The arguments raised in [a recent article about euthanasia] are heard daily in I.C.U.'s when we deal with massively brain-damaged adults. Once it is decided, either in advance by the patient or by the responsible family members, that not living is the better choice, then withholding treatment is what allows death; it does not cause death. Respirators, IV tubes, feeding tubes and operations are not found anywhere in nature, and it is in the use of these interventions that we play God, not in the withholding. It is the failure to understand this crucial distinction that leads to so much unnecessary anguish and pain in grieving relatives. 

-- Howard Belfer, M.D., letter to the editor, New York Times Magazine, July 24, 2005