Shadows can be very dangerous...

As universal as possible, yes. Not universal, period.
The fact that there are limits is proof that while Bonisagus was indeed trying to cover as much as he could, he did not succeed in covering EVERYTHING.

Once again, you seem to forget what the book actually says: "Rego spells can create wards which protect the target from things of the appropriate Form. These use the normal targets, but the target is the thing protected, rather than the things warded against (...)" (ArM p. 114). So, as you can see, a magus can still create a ward that will protect him from PeIg effects, since the target of such ward is himself, not the cold, which he cannot target.

Before you try to argue that if Ignem cannot target cold, then it cannot protect from it, I'd point you out to p. 78 once again, which clearly states that Ignem does indeed soak against cold.

Oh boy, here we go again. In logical steps, so you can use your 191 IQ.

1- IGNEM is a magical form that "concerns fire, heat and light" (ArM p. 78).
2- We can target fire, heat and light with IGNEM, as shown in the example spells in the book.
3- "Heat also includes relative absence of heat, so spells that result in cold temperatures are possible through Ignem," bold mine, (ArM p. 139).
4- Absence of heat can be obtained with PeIg.
5- Perdo concerns destruction or worsening. Ignem concerns fire, heat and light.
6- Thus, PeIg stands for destroying or worsening fire, heat and light.
7- Destryong heat results in cold. Destroying light results in darkness.
8- Worsening heat results in tepidness. Worsening light results in dimness.
9- Cold, darkness, tepidness and dimness are consequences of destroying or worsening heat and light.
10- As a consequence of the manipulation of heat and light, cold and darkness can be achieved.
11- They cannot, however, be targeted -not any more than death or aging can (consequence of PeCo).
12- Were cold and light possible targets, CrIg would be able to "create" cold and darkness, as the target of Cr spells are the things being created.

Now if you cannot follow that logic, I'm not sure what else I can do, really, as I'm not very good with drawings.

No, I base that specific argument on IN GAME TERMS, which is perfectly logical since we are discussing the IN GAME workings of magic.

My point exactly, here's a link so you can go back and re-read it: [url]Card & Board Games ARCHIVE & LINKS]

Thank you, read above.

Wow.

Well...
Time: It doesn't do well with your idea that hermetic magic affects everything... So you discard it because it's one of the greater limits? Impressive.
Humours: Indirectly affected. Just like shadow and cold. This doesn't mean you can have total control on either of these, just like, being able to affect indirectly the local gravity field (however lightly) by piling on lead at some place doesn't mean I can control gravity.
Mutoing species: My bad, I was in a hurry. I meant Mutoing species to transform them into a physical form (HoH: S p63). Your confusion is understandable. Now, this is something hermetic magic can't do.
Regio: Just like time, you may dismiss it because you don't like it or find it useful, yet this is something basic hermetic magic can't do, so your claims of it being universal are nonetheless wrong.

May I also add all the lesser limits?
After all, hermetic magic can only partially affect Aging. Just like Species, humors, or shadows.

Hermetic Magic is also unable to totally control fertility. For exemple, determining a child's sex is, unless I'm wrong, impossible without integrating non-hermetic magic.

I perfectly agree it tries to be universal. It just ain't, or some of these integration rules from Ancient Magic and Hedge Magic, as well as Mysteries, would be unnecescary.

Okay, I understand you may be angry at yan's implication that you may chose desire over logic. Still, this was a little excessive, wasn't it? Worse, it sounds boastfull, which can only deserve you and your arguments.

IMO, part of the charm of Ars Magica is trying to conceive the world through these wacky medival physics. If these are real, shouldn't they impact somewhat on the working of Magic? It also gives us more of a guideline instead of D&D-like "I want this effect to work".

Then, sure, there are these stories. You'll recall I don't discard these, but, instead of allowing him to do something that, IMO, he couldn't do, I propose other possibilities:

  • Work with the sigil. in Novus Mane, for exemple, Wirth's sigil is "A darkness, diminution of light, sometimes coming with a chill". Why couldn't his character use voice-ranged PeCo spells that LOOK like someone's shadow comes to life and rips him?
  • Introduce later "living shadows", which, in Ars terms, would be spirits of darkness.
  • There's also demonic/faerie powers and stories.

The fact that there are humors (medival science) doesn't mean demons can't cause illness or humour imbalance (medieval fantasy). Likewise, if Shadows are species, it doesn't mean a faerie can't steal them (with a rego-like effect) or that a darkness spirit can't manifest through an otherwise mundane shadow, grabbing someone's ankles.

No not impressive at all, but the limits dont conform into to "normal". And the limits are also explicitly stated as exceptions, meaning that everything else should fall under some category.
Otherwise those other things would also be limits.

Ok that is at least arguable. But based on what specifically cant hermetics do this?

No you misunderstand, i meant the comparison rather specifically, it falls into an area of essentially "too big", or do you run the game with direct control of the earth, moon, sun etc?

Yes i perfectly well know that. When i wrote it. And i still did so. Because he completely failed in logic and still berated me for lack of it. Im perfectly happy(in theory at least) with people arguing with the assumptions or facts the logic is based on, but coming up with something that is unlogical and berate my logic with it is really beyond crappy.

And if we want to be REALLY correct we have to add that the "humours" idea isnt the only one in existence at the time, its just the one whose documentation happened to survive in a greater extent.

Anyway, one of the relevant points still remains, in medieval paradigm, cold and shadows DO exist as something separate which means unless they are additional limits should still be controllable.
And if instead you skip the medieval paradigm, the fact is that down to zero K, cold is still heat, and for a shadow to exist, it must be possible to see it or its just complete and total darkness.

And then comes the big problem, at what point does cold become uncontrollable because its no longer "heat"? This can only be settled arbitrarily, meaning that i would much rather NOT settle it as having Ignem control either is perfectly fine both mechanically and theoretically.
And the same argument can be used for shadows as well even if it gets a bit more complicated.