In You Provably Can't Trust Yourself, Eliezer tried to figured out why his audience didn't understand his meta-ethics sequence even after they had followed him through philosophy of language and quantum physics. Meta-ethics is my specialty, and I can't figure out what Eliezer's meta-ethical position is. And at least at this point, professionals like Robin Hanson and Toby Ord couldn't figure it out, either.
Part of the problem is that because Eliezer has gotten little value from professional philosophy, he writes about morality in a highly idiosyncratic way, using terms that would require reading hundreds of posts to understand. I might understand Eliezer's meta-ethics better if he would just cough up his positions on standard meta-ethical debates like cognitivism, motivation, the sources of normativity, moral epistemology, and so on. Nick Beckstead recently told me he thinks Eliezer's meta-ethical views are similar to those of Michael Smith, but I'm not seeing it.
If you think you can help me (and others) understand Eliezer's meta-ethical theory, please leave a comment!
Update: This comment by Richard Chappell made sense of Eliezer's meta-ethics for me.
It seems to me that EY himself addressed all three of the objections you list (though of course this doesn't imply he addressed them adequately).
Moral Error and Moral Disagreement confronts this.
My own thinking is that humans tend to have the same underlying (evolved) structures behind our hard-to-articulate meta-ethical heuristics, even when we disagree broadly on object-level ethical issues (and of course hand-pick our articulations of the meta-criteria to support our object-level beliefs- the whole machinery of bias applies here).
This implies both that my object-level beliefs can be at odds with their meta-level criteria (if this becomes too obvious for me to rationalize away, I'm more likely to change one or other object-level belief than to change the meta-level heuristic), and that you and I can disagree fundamentally on the object level while still believing that there's something in common which makes argumentation relevant to our disagreement.
Yeah, I'm the "Richard4" in the comments thread there :-)