Vital prostheses: Killing, letting die, and the ethics of de-implantation.

Disconnecting a patient from artificial life support, on their request, is often if not always a matter of letting them die, not killing them-and sometimes, permissibly doing so. Stopping a patient's heart on request, by contrast, is a kind of killing, and rarely if ever a permissible one. The difference seems to be that procedures of the first kind remove an unwanted external support for bodily functioning, rather than intervening in the body itself. What should we say, however, about cases at the boundary-procedures involving items that seem bodily in some respects, but not others? When, for instance, does deactivating an implanted device like a pacemaker count as killing, and when as letting die? Contra existing proposals, I argue that the boundaries of the body for this purpose are not drawn at the boundaries of the self, or (if this is different) the human organism. Nor should we determine when we are killing and when we are letting die by deferring to existing practices for distinguishing ongoing from completed treatment. Rather, I argue that whether something (organic or inorganic) counts as body part for purposes of this distinction depends on the results of a normative analysis of the particular character of our rights in it-particularly, whether and in what way these rights ought to be alienable. I conclude by arguing that there are likely good reasons to recognize distinctively "bodily" rights and restrictions in at least some implantable devices.