In her important and well-known discussion “On the Moral and Legal Status of Abortion,” Mary Anne Warren regrets that “it is not possible to produce a satisfactory defense of a woman’s right to obtain an abortion without showing that the fetus is not a human being, in the morally relevant sense.” Unlike some more cautious philosophers, Warren thinks that we can definitively demonstrate that the fetus is not a person. In this paper, Warren’s argument is critically examined with a focus (...) especially on the question of the foundation and the boundaries of the moral community. The fundamental thesis of the paper is that Warren’s approach is flawed for at least four reasons: (1) that being a person is not as obviously central to having full moral rights as Warren assumes, (2) that her exclusivism regarding moral status has dubious moral consequences independent of the abortion issue, (3) that it is not clear that a fetus is not a person, even on Warren’s own criteria, and (4) her criteria for personhood are themselves suspect. (shrink)