It doesn’t have to be “real” for people to believe it is real. And really, it doesn’t matter if it was “real” if people believed it was real. Because if people

It doesn’t have to be “real” for people to believe it is real. And really, it doesn’t matter if it was “real” if people believed it was real. Because if people believe something is real, it can have a real world impact, regardless of whether or not the “magic” was “real”. People are strange like that and medieval people would have been no different from us in this regard.