Double Effect

This post is on the meaning of the term "intention". I will explain the intended/forseen distinction, explain some of the common misunderstandings, and provide some examples.

An event is intended when someone desires the event, either as an end or as a means.
An event is foreseen when someone believes that an event will occur, but desires it neither as an end nor as a means.

There are two misconceptions, usually by utilitarians, as to this distinction.

a) treating means as though they are not intended.
b) treating foreseen events as though they are intended.

The moral significance of this distinction is that certain, intrinsically evil actions, may never be done intentionally. These actions include raping, killing, etc. There is no moral justification for intentionally raping or killing someone.

However, the category of intrinsic evil does not apply to foreseen events. For instance, a politician may have limited funds to divide between health care and crime prevention. The politician may decide that more good can be done in health care, foreseeing that the crime rate, including murders, will increase. However, the politician intends the increased murder rate neither as an end nor a means, and is in no meaningful sense of the term a "murderer". It is an unintended side-effect of spending the money on health care.

The benefit of using the principle of double effect is that it allows us to keep two important moral intuitions. First, morality includes certain unbreakable rules, such as an absolute prohibition against rape and killing. Second, morality is about weighing the benefits and harms of actions. (As a side note, rule utilitarianism tries to keep the same two intuitions, but gets stuck in the logical problem of having no theoretical limit to rule-exceptions). The principle of double effect gives us a two-step process for making decisions.

a) Ensure that no inherently wicked actions are being performed intentionally
b) Then, weigh the benefits and harms associated with a given action.

The principle of double effect enables us to say things that might otherwise seem contradictory. For instance, one can say that one should never kill oneself, but it is heroic to jump on a grenade to save one's friends. When one jumps on a grenade, the end is to save one's friends and the means is stopping the shrapnel. One's death is an unintended side-effect of the stopping of the shrapnel, and is in no way intentional. It is neither an end nor a means to saving one's friends' lives.

The principle of double effect, then, is a useful tool for making distinctions in ethics, and enables us to reconcile the intuitive requirements of universal prohibitions with maximizing benefit.