An excerpt from A Concise History of Book Burning, 2nd edition 2013
Estimates of the number of works collected within the library of Alexandria range from 500,000, to more than a million, but as no list or catalogue of the library’s contents has ever come to light, these figures must remain possibilities. The number of scrolls, however, must have been great, as the library was founded by Ptolemy I Soter, and continued to exist in some form until the sack of Alexandria by the Arab leader Amr ibn al’Aas in 639 AD. Asked what should be done with the library, Amr ibn al’Aas is reported to have said that the books ‘either contradict the Koran, in which case they are heresy, or they agree with it, in which case they are superfluous,’ and ordered they be burned to heat the baths for his soldiers. Debate remains over the truth of this, as it does over much that is said about the library, but by this time it had been accidentally burned by Julius Caesar, when he inadvertently set fire to it while trying to prevent Ptolemy III from reaching his ships (48 BC); suffered pillage by the Emperor Aurelian (273 AD); and was destroyed by the Christian Patriarch Theophilus in 391, when the Christian Emperor Theodosius ordered the destruction of all pagan temples. On this occasion, the Serapeum, dedicated to the worship of the syncretic god Serapis, was also destroyed, as were temples to Mithras and other heathen deities.
Alexandria had been a remarkably tolerant city under Greek and pagan Roman rule, but by the time the Christians had control, this liberal attitude had vanished, and Theodosius is credited with inaugurating the practice of burning books on purpose (unlike Julius Caesar, who only did it by accident.) Not long after Theophilus started scouring Alexandria clean of heathens, the pagan philosopher Hypatia, one of the most brilliant women of the ancient world, was attacked by a mob of Christian fanatics, who skinned her alive with oyster shells and burned her remains. They were encouraged in this by Cyril, the Christian patriarch who followed Theophilus, and who was later canonized. Although the Platonic Academy would carry on for another century or so, to all intents and purposes, the pagan world ended with Hypatia’s death.
As the library housed most of the world’s great knowledge it understandably attracted the world’s thinkers and scholars. We can only surmise what other writings could be found in this lost treasure — many, no doubt, that we have never heard of — but known to have been contained in its shelves were the works of Euclid, Archimedes, and the astronomer Ptolemy, whose view of the cosmos would remain dominant until Copernicus pointed out its discrepancies in 1543. Among others whose work could be found in the library were Eratosthenes, who knew the circumference of the Earth, and Aristarchus, who argued that the planets orbit the sun, centuries before Copernicus did. The forty-two books that Clement of Alexandria attributed to Hermes Trismegistus were, he believed, available at the library. These, alas, he also believed had been destroyed by Julius Caesar’s clumsiness.