Abstract
In Catholic moral theology, the principle of double effect has been an effective normative tool for centuries, and it can be used to determine the ethicality of actions that contain both good and evil consequences. The principle of double effect is especially useful in end-of-life care, because many end-of-life treatment options inherently have both good and evil consequences. The principle of double effect can be used to make both practical and moral distinctions between the acts of euthanasia, physician-assisted suicide, palliative sedation, and the withholding and withdrawal of life-sustaining treatment, which can be classified as either unjustified acts of killing or justifiable acts of allowing to die.