- Apr 2019
There's still a lot to be found, I expect. As Tulius noted, medieval manuscripts were sometimes recycled into early modern bookbindings or simply erased, and now we know to look in the bindings and we have the technology to read those that were erased. We also need to consider the linguistic gap. Latin materials are usually catalogued fairly well in western libraries, but other materials have not always received the requisite attention. A librarian friend at Major Research University in the USA who is specialized in just this said that American libraries typically have very poor and outdated catalogues of their holdings in Greek, to say nothing on non-western or non-Indo-European languages. There is also a lot of discovery to be made simply by integrating a wider range of texts and languages. This may not have much to add to, say, the religious history of 14th c. England, but in my own field of Byzantine Studies, where many languages and cultures crossed but where the history has largely been written from Greek sources, there's so much more to be learned.
There certainly seemed to be many manuscripts that were re-used. When the church deemed many ancient works inappropriate and had them banned a lot were written over, and as you say now people know where to look. Hopefully more of these can be uncovered.