Covenants states:
For nine of the Arts, there is a basic text that, over time, has come to be accepted as the preferred primer for a magus seeking the competence necessary to train an apprentice. These texts, called the Roots of the Arts, are widely and cheaply available. A Redcap can arrange the delivery of any of these texts, for a very small consideration.
... but then never mentions which nine, nor the qualities of these books. Do any Ars Magica books have a list of these "standard" books?
There is no list, Tyrell is correct.
Timothy Ferguson (who wrote that section of the book).
It was the intention of the authors to leave space open for PC's to write a book so good it became the preferred primer (and getting the word out about your book would be a good hook to hang stories on). To do this they choose to leave the arts that have been covered undefined. I'm fairly certain that this was written on the official message board someplace but I didn't double check my memory by searching for the post.
Quality of books varies a significant amount from saga to saga I suspect that the numbers on these books are also left undefined so that they could fit anyone's game. I believe that the covenants chapter of the core book has guidelines regarding how good a suma should be. I'd take the top end of these as the roots of the arts (but that's just my preference).
This link lists the Roots and Pillars of the Arts. I do not know if this is formatted for 5th edition, however.
