  One motivation for accepting a sparse conception of propositions is expressivism in metaethics. “Old-fashioned” expressivists (e.g., Ayer and Stevenson) claimed that moral sentences are non-cognitive. We cannot believe that lying in politics is wrong, nor can we have any broadly cognitive attitudes (e.g., disbelief) of the form ‘A-ing that p’ where ‘p’ contains moral terms. If we cannot have such attitudes, then presumably there are no moral propositions. (If there were such propositions, why wouldn’t there be possible cognitive attitudes having them as contents?). And if there are no moral propositions, then moral sentences do not express propositions, and so lack truth-value.