What is the doctrine of double effect and share an example of how is it used or could be used to resolve conflicting moralduties

The doctrine of double effect is an argument against the killing of non-combatants, even in a just war. The argument states that it is permissible to use force in order to achieve a good end, even if the means used is not itself morally good or neutral (Govindarajulu et l., 2019). In other words, one may commit an act which has both good and bad effects if the bad effect is not intended but merely foreseen as a side-effect of doing what is morally required (Govindarajulu et l., 2019). The doctrine of double effect can be traced back at least as far as St Thomas Aquinas (1225–1274) who used it to argue against killing civilians in wartime. It was later adapted by John Duns Scotus (1266–1308) who argued that it could never be morally permissible to kill innocent people (Uniacke 1984). The doctrine became controversial following its use by Catholic theologians during World War II who justified bombing civilian targets on the grounds that although it would cause civilian casualties, this was not intended but merely foreseen as an unavoidable side-effect of doing what was morally required; namely, defeating Hitler’s Germany by whatever means necessary.

For example, consider the following scenario:

A doctor has five patients who need organ transplants. Unfortunately, there are only five organs available for transplantation. If the doctor does not take action, all five patients will die within a week. However, if she performs an operation on one patient in order to save their life, she will also kill them (through organ removal).

The doctrine of double effect says that it is acceptable for the doctor to perform this operation because A) performing this surgery is morally good (saving someone’s life), B) removing this person’s organs is not morally bad (it’s not murder or something else), and C) since there are no other options for saving these patients’ lives, there’s nothing she can do to avoid killing them anyway (Govindarajulu et l., 2019).

References

Govindarajulu, N. S., Bringsjord, S., Ghosh, R., & Peveler, M. (2019). Beyond the doctrine of double effect: A formal model of true self-sacrifice. In Robotics and Well-Being (pp. 39–54). Springer, Cham.

Uniacke, S. M. (1984). The doctrine of double effect. The Thomist: A Speculative Quarterly Review, 48(2), 188–218.