  where a speaker is “truthful in \(L\)” iff she tries to avoid uttering sentences not true in \(L\), and a speaker is “trusting in \(L\)” iff she believes that sentences uttered by other speakers are true in \(L\). Given that this convention prevails, speakers who want to communicate have reason to conform to it, which in turn perpetuates the convention. Note that Lewis’s account avoids the Russell-Quine regress argument from  section 1.1, since Lewisian convention does not presuppose explicit agreement between participants.