The philosophical principle or rule of double effect, attributed to the 13th century Roman Catholic philosopher Thomas Aquinas, states that even if there is a foreseeable bad outcome, like death, it is acceptable if it is unintended and outweighed by an intentional good outcome ”” the relief of unyielding suffering before death.
The principle has been applied to ethical dilemmas in realms from medicine to war, and it is one of the few universal standards on how end-of-life sedation should be carried out.
Reference: New York Times article December 26, 2009.