Technological advances are making devices that functionally replace body parts-artificial organs and limbs-more widely used, and more capable of providing patients with lives that are close to "normal." Some of the ethical issues this is likely to raise relate to how such prostheses are conceptualized. Prostheses are ambiguous between being inanimate objects and sharing in the status of human bodies-which already have an ambiguous status, as both objects and subjects. At the same time, the possibility of replacing body parts with artificial objects puts pressure on the normative status typically accorded to human bodies, seemingly confirming that body parts are replaceable objects. The paper argues that bodies' normative status relies on the relation of a body to a person and shows that persons could have similar relations to prostheses. This suggests that in approaching ethical issues surrounding prostheses, it is appropriate to regard them as more like body parts than like objects.