Jeremy Waldron has posted a paper arguing that the idea of every human being having “equal moral status” is useful only if we distinguish between “sortal” and “condition” status. He notes that the paper was originally prepared for the 2004 Annual Meeting of the American Political Science Association. He explains “sortal” and “condition” status this way in the abstract to his paper:
This paper explores the possibility that the principle of basic equality might be explicated by reference to the idea that humans constitute a “single-status” community. It explores some difficulties with the idea of status in its original legal habitat. These difficulties include skepticism about status fostered by John Austin and others. The paper attempts to answer this skepticism, and it concludes (along with Jeremy Bentham, who in this respect disagreed with his disciple) that once one takes a dynamic view of a legal system, the idea of legal status is not an eliminable idea. The paper then examines the distinction between what I call “sortal-status” and “condition-status.” Sortal status works from the idea that law recognizes different kinds of human being: racist and sexist legal systems are characterized by sortal-status concepts. Condition-status recognizes that persons may get into various scrapes, situations, conditions, and vicissitudes, or pass through certain stages, that are marked by status distinctions. (These include infancy, alienage, felony, bankruptcy, matriage, military service etc.) Once one makes this distinction, then the idea of a single (sortal) status society becomes a promising vehicle for expressing ideas about moral equality.
While he does not discuss the unborn, it is clear from his acceptance of “condition” status, that such children’s moral standing, if any, could be distinguished from that of competent adults. A copy of the complete manuscript can be found here.