Taken from the Catholic Encyclopedia (http://www.newadvent.org/cathen/05630a.htm)
(From Greek eu, well, and thanatos, death), easy, painless death. This is here considered in so far as it may be artificially brought about by the employment of anaesthetics. When these last are of acharacter to deprive the sufferer of the use of reason, their effect at this supreme hour of human life is not viewed with approbation by the received teaching of the Catholic Church. The reason for this attitude is that this practice deprives a man of the capacity to act meritoriously at a time when the competency is most necessary and its product invested with finality. It is equally obvious that this space is immeasurably precious to the sinner who has still to reconcile himself with his offended God.
An additional motive assigned for this doctrine is that the administration of drugs of the nature specified is in the premises if not formally at all events equivalently a shortening of the life of the patient. Hence as long as the stricken person has as yet made no adequate preparation for death, it is always grievously unlawful to induce a condition of insensibility. The most that may be granted to those charged with responsibility in the case is to take up a passively permissive demeanour whenever it is certain that the departing soul has abundantly made ready for the great summons. This is especially true if there is ground for apprehending, from the dying person’s continued possession of his faculties, a relapse into sin. In no contingency, however, can any positive endorsement be given to means whose scope is to have one die in a state of unconsciousness. What has been said applies with equal force and for the same reasons to the case of those who have to suffercapital punishment by process of law.
CCC on Euthanasia
2276 Those whose lives are diminished or weakened deserve special respect. Sick or handicapped persons should be helped to lead lives as normal as possible.
2277 Whatever its motives and means, direct euthanasia consists in putting an end to the lives of handicapped, sick, or dying persons. It is morally unacceptable.
Thus an act or omission which, of itself or by intention, causes death in order to eliminate suffering constitutes a murder gravely contrary to the dignity of the human person and to the respect due to the living God, his Creator. The error of judgment into which one can fall in good faith does not change the nature of this murderous act, which must always be forbidden and excluded.
2278 Discontinuing medical procedures that are burdensome, dangerous, extraordinary, or disproportionate to the expected outcome can be legitimate; it is the refusal of “over-zealous” treatment. Here one does not will to cause death; one’s inability to impede it is merely accepted. The decisions should be made by the patient if he is competent and able or, if not, by those legally entitled to act for the patient, whose reasonable will and legitimate interests must always be respected.
2279 Even if death is thought imminent, the ordinary care owed to a sick person cannot be legitimately interrupted. The use of painkillers to alleviate the sufferings of the dying, even at the risk of shortening their days, can be morally in conformity with human dignity if death is not willed as either an end or a means, but only foreseen and tolerated as inevitable Palliative care is a special form of disinterested charity. As such it should be encouraged.
More reading on Euthanasia:
- A Catholic Perspective – Euthanasia and End of Life Issue (Archdiocese of Toronto)
- Brief Reflections on Euthanasia (Priests for Life)
- End of Life Issues / Euthanasia (United State Conference of Catholic Bishops)