families are families, churches are churches, and the academy is the academy. So if the young man were to complain to his mother, “How can you fire me from my teaching job?—I’m your son,” he would be blurring the boundaries of the spheres. Kuyper’s sphere sovereignty idea is often compared favorably to a similar notion that looms large in Roman Catholic thought: what the Catholics call “the principle of subsidiarity.” On this view, “higher” structures should never