Case Study: Terri Schiavo

Background

In 1990, at the age of 26, Terri Schiavo suffered a heart attack and permanently lost consciousness.
After three years in a coma, she was diagnosed as being in a persistent vegetative state, or PVS.
PVS differs from brain death. In PVS, the brain stem is still functional. Schiavo could still breathe on her own and react in basic, reflexive ways.
Doctors determined that Terri Schiavo was not aware of her surroundings and would never wake up.
In 1998, her husband requested that Terri’s feeding tube be removed. Without the feeding tube, she would slowly die of dehydration.
Terri’s parents objected. They argued that Terri would not have wanted this because she was Roman Catholic.
Terri did not have a living will to direct doctors as to her wishes.
Terri Schiavo’s feeding tube was removed three times and replaced twice by court order. On the final removal in 2005, Terri died at the age of 41.

Suppose Terri Schiavo had a living will saying that she wanted to be kept alive at all costs. Should we honor that wish? Is someone in a PVS a moral being, or are they something more like another non-sentient living thing, such as a sponge?
Is there any moral difference between life support and support such as a feeding tube?
Is there any way we could have determined what Terri would have wanted for herself?
Some people say that Terri Schiavo was already dead because the person who was Terri was gone forever. On this view, death is not the loss of a body, but the loss of a person. Is this a good definition of death? What matters more to us: the body or the person? Or is this a bad way of asking the question?
PVS is difficult to diagnose. Some doctors maintain that it can never be distinguished with certainty from a minimally conscious state, which does offer a slim hope of recovery. What moral difference does this make?

Note: in the Terri Schiavo case, she was confirmed to be in a PVS by autopsy.