Abortion is one of the great moral debates of the epoch. Is there a rational method by which the debate can be resolved? Can bioethics' promise of such a method be fulfilled? Surely, a strictly rational approach can establish solid grounds for our beliefs once and for all. We would then be justified in deeming as unreasonable anyone who does not accept the perfectly rational conclusions. I present two scenarios to show that there can be no such philosophically grounded method (...) and therefore no such facts to which everyone must agree. This does not mean that it is in fact impossible for people to reach agreement. It simply means that there is no incontrovertibly rational means by which they must do so. (shrink)