 Medical ethics traditionally instructs clinicians not to harm people. Taking organs from healthy people does seem to harm them, so living donor transplantation appears contrary to traditional medical ethics. One reply is to say that the “do no harm” rule is a relic of the medical profession’s paternalism; if people want to donate their organs and know what they are doing, why stop them (Veatch and Ross 2015)? This reply raises the difficult problem, discussed below, of how far consent justifies harm. Another reply is to say that taking organs from willing living donors may not be all-things-considered harmful to them (Spital 2004). This reply usually draws on one of the following normative views: (a) that living donation is only permissible when we expect the donor not to be harmed; or (b) that it is only permissible when we expect the donor to benefit (in both cases, all things considered, taking account of a wider range of factors than just physical wellbeing) (Williams 2018).