This summary of Eliezer's position seems to ignore the central part about computation. That is, Eliezer does not say that 'Right' means 'promotes external goods X, Y and Z' but rather that it means a specific computation that can be roughly characterized as 'renormalizing intuition'
I see the project of morality as a project of renormalizing intuition. We have intuitions about things that seem desirable or undesirable, intuitions about actions that are right or wrong, intuitions about how to resolve conflicting intuitions, intuitions about how to systematize specific intuitions into general principles.
which eventually outputs something like 'promotes external goods X, Y and Z'. I think Eliezer would argue that at least some of the objections list here are not valid if we add the part about computation. (Specifically, disagreements and fallibility can result from from lack of logical omniscience regarding the output of the 'morality' computation.)
Is the reason for skipping over this part of Eliezer's idea that standard (Montague) semantic theory treats all logically equivalent language as having the same intension? (I believe this is known as "the logical omniscience problem" in linguistics and philosophy of language.)
The part about computation doesn't change the fundamental structure of the theory. It's true that it creates more room for superficial disagreement and fallibility (of similar status to disagreements and fallibility regarding the effective means to some shared terminal values), but I see this as an improvement in degree and not in kind. It still doesn't allow for fundamental disagreement and fallibility, e.g. amongst logically omniscient agents.
(I take it to be a metaethical datum that even people with different terminal values, or different Eliezerian &...
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.