Principle of double effect

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The principle of double effect; also known as the rule of double effect; the doctrine of double effect, abbreviated to DDE; double-effect reasoning; or simply double effect, is a set of ethical criteria for evaluating the permissibility of acting when one's otherwise legitimate act (for example, relieving a terminally ill patient's pain) will also cause an effect one would normally be obliged to avoid (for example, the patient's death.) Double-effect originates in Thomas Aquinas's treatment of homicidal self-defense (Summa Theologiae, IIa-IIae Q. 64, art. 7).

This set of criteria states that an action having foreseen harmful effects practically inseparable from the good effect is justifiable if upon satisfaction of the following:

• the nature of the act is itself good, or at least morally neutral;
• the agent intends the good effect and not the bad either as a means to the good or as an end itself;
• the good effect outweighs the bad effect in circumstances sufficiently grave to justify causing the bad effect and the agent exercises due diligence to minimize the harm.

Intentional harm versus side-effects

Although different writers state and employ double effect differently, they share the position that consequentially similar acts having different intentional structures make for ethically different acts. So, for example, advocates of double effect typically consider the intentional terror bombing of non-combatants having as its goal victory in a legitimate war morally out of bounds while holding as ethically in bounds an act of strategic bombing that similarly harms non-combatants with foresight but without intent as a side effect of destroying a legitimate military target. Because advocates of double effect propose that consequentially similar acts can be morally different, double effect is most often criticized by consequentialists who consider the consequences of actions entirely determinative of the action's morality.

In their use of the distinction between intent and foresight without intent, advocates of double effect make three arguments. First, that intent differs from foresight, even in cases in which one foresees an effect as inevitable. Second, that one can apply the distinction to specific sets of cases found in military ethics (terror bombing/strategic bombing), medical ethics (craniotomy/hysterectomy), and social ethics (euthanasia). Third, that the distinction has moral relevance, importance, or significance.

Examples

Medicine

A vaccine manufacturer typically knows that while a vaccine will save many lives, a few people may die from side-effects of vaccination. The manufacture of a drug is in itself morally neutral. Lives are saved as a result of the vaccine, not as a result of the deaths due to side-effects. The bad effect, the deaths due to side-effects, does not further any goals of the manufacturer, and hence is not intended as a means to any end. Finally, the number of lives saved is much greater than the number lost, and so the proportionality condition is satisfied. This is more a case of side-effects/benefit analysis than of a real Principle application and is common in medicine.

The principle of double effect is frequently cited in cases of pregnancy and abortion. A doctor who believes abortion is always morally wrong may nevertheless remove the uterus or fallopian tubes of a pregnant woman, knowing the procedure will cause the death of the embryo or fetus, in cases in which the woman is certain to die without the procedure (examples cited include aggressive uterine cancer and ectopic pregnancy). In these cases, the intended effect is to save the woman's life, not to terminate the pregnancy, and the effect of not performing the procedure would result in the greater evil of the death of both the mother and the unborn child.^[1][2]

Palliative care

It is often thought that the administration of a high dosage of opioids is sometimes allowed for the relief of pain in cases of terminal illness, even when this can cause death as a side effect. This argument played a great part in the 1957 acquittal of suspected serial killer Dr. John Bodkin Adams, a case which established the principle in British law.^[3]

Some, including most Catholic ethicists, hold that this concept is morally different from deliberate euthanasia for the relief of pain. In addition, support for the view that palliative care and euthanasia are close companions is based on the assumption of a fine line between pain relief, or relief of severe distress, and causing death. In practice, opioids have a very wide safety margin when used appropriately and in the context of pain relief that is titrated (adjusted) to the individual patient. Similarly, sedatives are not lethal when used only to relieve distress and at the lowest dose to avoid dangerous adverse effects. Today, palliative care experience and research has shown that it is possible to manage pain or distress without hastening death (see opioids) and double effect is not viewed as being part of palliative care practice.^[4]

War

The principle appears useful in war situations. In a war, it may be morally acceptable to bomb the enemy headquarters to end the war quickly, even if civilians on the streets around the headquarters might die. For, in such a case, the bad effect of civilian deaths is not disproportionate to the good effect of ending the war quickly, and the deaths of the civilians are side effect and not intended by the bombers, either as ends or as means. On the other hand, to bomb an enemy orphanage in order to terrorize the enemy into surrender would be unacceptable, because the deaths of the orphans would be intended, in this case as a means to ending the war early, contrary to condition 2.

Passive suicide by refusal of medical treatment

Suppose a patient has been diagnosed with a terminal illness where the chances of survival are even or better if treated, but certainly lethal if not. Suppose that the patient has no great desire to live. By the principle of double effect, the patient could choose to end his or her life simply by refusing the prescribed medical treatment. The law usually provides that any patient may choose to refuse treatment for any reason, or for no reason at all. The effect would be the same as that of a suicide, but it would not actually involve the direct action of ending one's own life.

Criticisms

Despite some apparent plausibility, the doctrine of double effect is controversial. Here are some common criticisms:

1. Consequentialists, in particular, reject the notion that two acts can differ in their moral permissibility, if both have exactly the same consequences, or expected consequences.

2. Many contemporary moral philosophers reject Consequentialism, but few defend moral theories that give no role whatever to consequences. In other words, while most reject the idea that the moral status of an action fundamentally depends only on its (expected) consequences, most accept the idea that the moral status of an action at least in part fundamentally depends on its (expected) consequences. A major argument against the DDE is the hypothetical case where some evil must be intended and acted upon in order to bring about an enormous good, such as in a ticking time bomb scenario. For example, suppose a nuclear bomb has been planted in a major city, and a person is held in custody who knows where it is, but who refuses to disclose the bomb's location. May the interrogators torture this person's family in front of his or her eyes, exploiting the family attachment to extract information and save millions of lives? The argument against DDE thus becomes a question of how high must the stakes be before intending and doing any evil is permissible for good ends, while the DDE maintains that intending and doing evil is never permissible even as an instigator to good ends.

3. The DDE seems to require distinguishing between intended means and (foreseeable) mere side-effects. A defender of the DDE might say that something is an intended means just in case it is a necessary means to one's aim or end; something is a mere side-effect just in case if it could possibly be avoided whilst still achieving one's aim or end, it would be. For instance, consider the distinction between foreseeably killing non-combatants in strategic bombing, and foreseeably killing non-combatants in terror bombing. In the former case, the defender of the DDE might claim that the strategic bombing is morally permissible in that the deaths of the non-combatants are mere side-effects, and not necessary means to achieving the end or aim of destroying vital military equipment. If, for example, the military targets could be destroyed without the non-combatant fatalities, the strategic bombing would still have succeeded. On the other hand, since the aim of terror bombing is to increase terror (in order to, say, help end a war), the suffering and deaths of non-combatants must be intended, and are not merely side-effects. But one might think that, all else equal, there cannot be such a morally significant difference between strategic bombing and terror bombing—after all, in both cases, innocent non-combatants are foreseeably killed for the sake of some presumably morally desirable end. It may help to distinguish between ultimate intentions and proximate intentions. (For example, if my ultimate intention is to save thousands of lives by preventing the bomb from exploding, and I must torture Sally in order to do so, then intending to torture Sally is my proximate intention.) The DDE appears to focus on the proximate intentions of agents. But some might claim that this is arbitrary or implausible. Why shouldn't the agent's ultimate intentions be the most (or at least more) relevant factor in assessing the moral permissibility of her actions? Can we maintain that what the terror bomber did was morally impermissible and what the strategic bomber did morally permissible, even if they have the same ultimate intentions (e.g., to save the most innocent lives) and brought about equally good or bad results (e.g., saved net 10,000 innocent lives) through their actions?

4. The DDE makes distinctions about the moral status of actions that are not countenanced by commonsense moral thinking. Consider a famous thought-experiment in moral philosophy: the Trolley Problem: A runaway trolley is headed down a track on which five innocent, non-consenting people are stuck. You happen to be standing nearby, and realize that you can pull a lever to divert the trolley down a different track, on which one innocent, non-consenting person is stuck. (Imagine the track is Y-shaped, and the five are on the left and the one is on the right). Commonsense moral thinking, and the DDE, would countenance doing so. On the DDE, such an act is permissible because the death of the one person is a mere side-effect. If one could pull the lever and divert the trolley without it running over and killing the one person, one's aim of saving the five would nonetheless have been accomplished. But now consider a revised version of the Trolley Problem in which the five remain on the left and the one on the right, but where the track on the right forms a loop which rejoins the main track. Now, if the trolley is diverted to the right, it will kill the one person on the loop, and come back to kill the five. But suppose the person on the loop is large enough to stop the trolley if run over by it). Now it seems that, in diverting the trolley to the right in order to prevent the five from being killed, one must intend killing the one large person (as this person's death is a necessary means to stopping the trolley and thus saving the five). Hence, the DDE would imply that it's permissible to pull the lever in the original trolley problem, but impermissible to do so in the revised (looping) version. But commonsense moral thinking would not distinguish between these two cases. Moreover, commonsense moral thinking would tend to suggest that it is permissible to save the five in both versions. One need not embrace Consequentialism to agree with this.

See also

• Opioids
• Trolley problem

References

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External links

• Principle Of Double Effect (theological perspective)
• Stanford Encyclopedia of Philosophy entry
• What is the doctrine of double effect?