Why does it matter when life begins?

Wow, it's been a while. One would think I'd have spent MORE time thinking about blogs over the summer and LESS during the school year, but such are the contradictions of teenage life.

Another vague, half-formed thought I've been masticating crystallized as I viewed the comment thread of this post over at Hot Air. The post itself castigates Pelosi for her poor attempt to reconcile her pro-abortion stance with her Catholicism (not that I care, since I'm not Catholic), so of course the comment thread walks through the whole abortion debate again.

The only part of the abortion debate I'm interested in is the "murder of an unborn child" question. After all, that IS the deciding factor of the debate. If abortion is indeed murder, that obviously outweighs any considerations about women's freedom and so on, and the pro-lifers carry the day. If not, then the idealistic argument of a woman's right to choose (even if I often feel that it should be a choice of whether or not to have sex rather than a choice of whether or not to get an abortion) and the practical argument that the government has no business legislating the issue will outweigh any moral arguments the right can muster. A lot of people have gotten this far, which is why one so often hears the question, "when does human life begin?" For many, that question was answered by the Pope in 1869, when he announced that the cutoff mark was conception. This is the foundation of many a pro-lifer's position on abortion.

But upon looking at the issue, I was confounded by the question you see up top. Why is it that the primary factor everyone thinks of is life? Bacteria are alive, broccoli are alive, cows are alive, yet few have any compunction about ending the life of these creatures. More to the point, my arm is alive; the cells in my kidney are alive; that tumor that had to be cut out of my aunt Louise was alive, and human to boot, but we have no moral qualms about amputation or kidney removal or chemotherapy. When it comes to defining the boundaries of murder, "life" and "human" seem wholly inadequate. For the true crime of murder is not the death of the cells comprising a human being, but the death of the mind (to the religious, the "soul") that resides within.

That's why, to me, the relevant word is "consciousness". When Mazer Rackham describes the buggers' clearing of Eros to Ender, he makes sure to mention that the buggers don't see what they did as murder. As a hive race, they expected to encounter another such; what they did was "trimming", not murder. By the same token, until the foetus reaches independent consciousness, it's naught but a part of the mother, and the mother can decide to remove it if she wants.

Don't confuse this with the "personhood" criteria that one can find on Wikipedia. I do not require that a foetus be able to tell the world, "I think, therefore I am," to be a person. The minimum standard for consciousness, according to the few websites I've visited that discuss the subject, appears to be the ability to feel pain, which develops around the 26th week (regardless of when the foetus starts actually feeling pain). So in my opinion, till then, the mother can do what she darn well pleases; afterwards, she should treat the foetus with all the respect she would give any other living human being. Which may not be much, but it's a start.

EDIT: Both Alioth, here, and BKennedy at Hot Air have pointed out that the potential for consciousness could be used as an alternative cutoff point, and one that would establish the sanctity of the foetus from conception (since this standard requires that the entity in question would do so if left alone, we can ignore gametes, since they must first find another gamete to reach this stage). Also, Think_B4_Speaking at Hot Air has offered a second possible milestone for the establishment of independent consciousness, namely the point when the foetus' brain waves begin registering (around week 11), which would change the cutoff point to near the end of the first trimester.

Finally, a couple of clarifications:
1. "Independent consciousness" does not mean that the foetus be self-sufficient or awake, merely that it have a "self" which is separate from the mother.
2. I am not trying to equate cancer cells with human foetuses (foeti? heh). However, both of them are alive, human, and genetically unique, thereby disqualifying those three criteria from consideration. Obviously a foetus either has independent consciousness, or it has the potential for such, while tumors have neither, so we're right back to those two criteria.
3. When I draw a line, I draw a line. I don't draw a slippery slope. So please, no comments about how next I'll be excluding female foetuses, or foetuses with Down's Syndrome, or gay foetuses (and how am I supposed to tell that last, anyway?). None of these characteristics become apparent until after brain waves begin registering, anyway, so the point is moot.