Thanks for the explanation. I was looking more for theoretical justification (if theoretical justification played a part for you in deciding how to choose an ethical theory). What I had in mind was, if you were going to try to convince other people that they should choose an ethical theory for the same reasons that you chose yours and should adopt the same theory you did, what would be the arguments that you would use to persuade them (limited to good-faith arguments that you actually believe rather than rhetorical strategies aimed primarily at convincing)? And there's a little of that in your answer here. Thanks for your time.
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.