Kripke's epistemic argument against descriptivism is reconstructed as follows. Premise 1: if descriptivism is correct, then “N is the F” should be knowable a priori; Premise 2: in fact, “N is the F” is not knowable a priori; Conclusion: descriptivism is wrong. This article accepts P2 of the argument as true, but rejects P1 by arguing for the evolution of language and the growth of meaning; so it concludes that the argument fails. It also criticizes Kripke's conception of “a priori,” and interprets why “N is the F” is not knowable a priori. Sometimes this article uses materials from Chinese ancient philosophers, for example, Xunzi and later Moists, to support its arguments.