I have been thinking a bit about metaethical expressivism lately. As I read through some of the criticisms of the view, I realized just how misunderstood this view is. I am not going to review the criticisms here. But I do want to state what I believe the view amounts to. Expressivism is not a theory of the nature of wrongness. It doesn't have anything to say about what makes an action right or wrong. Furthermore, the view doesn't offer truth-conditions for moral statements.
What then does expressivism do? It tells us what it takes for a moral assertion to be correct. If, for example, I assert 'lying is always wrong', then that assertion is correct just in case I have a particular kind of negative attitude toward lying. It is perfectly consistent with this view that lying is sometimes morally okay. If, however, I am to make a correct assertion of a moral statement, I'd better have a fitting negative (or positive) attitude toward the action.
We might compare this view to more general theories of assertion. Take Timothy Williamson's rather popular view that you should assert only what you know. On this view, if I assert 'Copenhagen is the capital of Sweden', I would not only have said something false, I would also have violated the norm of assertion. Though popular, Williamson's view is not widely accepted. Some would hold that you should assert only what you justifiably believe. On this view, I could correctly assert 'Copenhagen is the capital of Sweden', even though the proposition expressed by this sentence is false.
Expressivism makes a claim about assertion that is analogous to the justified-belief account of assertion. I can correctly assert 'lying is always wrong', even if lying in fact is sometimes alright. Once expressivism is understood in this way, many of the criticisms of the view do not even get off the ground. For example, it is sometimes said that expressivism cannot account for the fact that an action can be morally bad but aesthetically good. Imagine an artist creating a beautiful work of art, which requires keeping seven naked women captive. His action then would be aesthetically good but morally bad. Expressivism, it is sometimes said, cannot account for these conflicting attitudes. This, however, is not quite right. An expression of moral condemnation of the artist's creation using a word like 'bad' would be ambiguous. Once disambiguated, the assertion is either right or wrong, depending on the speaker's attitudes.
If expressivism is a bad view, then it's because it provides a mistaken account of assertion. One could hold that all assertions are to obey the knowledge norm of assertion, in which case expressivism would be false. After all, if I do not express any truth-apt attitudes when making moral assertions, I cannot know what I asserted.
But it's kind of cheating to start off with the knowledge norm of assertion and then rule that expressivism is wrong. Expressivism probably has more going for it than the knowledge norm of assertion (e.g. a lot of moral psychology supports the former).
On weaker versions of expressivism, moral assertions express both truth-apt and non-truth-apt attitudes. If moral assertions express both belief and desire, then expressivism can be seen to support motivational internalism, which I take to be a good thing.
It's also really hard to imagine that no one believes what they say when they make moral assertions. For that reason alone the weaker view seems more plausible than a stricter view that says that moral assertions express only non-truth-apt attitudes.
But I doubt this weaker view really is the view hard-core expressivists want to defend. It seems important to them that we only express non-truth-apt attitudes when we make moral assertions.
This stricter variety of expressivism seems a bit odd to me for the reason I just mentioned. When I sincerely assert that lying is wrong, I believe what I assert, don't I?
Even if I don't, the stricter view is not off the hook. The idea that moral assertion requires a noncognitive attitude seems a bit suspect. It seems suspect for several reasons, one being that it is hard to see how abstract moral claims, such as 'it is often bad to inflict pain on others', would always make us feel or desire something.
If you are interested in reading more about this view, check out my website. There is an online version of a paper on expressivism.