I thank Professor van der Breggen for his response to my brief review of his book, which is itself partially a response to our book. So this response here is a response to a response which is a response.
you are sick, about to die, but you will be healed if your favorite celebrity touches your fevered brow.
pregnancy (in non-rape cases) is like freely giving your kidney (which you can live without) to another person (a vulnerable, dependent person whom you’ve created) so the other person can live, whereas abortion is like tearing out from that person the kidney you’ve donated to him/her—and thereby kills that other person—because you’ve changed your mind about your previously-freely-made decision to donate it.
So persons indeed do have a moral right to what was someone else's kidney, if they need that kidney to live AND if one has already, in a fully-informed manner, engaged in freely giving/ donating one’s kidney to the person in question (and the donation isn’t a physical threat to the life of the donor). Ditto for fetuses—which we and Thomson concede are persons—and the biological systems gifted/donated to them also freely and in a fully-informed manner.
one cannot “undo” or “reverse” the fact of reproduction or pregnancy. That is, one cannot return to the previous state in which reproduction and pregnancy did not occur
If you consent to something, then you consent to accepting that something's not likely causal consequences, especially if you know what those consequences may be and choose to go ahead anyway, and so you must accept them because you can no longer address those consequences, meaning you can no longer do something to make it such that those consequences hadn't occurred.
the state of being of the fetus is more like a non-permanent coma or non-permanent vegetative state: the fetus will awaken/ gain consciousness—if we don’t kill him/ her.