As we begin to think seriously about the ethics of enhancement technologies as Christians and as citizens, how can we make clear our deep uneasiness as we reflect on the changes that are being proposed for our species, and do so in a way that can direct policy? As Yubal Levin has observed, “bioethics is necessarily focused on the deepest and most sensitive of human moral intuitions and taboos,” while “at the same time it is directed toward policy, which in a liberal democracy means that it must be an ethics of fully public argument.” Ultimately one has to ask questions about what sorts of interventions are appropriate for human beings living in the social world. I will attempt to address this question by looking at some special problems that arise for those enhancements that can broadly be called “mechanical,” leaving aside for our purposes genetic and other biological innovations. To do this I will reflect on some aspects of our moral, legal, and social self understandings that are in strong tension with the presence within society of mechanically enhanced individuals, and argue that in important ways such altered individuals, or cyborgs, would be unsociable, that is, inassimilable into existing moral and legal institutions.