Mysteries RE - Arithmetic Magic & Fraternity of Samos

Could someone clarify some things for me

First Arithemetic Magic:
Hermetic Geometry gives the new R/D/Ts Line, Arcane Circle & Ring

How would I ever pull off a R:Line spell on a living, active subject? The time needed requires the target to be very still for a long time.
Could I use some InIm R:Arcane to sense the subject or area (which would be illegal vs. Magi) and then target him via a Line? That sure would beat casting through The Intangible Tunnel. As I see it, one needs good preparations in order to make this useful. But then it would be, for those very skilled in Artes Liberales.

And what about D:Arcane Circle and T:Arcane Ring, the text does not seem fully clear to me, or perhaps I just suck.
You may trace a different circle/ring than the one arund the target, but it must be same size. And the distance between this traced ring/circle must be calculated as the rules for R:Line spells. Am I right?
You'd have the same troubles as regular ring/circle spells if the target moves around or tries to sabotage it. But you need not be as close yourself, s a bunch of unfortunate Grogs could pin down the burning demon, while you stood back in the cool shade and did your thing. Nice. And the only drawback is that if either ring/circle is broken, the spell fizzles.

And about the initiations of Fraternity of Samos, the "Pythagorean or true initiate" on TMRE p129 lists that you can initiate the Virtue Potens Magic (Artes Liberales and Philisophiae).
How does this work?
Potent Magic is listed on TMRE p31 as being attuned to a narrow field of magic, like a Focus. Benefits are making Potens spells getting casting bonus from items with a Shape & Material bonus, right?
But Potent Magic needs a speciality like Focus, and as narrow as these.
Should I read the "Artes Liberales & Philisophiae" as the speciality, so whenever I cast a spell concerning these things, i can get the bonus? And what spells do fall into this category? Any spells where I use these Abilities, like for Ceremonial or Ritual Casting?

And a linked question, but about Abilities, the Specialities in them and how to change this.
The Fraternity of Samos lists for the different initiations that you must have Artes Liberales (Mathematics) 3. So do I add in the +1 for the speciality, so I need a score of 4 if i have another speciality? And how and when can specialites be changed? Suppose I started learning Artes Liberales specializing in Grammar as an apprentice. Suddenly I find myself getting deeper into this mystery cult, si I'd want to focus on Mathematics or Geometry, can I change?



Cast the spell with target room?
Wait until your target is having a meal or sleeping?
Don't use it on living active targets

That's completely OK. We've had similar discussions regarding the Faerie range of road and no valid objections were raised (IMO).

High Artes liberales may not even be needed. The total is int + artes liberales + die roll, so even with Artes Linerales 3 and intellegence of +1 you've got a better than even chance of hitting a target at 225 paces, throw in a confidence pint and you'll hit 330 paces more than half of the time.

Yes you're right. It might also help with immobile targets as well such as a casting a ward versus heat around a burning building, Rego Teram spell that does not allow rock to pass through it in an unstable area, or target arcane circle spell to turn water to air coupled with a duration arcane ring spell to prevent water from entering an area to create a a habitable area on the sea floor.

Yes I believe that "Artes Liberales & Philisophiae" is the specialty.

As far as what spells fall into this category, I think that's a stumper. Certainly spells that help compute horoscopes and distances would qualify, but what spells do this? I think that the Numerologist's spells on page 95 would qualify.
I might allow the bonus for spells of range line, target arcane circle or duration arcane ring.
I wouldn't allow it for ceremonial or ritual spells that just use artes lieberales or philosophie to create unrelated effects.

I believe that you'd need a score of 4 if you have another specialty.

By the rules as written there is no provision for changing specialty, I've seen people house rule it a few ways. If I were adding such a rule to my game, I wouldn't make it a particularly difficult thing to accomplish (perhaps just let the player change specialty whenever his score increases a level, I like the simplicity of it).

It only takes a few rounds. The table shows it takes 7 rounds for something a thousand paces away but which you cannot see, and less for shorter distances.

I'm not sure you could, unless you could first figure out where exactly is the person you are so observing.

Some, but not that much.

Yes, though there doesn't need to be an actual circle around the target you are trying to affect: a magical one gets created. And the circle you actually trace needs some extra care.

It needs to be able to perceive the magical circle.

That, and Arcane Ring/Circle spells are significantly higher level than ordinary Ring/Circle spells.

I do not know, I guess so.

AFAIK there is no way to change specialties, although some storyguides allow them to be changed each time you go up in skill. I would probably also require you to have a text on that specific topic rather than just on the Ability (i.e. if you want to switch to Mathematics, you need an Artes Liberales book that deals with mathematics rather than just any liberal art).

Correct. Artes Liberales (Mathematics) 3 or Artes Liberales (something else) 4.