Two Histories of the Principle of Double
Effect
Nancy Rourke, Division of Humanities,
College of Professional Studies
Abstract
The principle of double effect is a significant moral
principle in traditional Catholic ethics. Moralists employ
the principle to evaluate acts that would produce both a good
effect and an evil effect. For example, in the area of
medical ethics at the end of life, hospice care-givers might wish
to treat a patient’s pain with morphine. However, morphine
may also hasten the death of a terminally ill patient. Given
the possibility of hastening death, would it be wrong to administer
morphine to a patient near the end of life? To address this
question and any similar acts that produce both an evil and a good
effect, the principle of double effect employs four criteria, each
of which must be satisfied in order for the act to be deemed
morally good. First, the act must not be evil in
itself. Second, the evil effect must not be directly
intended. Third, the evil effect must not function as the
means by which the good effect is produced. Finally,
proportionate reason must justify the production of the evil
effect. Although all four of these criteria are necessary,
moralists often rely primarily on either proportionate reason
(criterion four), or the indirectness of intention (criterion two),
and some even argue that the principle as a whole boils down to one
or the other of these two criteria. Proponents of these two
extreme interpretations turn to two different seminal histories of
double effect to support their thinking. A comparison of
these two histories may clarify this confusion. My research
compares these two works: Joseph Mangan’s “An Historical
Analysis of the Principle of Double Effect” (1949) and Jozef Ghoos’
“L’Acte A Double Effet: Étude De Théologie Positive” (1957).