I was just reading leading conservative bioethicist Leon Kass on organ transplants — he reluctantly approves of them generally, but categorically rejects any compensation for organ providers (compensation for the organ transplanters is just fine). Here's one paragraph that particularly struck me; recall that this isn't just psychological description, but part of a broader moral argument:
Regarding the recipients of transplantation, there is some primordial revulsion over confusion of personal identity, implicit in the thought of walking around with someone else's liver or heart. To be sure, for most recipients, life with mixed identity is vastly preferable to the alternative, and the trade is easily accepted. Also, the alien additions are tucked safely inside, hidden from sight. Yet transplantation as such — especially of vital organs — troubles the easygoing presumption of self-in-body, and ceases to do so only if one comes to accept a strict person-body dualism or adopts, against the testimony of one's own lived experience, the proposition that a person is or lives only in his brain-and-or-mind. Even the silent body speaks up to oppose transplantation, in the name of integrity, selfhood, and identity: its immune system, which protects the body against all foreign intruders, naturally rejects tissues and organs transplanted from another body.
This is poetry, it seems to me, not argument. The images and concepts are vivid enough, but the logical connections seem to be to missing. The self-consciously self-contradictory metaphor of "the silent body speaks up" exemplifies it best. If you really "listen" to what the silent body "says," you'll hear it speaking up against:
All major surgery, which causes excruciating pain and is usually sure to kill the patient without special care being taken to overcome the body's natural patterns of susceptibility to infection, shock, blood loss, and so on (much like the care taken to overcome the body's immune system).
Childbirth, which likewise causes excruciating pain and often kills the patient without special — and in many ways highly unnatural — modern medical treatment.
Blood transfusions, which likewise trigger the immune system at least if one doesn't take care to do proper blood typing — though in some ethnically highly homogeneous groups that's not a problem; is the silent body speaking up against racial mixing?
To the extent the body "speaks," it doesn't speak about what is right. It speaks about what is likely to happen. We should "listen" to it, but in order to make our interventions more effective, not in order to decide what is morally right or wrong.
This is, I think, a variant of the Is-Ought problem, with a dollop of coming to believe one's own metaphors. A procedure is physically dangerous; therefore it ought to be seen as morally troubling. A procedure is revolting to many people (as are prostate exams, I suppose, or changing diapers); therefore we ought to assume that it's presumptively improper. If we'd consistently adopted such an approach, in what century would medicine be stranded?
UPDATE: My favorite comment so far, from commenter Dave Griffith: "As someone with an auto-immune problem, I presumably am passing histological moral judgements against myself. I'll admit it's probably a fair cop in my case, but that's beside the point."