I literally just edited my comment for clarity. It might make more sense now. I will edit this comment with a response to your point here.
Edit:
If I said “when we talk about Peano arithmetic, we are referring to a logical object. If counterfactually Peano had proposed a completely different set of axioms, that would change what people in the counterfactual world mean by Peano arithmetic, but it wouldn’t change what I mean by Peano-arithmetic-in-the-counterfactual-world,” would that imply that I’m not a mathematical Platonist?
Any value system is a logical object. For that matter, any model of anything is a logical object. Any false theory of physics is a logical object. Theories of morality and of physics (logical objects both) are interesting because they purport to describe something in the world. The question before us is do normative theories purport to describe an object that is mind-independent or an object that is subjective?
Okay. I don’t think we actually disagree about anything. I just don’t know what you mean by “realist.”
So morality doesn’t change in a world where people’s attitudes change because you’re using the same brain to make moral judgments about the counterfactual world as you use to make moral judgments about this world.
I literally just edited my comment for clarity. It might make more sense now. I will edit this comment with a response to your point here.
Edit:
Any value system is a logical object. For that matter, any model of anything is a logical object. Any false theory of physics is a logical object. Theories of morality and of physics (logical objects both) are interesting because they purport to describe something in the world. The question before us is do normative theories purport to describe an object that is mind-independent or an object that is subjective?
Okay. I don’t think we actually disagree about anything. I just don’t know what you mean by “realist.”
Yes, that sounds right.