伊本·西那（阿維森納）

Abu Ali al-Husayn ibn Abd Allah ibn Sina was born around 980 in Afshana near Bukhara, then the capital of the Persian Samanid empire. His father was an administrator from Balkh. The family moved to Bukhara, a centre of Persian and Arabic learning. In Europe he became known by the Latinised name Avicenna.

According to the autobiography he dictated to his student al-Juzjani, he knew the Qur'an and much literature by the age of ten. He studied arithmetic, jurisprudence, logic and medicine, partly on his own. By his own account he understood Aristotle's Metaphysics only after reading a commentary by al-Farabi. This autobiography is an important but also deliberately stylised source.

Around 997 he successfully treated the Samanid emir Nuh II and was then allowed to use the royal library. After the collapse of the Samanid empire he moved between courts in Khwarazm, Gorgan, Rey, Hamadan and Isfahan. He worked there as a physician, administrator and vizier, which also drew him into political conflicts and a brief imprisonment.

His 'Canon of Medicine' combined Greco-Roman medicine, above all Galen's, with Persian and Indian knowledge and his own observations, in five books: general principles, simple drugs, diseases by organ, general conditions and compound medicines. The work is systematically organised and discusses topics including contagion, quarantine and rules for testing drugs.

In 'The Book of Healing' and shorter works he developed his own philosophy in the tradition of Aristotle and Neoplatonism. He is known for his distinction between essence and existence, his argument for a 'necessary existent' and the thought experiment of the 'floating man', meant to show self-awareness independent of sense perception.

Around the year 1000 the Abbasid caliphate was politically fragmented. Regional dynasties such as the Samanids, Ghaznavids, Buyids and Kakuyids fought for power but also competed as patrons of poets, physicians and scholars. Scholars were therefore mobile, but also dependent on the favour and fortunes of their rulers.

The translation movement of the 8th to 10th centuries had made Greek philosophy, medicine and mathematics available in Arabic. Arabic was the language of science and religion, while Persian flourished again as a literary language. Ibn Sina wrote mainly in Arabic but also some works in Persian, such as the encyclopaedia Danishnama-yi Ala'i.

The Canon became a standard work in the Islamic world and, after its Latin translation by Gerard of Cremona in the 12th century, also at European universities such as Montpellier and Padua. Numerous commentaries and printed editions appeared; in Europe the work was taught into the 17th century, although criticism of it grew from the 16th century.

His philosophy provoked fierce responses. In the late 11th century al-Ghazali attacked, in 'The Incoherence of the Philosophers', his views on the eternity of the world and on God's knowledge of particulars, among others. In Latin Europe, Avicenna influenced thinkers such as Thomas Aquinas and Duns Scotus, while his work was taught for centuries in Persia and the Ottoman Empire.

Ibn Sina died in June 1037 in Hamadan, according to his biographer from an intestinal illness contracted during a military campaign. His grave is in Hamadan; the present mausoleum dates from the mid-20th century. He left more than a hundred works, although the attribution of some texts is uncertain.

In Iran, Uzbekistan and Tajikistan, hospitals, universities and prizes bear his name, and several countries honour him as a national figure. Historians stress that much of his medical knowledge built on Galen and earlier Islamic physicians such as al-Razi; his significance lies above all in his systematic synthesis and the influence of his philosophy.