There's a thread over at IlliniPundit about the recent stem cell breakthrough. In it, one commenter spouts the usual pro-life and anti-stem-cell line "We must not take life to save life." It's the same mentality that you get from pro-lifers about abortion, namely the valuable part of a person is that he is "alive." They never seem to explain under what definition of "life" a zygote is alive but the sperm and ovum are not.
That kind of belief system, however, isn't consistent with permitting organ donations for organs like the heart. Such transplants can come from people that are brain-dead. But I'm not even sure that the position that a person can even be brain-dead is compatible with the extreme pro-life position.
A brain-dead person is still, at the cellular level, alive. With the exception of breathing, many of the normal bodily functions are going on. His heart still beats; his hair still grows; his body is still warm. A blastocyst is alive only in this sense.
I'm of the opinion that brain activity isn't just the most important thing about a person, it's the only thing that's valuable. It's what makes the difference between living tissue and a person. Cut my arm off, and no one will argue that I'm less of a person; pick up my severed arm and no one will argue that it is in any way a person. So there must be something other than being alive at the cellular level that defines the important part of a person's existence.
I just don't see how anyone who's thought it through can claim these two positions are anything other than logically inconsistent. I guess it's that "logically" part that's tripping me up. The pro-life, "an embryo is equivalent to a full grown human being" position isn't a logical argument; it's an emotional one. It has emotional resonance and it soundbites really well.
I'm sure many people will disagree with me and that's fine. Just give me a usable definition of "alive" that applies to a zygote but not a brain-dead person. For bonus points, give me a meaningful definition of "person" that applies to a zygote but not a puppy.
UPDATE: To respond to Glock21's question "At what point are we a human being or person?" I'd like to hand that one off to The Frontal Cortex:
Both political extremes are wrong. A zygote isn't a baby, and a third-trimester fetus isn't a zygote. If cellular biology knows anything, it's that life is a gradient. Our consciousness slowly accumulates. There is no magic spark when an egg starts dividing and differentiating. It's just DNA doing it's thing. Of course, let those cells divide for long enough, and you'll end up with something pretty miraculous. Deciding at what point the miracle begins - at what point that bundle of cells accumulates a "soul" or "mind" or "brain" - is, of course, the really difficult part. But other countries - like Britain, where abortion is an issue debated by doctors, not grandstanding Parliamentarians - show us that this question can be answered in a methodical and rational manner.
I have to say that the obsession and fascination with a fertilized egg because it's apparently "whole" or "complete" is odd. Really, the only difference between separated gametes and a zygote is that the DNA has come together. Big deal. You can have tons of unique DNA in a test tube and it's not a person. DNA isn't even alive. And looking closely at the biology just makes the soundbite even more invalid. From The Island of Doubt:
...there is no "moment of conception."
For starters, the process of fertilization take a measurable amount of time. First the living sperm and living egg membranes fuse, then the egg completes the second stage of meiotic division -- the process that produces a haploid gamete with only half the DNA of a non-sex cell. Then the sperm loses its tail and the energy factory known as the mitochondria. Then the nuclear material from egg and sperm fuse, a process that again takes time. DNA must be wrangled and manipulated until new diploid chromosomes are ready for the next steps. It doesn't happen all at once...
Furthermore, it's only going to get worse. The better the temporal and spatial resolution of our technology,which is improving with each passing day, the more detail and complexity emerges in the reproductive cycle.
So I ask again: when exactly does in this process does one become a "human being" whose destruction is tantamount to murder? Where precisely is this moral boundary of which Mr. Bush speaks?
I understand that to admit to the fact that there is no boundary, that life is continuum, opens a lot of uncomfortable doors for those who like their ethical architecture to be straight and narrow. Sorry, but that's ... life.
I think a lot of the arguing here happens because a segment of the population is very uncomfortable with greyness. Black or white. Good or evil. You're either with us or against us. By framing the discussion in these terms, there isn't any measured or critical analysis or discussion. But it does make things oh so morally uncomplicated.
UPDATE II: Fig pointed out that this post disappeared from the site. When I wrote the above update, I accidentally saved it as a draft, rather than publishing it to the site. Sorry.