This article develops a conception of linguistic meaning that treats it as an attitude on the part of language users towards pairs of expressions. As with propositional attitudes, these meaning attitudes are subject to being deliberately altered over time by language users, with the aim of maximizing the efficiency of their language use. Therefore, meaning attitudes can be justified or refuted in practical terms. Our instrumentalistcoherentist approach, which allows for meanings to be advocated for alongside beliefs, provides a viable theory of justification of that kind. This view fits better with the evolutionary nature of linguistic phenomena, and resolves the problem of substitutability in opaque contexts.