All of these more or less biological concepts may themselves be rather vague, and, from a moral point of view, insignificant. Without settling any of the disputes about the extension of such concepts, we can still ask the important question directly–while still acknowledging all of the fine-grained biological details: at what point, and under what circumstances, does destroying the entity (described in all the fine-grained biological detail) become morally equivalent to murdering an adult human being? In other words, we don’t have to assume that normative significance attaches to any of the higher-level biological categories (why should we?).

Jeremy, it’s hard for me to understand how they can justify to themselves that it’s not an organism. It’s amazing the intellectual tricks people can play on themselves to avoid the truth when it’s inconvenient for them.

I just noticed that the “killing human life” line was removed from The Washington Post. I linked above to a couple places where it’s still out there from other online newspapers.

the valuable-human life distinction is helpful because it does get to the heart of the matter (great post, btw!). One other that is helpful is living human embryo vs. dead human embryo, because no scientist wants to work with dead ones.

Personhood is a philosophical category that science in and of itself can’t speak to thinks it can. The worldview of those in science has got to be a top priority for the church because horizontal ethics will always leave the embryo unprotected.

I do think it’s crazy to say that I wasn’t once a yet-to-be-implanted embryo, though. It’s not as if the embryo stopped existing for me to come into existence. I was once an embryo. But the dispute with embryos isn’t as clear-cut among scientists as the dispute about developing fetuses. The latter are clearly human organisms, and people dispute whether they have full moral status. The former aren’t universally agreed to be human organisms to begin with, because they hesitate to say they’re even organisms.