How do magi know what to read?
Your magus helps out another covenant and, in thanks, they let your character study from their library for a season. In the real world, the Storyguide hands you a sheet of titles, each marked with level and quality, and you pick the one you’d like your magus to read.
What’s happening in Mythic Europe that is being extrapolated by this process of you getting a sheet of numbers?
There are, I think, two possibilities.
The first is that, like a librarian, you are assessing the books. As a non-specialist, you don’t really understand some of the data you are looking at, but you can grasp enough to know the value of the book, in comparison to other books. You can assess its reading level, intended audience, and physical quality of the book.
The other possibility is that you know titles by their reputations. Medieval people used to hunt around in monasteries looking for pieces by Livy, or Aristotle. They didn’t need to see the book to know that it was considered a capstone of study for their area of interest.
This second model requires you to be aware of titles before you read them. This can happen in two ways/ In some subjectsm like classic English literature, there is a corpus of work that interconnects, so that by studying part you are drawn to the other parts.
As Arnold Bennett notes, If you read Charles Lamb, you are introduced to various people in his circle, and to Shakespeare, and from there you can work up and down the canon.
The other way is for your character to have read books reviews.
Some of the earliest books of review are attempts to systematically describe every book of note in a particular field. These, unhelpfully, often have “Bibliotheca” in their title. This means “Library”. They are backward-looking: reviewing great works of the past, rather than contemporary writing.
The earliest journals of review might already exist, because they were not academic: they were mercantile. The earliest journals were basically trade catalogues put out by bookshops. Over time, these became increasingly large and were sectioned into genres. Then, people not interested in select fields began to demand journals that only included material suited to their own specialization. Certain critics, independent of the booksellers, were paid for their unbiased advice on the value of potential purchases.
Journals in which people discussed ideas were a related idea, because review journals contained excerpts, but the two only merged far later.
Journals of review might exist either because libraries have put out catalogues to tempt custom for loan or sale, or because House Mercere needs to be able to source material to fill requests.
Players have noted that tractatus are numerous and useful in Ars Magica. It seems possible that a magus might make a living by helping others sort through these, so they know which ones to read.
An annoyed Flambeau magus is seeking the identity of a reviewer, who has given his Summa a poor score. Sensibly the reviewer uses a pseudonym, and his friends are careful not to let information slip. The Flambeau hires the player characters to find more clues, because they have a reputation for greater stability than he does.
A magus published an acclaimed book, but the player characters discover an earlier, lost, work, which is word-identical. If they expose the plagarist they gain his emnity, but may make allies of the original author’s descendants. They could, instead, attempt blackmail.
The player characters discover a unique, excellent book, miscovered, in a covenant library. Do they make an offer for it, or expose its higher quality to the current owners? If they draw attention to the book, they invite cautious harassment from their hosts. The book was salvaged from a fallen covenant and the deliberately miscovered. These books are usually held in a section to which visitors may not go, but this was was accidentally shelved by its false title by a non-magical librarian. The player characters may piece together why this is happening by researching the book, and discovering a review in a catalogue for the fallen covenant.