 Lewis, it seems, has a way to reply to Davidson’s objection. We will only sketch such a reply here. Recall the central tenets of Lewis’s account. First, languages (all of them, including natural ones) are abstract objects, a function from sentences to meanings. These functions may be as complex as required; they may take as arguments more than just sentences (i.e., occasions of use, times, worlds, speakers, etc.). As with any abstract object, these functions are what they are independently of any convention that may hold among human populations. Second, humans face a coordination problem. To solve it, they use some language or other, some abstract set of functions or other. Third, for the use of an abstract object L to successfully solve the coordination problem among members of a population P, at least two conventions must hold among members of P: the conventions of truthfulness and of trust in L. Finally, it is assumed that members of P know all relevant functions, or have a way to know them, for any possible sentence of L. In short, members of P antecedently know (in some sense) all the relevant sentence-to-meaning functions of L.