I actually pretty much agree with Jonah Goldberg here: It’s a mistake to cast such issues as the debate over stem cell research in terms of a battle between “pro-science” and “anti-science” forces, although it’s a little tempting insofar as some of the religiously motivated opponents do seem to have a more general hostility to science. Of course there are some kinds of scientific research that should be banned—see Dr. Mengele for details—and I very much doubt it’s in the interest of those who support stem cell research to give the impression that what they’re rejecting is the very idea of any moral constraints on the pursuit of science. Nobody actually would argue that, I think, but you see the odd soundbite that might uncharitably be read that way.
In particular, though, I want to agree that “the determination that embryos have no moral worth is not a scientific conclusion but a moral one. ” That’s certainly true, but seems to cut against the primary rhetorical tactic of pro-lifers looking to make secular arguments, which entails treating the biological category of “human” as though it were identical with the moral category of “person.” So tempting is this conflation, in fact, that in a later discussion of this very point, Jonah accidentally refers to “life” when he means “personhood.” Certainly investigation of biological properties will tell us a great deal that will be helpful in determining the morally relevant traits of an organism in fuzzy cases. But it would be an awfully funny coincidence if the boundary lines of scientific taxonomy happened to neatly map those of ethical evaluation, given (as Jonah notes) that these are indeed two very distinct sorts of inquiry whose very distinct purposes determine where those boundary lines fall.