MANY WHO SUPPORT Terri Schiavo's threatened dehydration assert that removing a feeding tube from a profoundly cognitively disabled person results in a painless and gentle ending. But is this really true? After all, it would be agonizing if you or I were locked in a room for two weeks and deprived of all food and water. So, why should we believe that cognitively disabled patients experience the deprivation differently simply because they receive nourishment through a feeding tube instead of by mouth?