Similar to the thread: https://forum.atlas-games.com/t/inventing-hedge-magic-theory/8687/1 ; in page 16 of the "Hedge Wizards" it mentions a Hermetic Wizard can invent a (hedge) magic theory for a tradition. If they're not a practitioner, how would they design effects to do this?
Same as normal.
Study relics or texts of the tradition. Gain Insight. Use the Insight to produce semi-Hermetic effects. Earn Breakthrough points.
In-game, I would imagine it's a similar process as what a number of missionaries did in the 19th and 20th centuries, in creating a written language for a group of people that didn't have one. (Usually in order to translate the Bible into that language.) That is, it's a system by which you have the formal study of Linguistics, and then you use that to analyze and codify the target language using the scholastic tools at your disposal. After a few years or so of being taught the language and stories and whatnot, you've got enough source material that you can create a new written language that the native people can use.
Ok, this makes sense to me. I was thinking of a Magus using hermetic experimentation to develop a hedge magic theory and my brain sort of went whaa???