One crucial question facing epistemic relativism is how to identify and individuate alternative epistemic systems. The intuitive idea is that varying and possibly incompatible cognitive principles, ground-level beliefs and presuppositions, or what Wittgenstein calls “hinge” and “bedrock” propositions (Wittgenstein 1969: §§341–343) separate non-convergent epistemic schemes. A simple and quite commonly used example is the contrast between scientific and religious belief systems. Boghossian, for instance, uses the debate between Galileo and Cardinal Bellarmine as a case study of an encounter between antagonists operating within putatively different epistemic frameworks, who use different frameworks, or as Rorty (1979) put it “grids”, for determining what would count as appropriate evidence on planetary movements. The relativist claims that there is no fact of the matter about whether the Copernican theory or the geocentric view is justified by the evidence, “for there are no absolute facts about what justifies what” (Boghossian 2006a: 62) while the anti-relativist attempts to show the unintelligibility or the implausibility of such a claim.