One setting I am working on is steampunk. And while it has magic -- dragons, gryphons, and, I have finally decided, shape-shifters -- it has no wizards of any way, shape or kind. Men can not manipulate magic. Hardly need to, do they, when between steampunk gadgetry and mad scientism, I thought I could get all the plot devices I needed.
Then you start to wrestle.with the question of how much magic to put in the science. You have a lot of leeway with mad scientists, but the flavor of the stuff has to be technological, not magical. Sure, throw in a few Jacob's Ladders with the sparks flying, beakers and distilleries, but you still have keep it feeling techie, and there's only so much that local color and setting can do to make people think techie. Cue technobabble, I suppose. . . though reading primary source is wise, since it gives the right sort of terms to use for the era. . . except they might not have the terms for the things I want to have. . . .