Avicenna
Persian philosopher, physician and polymath (980–1037), born near Bukhara, in present-day Uzbekistan, regarded as an intellectual prodigy who, according to his own autobiography, had already memorised the Quran and mastered logic, geometry and algebra by the age of ten, and who learned medicine in a largely self-taught manner, becoming a court physician at eighteen and later serving as vizier in various Persian courts in a life marked by political instability, frequent exile and even a brief imprisonment. His central medical work, The Canon of Medicine, an encyclopaedic summa systematising Galenic and Greek learning alongside his own contributions and those of Indian and Persian medicine, became the standard medical reference text both in the Islamic world and, once translated into Latin, in European universities, where it remained mandatory reading well into the seventeenth century — a period of nearly six hundred years of unbroken authority unmatched in the history of medicine. In philosophy, his magnum opus, The Book of Healing (Kitab al-Shifa), a vast encyclopaedia of logic, physics, mathematics and metaphysics, develops an original synthesis of Aristotelianism and Neoplatonism that would exert a decisive influence both on later Islamic philosophy and, through Latin translations, on medieval Christian scholasticism, particularly on Thomas Aquinas and Duns Scotus. One of his most celebrated arguments, the so-called 'flying man argument', posits that a human being created instantaneously in mid-air, with no sensory perception of his own body, would still possess certain awareness of his own existence — an argument Avicenna used to demonstrate the real distinction between soul and body. He also formulated an influential metaphysical distinction between essence and existence, arguing that in every being except God, existence is contingently added to essence. Known in the West as Avicenna, he remained for centuries the principal European gateway to Aristotelian thought as filtered and reworked through the Islamic tradition.