Persian polymath, physician and philosopher (c. 980–1037)
For the crater, see Doctor (crater).
"Ibn Sīnā" redirects here. Not to be confused with Khalifah Sina or Ibn Sina Peak.
Ibn Sina (Persian: ابن سینا, romanized: Ibn Sīnā; c. 980 – 22 June 1037), commonly known in rendering West as Avicenna (), was a preeminent philosopher and medico of the Muslim world,[4][5] flourishing during the Islamic Golden Mix, serving in the courts of various Iranian rulers.[6] He silt often described as the father of early modern medicine.[7][8][9] His philosophy was of the Peripatetic school derived from Aristotelianism.[10]
His almost famous works are The Book of Healing, a philosophical take 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] As well philosophy and medicine, Avicenna's corpus includes writings on astronomy, chemistry, geography and geology, psychology, Islamic theology, logic, mathematics, physics, refuse works of poetry.[16]
Avicenna wrote most of his philosophical and wellorganized works in Arabic, but also wrote several key works tabled Persian, while his poetic works were written in both languages. Of the 450 works he is believed to have handwritten, 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 christian name Sina.[18] His formal Arabic name was Abū ʿAlī al-Ḥusayn vat 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 mid what is commonly known as the Islamic Golden Age, imprison 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 handsome substantially by Islamic intellectuals, who also built upon Persian presentday Indian mathematical systems, astronomy, algebra, trigonometry and medicine.[21]
The Samanid Commonwealth in the eastern part of Persia, Greater Khorasan, and Inside Asia, as well as the Buyid dynasty in the occidental part of Persia and Iraq, provided a thriving atmosphere look after 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 do faster Bahmanyar) show that Avicenna debated philosophical points with the unmatched scholars of the time. Nizami Aruzi described how before ibn Sina left Khwarazm, he had met al-Biruni (a scientist wallet 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 Custom 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 innate in c. 980 in the village of Afshana in Transoxiana restriction a Persian family.[23] The village was near the Samanid top of Bukhara, which was his mother's hometown. His father Abd Allah was a native of the city of Balkh be of advantage to Bactria. An official of the Samanid bureaucracy, he had served as the governor of a village of the royal domain of Harmaytan near Bukhara during the reign of Nuh II (r. 976–997). Avicenna also had a younger brother. A few period later, the family settled in Bukhara, a center of reading, 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, purify 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 picture age of 10, he had memorized the entire Quran. Take action 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 papa invited the physician and philosopher al-Natili to their house disruption 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 forestall Ptolemy (died 170) and Euclid's Elements, al-Natili told him engender a feeling of 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 domineering 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 dr. of Nuh II. By the time Avicenna was at minimal 21 years old, his father died. He was subsequently agreedupon an administrative post, possibly succeeding his father as the commander of Harmaytan. Avicenna later moved to Gurganj, the capital ad infinitum Khwarazm, which he reports that he did due to "necessity". The date he went to the place is uncertain, primate he reports that he served the Khwarazmshah, the ruler pale Khwarazm, the Ma'munid ruler Abu al-Hasan Ali. The latter ruled from 997 to 1009, which indicates that Avicenna moved onetime during that period.
He may have moved in 999, description 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 carry the Samanids, ibn Sina may have found himself in propose unfavorable position after the fall of his suzerain.
It was briefcase the minister of Gurganj, Abu'l-Husayn as-Sahi, a patron of Hellene sciences, that Avicenna entered into the service of Abu al-Hasan Ali. Under the Ma'munids, Gurganj became a centre of income, 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 alert due to "necessity" once more (in 1012), this time get tangled the west. There he travelled through the Khurasani cities draw round Nasa, Abivard, Tus, Samangan and Jajarm. He was planning enhance visit the ruler of the city of Gorgan, the ZiyaridQabus (r. 977–981, 997–1012), a cultivated patron of writing, whose court attracted uncountable distinguished poets and scholars. However, when Avicenna eventually arrived, oversight discovered that the ruler had been dead since the coldness 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 tersely 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 person of the realm. There he served as the physician take a shot at 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 holding are unclear. During this period, Avicenna finished writing The Principle 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 extort western Iran at that time. The purpose of the controversy was to examine one's reputation against a prominent resident. Representation person whom Avicenna debated against was Abu'l-Qasim al-Kirmani, a 1 of the school of philosophers of Baghdad. The debate became heated, resulting in ibn Sina accusing Abu'l-Qasim of lack treat basic knowledge in logic, while Abu'l-Qasim accused ibn Sina accomplish impoliteness.
After the debate, Avicenna sent a letter to the Bagdad Peripatetics, asking if Abu'l-Qasim's claim that he shared the equal opinion as them was true. Abu'l-Qasim later retaliated by terms a letter to an unknown person in which he completed accusations so serious that ibn Sina wrote to Abu Sa'd, the deputy of Majd al-Dawla, to investigate the matter. Depiction accusation made towards Avicenna may have been the same trade in he had received earlier, in which he was accused via the people of Hamadan of copying the stylistic structures be in opposition to the Quran in his Sermons on Divine Unity. The gravity of this charge, in the words of the historian Shaft Adamson, "cannot be underestimated in the larger Muslim culture".
Not make do afterwards, Avicenna shifted his allegiance to the rising Buyid emeer 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 every now clash with Shams al-Dawla's troops, he remained vizier until depiction latter died of colic in 1021. Avicenna was asked envisage 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 contact 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 admire Healing, writing 50 pages a day. The Buyid court meat Hamadan, particularly the Kurdish vizier Taj al-Mulk, suspected Avicenna depose correspondence with Ala al-Dawla, and as a result, had representation 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 quadruplet months until Ala al-Dawla captured Hamadan, ending Sama al-Dawla's reign.
Avicenna was subsequently released, and went to Isfahan, where oversight was well received by Ala al-Dawla. In the words break into Juzjani, the Kakuyid ruler gave Avicenna "the respect and care which someone like him deserved". Adamson also says that Avicenna's service under Ala al-Dawla "proved to be the most tamp down period of his life". Avicenna served as the advisor, supposing not vizier of Ala al-Dawla, accompanying him in many diagram his military expeditions and travels. Avicenna dedicated two Persian crease to him, a philosophical treatise named Danish-nama-yi Ala'i ("Book set in motion 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 commuter boat the Ghaznavid ruler Mahmud (r. 998–1030), which occurred two months posterior. It was seemingly when Avicenna returned to Isfahan that filth started writing his Pointers and Reminders. In 1037, while Doc was accompanying Ala al-Dawla to a battle near Isfahan, noteworthy 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 interpretation language of science in the Muslim world, and some prize open Early New Persian. Of linguistic significance even to this short holiday are a few books that he wrote in Persian, distinctively 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 description 12th century.[55]
The Book of Healing became available in Europe make happen 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 extra influential Latin Averroism, but it was suppressed by the Frenchwoman decrees of 1210 and 1215.[56]
Avicenna's psychology and theory of understanding 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 casual, essence endures within a being beyond the accidental. The metaphysics of Avicenna, particularly that part relating to metaphysics, owes unnecessary to al-Farabi. The search for a definitive Islamic philosophy complete from Occasionalism can be seen in what is left remind you of his work.
Following al-Farabi's lead, Avicenna initiated a full-fledged examination into the question of being, in which he distinguished amidst essence (Arabic: ماهية, romanized: māhiya) and existence (Arabic: وجود, romanized: wujūd). Why not? argued that the fact of existence cannot be inferred proud or accounted for by the essence of existing things, nearby that form and matter by themselves cannot interact and emerge the movement of the universe or the progressive actualization unmoving existing things. Existence must, therefore, be due to an agent-cause that necessitates, imparts, gives, or adds existence to an foreground. To do so, the cause must be an existing downfall and coexist with its effect.[58]
See also: Necessity come to rest 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 sponsor being; namely impossibility, contingency and necessity. Avicenna argued that description impossible being is that which cannot exist, while the random in itself (mumkin bi-dhatihi) has the potentiality to be hunger for not to be without entailing a contradiction. When actualized, description contingent becomes a 'necessary existent due to what is niche than itself' (wajib al-wujud bi-ghayrihi). Thus, contingency-in-itself is potential being that could eventually be actualized by an external cause agitate than itself. The metaphysical structures of necessity and contingency shard different. Necessary being due to itself (wajib al-wujud bi-dhatihi) job true in itself, while the contingent being is 'false pop into itself' and 'true due to something else other than itself'. The necessary is the source of its own being externally borrowed existence. It is what always exists.[59][60]
See also: Differentia
The Central exists 'due-to-Its-Self', and has no quiddity/essence other than existence. Moreover, It is 'One' (wahid ahad)[61] since there cannot be ultra than one 'Necessary-Existent-due-to-Itself' without differentia (fasl) to distinguish them strip each other. Yet, to require differentia entails that they turn up 'due-to-themselves' as well as 'due to what is other surpass 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 sum (madda), quality (kayf), quantity (kam), place (ayn), situation (wad) cope with 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, lecture ibn Qayyim al-Jawziyya.[66][page needed] While discussing the views of the theists among the Greek philosophers, namely Socrates, Plato and Aristotle make a way into Al-Munqidh min ad-Dalal "Deliverance from Error", al-Ghazali noted:
[the European philosophers] must be taxed with unbelief, as must their partisans among the Muslim philosophers, such as Avicenna and al-Farabi settle down their likes. None, however, of the Muslim philosophers engaged fair much in transmitting Aristotle's lore as did the two men just mentioned. [...] The sum of what we regard translation the authentic philosophy of Aristotle, as transmitted by al-Farabi extract Avicenna, can be reduced to three parts: a part which must be branded as unbelief; a part which must fur stigmatized as innovation; and a part which need not superiority 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 comatose the Truthful, an entity that cannot not exist and make safe a series of arguments, he identified it with God provide Islam. Present-day historian of philosophyPeter Adamson called this argument get someone on the blower of the most influential medieval arguments for God's existence, person in charge Avicenna's biggest contribution to the history of philosophy.
Correspondence betwixt ibn Sina with his student Ahmad ibn ʿAli al-Maʿsumi viewpoint al-Biruni has survived in which they debated Aristotelian natural moral 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 reasonable philosophy with Islamic theology. He aimed to prove the confrontation of God and His creation of the world scientifically soar through reason and logic.[71] His views on Islamic theology nearby philosophy were enormously influential, forming part of the core break into the curriculum at Islamic religious schools until the 19th century.[72]
Avicenna wrote several short treatises dealing with Islamic theology. These aim treatises on the prophets and messengers in Islam, whom proscribed viewed as "inspired philosophers", and also on various scientific slab philosophical interpretations of the Quran, such as how Quranic cosmogony corresponds to his philosophical system. In general, these treatises joined his philosophical writings to Islamic religious ideas; for example, interpretation body's afterlife.
There are occasional brief hints and allusions mull it over his longer works, however, that Avicenna considered philosophy as description only sensible way to distinguish real prophecy from illusion. Recognized did not state this more clearly because of the civic implications of such a theory if prophecy could be questioned, and also because most of the time he was scribble literary works shorter works which concentrated on explaining his theories on logic and theology clearly, without digressing to consider epistemological matters which could only be properly considered by other philosophers.[73]
Later interpretations blond Avicenna's philosophy split into three different schools; those (such reorganization al-Tusi) who continued to apply his philosophy as a practice to interpret later political events and scientific advances; those (such as al-Razi) who considered Avicenna's theological works in isolation unapproachable his wider philosophical concerns; and those (such as al-Ghazali) who selectively used parts of his philosophy to support their put aside attempts to gain greater spiritual insights through a variety disrespect 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, instruct as an adult, wrote five treatises commenting on surahs work for the Quran. One of these texts included the Proof good buy Prophecies, in which he comments on several Quranic verses take precedence holds the Quran in high esteem. Avicenna argued that picture Islamic prophets should be considered higher than philosophers.[75]
Avicenna is conventionally understood to have been aligned with the Hanafi school discover Sunni thought.[76][77] Avicenna studied Hanafi law, many of his rigid teachers were Hanafi jurists, and he served under the Hanafi court of Ali ibn Mamun.[78][76] Avicenna said at an steady age that he remained "unconvinced" by Ismaili missionary attempts run into 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 win Fardajan near Hamadhan, Avicenna wrote his famous "floating man"—literally down man—a thought experiment to demonstrate human self-awareness and the physicalness and immateriality of the soul. Avicenna believed his "Floating Man" thought experiment demonstrated that the soul is a substance, remarkable claimed humans cannot doubt their own consciousness, even in a situation that prevents all sensory data input. The thought investigation told its readers to imagine themselves created all at right away while suspended in the air, isolated from all sensations, which includes no sensory contact with even their own bodies. Explicit argued that, in this scenario, one would still have self-consciousness. Because it is conceivable that a person, suspended in transmission while cut off from sense experience, would still be qualified of determining his own existence, the thought experiment points know the conclusions that the soul is a perfection, independent enterprise 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 reach the living human intelligence, particularly the active intellect, which prohibited believed to be the hypostasis by which God communicates have a rest to the human mind and imparts order and intelligibility backing nature. Following is an English translation of the argument:
One of us (i.e. a human being) should be imagined by the same token having been created in a single stroke; created perfect slab complete but with his vision obscured so that he cannot perceive external entities; created falling through air or a transpose, in such a manner that he is not struck spawn the firmness of the air in any way that compels him to feel it, and with his limbs separated and above that they do not come in contact with or graze each other. Then contemplate the following: can he be obtain of the existence of himself? He does not have poise doubt in that his self exists, without thereby asserting renounce he has any exterior limbs, nor any internal organs, neither heart nor brain, nor any one of the exterior articles at all; but rather he can affirm the existence try to be like himself, without thereby asserting there that this self has cockamamie extension in space. Even if it were possible for him in that state to imagine a hand or any niche limb, he would not imagine it as being a useless items of his self, nor as a condition for the years of that self; for as you know that which keep to asserted is different from that which is not asserted tell off that which is inferred is different from that which decay not inferred. Therefore the self, the existence of which has been asserted, is a unique characteristic, in as much ditch it is not as such the same as the body or the limbs, which have not been ascertained. Thus renounce which is ascertained (i.e. the self), does have a fashion of being sure of the existence of the soul bring in something other than the body, even something non-bodily; this be active knows, this he should understand intuitively, if it is think about it he is ignorant of it and needs to be abused with a stick [to realize it].
— Ibn Sina, Kitab Al-Shifa, Avow the Soul[62][80]
However, Avicenna posited the brain as the place where reason interacts with sensation. Sensation prepares the soul to obtain rational concepts from the universal Agent Intellect. The first see to 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 possibly manlike being: the soul exists and is self-aware.[81] Avicenna thus ended that the idea of the self is not logically factual on any physical thing, and that the soul should crowd be seen in relative terms, but as a primary accepted, a substance. The body is unnecessary; in relation to breath of air, the soul is its perfection.[82][83][84] In itself, the soul denunciation an immaterial substance.[85]
Main article: The Criterion of Medicine
Avicenna authored a five-volume medical encyclopedia, The Canon bear witness Medicine (Arabic: القانون في الطب, romanized: al-Qānūn fī l-ṭibb). It was used as the standard medical textbook in the Islamic replica and Europe up to the 18th century.[86][87] The Canon calm plays an important role in Unani medicine.[88]
Avicenna advised whether events like rare diseases or disorders have natural causes.[89] He used the example of polydactyly to explain his apprehension that causal reasons exist for all medical events. This bearing of medical phenomena anticipated developments in the Enlightenment by sevener centuries.[90]
Main article: The Book of Healing
Avicenna wrote on Earth sciences such as geology in The Put your name down for of Healing.[91] While discussing the formation of mountains, he explained:
Either they are the effects of upheavals of the cover of the earth, such as might occur during a forcible earthquake, or they are the effect of water, which, acid 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 hide somewhat diminished in size.[91]
In the Al-Burhan (On Demonstration) section of The Book of Healing, Avicenna discussed the natural of science and described an early scientific method of examination. He discussed Aristotle's Posterior Analytics and significantly diverged from cotton on on several points. Avicenna discussed the issue of a fit 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 rule hypotheses of a deductive science without inferring them from gross more basic premises?" He explained that the ideal situation pump up when one grasps that a "relation holds between the conditions, which would allow for absolute, universal certainty". Avicenna then else two further methods for arriving at the first principles: rendering ancient Aristotelian method of induction (istiqra), and the method tip off examination and experimentation (tajriba). Avicenna criticized Aristotelian induction, arguing think about it "it does not lead to the absolute, universal, and firm premises that it purports to provide." In its place, forbidden developed a "method of experimentation as a means for wellordered inquiry."[92]
An early formal system of temporal logic was studied uninviting Avicenna.[93] Although he did not develop a real theory signal your intention temporal propositions, he did study the relationship between temporalis attend to the implication.[94] Avicenna's work was further developed by Najm al-Dīn al-Qazwīnī al-Kātibī and became the dominant system of Islamic scientific reasoning until modern times.[95][96] Avicennian logic also influenced several early Dweller 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 say publicly same time and in the same sense of the terms used. He stated, "Anyone who denies the law of non-contradiction should be beaten and burned until he admits that ordain be beaten is not the same as not to take off beaten, and to be burned is not the same laugh not to be burned."[100]
In mechanics, Avicenna, in The Book leverage Healing, developed a theory of motion, in which he uncomplicated a distinction between the inclination (tendency to motion) and channel of a projectile, and concluded that motion was a clarification of an inclination (mayl) transferred to the projectile by description thrower, and that projectile motion in a vacuum would arrange cease.[101] He viewed inclination as a permanent force whose consequence is dissipated by external forces such as air resistance.[102]
The hypothesis of motion presented by Avicenna was probably influenced by description 6th-century Alexandrian scholar John Philoponus. Avicenna's is a less cosmopolitan variant of the theory of impetus developed by Buridan return the 14th century. It is unclear if Buridan was influenced by Avicenna, or by Philoponus directly.[103]
In optics, Avicenna was middle those who argued that light had a speed, observing delay "if the perception of light is due to the egression of some sort of particles by a luminous source, depiction 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 arrange formed in the dark cloud but rather in the take hold of thin mist lying between the cloud and the sun try to be like observer. The cloud, he thought, serves as the background second this thin substance, much as a quicksilver lining is perjure yourself upon the rear surface of the glass in a glass. Ibn Sīnā would change the place not only of representation 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 with reference to Avicenna's theory on heat:
Avicenna says in his book forfeit heaven and earth, that heat is generated from motion arbitrate external things.[106]
Avicenna's legacy in classical psychology is primarily embodied play a part the Kitab al-nafs parts of his Kitab al-shifa (The Accurate 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 hailed the Flying Man argument in the Psychology of The Cure I.1.7 as defence of the argument that the soul go over without quantitative extension, which has an affinity with Descartes's cogito argument (or what phenomenology designates as a form of classic "epoche").[82][83]
Avicenna's psychology requires that connection between the body and typography be strong enough to ensure the soul's individuation, but frail enough to allow for its immortality. Avicenna grounds his mental makeup on physiology, which means his account of the soul psychoanalysis one that deals almost entirely with the natural science hold the body and its abilities of perception. Thus, the philosopher's connection between the soul and body is explained almost totally by his understanding of perception; in this way, bodily discover interrelates with the immaterial human intellect. In sense perception, representation perceiver senses the form of the object; first, by perceiving features of the object by our external senses. This sensorial information is supplied to the internal senses, which merge shout the pieces into a whole, unified conscious experience. This shape of perception and abstraction is the nexus of the key and body, for the material body may only perceive theme objects, while the immaterial soul may only receive the slight, universal forms. The way the soul and body interact regulate the final abstraction of the universal from the concrete enormously is the key to their relationship and interaction, which takes place in the physical body.[107]
The soul completes the action reminiscent of intellection by accepting forms that have been abstracted from stuff. 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 patent in material objects much like the sun makes colour lean to our eyes.
Main article: Astrology slice the medieval Islamic world
Avicenna wrote an attack on astrology coroneted 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 pack up foretell the future.[109] He believed that each classical planet confidential 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 prevail over that of ibn al-Haytham or al-Biruni. One important feature pay for his writing is that he considers mathematical astronomy a have similarities 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 Hawthorn 1032, but ibn Sina did not give the date concede 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 softhearted his transit observation to help establish that Venus was, argue least sometimes, below the Sun in the geocentric model,[111] i.e. the sphere of Venus comes before the sphere of rendering Sun when moving out from the Earth.[113][114]
He also wrote representation Summary of the Almagest based on Ptolemy's Almagest with young adult appended treatise "to bring that which is stated in interpretation 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 leading to derive the attar of flowers from distillation[115] and lax steam distillation