LIke human cultures, book cultures depend on reproduction for their survival. In the evolution of the written book in Western Europe, the passage from the ancient Roman world to the middle ages was a critical moment, as many books of the ancient world were endangered with extinction during the 5th to the 9th centuries.
The Dark Ages are the age of booklessness.
At no other point since the literary explosion of the Hellenistic age was the textual output of the Western cultures in greater peril.
The first cause was reproduction. This is very obvious. Fewer books were copied. Low fertility rate. Not everything was copied at the same rate – survival of the fittest book. Ideological and practical filtering privileged certain texts at the expense of others. While some flourished, others became extinct or critically endangered. Not everybody wins, there is always competition because time and scribal hands are limited, and a preserve-all notion hadn’t been invented yet.
The other cause was circulation. Texts thought to have disappeared by the 15th century were discovered in century-old books in secluded spaces. Although those texts were copied and reproduced, they were not marketed and did not circulate. Affected by a long-term critically-endangered status, these books lingered on forgotten shelves waiting to be discovered. The attrition rate of such books is surprisingly low. They were eventually discovered. It’s astonishing that in many cases the survival of an ancient text depended on a single rotting book on a tucked-away medieval shelf.
How lucky we are.