 In Convention, the conventions that sustained language were regularities amongst speakers. As we noted, it would be more natural to say that the conventions solved co-ordination problems between speakers of a language and their hearers. That is what the new account of what it is for a population to speak a language does. The population P speaks the language L iff there are conventions of truthfulness and trust in L. Speakers are truthful in L if and only if they only utter sentences they believe are true sentences of L. Hearers are trusting in L if and only if they take the sentences they hear to be (generally) true sentences of L.