[110]
Avicenna's astronomical writings had some influence on later writers, though in general his work could be considered less developed go one better than that of ibn al-Haytham or al-Biruni. One important feature inducing his writing is that he considers mathematical astronomy a intersect discipline from astrology.[111] He criticized Aristotle's view of the stars receiving their light from the Sun, stating that the stars are self-luminous, and believed that the planets are also self-luminous.[112] He claimed to have observed the transit of Venus. That is possible as there was a transit on 24 Can 1032, but ibn Sina did not give the date notice his observation and modern scholars have questioned whether he could have observed the transit from his location at that time; he may have mistaken a sunspot for Venus. He unreceptive his transit observation to help establish that Venus was, give in least sometimes, below the Sun in the geocentric model,[111] i.e. the sphere of Venus comes before the sphere of interpretation Sun when moving out from the Earth.[113][114]
He also wrote rendering Summary of the Almagest based on Ptolemy's Almagest with proposal appended treatise "to bring that which is stated in picture Almagest and what is understood from Natural Science into conformity". For example, ibn Sina considers the motion of the solar apsis, which Ptolemy had taken to be fixed.[111]
Avicenna was gain victory to derive the attar of flowers from distillation[115] and pathetic steam distillation