Why is that the test of a metaethical theory rather than the theory which best explains moral discourse?

Because there is a practical aspect to ethics. Moral discourse involves the idea that people should do the obligatory and refrain from the forbidden. -- irrespective of who they are. That needs explaining as well.

I agree with all the claims you're making about morality and about moral discussion. But I don't quite see where any of this is giving me any new insights or tools. Sure, people have different but often overlapping values. I knew that. I think most adults who ever have conversations about morality know that. And we know that without worrying too much about the definition of morality and related words.

But I think everything you've said is also true about personal taste in non moral questions. I and my friends have different but overlapping taste in music, because we have distinct but overlapping set of desiderata for what we listen to. And sometimes, people get convinced to like something they previously didn't. I want a meta-ethics that gives me some comparative advantage in dealing with moral problems, as compared to other sorts of disagreements. I had assumed that lukeprog was trying to say something specifically about morality, not just give a general and informal account of human motivation, values, and preferences.

Thus far, this sequence feels like a lot of buildup and groundwork that is true but mostly not in much dispute and mostly doesn't seem to help me accomplish anything. Perhaps my previous comment should just have been a gentle nudge to lukeprog to get to the point.

It may be routine in the sense that it often happens, but not routine in the sense that this is a reliable approach to settling moral differences.

Do you know of anything better?

Morality as the expression of pluralistic value sets (and the hypothetical imperatives which go along with them) is a very neat explanation of the pattern we see of agreement, disagreement, and partially successful deliberation.

OTOH, the problem remains that people act on their values, and that one persons actions can affect another person. Pluralistic morality is terrible at translating into a uniform set of rules that all are beholden to.

I feel like your austere meta-ethicist is mostly missing the point. It's utterly routine for different people to have conflicting beliefs about whether a given act is moral*. And often they can have a useful discussion, at the end of which one or both participants change their beliefs. These conversations can happen without the participants changing their definitions of words like 'moral', and often without them having a clear definition at all.

[This is my first LW comment -- if I do something wrong, please bear with me]

This suggests that precise definitions or agreement about definitions isn't all that critical. But it's sometimes useful to be able to reason from stipulated and mutually agreed definitions, in which case meta-ethical speculation and reasoning is doing useful work if it offers a menu of crisp, useful, definitions that can be used in discussion of specific moral claims. Relatedly, it's also doing useful work by offering a set of definitions that help people conceptualize and articulate their personal feelings about morality, even absent a concrete first-order question.

And part of what goes into picking definitions is to understand their consequences. A philosopher is doing useful work for me if he shows me that a tempting-sounding definition of 'morality' doesn't pick out the set of things I want it to pick out, or that some other definition turns out not to refer to any clear set at all.

Many mathematical entities have multiple logically equivalent definitions, that are of different utility in different contexts. (E.g., sometimes I want to think about a circle as a locus of points, and sometimes as the solution set to an equation.) In the real world, something similar happens.

When I discuss, say, abortion, with somebody, probably there are multiple working definitions of 'moral' that could be mutually agreed upon for the purpose of the conversation, and the underlying dispute would still be nontrivial and intelligible. But some definitions might be more directly applicable to the discussion -- and philosophical reasoning might be helpful in figuring out what the consequences of various definitions are. For instance, a non-cognitive strikes me intuitively as less likely to be useful -- but I'd be open to an argument showing how it could be useful in a debate.

Probably a great deal of academic writing on meta-ethics is low value. But that's true of most writing on most topics and doesn't show that the topic is pointless. (With academics being major offenders, but not the only offenders.)

*I'm thinking of the individual personal changes in belief that went along with increased opposition to official racism in America over the course of the 20th century. Or opposition to slavery in the 19th.

Sounds like a form of speaker relativism, with the 'empathetic' project being about going beyond merely saying that people are expressing different fundamental standards, values, etc. to developing ways to bring those out into the open.

I've gone through massive reversals in my metaethics twice now, and guess what? At no time did I spontaneously acquire the urge to rape people. At no time did I stop caring about the impoverished. At no time did I want to steal from the elderly. At no time did people stop having reasons to praise or condemn certain desires and actions of mine, and at no time did I stop having reasons to praise or condemn the desires and actions of others.

Metaethics: what's it good for...

I wasn't worried, until the pre-assurances started.

Watching this series with interest. I liked the taboo thing in the first post; reminds me of my favorite Hume quote:

'tis usual for men to use words for ideas, and to talk instead of thinking in their reasonings.