 Now, Wright has urged that Hume’s Principle might be regarded as analytic, and perhaps this claim could be sustained by an examination of the language faculty along the lines of a Chomskyan linguistics set out in the supplement. If so, then wouldn’t that vindicate the suggestion that arithmetic can be known a priori? Not obviously, since Hume’s Principle is a claim not merely about the concepts F and G, but about the presumably concept-independent fact about the number of things that are F and the number of things that are G, and, we can ask, what justifies any claim about them? As George Boolos (1997) asked in response to Wright: