Two stalemates in the philosophical debate about abortion and why they cannot be resolved using analogical arguments.

Philosophical debate about the ethics of abortion has reached stalemate on two key issues. First, the claim that foetuses have moral standing that entitles them to protections for their lives has been neither convincingly established nor refuted. Second, the question of a pregnant woman's obligation to allow the gestating foetus the use of her body has not been resolved. Both issues are deadlocked because philosophers addressing them invariably rely on intuitions and analogies, and such arguments have weaknesses that make them unfit for resolving the abortion issue. Analogical arguments work by building a kind of consensus, and such a consensus is virtually unimaginable because (1) intuitions are revisable, and in the abortion debate there is great motive to revise them, (2) one's position on abortion influences judgments about other issues, making it difficult to leverage intuitions about other ethical questions into changing peoples' minds about abortion, and (3) the extent of shared values in the abortion debate is overstated. Arguments by analogy rely on an assumption of the commensurability of moral worldviews. But the abortion debate is currently unfolding in a context of genuinely incommensurable moral worldviews. The article ends by arguing that the default position must be to permit abortion as a consequence of the freedom of conscience protected in liberal societies.