My argument is that the people being punished in this way have in some sense forfeited part of their right not to have their autonomy violated, by demonstrating inability to stick to a social contract that has been agreed on as reasonable. Views can differ on whether that's reasonable or not, but it's firmly distinguishable from someone forfeiting their autonomy because they got pregnant.
I don't see why you would elevate the social contract in any extreme way like that; you mean abortion is OK, and execution not OK, solely because the latter is imposed (hopefully) on those who have violated the social contract in some way? This seems rather relativistic. So what if we have a social contract, like in Catholic countries, which says abortion is not OK?
Also doesn't deal with the draft or taxation examples, or additional examples like duty to rescue.
So under this view of autonomy, abortion belongs in the same category.
Or goes quite the other way: what loss of a woman's autonomy for 9 months could possibly compare to losing an entire life of autonomy, which is what the fetus's loss will be? Bioethics calls this the violinist thought experiment.
I agree that the merits of any given social contract can be debated and shouldn't be taken as intrinsically ok, so I don't think I want to be relativistic in that sense. But if there is to exist a social contract at all (which I do think is a good thing), there has to be a way of removing people from it who can't uphold it, and perhaps helping them to get to a position where they can, if possible. (Ideally I think incarceration etc would be more about rehabilitation than anything else; in practice I don't think this is true at all, at least not where I liv...
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.