Speciesist or biological accounts of moral status can be defended by showing that all members of Homo sapiens have a moral status conferring property. In this article, I argue that the most promising defense locates the moral status conferring property in the relational property of being biologically tied to other humans. This requires that biological ties ground moral obligations. I consider and reject the best defenses of that premise. Thus, we are left with compelling evidence that biological ties and membership (...) in a biological category like “species” ground neither moral obligations nor moral status. Because it is crucial to account for the moral significance of family bonds, I conclude by describing the sense in which biological ties matter morally. (shrink)

If a person requires an organ or tissue donation to survive, many philosophers argue that whatever moral responsibility a biological relative may have to donate to the person in need will be grounded at least partially, if not entirely, in biological relations the potential donor bears to the recipient. We contend that such views ignore the role that a potential donor's unique ability to help the person in need plays in underwriting such judgments. If, for example, a sperm donor is (...) judged to have a significant moral responsibility to donate tissue to a child conceived with his sperm, we think this will not be due to the fact that the donor stands in a close biological relationship to the recipient. Rather, we think such judgments will largely be grounded in the presumed unique ability of the sperm donor to help the child due to the compatibility of his tissues and organs with those of the recipient. In this paper, we report the results of two studies designed to investigate the comparative roles that biological relatedness and unique ability play in generating judgments of moral responsibility in tissue donation cases. We found that biologically related individuals are deemed to have a significant moral responsibility to donate tissue only when they are one of a small number of people who have the capacity to help. (shrink)