Ibn Sina (Avicenna)

A prodigy who had memorised the Qur'an by ten and was practising medicine at sixteen, Ibn Sina produced The Canon of Medicine, a five-volume synthesis that organised all known medicine into a searchable system, and The Book of Healing, which fused Aristotle with Islamic theology and set the agenda for scholastic philosophy.

• Wrote The Canon of Medicine, a standard European university text for over 500 years
• Described contagion, quarantine, clinical drug trials and the link between emotions and physical health
• Formulated the 'floating man' thought experiment, an early argument for self-awareness independent of the senses
• Advanced the distinction between essence and existence, which Thomas Aquinas built upon

His rules for testing a drug — test on a single uncomplicated disease, in two contrasting cases, observe timing and reproducibility — are recognisably the logic of the modern clinical trial that licenses every medicine on sale. Quarantine practice during COVID-19 traced to principles he codified. In philosophy, his essence/existence distinction runs through Aquinas into contemporary metaphysics.

Ibn Sina's restless, itinerant life at rival Persian courts left no record of a wife or children; his biography was dictated to his student al-Juzjani, who completed it and preserved the corpus.