Is there anything in the Code that prohibits this? Ie, teaching Bonisagus' Magic Theory to non-magi? In context, my magi wants to set up the equivalent of a parish school in the covenant, to teach the grogs Latin, and a smattering of Magic Theory, Farie Lore, and Artes Liberales. The main reason for this is "He doesn't like being surrounded by stupid people" (Int 5, Com -2, Magic Theory 10). Realistically, he knows that most aren't as smart as he is, but he's really getting irritated by the idea that folks don't even know what wards or vis or Realms are. (Plus, he's using this as a trial run before he starts teaching apprentices).
But anyway - the only thing I can find is the strict prohibition against teaching Parma - and while I suppose you could (in theory) deduce Parma from MT, it's not fully integrated - so that doesn't seem to be an issue. Also, I'm guessing it's pretty easy for long-term grogs who work around the magi to have already picked up a level of Magic Theory, just by exposure.
Finally, there's the example in A&A, pg 97, of the Jerbiton actually teaching a class on MT at a university. The story seed here doesn't seem to be that Jerbiton is letting loose the secrets of Magic, but rather that the magus is doing so on the PC's turf, without telling anyone, and potentially sniping apprentice-quality grogs.
In contrast, the difficulties of teaching a non-Gifted student is that MT is completely abstract - which is why he's only planning on teaching the low level stuff: Magic Theory (Identifying) at a 2 is a decent score to have, if the only thing you need to do is to be able to understand that it's a bad idea to scuff the chalk line of the circle the magus is standing in.
Anyway - am I missing anything, here? This came up at today's gaming session, and I was rather surprised when most of the other players thought this was a bad idea. (Mainly in the "exposing secrets of the Order" line, rather than "why are you teaching the Grogs magic, they're going to get us all killed in a thaumaturgical fireball of idiocy" line.)