lukeprog gave a list of metaethics questions here:
What does moral language mean? Do moral facts exist? If so, what are they like, and are they reducible to natural facts? How can we know whether moral judgments are true or false? Is there a connection between making a moral judgment and being motivated to abide by it? Are moral judgments objective or subjective, relative or absolute? Does it make sense to talk about moral progress?
Most of these questions make no sense to me. I imagine that the moral intuitions in my brain come from a special black box within it, a "morality core" whose outputs I cannot easily change. (Explaining how my "morality core" ended up a certain way is a task for evo psych, not philosophy.) Or I can be more enlightened and adopt Nesov's idea that the "morality core" doesn't exist as a unified device, only as an umbrella name for all the diverse "reasons for action" that my brain can fire. Either perspective can be implemented as a computer program pretty easily, so I don't feel there's any philosophical mystery left over. All we have is factual questions about how people's "morality cores" vary in time and from person to person, how compelling their voices are, finding patterns in their outputs, etc. Can someone explain what problem metaethics is supposed to solve?
If there is a problem worth solving, it has to be related to "how compelling their voices are". In the philosophy of logic, we classify "Modus Ponens" differently from "Appeal to Inappropriate Authority" - and not simply by asking statistically which is more convincing. An empirical discovery that arguments quoting Justin Bieber are highly likely to convince the listener do not move such arguments out of the "fallacy" category. Similarly, if metaethics is worthy of study, it must be able to say that certain arguments are better than others independently of their likelihood to convince the listener, and why.
If you believe that categories like "fallacy" are useless, then logic is just a crude stab at the true science of persuasion. If you believe there is no analogous category in ethics, it's unlikely that you'll find anything worthy of study.
Very well said. It should be noted that there are logic problems most people get wrong. Valid reasoning is not defined by majority verdict or observation of patterns.