Of the literary works of classical antiquity, only a fraction have survived to the present day. What fraction this is, we do not know; one estimate places it at one-fourth, but the true figure will never be known. The reader may wonder how it can be that literary masterpieces could have been permitted to fade into obscurity, and then oblivion; but, on further reflection, he will marvel more at the fact that anything at all survived from antiquity than rue the losses we have suffered. Printing and the mass production of books are relatively new inventions. For most of history (in Europe at least) books could only be reproduced as fast as a copyist could transcribe them. Multiplicity was the only insurance against destruction: the more copies in existence, the better the book’s chance of survival.