This guy Ross, guest-blogging at Andrew Sullivan’s site…he’s good.

Yet acknowledging that all deaths aren’t the same, and that all murders aren’t equally wicked, doesn’t mean that all lives don’t deserve legal protection. If I shoot a mother of four, it’s a much greater tragedy than if I shoot a friendless bum, and you’d probably want to give me a much stiffer prison sentence. But it doesn’t mean the mom should have the right to life and the bum – or the fetus, the embryo, or the zygote – shouldn’t.

And of course, the other reason we don’t respond emotionally to zygote deaths is because we don’t know they’re happening. The “zygote intuition” argument would make a little bit more sense, in this regard, if people never felt grief over a miscarriage. Then you could argue – “look, our moral intuitions tell us not to grieve over human life before that life acquires a personality, or self-awareness, or a face.” But of course, people do feel grief over miscarriages, by and large – just as they feel guilt (again, by and large) over abortions. Which suggests, in turn, that we don’t grieve for zygotes not because we somehow intuit that they aren’t really people, but because – unlike embryos and fetuses – we aren’t aware of their deaths. You can’t grieve for something you don’t know exists.