Sam Harris is here offering a substantial amount of money to anyone who can show a flaw in the philosophy of 'The Moral Landscape' in 1000 word or less, or at least the best attempt.
http://www.samharris.org/blog/item/the-moral-landscape-challenge1
Up to $20,000 is on offer, although that's only if you change his mind. Whilst we know that this is very difficult, note how few people offer large sums of money for the privelage of being disproven.
In case anyone does win, I will remind you that this site is created and maintained by people who work at MIRI and CFAR, which rely on outside donations, and with whom I am not affiliated.
Note: Is this misplaced in Discussion? I imagine that it could be easily overlooked in an open thread by the sorts of people who would be able to use this information well?
I did read his response to critics in addition to skimming through his book. As far as I remember his position really does seem vague and inconsistent, and he never addresses things like the supposed is-ought problem properly. He just handwaves it by saying it does not matter, as you point out, but this is not what I would call addressing it properly.
Utility always means satisfying preferences, as far as I know. The reason his answer is not obvious is that it assumes that what is desirable for the aliens must necessarily be desirable for us. In other words, it assumes a universal morality rather than a merely "objective" one (he assumes a universally compelling moral argument, to put it in less wrong terms). My greatest frustration in discussing morality is that people always confuse the ability to handle a moral issue objectively with being able to create a moral imperative that applies to everyone, and Harris seems guilty of this as well here.
I don't know. What more is there to say about it? It's a special case of the fact that for any sets of sentences P and Q, P cannot be derived from Q if P contains non-logical predicates that are absent from Q and we have no definition of those predicates in terms of Q-sentences. All non-logical words work in the same way, in that respect.
The interesting question isn't Hume's is/ought distinction, since it's just one of a billion other distinctions of the same sort, e.g., the penguin/economics distinction, and the electron/bacon distinction. Rather, the interesting question is Moore's Open Question argument, which is an entirely distinct point and can be adequately answered by: 'Insofar as this claim about the semantics of 'morality' is right, it seems likely that an error theory of morality is correct; and insofar as it is usefully true to construct normative language that is reducible to descriptions, we will end up with a language that does not yield an Open Question in explaining why that is what's 'moral' rather than something else.
I agree Harris should say that somewhere clearly. But this is all almost certainly true given his views; he just apparently isn't interested in hashing it out. TML is a book on the rhetoric and pragmatics of science (and other human collaborations), not on metaphysics or epistemology.
Ideally desirable, not actually desired.
No. See his response to the Problem of Persuasion; he doesn't care whether the One True Morality would persuade everyone to be perfectly moral; he assumes it won't. His claim about aliens is an assertion about his equivalent of our coherently extrapolated moral volition; it's not a claim about what arguments we would currently find compelling.