More trade means more taxes collected and more power for government. Education Literacy is 1 to 3 percent. Growth of trade at the end of the Dark Ages increases literacy only slightly. In the worst periods many monarchs are not literate. There are few, often no schools of higher learning.
Society is fuedal.
Lack of social mobility impedes growth of literacy. He may have read two other books on the same subject. He reads sections of the book and makes comments. Students take extensive notes in order to be able to recall something from the course later. The vast majority of books are printed in Latin.