Of Aeschylus' eighty or ninety plays and the roughly one hundred twenty by Sophocles, only seven each have survived; Euripides and Aristophanes did slightly better: eighteen of ninety-two play by the former have come down to us; eleven of forty-three by the latter.
These are the great success stories. Virtually the entire output of many other writers, famous in antiquity, has disappeared without a trace. Scientists, historians, mathematicians, philosophers, and statesmen have left behind some of their achievements -- the invention of trigonometry, for example, or the calculation of position by reference to latitude and longitude, or the rational analysis of political power -- but their books are gone. The indefatigable scholar Didymus of Alexandria earned the nickname Bronze-Ass for having what it took to write more than 3,500 books; apart from a few fragments, all have vanished. At the end of the fifth century CE an ambitious literary editor known as Stobaeus compiled an anthology of prose and poetry by the ancient world's best authors: out of 1,430 quotations, 1,115 are from works are now lost.
In this general vanishing, all the works of the brilliant founders of atomism, Leucippus and Democritus, and most of the works of their intellectual heir Epicurus, disappeared. Epicurus had been extraordinarily prolific. He and his principal philosophical opponent, the Stoic Chrysippus, wrote between them, it was said, more than a thousand books. Even if the figure is exaggerated or if it counts as books what we would regard as essays and letters, the written record was clearly massive. That record no longer exists. . . .
There was a time in the ancient world -- a very long time -- in which the central cultural problem must have seemed an inexhaustible outpouring of books. Where to put them all? How to organize the groaning shelves? How to hold the profusion of knowledge in one's head? The loss of this plenitude would have been virtually inconceivable to anyone living in its midst.
--Stephen Greenblatt, The Swerve