Think of religious exemptions as a series of concentric circles.
Since Plato had described the city as having been composed of concentric circles, then this, said the Germans, might well be it.
He drew a series of concentric circles on a page with a single dot—Robert Moses—in the center.
concentric con·cen·tric (kən-sěn'trĭk)
Having a common center or center point, as of circles.