Genetic enhancement, post-persons and moral status: a reply to Buchanan

Responding to several leading ideas from a paper by Allen Buchanan, the present essay explores the implications of genetic enhancement for moral status. Contrary to doubts expressed by Buchanan, I argue that genetic enhancement could lead to the existence of beings so superior to contemporary human beings that we might aptly describe them as post-persons. If such post-persons emerged, how should we understand their moral status in relation to ours? The answer depends in part on which of two general models of moral status--one based on respect and one based on interests--is more adequate. Buchanan tentatively argues that a respect-based model is preferable. I challenge Buchanan's view, along these lines: If we embrace a respect-based model of moral status featuring a threshold that divides persons, who are thought to have full and equal moral status, from sentient nonpersons, thought to have less moral status, then we should acknowledge a second threshold and a level of moral status higher than ours. A better option, I tentatively suggest, is to drop the idea of levels of moral status, accept that all sentient beings have moral status, and allow that some differences in interests and capacities justify some significant differences in how we should treat beings of different kinds.