Over at Why Evolution is True, Jerry Coyne has invited readers to take up Sam Harris's question:
If you think the criterion of well being is not a good one for morality, give me an example of an act that we’d all consider moral that unquestionably decreases well being.If I were to quibble, I could imagine a case where I see a golf ball hurling toward a small child and choose to block its path with my arm, knowing it could injure my arm and destroy my most expensive watch. This would decrease my well-being, leave the child's situation unchanged, alter the lie of the golfer's drive to the detriment of the competition, and yet it would still be the morally right thing to do. Clearly this is only a quibble; the good in it still lies in its effect on human well-being even though everyone in the scenario either goes down or stays constant in well-being.
In the comments to Coyne's post, Ophelia Benson takes an more substantial crack at it:
morality has to do, for one thing, with looking beyond the local. It’s quite possible to be a lovely person locally while still being the cause of misery elsewhere in the world ... morality isn’t just “well-being”; it’s about conflicts between and among kinds of well-being and above all about distribution of well-being.True enough, but Harris addresses this objection more than once in The Moral Landscape when he talks about the inevitability of multiple equivalent peaks on the moral landscape, but remains fixed in defining those peaks in terms of well-being. Whether science can reveal the One Right Moral Answer for Everyone in All Cases is (a) unlikely in practice and (b) beside the point (p.190):
Whether morality becomes a proper branch of science is not really the point. Is economics a true science yet? Judging from recent events, it wouldn't appear so. Perhaps a deep understanding of economics will always elude us. But does anyone doubt that there are better and worse ways to structure an economy? Would any educated person consider it a form of bigotry to criticize another society's response to a banking crisis? Imagine how terrifying it would be if great numbers of smart people became convinced that all efforts to prevent a global financial catrastrophe must be either equally valid or equally nonsensical in principle. And yet this is precisely where we stand in the most important questions in human life.The well-being of conscious creatures is intended as a ground of morality that's better than the leading brand, i.e., the morality that is grounded in the revealed commands of a god. It's better because it's intuitively appealing, grounded in reality (including but not limited to knowable human experience), and, in a great many cases, amenable to scientific analysis.
There's a danger to over-thinking Harris's question. It serves to bring out the contrast between what Harris wants to call authentic morality and many ersatz moralities. Widely-accepted divine command moralities call for the killing of homosexuals, adulterers, disobedient children, non-believers, "witches," and people found working on the Sabbath. Harris simply wants to say this approach to morality is profoundly wrong because it is grounded in something other than the well-being of those subject to it.
Sam Harris recently debated William Lane Craig on the question "Does Good Come from God?" I have not yet had the chance to watch the video, but I hope to do so soon.