As is the case with most of my books, a good deal of the background to Goddess of the Ice Realm is real. The general religion of the Isles is Sumerian, though in some cases I’ve interpolated cult practice from the late Roman Republic where we simply don’t know the Sumerian details.
The magic, which is separate from religion in virtually every culture and in at least my fiction, is that of the Mediterranean basin during the Classical period. The words of power, technically voces mysticae, are the language of demiurges who act as intercessors between humans and the gods.
I prefer not to voice the voces mysticae, but I have done so in conjunction with the audiobook versions of the Isles series. So far as I can tell, there was no ill result. On the other hand, I’ve also dropped loaded firearms without anything bad happening–that time. I don’t recommend doing either thing.
The works of literature imbedded in Goddess are Latin classics. Rigal equates with Vergil, Celondre with Horace, and Pendill is Ovid, whom I find to bountifully repay the close readings I’ve been giving him this past year.