Is it your contention, then, that a feeding tube could/should be inserted against the patients' will?
I'll have to think that one over for a while. I don't like the idea of forced medical procedures any more than I like the idea of deliberately letting someone die.
Here's my first-draft solution to that dilemna:
First, living wills should be considered null and void on the basis that there is no way to know what one really wants until they are actually in that position.
Second, a person should be free to refuse any treatment, if their will can be established beyond any doubt. In the case of refusing a treatment where such a choice could reasonably be considered life-or-death, it should be recorded in either signed or otherwise recorded form with affidavits signed by three unrelated adult witnesses (the standard for capital punishment in Texas is my reference here).
Third, if a person is not capable of expressing their will, no reasonable treatment on which his life is dependent should be refused or denied to him under any circumstances.
I'm sure there'll be holes in this, it's a first draft. But I think it will help to get the idea, in preserving the right to life while also retaining the other rights of free men.
The more I think about it, the more I find the very concept of a "living will" to be repulsive, with little purpose other than to be an instrument for justifying euthanasia. It also makes sense, that the least questioned, most generally accepted element in this entire equation is also the most insidious. It seems innocuous, but almost all scenarios in which a person is unjustly put to death depend on a living will OR (especially important) the absence thereof having legal weight, for the absence case is being defined towards death.