It’s not that the concept of plagiarism didn’t exist in the medieval or Renaissance period, but that the idea of authorship had a far larger scope than it does for us today.
Medieval authors copied from each other in a way that would have involved them in lawsuits with each other if they were living in the 21st century.
As I pointed out in a past post, Renaissance intellectual property did exist, even though authors rarely protested. Albrecht Durer broke the silence of the age on the topic.
But medieval writers were aware of others using texts that weren’t their own. It wasn’t so much a question of making a living from other people’s literary creations than boosting their status from proposing texts that were not their own.
Authorship was a fluid notion, and writers often used other writers’ creations without crediting the authors. It didn’t seem to bother anyone.
History and fiction writers often incorporated texts by other authors, and philosophers and theologians used ideas and views reached by previous thinkers to advance their own.
For instance, we don’t quite know where and how exactly the myth of King Arthur was born, but we know that by the 14th century, writers were copying bits of text from each other, sometimes transforming the stories, sometimes not.
For a historian seeking to tell the story of everything (and medieval history writing was almost always a matter of telling the most complete story), pillaging other texts, even verbatim, was not beyond the scope of acceptable. After all, the root of our word ‘compilation’ and ‘to compile’ is ‘to pillage’ and ‘to rob’.
Bu where we see pillage, a medieval author saw community. A community of writers advancing the rising influence of writing, of books and of written records.
In a culture characterised by communality, text belonged to everyone, and the book, though an exclusive and expensive item, was the embodiment of the collective intelligence of groups of authors each struggling to transcend time and space through ink and parchment.