Hume’s Principle (HP) states that the cardinal number of the concept F is identical with the cardinal number of G if and only if F and G can be put into one-to-one correspondence. The Schwartzkopff-Rosen Principle (SR Principle) is a modification of HP in terms of metaphysical grounding: it states that if the number of F is identical with the number of G, then this identity is (strictly, fully, and immediately) grounded by the fact that F and G can be paired one-to-one (Rosen 2010, 117; Schwartzkopff Grazer Philosophische Studien, 82(1), 353–373, 2011, 362). HP is central to the neologicist program in the philosophy of mathematics (Wright 1983; Hale and Wright 2001); in this paper we submit that, even if the neo-logicists wish to venture in...