Feyerabend’s arguments for epistemological anarchism in Against Method have attracted continued attention from philosophers of science. The complexity of the history of scientific practice and an unrelenting fallibilism, Feyerabend argues, provide crucial motivations for an open-ended theoretical and methodological pluralism. The purpose of this paper is to consider another argument Feyerabend provides in his correspondence with J.J.C. Smart in the mid-1960s that supports epistemological anarchism. My goal, here, is to reconstruct the argument, show how it builds on quieter themes in Feyerabend’s corpus and how it relates to his later proclamations that ‘anything goes.’ In doing so, I show how Feyerabend attempts to reimagine the purpose of philosophy of science.