 The basic problem for Frege’s strategy, however, is that for his logicist project to succeed, his system must at some point include (either as an axiom or theorem) statements that explicitly assert the existence of certain kinds of abstract entities and it is not obvious how to justify the claim that we know such explicit existential statements. Given the above discussion, it should be clear that Frege at some point in Gg endorsed existence claims, either directly in his formalism or in his metalanguage, for the following entities: 