Now that the political and media circus surrounding Terri Schiavo has quieted, let me try out my “ethics of subjective experience” perspective on the issue. I don’t know the specifics of Schiavo’s neurobiology, so I’ll keep the discussion general.
I have been tentatively trying out the idea of assigning moral value to the quality and robustness of subjective experience as a crucial (but never sole) guide to ethical issues (see posts here and here). The healthy human represents the pinnacle of high quality, robust first-person experience, but some level of subjective experience exists in other natural systems as well (see for instance this recent post).
Severe damage to the neocortex might eliminate higher cognitive brain functions, and radically diminish experience. But if other parts of the brain (as well as the rest of the body) were functioning, and if we could determine that the patient was not in pain, it would be wrong to assign zero value to the patient’s subjective experience. Not to be flippant, but what if the person’s experience were akin some kind of lower mammal, or bird or fish? I would assign some value to this status. I object to the term “vegetative state”, which seems to make so many implicit assumptions. Of course the more we can learn about the neurobiology of the patients, the more we can infer about their experience.
Beyond the experience criteria, other positive considerations for valuing the person’s life would include special consideration that the person is a member of the human family, and not actually an animal (some limited species-ism is OK, in other words); and an “uncertainty premium” associated with our imperfect knowledge of neurobiology. Weighed with these issues would be the expressed wishes of the patient (absent in Schiavo’s case), then the wishes of kin (unfortunately conflicting in Schiavo’s case), and finally the cost to broader society (modest in Schiavo’s case).
As usual there are shades of gray. Given the above considerations, I must disagree with those who argue that loss of distinctively human cognition is equivalent to death. Of course, those who likened removal of Schiavo’s feeding tube to murder are wrong also. Given a very low but positive value to be placed on a patient’s subjective experience, it is appropriate that the decision lay in weighing some of the secondary issues mentioned above such as the wishes of kin and the cost to society.