 Without a domain of analytic truths—truths that are a priori and hold in virtue of meaning—it becomes unclear what special domain of expertise for philosophical reflection remains. If all claims are, in principle, revisable in light of empirical evidence, why not let all questions fall to empirical science? Philosophy would be out of business, except perhaps as the abstract, reflective branch of empirical science. This Quinean attack has consequences for the traditional philosophical business of conceptual analysis, since on the dominant view from Plato through Carnap “every analysis of a concept is inextricably bound to a collection of purported analyticities” (Laurence &amp; Margolis 1999, p. 18). The conclusion Replacement Naturalists draw from the preceding is that since any claim of conceptual analysis is vulnerable to the demands of a posteriori (i.e., empirical) theory construction, philosophy must proceed in tandem with empirical science, not as the arbiter of its claims, but as a reflective attempt at synoptic clarity about the state of empirical knowledge.