Presuppositions , Truth Values , and Expressing Propositions ∗

Philosophers like to talk about propositions. There are many reasons for this. Perhaps the most common is that philosophers are sometimes more interested in the content of a thought or utterance than in the particular sentence or utterance that might express it on some occasion. Propositions are offered as these contents. Like many philosophical notions, this one has been the subject of extensive debate. For instance, it has been challenged on the basis of Quinean queasiness about intensional objects, and Chomskian qualms about the explanatory value of truth-conditional semantics. These are foundational worries about the notion of proposition. But there is another kind of worry about propositions, which leads to the topic of this essay. The notion of proposition has been used to make some highly contentious philosophical claims. In particular, strong claims have been made by declaring that particular utterances, or whole classes of utterances, do not express propositions. Consider the following classes: