My focus is Q: Are there really such things as public languages? I address an argument for a negative answer, extracted from Davidson’s “A Derangement of Epitaphs”. The argument appeals to an empirically attested phenomena, namely novelty and speech errors in successful conversational interactions, to show that knowledge of public language is neither necessary nor sufficient. Thus public languages have no explanatory role. Continues the idea, one should substitute in place of the convention-centric public language picture an alternative, with Prior and Passing theories. My first rebuttal is that there are senses in which knowledge of public language is necessary, and that where there is lack of necessity, this is not probative with respect to Q. The second rebuttal is that once a proper model of conversational interaction is recognized and endorsed, namely the Relevance Theoretic model, non-sufficiency ceases to be an objection as well. Finally, I urge that public languages have explanatory roles to play that have little to do with quotidian conversational interaction. The ultimate result: the deranged argument against public languages which is my focus, and which one may extract from Davidson’s famous paper, is unsound.