> I don't think rights can be tied to sentience. What about people in comas, or people who are severely mentally retarded to the point where they will never be more than vegetables?
>
> I think normal people agree that all humans have rights, but then we have to start defining humanity.

Consider; is your view of where "animal nature" ends, and humanity begins, tempered by your awareness (and experience) that some people under palliative care are little more than animals or vegetables in their final days? How would you take a stab at defining "humanity"?

And just to tie this thread back to the original set of controversies...
I am troubled by whether the bare difference between killing (active euthanasia) and letting die "naturally" produces a significant moral difference. Letting die "naturally" is *passive euthanasia* -- through the withholding of heroic life-saving methods from a person who is thought will "eventually die anyway, and for whom artificial prolongation of life needlessly increases their total suffering". I am not certain, however, that a Christian recognizing the sanctity of life can rationalize even passive euthanasia of a dying relative, ultimately. Even if they are in an extremis of anguish that not even heavy-duty pain-killers like demerol can effectively erase?