Russell’s claim that only structural knowledge of the world is possible was influentially criticized by Newman as rendering scientific discoveries trivial. I show that a version of this criticism also applies to the “structural realism” more recently advocated by Worrall, which requires continuity of formal structure between predecessor and successor scientific theories. The problem is that structure, in its common set-theoretical construal, is radically underdetermined by the entities and relations over which it is defined, rendering intertheoretic continuity intolerably cheap. I (...) show that this problem may be overcome by supplementing the purely formal relation of intertheoretic isomorphism with the semiformal “Ontological Reductive Links” developed by Moulines and others of the German “structuralist” approach to the philosophy of science. (shrink)