Not for banning abortion, though, unless you see getting pregnant as a violation of the social contract --- which we don't.
But where is this claim 'it is not a violation of the social contract' coming from? You say the social contract does not define what is moral, so presumably the social contract here matters as reflecting a consensus that something is moral or immoral - so now we need to justify the consensus. Buck-passing has to stop somewhere, and in abortion debates that's usually going to come back to personhood.
As for duty to rescue, doesn't that have a clause about not having to endanger oneself? If so, it's not a particularly heavy imposition on autonomy.
Particular legal versions may or may not, I don't know. The listing of examples makes it sound like not-endangering oneself may be irrelevant (do many firefighters run into situations where they can rescue someone at no risk to themselves?).
I'm familiar with the violinist scenario but I definitely perceive it as supporting abortion; I'd find it morally abhorrent to argue that the kidnapped person should be forced to continue providing lifesupport. Do you think they should?
Yes, but recall that my own position is closer to Apologist in the dialogue. So my reaction to the violinist scenario is to say that yes you should save the violinist in much the same way you should donate a lot of money to the charities which save the most lives; but that I reject any subsequent claim that the violinist scenario is identical to pregnancy, because the fetus has far less personhood and hence far less value than the violinist, and the disparity is great enough to flip my belief.
Something I find interesting about these analogies is the introduction of exciting new emotionally significant detail — a famous violinist, a firefighter — while the emotional detail of the situation being supposedly discussed (a woman seeking an abortion) is not discussed. As Emily put it above, "the most germane point in the abortion debate: any reference to the person who wants the abortion" seems to get wiped out in the analogy.
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.