Without commenting on whether this presentation matches the original metaethics sequence (with which I disagree), this summary argument seems both unsupported and unfalsifiable.
Would this be an accurate summary of what you think is the meta-ethics sequence? I feel that you captured the important bits but I also feel that we disagree on some aspects:
V(Elves, ) = Christmas spirity
V(Pebblesorters, ) = primality
V(Humans, _ ) = morality
If V(Humans, Alice) =/= V(Humans, ) that doesn't make morality subjective, it is rather i...
Unpacking "should" as " morally obligated to" is potentially helpful, so inasmuch as you can give separate accounts of "moral" and "obligatory".
The elves are not moral. Not just because I, and humans like me happen to disagree with them, no, certainly not. The elves aren’t even trying to be moral. They don’t even claim to be moral. They don’t care about morality. They care about “The Christmas Spirit,” which is about eggnog and stuff
That doesn't generalise to the point that non humans have no morality. You have m...
Morality binds and blinds. People derive moral claims from emotional and intuitive notions. It can feel good and moral to do amoral things. Objective morality has to be tied to evidence what really is human wellbeing; not to moral intuitions that are adaptions to the benefit of ones ingroup; or post hoc thought experiments about knowledge.
Maybe we should also consider in parallel the question of whether objectivity is necessary. If objectivity is both necessary to morality and impossible, then nihilism results.
The basic, pragmatic argument for the objectivity or quasi-objectivity of ethics is that it is connected to practices of reward and punishment, which either happen or not.
The essential problem with the tablet is that it offers conclusions as a fait accompli, with no justification of argument. The point does not generalise against objectivity morality.
if you are serious about the unselfish bit, then surely it boils down to "what do they want" or "what do we want".
i don't accept the Moral Void argument, for the reasons given. Do you have another?
The idea that humans are uniquely motivated by human morality isn't put forward as a an answer to the amoralist challenge, it is put forward as a a way of establishing something like moral objectivism.