Euthanasia

Euthanasia (literally "good death" in Ancient Greek) refers to the practice of ending a life in a painless manner. There are a few classifications of what euthanasia is. One, termed euthanasia by consent, differentiates euthanasia according to consent given. According to this classification, euthanasia is either conducted with consent (voluntary euthanasia) or without consent (involuntary euthanasia, where another individual makes the decision for the person incapable of doing so). Another is euthanasia by means (passively, non-aggressively, and aggressively). Passive euthanasia entails the withholding of common treatments or the distribution of a medication to relieve pain, knowing that it may also result in death. Non-aggressive euthanasia entails the withdrawing of life support, while aggressive euthanasia entails the use of lethal substances or forces to kill.
The Catholic Church condemns all forms of euthanasia as "crimes against life".This teaching rests on several core principles of Catholic ethics- the sanctity of human life, the dignity of the human person, concomitant human rights, due proportionality in casuistic remedies, the unavoidability of death, and the importance of charity. However allowing patients who can't be saved from death to die without medical interventions that would be considered "extraordinary" or "disproportionate" is permitted. The Declaration on Euthanasia states that:

"When inevitable death is imminent... it is permitted in conscience to take the decision to refuse forms of treatment that would only secure a precarious and burdensome prolongation of life, so long as the normal care due to a sick person in similar cases is not interrupted."

Although the Declaration allows people to decline heroic medical treatment when death is imminently inevitable, it unequivocably prohibits the hastening of death. In other words, allowing terminal patients to die is OK, while making them die earlier is not. [Taken from Wikipedia]