I understand why a lot of fantasy settings with Ambiguously Catholic organised religions go the old "the Church officially forbids magic while practising it in secret in order to monopolise its power" route, but it's almost a shame because the reality of the situation was much funnier.
Like, yes, a lot of Catholic clergy during the Middle Ages did practice magic in secret, but they weren't keeping it secret as some sort of sinister top-down conspiracy to deny magic to the Common People: they were mostly keeping it secret from their own superiors. It wasn't one of those "well, it's okay when we do it" deals: the Church very much did not want its local priests doing wizard shit. We have official records of local priests being disciplined for getting caught doing wizard shit. And the preponderance of evidence is that most of them would take their lumps, promise to stop doing wizard shit, then go right back to doing wizard shit.
It turns out that if you give a bunch of dudes education, literacy, and a lot of time on their hands, some non-zero percentage of them are going to decide to be wizards, no matter how hard you try to stop them from being wizards.
