Full Idea
It seems to have become accepted that passive euthanasia (by withholding treatment and allowing a patient to die) may be acceptable, whereas active euthanasia (direct action to kill the patient) is never acceptable.
Gist of Idea
It has become normal to consider passive euthanasia while condemning active euthanasia
Source
James Rachels (No Moral Difference [1975], p.97)
Book Reference
'Ethics for Modern Life', ed/tr. Abelson,R./Friquegnon,M [St Martin's 1987], p.97
A Reaction
He goes on to attack the distinction. It is hard to distinguish the two cases, as well as being hard to judge them.