Pope John Paul II on Care for Disabled Persons:

"As ecumenical witness in defense of life develops, a great teaching effort is needed to clarify the substantive moral difference between discontinuing medical procedures that may be burdensome, dangerous or disproportionate to the expected outcome -- what the Catechism of the Catholic Church calls "the refusal of 'over-zealous' treatment" -- and taking away the ordinary means of preserving life, such as feeding, hydration and normal medical care. "
John Paul II - "Bishops Must Stand Firmly on the Side of Life -- Encouraging Those Who Defend It Against the Culture of Death" - ad limina address to US bishops October 2, 1998