Authorities Summae Stats

Does anyone have thoughts on generating Quality and Level for Authorities? I take it these are summae, but there's no particular guidance on the subject.

The authority that brought this up was Principia Magica, but the subject is broad.

I don't see any necessary correlation between a book's ArM5 Stats, and its status as an Authority.

Bonisagus' Principia Magica is a very early Hermetic book, perhaps the very first Summa on Magic Theory. It's contents might indeed have been superseded in most respects by later books on Magic Theory - but still the Order of Hermes considers Bonisagus and his book an Authority to quote again and again.

Look at Abélard ( for an example, how early scholastics use old Authorities to advance their disciplines and sharpen their tools.


EDIT: Principia Mathematica => Principia Magica. Not so much a Freudian slip than the remains of a train of thought trying to equate Hermetic Magic and Newtonian Mechanics, which I - nearly - cancelled, as it led nowhere.

Would you consider the Authorities to be primer-level books? Basics that any student of the ability can be expected to have read?

Treating them as primers makes sense to me. If everyone with the skill at 3+ has read it thoroughly, there can't be much in there that's not known to someone with the skill at 3.

They were probably more advanced when they were written, but science marches on. Partially because of them.


There are disciplines of medieval learning - like the laws and scholastic theology - where a primer needs to reference the Authorities to an extent, which lets it appear to be their commentary.

But AFAICS the Principia Magica will not be sleek and concise enough to work as a primer.

IOC we made it a Level 10 Quality 3 Summa: still a source of inspiration even for the reader knowledgeable in Magic Theory, but far too time-consuming for a beginner in need of spoon-feeding. Other campaigns may see the book's value differently, of course.


I would not necessarily. From my own experience, I only had one book that would be considered an authority. I don't even remember the book's actual name because everyone just refers to the author by last name: Jackson (e.g. "I did Jackson last semester."). It may well be the only textbook used for electricity and magnetism in any first-year graduate physics class in the US. I can't guarantee it, but it's that universally accepted and so that's why I say it's an authority. But it's far different from something like Halliday, Resnick, and Walker's Fundamentals of Physics, which would be a really sound primer for students with sufficient math skills. Jackson would be extremely hard for most students to use as a primer, though if your math skills are truly exceptional it might be an OK place to start.


Books that are commonly used as preferred texts nowadays are (usually) used because they are good, not because they are Authorities in the medieval sense.

In theory, the idea of an Authority is antithetical to modern academics. Things are murkier in practice, especially as subjects get "softer" and further away from science. The guy who wrote a favored math textbook is not an Authority--he is a reference--because that's not how we arbitrate issues pertaining to mathematics, in the same way that the only eyewitness to record some historical event might be.

Basically, a real Authority is the guy who got it right. He might not have been clear. He might have not discussed specific issues, implications and consequences. He might not have refuted attractive but erroneous related ideas. He might not have reconciled ideas that he got right with other ideas known to be correct. He might have left many exercises for the reader. This leaves room for many other books, to the point where going to the authoritative text is a last resort. To win an argument, it is also the best result because, broadly speaking, in a scholastic environment, whoever cites the best book wins.

No AM editions represent individual books very well, so I hesitate to associate numbers with authoritative texts.

In a non-mechanical way, however, I would expect an authoritative text to always have something more to offer (until the reader either has complete understanding of the topic or has achieved a breakthrough that topples the authority), but also quite possibly opaque.

I would not expect any subsequent text to offer more than the authority, because that means the author understands the topic better. I would not even expect a subsequent text to offer as much. But it might be easier to understand, it might illuminate side-topics that the authoritative text didn't see fit to explore but that if you study it hard enough you will understand without needing other texts.

The idea the Bonisagus' text is primitive because it stands at the beginning of Hermetic Magic.... well, no. Subsequent writers have a great deal to offer, but none of them are likely to understand Bonisagus' theory as well as Bonisagus.

Ok, I'll do the mechanics because I like mechanics.

Bonisagus's Big Book of Magic: Summa on Parma L2Q15; Summa on all Arts, MT and Arcane Abilities L10Q5, LinfiniteQ2. Basically, this is the only book you need if you have all the time in the world.



If you want to bother with more bookeeping - which I don't - you can also consider that some Authorities require minimum level to be understand by the reader. Instead of having a low quality score to indicate that the author was a genius, but had a hard time expressing his ideas, you can say that the author did not bother to cover the basics (too tedious for him to cover, below his station, whatever reason) and set for a given Authority, a minimum level to read it, of 10 or 12 (for Arts), or 4-5 for Abilities.

Obviously, it cannot apply to Bonisagus MT and Parma since he set the base foundation and needed to write documents that would be understood by any beginners (with of course the provision on text about Parma...).

I would even consider as Authority, a group of 4+ Tractatus on the same topics, written by the same author. The simple fact that he was able to write at least 4 tractatus (for an ability) or 6 for an Art show that he knows his topic inside out. If the Quality is at least decent, then it is material to be considered worthy of Authority. If it is supplemented by a few spell labtexts and some mastery tractatus... have a master scribe and bookbinder do their magic and the author will achieve fame and be seen as the expert on the topic.

Actually you have the game statistics of mundane authorities in Art & Academe.

For example the authority on astrology is the Almagest

And it is clearly not a primer intended for beginners

So it seems like Authorities would need to be high level low quality books.

Because if primers are low level, high quality books that is where novices start. Eventually they will have exhausted the knowledge of this beginner's book and move on to more advanced books.
Sure, the authorities may seem pointless to read if quantities of medium to high quality tractatus are available, and eventually reach the level of the authority from reading these.

Why would they need to be low quality?

Cicero, certainly an authority on Artes Liberales (Rhetoric) [see also A&A p.13 and p.136], is an excellent author providing high quality works.


Perhaps - and I have not considered this at length - an authority can be approached as a re-readable tractatus. You only gain the text quality, but can read it repeatedly. This keeps the gain relatively low, compared to a summa, but the work can be re-read for additional insight.

To extend this unconsidered thought, it also has a level, like a summa. Once you are up to your ability level, you gain nothing further, having a sufficient grasp of the subject.

Please excuse me if I've missed this suggestion somewhere.

Yes, Ovarwa, that's the essence of Jackson's book. It's not always the clearest, but no one else has ever laid down classical electrodynamics as completely and properly as he did. That's probably why it's only now on its 3rd edition since being published in 1962. We have all sorts of other books that target specific issues, implications, and consequences, such as books on plasma physics. We have books that are clearer. But when it comes down to it, we all (physics grad students) have/had to study Jackson because if it doesn't follow from there it doesn't fit the theory.

This talk of repeated-use tractatus or unlimited use summas (same effect, different terms) is starting to sound distinctly like ArM4 books. ArM5 tried to move away from the complexities and problems that arose with ArM4 studying. ArM5 may not model reality perfectly, but it works well enough for me. I prefer the efforts to write up libraries/collections instead of expanding the types of books because that could model reality better in other ways, but the mathematics never seemed to work well.

I do not yet understand, why you request special rules for authorities.

It is not, that Cicero, Augustine, Boethius - or Bonisagus - at some time decided to write an authority, and lo behold - they succeeded.

To the contrary, the concept of a book as an authority is tied to scholasticism, which did not exist before 1100. And a book becomes an authority by the acclaim of the scholastic scholars with the best reputations in academia, not by being written in a specific way. So it makes sense, that A&A has one book - de inventione - become an authority, that is formed by three tractatus of excellent quality, while another authority - the Almagest - is a moderately high level summa of modest quality.

Consider .



Thanks. Yes, I guess that makes him a de facto authority, especially if you have to keep referring to Jackson to make sure you haven't gone off into the wild and woolly.

I also prefer AM5 to AM4. But AM4 books were not unlimited, unless I miss something. The extra complication, iirc, was about "intended reading level," that is, books whose usefulness depends on the knowledge score of the reader.

I have discussed an approach I prefer elsewhere.

But within the rules of AM5, it is completely possible to describe a book as LQ2. And various AM supplements associate multiple "book mechanics" to a given book title. No new rules here. (Bonisagus probably does not deserve an infinite score, but God surely does for the stuff He wrote!)



I didn't. I'm looking for an approach to a statting and studying books that do exist in game, both in the sense that there's a work (Principa Magica) and a type of book (Authority). I prefer to use rules that exist, which is why I am basing an idea and approach on rules in existence.

I have a player in my game who wants his character to read Principia Magica: I have no guidance at all on this. The book could be a summa or a tractatus. It could be a L1 Q1 or an L20 Q10 or who knows what. Authorities are spoken of as important and basic, but...

I realize that one of the troubles here is that pinning an authority down also indicates the author's ability; if you say the Principia Magica is a summa, and level 5 and quality 6, you've given an approximation for Bonisagus' Magic Theory at the time he wrote it (about 10).

Note that Q2 is effectively the same as Exposure Experience (2xp). It seems reasonable that an "Authority" would allow this in connected Arts or Abilities. I've suggested before that a proper library could allow the equivalent of Practice Experience (4xp) in Arts or otherwise prohibited abilities. This seems more appropriate and much easier than modeling thousands of low level texts.


pleased smile Why yes, yes it is. There is a point where it is just as good to get out and do rather than keep reading. Unless, of course, you happen to be one of those dusty scholar types with Book Learner....



Wait. What? I may have missed some errata or a rule in the extended line somewhere. In ArM5 main, p. 165, the level of a summa is defined as no more than half the author's Art or Ability "up to half of her score in the appropriate Art or Ability."

If, say, an author has Art 20, the level could be up to 10, plus or minus Virtues or Flaws. The quality is Communication +6, plus a bonus if the author limits the level, and again as affected by Virtues and Flaws. I don't know of a way to improve level by reducing quality - although certainly a poor communicator could write an unclear and confusing, thus low quality, book. (Certainly such low quality books are written, although they're probably not much circulated.)

  • Edited to fix misquote.

Don't ask me. You're not quoting me on that. I'd have to search back to see who actually wrote it.