The History of Literature is mainly the history of written monuments. So, at the end of our book, the history of literature, some questions arise, questions about the amount of Greek texts that have been preserved and about the form of their transmission.
If someone asks about the proportion of those that have been saved compared to those that have been lost, we are obliged to answer that only a very small part has been handed down to us, certainly much less than one tenth. One of the most important factors in preserving an author, as we have often noted so far, was teaching in schools and higher education; on the contrary, the hostility of the Church was destructive for many. Then, in the Byzantine years, the lack of love and understanding caused many to be lost. Thus, many excellent works reached us, certainly the most wonderful ones, but also some lesser ones, while several other excellent works, such as those of Sappho and Menander, Democritus and Aristotle's youthful writings, disappeared for us. However, the volume of Greek texts that have been saved is much larger than that of Latin texts. And this is because the Romans reached spiritual maturity much later than the Greeks, but because the latter had the gift of literary creation above all peoples.
[...] (from the Appendix of the book)