The Dirty Papist

Arguments for abortion I've seen just this week, numbered for your convenience:

1. "[Pro-lifers] do not care that the landmark ruling [of Roe] has stood for over 30 years. Nor do they care that its overturn could threaten the legitimacy of the institution where a change in decision would clearly be due to a change in membership."
   
2. Pro-lifers and pro-choicers tend to argue on a superficial level--how frequent abortions are, the demographics of who has them, and how the fetus/embryo/blastocyst appears. The real issue is when the fetus, etc. becomes a human person entitled to equal protection before the law.
   
3. Newly fertilized ova are biological entities with human DNA in the same way as unfertilized gametes. Fertilization does not make it a person. A kidney cell contains the full genetic code of a person, so why isn't it considered a human being?
   
4. Personhood does not begin at the advent of any milestone in development, like when the heart starts beating or when the child begins to "look like a child." After all, personhood is not lost by grossly disfiguring accidents or debilitating diseases, or temporarily suspended during a heart transplant.
   
5. Humans that are merely fertilized ova are not persons, and claims that they are human persons because their human DNA prevents them from becoming anything else falls flat, for no one denies it.
   
6. Failed implantation of zygotes is morally equivalent to voluntary abortion, so why aren't we focusing on all those tragically killed innocent humans?
   

Responses, respectively numbered for your convenience:

1. Abolitionists did not much care for the "landmark rulings" on Dred Scott or Plessey, nor were they interested in the preservation of the institution of slavery, nor did they feel that if the membership of SCOTUS continued to favor institutionalized servitude, then they should have just given up.
   
2. Arguing about how "human" an embryo looks may be superficial, but many people continue to judge a book by its cover ("If it just looks like a blob of cells, then it can't be a person"). See item #4.
   
3. A gamete may contain demonstrably human DNA, but it only contains half of what it's supposed to. Thus, it either lacks the discrete humanity of a zygote, or it's some kind of haploid miracle or it falls far short of viability and miscarriage before abortion could even be considered is all but a certainty. A kidney cell, as the kidney containing it, is by definition part of the whole, not the whole of an entity. Removing a kidney does not dehumanize a person; the zygote is not an interchangeable part of a person, but can only be removed as a whole (indeed, there is no way to remove part of it without great risk of destruction) from the mother. There's nothing to distinguish it from, as a kidney cell can be distinguished from the whole organ or organism, except the entire mother. Some philosopher must have already tried to make or disprove arguments of this form, of what constitutes a part versus an essence. Anyone care to point me that way? Bueller?
   
4. I'm surprised by this point. Most people pick the detection of brain activity for their arbitrary criterion of personhood. I wonder how many of them consider pets to be people. A good point is raised, though: humanity is not lost with a decrease in our ability to judge a human by sight. What are we left with, though? We have to choose either conception, or an arbitrary point based on such things as viability or risk to the mother, and neither of the latter is particularly satisfactory. The former will converge on the moment of conception as technology improves--and we've already shown conception to be possible through externally applied technology--so it doesn't have any inherent ethical capacity. The latter will also decrease as technology improves, but it leaves unanswered the question of whether we're pitting the rights and responsibilities of a pregnant woman against anyone else's rights, so this point is contingent on other arguments, none of which I find moving, as you can imagine.
   
5. No one denies it because such a ridiculous claim would comprise too direct a means of forfeiting the debate on the account of psychosis. This claim isn't a stand-alone argument; "I say you're wrong, because no one disagrees with your proof, which I will not believe is valid." An alternative criterion for humanity or personhood is still needed.
   
6. I don't know how to stop the famines in Africa, either. Should I then not volunteer at the local soup kitchen? Maybe my example should be reversed--I have no idea how many zygotes are miscarried versus the number of abortions. Either way, there is a world of difference between failing, being unable, to prevent deaths, even a lot of them, and deliberately killing someone, innocent or otherwise.