And here's a video of Harris giving a talk on the subject:
I'm afraid that Harris' approach to the issue is all too familiar.
He tries to make the point that science can address morality because science is about facts and morality, if it exists, is a fact. That's all well and good, but even if you assume that there is an existent morality how do you detect it using science? And that's where Harris falls flat on his face:
Now, to speak about the conditions of well being in this life, for human beings, we know there is a continuum of such facts. We know that it's possible to live in a failed state. Where everything that can go wrong does go wrong. Where mothers cannot feed their children. Where strangers cannot find the basis for peaceful collaboration. Where people are murdered indiscriminately.How do we know? We just know! What could be more convenient?
And we know that it's possible to move along this continuum, toward something quite a bit more idyllic, to a place where a conference like this is even conceivable. And we know, we know, that there are right and wrong answers to how to move in this space. Would adding cholera to the water be a good idea. Well probably not.Apparently we don't know quite enough about the cholera question to answer definitively!
Seriously, a guy with a degree in philosophy from Stanford can't do any better than this? It's not even difficult to illustrate the problem.
Suppose for the sake of argument that morality is an illusion. We have ideas of morality but moral precepts are not real. Now suppose in that scenario we know--we know--there is a continuum of moral facts. If that subjective impression of knowledge is sufficient to make morals real then this scenario results in a contradiction.
In the end, Harris adopts a strategy akin to that used by Ayn Rand and George Smith: assume that something basic ("well being") is an objective moral good and then propose that science can help figure out certain things that result in well being. Then claim that science can answer moral questions while ignoring the fact that the finding of science is utterly reliant on the axiomatic moral precept ("well being is good").
Though not on precisely the same subject, a just-published story by Michael Gerson about the brothers Hitchens seems like a good companion to the above.