[15] Besides philosophy and medicine, Avicenna's corpus includes writings on astronomy, alchemy, geography and geology, psychology, Islamic theology, logic, mathematics, physics, and works of poetry.

Greco-Roman (Middle Platonic, Neoplatonic, and Aristotelian) texts translated by the Kindi school were commented, redacted and developed substantially by Islamic intellectuals, who also built upon Persian and Indian mathematical systems, astronomy, algebra, trigonometry and medicine.

The study of the Quran and the Hadith also thrived, and Islamic philosophy, fiqh "jurisprudence", and kalam "speculative theology" were all further developed by ibn Sina and his opponents at this time.

[25] An official of the Samanid bureaucracy, he had served as the governor of a village of the royal estate of Harmaytan near Bukhara during the reign of Nuh II (r. 976–997).

He was planning to visit the ruler of the city of Gorgan, the Ziyarid Qabus (r. 977–981, 997–1012), a cultivated patron of writing, whose court attracted many distinguished poets and scholars.

[26][37] Avicenna stayed briefly in Gorgan, reportedly serving Qabus's son and successor Manuchihr (r. 1012–1031) and resided in the house of a patron.

[26] In c. 1014, Avicenna went to the city of Ray, where he entered into the service of the Buyid amir Majd al-Dawla (r. 997–1029) and his mother Sayyida Shirin, the de facto ruler of the realm.

Avicenna reportedly later served as the "business manager" of Sayyida Shirin in Qazvin and Hamadan, though details regarding this tenure are unclear.

[38] In 1015, during Avicenna's stay in Hamadan, he participated in a public debate, as was customary for newly arrived scholars in western Iran at that time.

It was during this period that Avicenna was secretly in contact with Ala al-Dawla Muhammad (r. 1008–1041), the Kakuyid ruler of Isfahan and uncle of Sayyida Shirin.

[58] 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.

[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 matter (madda), quality (kayf), quantity (kam), place (ayn), situation (wad) and time (waqt).

[77] While he was imprisoned in the castle of Fardajan near Hamadhan, Avicenna wrote his famous "floating man"—literally falling man—a thought experiment to demonstrate human self-awareness and the substantiality and immateriality of the soul.

Avicenna believed his "Floating Man" thought experiment demonstrated that the soul is a substance, and claimed humans cannot doubt their own consciousness, even in a situation that prevents all sensory data input.

The thought experiment told its readers to imagine themselves created all at once while suspended in the air, isolated from all sensations, which includes no sensory contact with even their own bodies.

Thus that which is ascertained (i.e. the self), does have a way of being sure of the existence of the soul as something other than the body, even something non-bodily; this he knows, this he should understand intuitively, if it is that he is ignorant of it and needs to be beaten with a stick [to realize it].However, Avicenna posited the brain as the place where reason interacts with sensation.

[85] Avicenna authored a five-volume medical encyclopedia, The Canon of Medicine (Arabic: القانون في الطب, romanized: al-Qānūn fī l-ṭibb).

[91]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.

[94] Avicenna's work was further developed by Najm al-Dīn al-Qazwīnī al-Kātibī and became the dominant system of Islamic logic until modern times.

Avicenna grounds his psychology on physiology, which means his account of the soul is one that deals almost entirely with the natural science of the body and its abilities of perception.

[118]Four works on alchemy attributed to Avicenna were translated into Latin as:[119] Liber Aboali Abincine de Anima in arte Alchemiae was the most influential, having influenced later medieval chemists and alchemists such as Vincent of Beauvais.

[120] The epistola de Re recta is somewhat less sceptical of alchemy; Anawati argues that it is by Avicenna, but written earlier in his career when he had not yet firmly decided that transmutation was impossible.

As an example, Edward Granville Browne claims that the following Persian verses are incorrectly attributed to Omar Khayyám, and were originally written by Ibn Sīnā:[122] از قعر گل سیاه تا اوج زحل کردم همه مشکلات گیتی را حل بیرون جستم زقید هر مکر و حیل هر بند گشاده شد مگر بند اجل From the depth of the black earth up to Saturn's apogee, All the problems of the universe have been solved by me.

"[124] As early as the 14th century when Dante Alighieri depicted him in Limbo alongside the virtuous non-Christian thinkers in his Divine Comedy such as Virgil, Averroes, Homer, Horace, Ovid, Lucan, Socrates, Plato and Saladin.

[127] Aristotle's dominant intellectual influence among medieval European scholars meant that Avicenna's linking of Galen's medical writings with Aristotle's philosophical writings in the Canon of Medicine (along with its comprehensive and logical organisation of knowledge) significantly increased Avicenna's importance in medieval Europe in comparison to other Islamic writers on medicine.

His influence following translation of the Canon was such that from the early fourteenth to the mid-sixteenth centuries he was ranked with Hippocrates and Galen as one of the acknowledged authorities, princeps medicorum ("prince of physicians").

[132] The 1982 Soviet film Youth of Genius (Russian: Юность гения, romanized: Yunost geniya) by Elyor Ishmukhamedov [ru] recounts Avicenna's younger years.

In his book The Physician (1988) Noah Gordon tells the story of a young English medical apprentice who disguises himself as a Jew to travel from England to Persia and learn from Avicenna, the great master of his time.

The treatises of Avicenna influenced later Muslim thinkers in many areas including theology, philology, mathematics, astronomy, physics and music.

There is also a حكمت مشرقيه (hikmat-al-mashriqqiyya, in Latin Philosophia Orientalis), mentioned by Roger Bacon, the majority of which is lost in antiquity, which according to Averroes was pantheistic in tone.