Strictly speaking, euthanasia is Greek for "good death," but it has come to be applied to cases of an ill or disabled person being helped to die or deliberately killed by another for the ill or disabled person's benefit. It is thus distinguished from murder. Euthanasia is also to be distinguished from mercy killing. Whereas mercy killing normally refers to an act on the part of a friend or relative, euthanasia is typically discussed in relation to health care professionals. A number of further distinctions are drawn between different types of euthanasia: between active and passive euthanasia, and between voluntary, non-voluntary, and involuntary euthanasia. Whereas active euthanasia implies a deliberate act of killing, passive euthanasia means causing death by not doing something: allowing to die by withdrawing or withholding treatment. Not all forms of withdrawing treatment count as euthanasia, as when the treatment is futile or constitutes an...