AVICENNA

Abu Ali al-Husayn ibn Sina was born around 980 CE in Afshana, a village near Bukhara in the Samanid Empire — the eastern edge of the Islamic world, where Persian culture flourished under nominal Arabic sovereignty. His father was a government official and Ismaili sympathiser; his household hosted philosophical discussions that young Avicenna absorbed precociously.

His intellectual development was explosive. He memorised the Quran by ten. He mastered logic, mathematics, and natural science by fourteen. He studied medicine and began treating patients at sixteen. At eighteen, he was summoned to treat the Samanid sultan Nuh ibn Mansur, whom he cured. As reward, he gained access to the royal library — and claimed he read its entire contents, mastering all knowledge available to his age.

“By the time I was eighteen,” he later wrote, “I had completed my study of all the sciences. Since then, I have not learned anything new.” The boast contains truth: his systematic works show comprehensive command of every discipline. What remained was deepening, applying, and integrating.

But stability eluded him. The Samanid dynasty fell in 999 CE; Bukhara was conquered by Turkic invaders. Avicenna began decades of wandering across Persia, serving various princes as physician, administrator, and sometimes vizier. He worked for the Buyid rulers of Rayy, Hamadan, and Isfahan, navigating court politics, surviving intrigues, occasionally imprisoned when patrons fell or turned hostile.

He wrote constantly — often at night, after days of administrative work and medical practice. His students accompanied him, taking dictation, copying manuscripts, asking questions that prompted new treatises. His servant Juzjani preserved a partial autobiography and completed the biography after his death. The picture is of relentless productivity: composing the Canon of Medicine (which would dominate medical education for 600 years), dictating the Shifa (a philosophical encyclopaedia), writing poetry, letters, treatises on particular problems, all while running bureaucracies and treating patients.

His lifestyle was controversial. He enjoyed wine, reportedly to excess. He had relationships with women (and perhaps men) outside marriage. When critics accused him of failing to live by philosophy’s standards, he countered that his constitution required stimulation, and besides, he harmed no one. The defence convinced few then; it anticipates modern arguments about victimless behaviour.

He settled finally in Isfahan under the Kakuyid prince Ala al-Dawla, his most stable patronage. There he completed major works and enjoyed intellectual companionship. But military campaigns required his attendance; his health deteriorated. Around 1037 CE, accompanying his patron on campaign, he fell seriously ill with colic. He treated himself aggressively but refused to moderate his activities. In Hamadan, en route, he died. He was 57.

His tomb in Hamadan became a pilgrimage site. His works spread throughout the Islamic world and, translated into Latin, throughout Christian Europe. The “Prince of Physicians” became, alongside Aristotle, one of the two philosophers most cited in medieval scholasticism.

Avicenna’s metaphysics centers on a single distinction: essence versus existence. For any contingent being, we can ask what it is (essence) without knowing whether it exists (existence). The essence of a triangle doesn’t include actual existence; triangles might or might not exist. Essence and existence are therefore distinct — existence is added to essence from outside.

This generates the fundamental question: why does anything exist? For any contingent being, its existence requires a cause. That cause is either itself contingent (requiring a further cause) or necessary. Infinite regress is impossible; therefore, there must be a Necessary Existent — a being whose essence includes existence, who cannot not exist, who is the ultimate cause of everything else. This is God.

God, the Necessary Existent, is absolutely simple — no composition of essence and existence, no distinction of attributes. God’s knowledge is not like ours (knowing particulars through sense and abstraction); God knows all things by knowing God’s own essence, which is the cause of all things. This raised problems: does God know individuals? Avicenna’s answer was complex and troubled later thinkers.

From God emanates the first intellect; from the first intellect, through contemplation of God and itself, emanate further intellects and celestial spheres — the Neoplatonic cascade adapted from al-Farabi. The tenth intellect, the Active Intellect, governs our world and illuminates human minds, enabling knowledge.

The soul is the body’s form but also a substance capable of independent existence. Avicenna’s “Flying Man” thought experiment demonstrates this: imagine yourself created suddenly, floating in air, limbs spread, perceiving nothing — not even your own body. Would you know you exist? Yes. Therefore, self-knowledge is independent of bodily knowledge. The soul knows itself directly, not through the body. This suggests (though doesn’t prove) that the soul can exist without the body — immortality.

Knowledge occurs when the soul, properly prepared through sensation, abstraction, and reasoning, receives intelligible forms from the Active Intellect. The highest knowledge is prophetic: the prophet’s soul is so perfectly prepared that intelligibles overflow into both intellect and imagination, producing theoretical knowledge and symbolic visions simultaneously. Prophecy is thus natural, not miraculous — the perfection of human cognitive capacity.

His ethics follows Aristotle: happiness is the soul’s perfection through knowledge and virtue. The afterlife continues this: souls that achieved intellectual perfection enjoy eternal contemplation; souls that remained attached to bodily things suffer from desires they cannot fulfil. Heaven and hell are psychological states of the disembodied soul, not physical places with physical rewards and punishments. This interpretation of resurrection caused great controversy.