SarahC:
[Harris is] conceding that his argument has limits. If you're going to say that science can give us answers about morality, you have to declare that some people are not worth listening to. In his case, this means non-humanists. Harris, and I, believe that what matters morally is the well-being of conscious creatures. The people who don't -- the people who think some races are vermin to be exterminated, for example -- are completely incompatible with our moral system. We can't listen to them, and we can't persuade them; we can only stop them from doing harm.
I'm not sure if I'm reading you correctly, but you seem to be implying that when one embraces Harris's worldview, the only people who have any serious disagreements ("non-humanists") will be various insane extremists. But this is completely false. Historically, there have been numerous human social orders that are not evil or crazy by any reasonable standard, and others might exist in the future. Reasonable and non-evil people will ultimately disagree on which exact one they favor, and there is no way to solve that conflict of values and preferences except by figuring out some practical way to disagree and let good fences make good neighbors, or by having one view imposed on others by force (and perhaps, in the long run, ideological propaganda).
There is no way that you can construct an argument based on vague claims like "what matters morally is the well-being of conscious creatures" that will provide valid evidence, let alone a valid proof, for even the roughest outlines of Harris's ideology. It's all vapid talk disguised as rational argument (or to make things even worse, as "science").
Nope, they won't be crazy extremists.
The point is, if you want universal morality, you have to exclude some points of view. If you want to be Sam Harris, you have to declare you won't listen to some people. If you want to claim that science can resolve questions of morality, it can only do that among people who already agree on a number of fundamental values. Nobody else counts; you have to override them, perhaps by force.
Because I'm in a bad mood right now, I say "Kill 'em all," even if that leaves about five survivors. lol.
Sam Harris has a new book, The Moral Landscape, in which he makes a very simple argument, at least when you express it in the terms we tend to use on LW: he says that a reasonable definition of moral behavior can (theoretically) be derived from our utility functions. Essentially, he's promoting the idea of coherent extrapolated volition, but without all the talk of strong AI.
He also argues that, while there are all sorts of tricky corner cases where we disagree about what we want, those are less common than they seem. Human utility functions are actually pretty similar; the disagreements seem bigger because we think about them more. When France passes laws against wearing a burqa in public, it's news. When people form an orderly line at the grocery store, nobody notices how neatly our goals and behavior have aligned. No newspaper will publish headlines about how many people are enjoying the pleasant weather. We take it for granted that human utility functions mostly agree with each other.
What surprises me, though, is how much flak Sam Harris has drawn for just saying this. There are people who say that there can not, in principle, be any right answer to moral questions. There are heavily religious people who say that there's only one right answer to moral questions, and it's all laid out in their holy book of choice. What I haven't heard, yet, are any well-reasoned objections that address what Harris is actually saying.
So, what do you think? I'll post some links so you can see what the author himself says about it:
"The Science of Good and Evil": An article arguing briefly for the book's main thesis.
Frequently asked questions: Definitely helps clarify some things.
TED talk about his book: I think he devotes most of this talk to telling us what he's not claiming.