Lockean and logical truth conditions
1. In ‘A problem for expressivism’ Frank Jackson and Philip Pettit argue ‘that expressivists do not have a persuasive story to tell about how ethical sentences can express attitudes without reporting them and, in particular, without being true or false’ (1998: 240). Briefly: expressivists say that ethical sentences serve to express non-cognitive attitudes, but that these sentences do not report non-cognitive attitudes. The view that ethical sentences do report non-cognitive attitudes is not Expressivism (and not non-cognitivism), but rather a version of cognitivism. According to (what we’ll call) Subjectivism, a typical ethical sentence like ‘Abortion is wrong’ reports the speaker’s non-cognitive attitude toward abortion; it says, in effect, that abortion is the object of some attitude of the speaker’s. Expressivists, by contrast, say that the sentence expresses a non-cognitive attitude toward abortion, but does not say that the speaker has it. Ayer put it this way: I can say that I am bored by uttering the sentence ‘I am bored’, but I can express boredom, without saying that I am bored, by yawning (Ayer 1952: 109). As Jackson and Pettit see it, a certain plausible Lockean story about how sentences come to express beliefs, and so how they come to have truth conditions and truth values, will cast serious doubt on the Expressivist claim that some sentences express attitudes without reporting them. The main Lockean idea starts from the uncontroversial point that bits of language get their meaning from conventions. What conventional facts give a sentence of the form ‘x is square’ its meaning? The fact that we have (implicitly) agreed ‘to use “x is square” as a way of conveying our taking it to be the case that x is square’ (Jackson and Pettit 2003: 86). Distinguish the assertibility conditions of a sentence from its success conditions. (For ordinary declarative sentences, the success conditions will be the truth conditions, but we want to allow the possibility of success conditions for sentences that lack truth conditions.) The conventions that give sentences meanings had better be conventions governing their assertibility