A companion character with no supernatural virtues but with academic contacts all over Europe - what non-hermetic traditions can he find with non-gifted practitioners? Is there anything he can do for himself with magic theory?
with magic theory no, but look for the learned magicians. Those have inscription scripts for the ungifted. Well, those scripts inflict such heavy flaws that their magic is crippled... but hey, this is still magic for mundanes!
See also the elementalist traditions.
And the folk witches
There is also the gruagach, but I see them less willing to let you join in.
Not the first one to ask that 
viewtopic.php?f=4&t=6406&start=0&hilit=magicless+magic
He can also be initiated into several traditions that do not require you to be Gifted. IIRC those are:
- Gruagach Magic
- Folk witch
- Elementalists (unsure about these)
And he can also become an infernalist, of course.
Cheers,
Xavi
As Xavi mentioned , no.
Magic Theory is Hermetic Magic only.
If a Hedge Tradition has an equivalent to magic theory , you need to learn that instead.
If of a religious bent , you could go on a Pilgrimage and gain a Divine Virtue (page 16 , The Church).
"Learned" perhaps not. I prefer to allow non-Gifted to have Astrological insights, so they can create a Peripat for a magus, for example, or a Horoscope in general.
A non-gifted person might gain the virtue "Touched by (Realm)" through warping in that realm or continued contact with it.
Peripherally in one saga, there was a covenant of Verditius, Jerbiton and Ex Miscellania trying to figure out how to instill this virtue through Hermetic magic or pseudo-Hermetic ritual. No success, and the story moved on...
For an academic, the "Craft" could be replaced by "Profession: Scribe" etc.
I might allow him to learn Mythic Herbalism, depending on one's interpretation of that tradition.
A combination of (Realm) Lore and Magic Theory might be enough for him to learn how to use innate magical properties of items to his advantage (Silver vs. Lycanthropes as a crude example.) This is somewhat of an extrapolation of the Major Flaw in HoH: Societas "Vulnerable to Folk Traditions" -- there are certain things that cancel or modify certain kinds of magic. If this could be better codified, it would be no small asset to a non-magical person in a magical world.
with a High magic Lore he can make some of the items of virtue mentioned in the Magic Realm book.
He could also use lots of Vis to transform himself.
A