I think the basic stumbling block in the typical abortion dialog isn't the criteria of personhood, it's that people don't like to deal with the real, practical reasons why you shouldn't kill people.
The basic reasons why murder is illegal are:
A. In general, people are much more valuable to society alive than dead. This does not apply to unwanted babies.
and
B. Attempts to legally identify the people who would be better off dead are prone to dangerous corruption and irreversible error, the costs of which far exceed the benefits. Again, this does not apply to u...
The basic reasons why murder is illegal are:
You left out what I would have said is the most basic reason murder is illegal. Simple self interested cooperation. A wants to be free to kill his enemies but really doesn't want his enemies to be free to kill him. B wants to be free to kill her enemies but doesn't want her enemies to be free to kill her. C, D and E have similar preferences. By mutual agreement and alliance they each sacrifice their right to kill other people so that they are less vulnerable to be killed themselves.
Naturally they attempt to wrangle it such that they are an in group who does get to kill people anyway but in Australia at least we have managed to stamp even that sort of behaviour out entirely - at least within our own borders.
Well, sure he's valuable NOW, but that's after years and years of investment. It's not that being unwanted takes a baby from super valuable to negative, babies are just not very valuable regardless.
On the other side of that argument, a fetus does not have the higher brain function or consciousness that would allow it to experience pain. When an adult is put under general anesthesia for surgery we do not generally consider them to be "experiencing pain" even though the body is still reacting the damage as though they were conscious. They still have brain function, they temporarily lack the higher brain function required for the meaningful experience of pain. A very similar argument could be applied to a fetus.
When you're considering a decision of exchanging two babies, you're making it based on what you know to anticipate. If you know nothing relevant, you're ambivalent between exchanging and not exchanging, which is what "fungible" means.
(The dollar bills are also not identical, and where one bill can buy you a snack, another won't work by being suspected counterfeit in a manner you didn't expect. Such considerations don't make cash non-fungible.)
Let me turn your question around. If your utility function puts value in the mere existence of people, regardless of how they interact with the larger world, doesn't that mean having babies is as wonderful as killing people is terrible? Is somebody with 12 kids a hero?
Is somebody with 12 kids a hero?
Or a serial killer with a large family? "Sure he might have killed 3 people -- but he's a father of 5!"
I think the last part of the dialogue is unconvincing: the Apologist weasels away from addressing the slippery slope argument. He seems to be saying that children aren't "human" until sometime after puberty--when they can "act all the acts, think all the thoughts, and feel all the feelings people can." The obvious response for the Contrarian is to ask whether the Apologist is opposed to infanticide, and if so, exactly where he draws the bright line between infanticide and abortion.
I just ran across this and clicked through to the discussion; sorry for being a year out of date, but I hope you don't mind the comment anyway!
I enjoyed reading the piece but I felt like it was missing any reference to what (to me) is the most germane point in the abortion debate: any reference to the person who wants the abortion. To my mind, the personhood or lack thereof of the foetus really doesn't matter very much, because it's growing in a person whose personhood is indisputable and who doesn't want it to be doing that. I think the piece would be muc...
So, you resolved my slippery slope by biting its bullet and saying there is a sharp discontinuity even if you didn’t know where.
Could't the Contrarian just as easily have accepted that different entities have different "levels" of personhood? The odds of a skin cell becoming sentient is quite low, after all. Of course, this would render abortion more palatable based on miscarriage rates, but at least they could have avoided claiming that GAIs aren't people :\
On the other hand, the Apologist seems a little too quick to bite the infanticide bull...
What I personally find of value is human-like mind. It doesn't matter what it's implemented in: silicon, cells, whatever. A human child has a mind that's too primitive to be of any value, and that's only when the brain is developed. So its death seems to me to be an insignificant loss (aside from personal loss for the parents, etc..., of course).
If I have a choice to save a fully grown human (let's say 30 years old, the issue becomes more moot the older the person gets) or a child (yes, even a born child), I would sooner save the adult. A dead child is a w...
A few years ago, I wrote a little dialogue I imagined between 2 materialists, one of whom was for and one against abortion, centering on the personal identity question. I recently cleaned it up and added a number of references for the biological claims.
You can read it at An Abortion Dialogue.
Early feedback from #lesswrong is that it's a 'nicely enjoyable read' and 'quite good'. I hope everyone likes it, even if it doesn't exactly break new philosophical ground.