It has also been claimed that alethic relativism gives rise to what J.L. Mackie calls “operational” (Mackie 1964: 202) and Max Kölbel “conversational” self-refutation (Kölbel 2011) by flouting one or more crucial norms of discourse and thereby undermines the very possibility of coherent discourse. One version of the argument, advanced most notably by Gareth Evans (1985: 346–63), begins with the premise that a publicly shared distinction between correct and incorrect, and hence true and false, assertion is a necessary condition for coherent assertoric discourse. As Evans puts it, a theory that