The following includes an article: “The Rule of Double Effect — A Critique of Its Role in End-of-Life Decision Making.” The New England Journal of Medicine — December 11, 1997 — Vol. 337, No. 24, by Timothy E. Quill, M.D., Rebecca Dresser, J.D., and Dan W. Brock; and 

Timothy Quill titled, Critique of the Double Effect, (NPR interview, All Things Considered, Monday, December 11th, 1997). To hear a tape of this show, go to: 

The New England Journal of Medicine — December 11, 1997 — Vol. 337, No. 24 
The Rule of Double Effect — A Critique of Its Role in End-of-Life Decision Making 
According to the ethical principle known as the “rule of double effect,” effects that would be morally wrong if caused intentionally are permissible if foreseen but unintended. This principle is often cited to explain why certain forms of care at the end of life that result in death are morally permissible and others are not. 

According to the rule, administering high-dose opioids to treat a terminally ill patient’s pain may be acceptable even if the medication causes the patient’s death. In contrast, the rule does not authorize practices such as physician-assisted suicide, voluntary euthanasia, and certain instances of forgoing life-sustaining treatment. 

The rule of double effect is a conceptually and psychologically complex doctrine that distinguishes between permissible and prohibited actions by relying heavily on the clinician’s intent. The doctrine’s complexities and ambiguities have limited its value as a guide to clinical practice. 

In this article, we examine the rule’s religious and philosophical origins, its inconsistencies with current law, and its shortcomings as a practical clinical guide. We also propose alternative principles to govern care at the end of life. 

The rule of double effect, which was developed by Roman Catholic moral theologians in the Middle Ages, is applied to situations in which it is impossible for a person to avoid all harmful actions. 

In such situations, a person must decide whether one potentially harmful action is preferable to another. 

Suppose a terminally ill man experiencing unrelenting pain and suffering asks his physician for help in ending his misery. If the physician kills the patient to end his suffering, the patient’s death is intended. According to the rule of double effect, the goal of relieving the patient’s pain and suffering is good, but the means chosen to achieve the goal is wrong within the moral system that prohibits the intentional killing of innocent persons. 

The word “intentional” suggests, however, that the deaths of innocent persons may be permissible if brought about unintentionally. With the same goal of relieving the patient’s unbearable pain and suffering, the physician might provide large doses of analgesic medication even though the patient could die sooner as a result. If the physician refrains from providing such medication because of the lethal risk it poses, the failure to intervene harms the patient by allowing the potentially treatable pain to continue. But if the physician provides the medication, the action may hasten the patient’s death and thus inflict a different harm. The rule of double effect construes the physician’s provision of medication in the second scenario as an intentional action to relieve pain and suffering with the foreseen but unintended risk of causing an earlier death. The physician’s action thus does not violate the prohibition against intentionally killing innocent persons. 

Classic formulations of the rule of double effect emphasize four key conditions. 

The first concerns the nature of the act, which must be good, such as the relief of pain, or at least morally neutral and not in a category that is absolutely prohibited, such as the killing of innocent persons. The second concerns the agent’s intention. The “good effect and not the evil effect must be intended.” The bad effect, such as respiratory depression after the administration of opioids, may be “foreseen, but not intended.” The third condition is the distinction between means and effects. The bad effect, such as death, must not be a means to the good effect, such as the relief of suffering. The fourth condition is the proportionality between the good effect and the bad effect. The good effect must outweigh the bad effect. The bad effect can be permitted only when there is “proportionally grave reason” for it. 

The first condition determines whether an act is ever potentially permissible, and the second and third conditions are used to determine whether the potentially inflicted harm is intentional or unintentional, as either a means or an end. The fourth condition requires the agent to compare the net good and bad effects of potentially acceptable actions to determine which course would produce an effect of proportionately greater value. Thus, the agent should choose the action with the most favorable balance of good and bad effects, within the limits set by the first three conditions of the rule of double effect. 

Clinical Applications of the Rule of Double Effect to End-of-Life Decisions

Many medical ethicists cite the rule of double effect to explain why a clinician is permitted to administer high doses of opioid analgesics to relieve severe pain in a terminally ill patient toward the end of life, even in amounts that could cause the patient to die sooner than he or she would otherwise. ( 

The physician’s goal in these circumstances is to relieve the patient’s suffering, and the means is the use of opioid analgesics in doses that might contribute to an earlier death. Neither the patient nor the physician intends for the patient to die, either as a means or as an end. If death occurs, it is an unintended (though possibly foreseen) side effect. The more severe and intractable the patient’s pain, the greater the justification for risking an earlier death. Thus, the amount of opioid pain reliever that is given and the rapidity with which it is increased must be in proportion to the amount of pain and suffering. 

Some physicians have been reluctant to use sufficient doses of opioid pain relievers, even when their patients are dying, in part because of fears (both ethical and legal) about contributing to an earlier death. 

The rule of double effect has helped some physicians to overcome this hesitation. Yet other clinicians remain unwilling to prescribe sufficient doses in part because they do not distinguish morally or psychologically between actions performed with the intent to cause death and those performed with the foreseen possibility of causing death 

Voluntary euthanasia, in which the physician administers a lethal injection at the request of a suffering patient, clearly violates the rule’s requirement that death not be intentionally caused as a means or an end 

However, problems arise when the rule is used to argue against physician-assisted suicide. The goal of physician-assisted suicide is to relieve intolerable suffering, but the means to this end is to provide the patient with a death-producing agent 

Providing a patient with a means to end life could be held to violate the prohibition against intentionally causing death (or contributing to the patient’s intentional act of ending his or her own life), even if the physician’s overarching purpose is to relieve intolerable suffering. Yet the physician may have many purposes in providing such prescriptions to offer a sleeping aid, to reassure the patient by providing a potential escape from suffering that the physician hopes or expects will not be used, or to relieve suffering, with death as an inevitable but unintended side effect. The simple classifications of intent provided by the rule of double effect are not easily applied to the physician’s intentions in this clinical setting. Moreover, it is the patient’s action, not the physician’s, that directly causes death in the case of physician-assisted suicide. 

The rule of double effect is also of limited assistance in evaluating the practice known as terminal sedation. In this situation, the consenting patient is sedated to the point of unconsciousness in order to relieve otherwise untreatable pain and suffering and is then allowed to die of dehydration or other intervening complications. The goal of administering the sedative, to relieve otherwise unrelievable suffering, is good. Whether death is intended or merely foreseen is less clear. Unlike the use of high-dose opioids to relieve pain, with death as a possible but undesired side effect, terminal sedation inevitably causes death, which in many cases is what the patient desires. Although the overall goal of terminal sedation is to relieve otherwise uncontrollable suffering, life-prolonging therapies are withdrawn with the intent of hastening death. Terminal sedation would thus not be permitted under the rule of double effect, even though it is usually considered acceptable according to current legal and medical ethical standards 

Finally, although there is a clinical, ethical, and legal consensus that patients have the right to refuse life-sustaining treatment, such decisions are sometimes problematic when analyzed according to the rule of double effect. Some patients with conditions such as advanced emphysema may decide to discontinue mechanical ventilation knowing they may die but hoping they will be able to live unencumbered by medical technology 

In such cases, the clinician is permitted to remove the ventilator under the rule of double effect. Other patients, however, may make the same decision with the explicit intention of escaping severe suffering by hastening death. 

In these cases, the rule of double effect does not permit the clinician to remove the ventilator, because of the intention to cause death. The rule may cause confusion about physicians’ responsibilities with regard to stopping life support and may account for the reluctance of some physicians to carry out patients’ wishes to forgo treatment. 

In one large series, 39 percent of physicians who had sedated patients while stopping life support reported that they had done so with the intention of hastening death, in clear violation of the rule of double effect. 

The recent Supreme Court rulings on physician-assisted suicide illustrate the similarities and differences in how current law and the rule of double effect evaluate the clinician’s conduct in various end-of-life practices. 

The law incorporates similar considerations in evaluating the administration of pain-relieving opioids. Although criminal law does not exempt from liability all persons who unintentionally cause another person’s death, conduct posing a risk to life is permissible if it is justified by the expected benefits. An example is risky surgery performed to correct a serious medical condition. Because the law includes a principle resembling the proportionality provision in the rule of double effect, clinicians may administer potentially lethal medications when they are necessary to relieve a terminally ill patient’s suffering. 

On the other hand, the rule of double effect and the criminal law have different views on forgoing life-sustaining treatment. In contrast to the rule of double effect, the law permits, indeed requires, clinicians to forgo treatment at the request of a competent patient, even when the expressed purpose is to cause the patient’s death. Similarly, terminal sedation with the patient’s informed consent is legally permissible. These practices are lawful because death results from omitting medical interventions refused by patients who are exercising their rights to self-determination and protection of their physical integrity. 

Current law joins the rule of double effect in prohibiting clinicians from providing or administering lethal medications with the explicit purpose of causing a patient’s death. Here one could argue that the law shares some of the rule’s weaknesses and uncertainties. As noted above, physicians may have various aims when they provide terminally ill patients with prescriptions for potentially lethal medications. In the case of a patient who ingests a lethal overdose of a drug prescribed by a physician, prosecutors ordinarily would have great difficulty establishing beyond a reasonable doubt that the physician acted intentionally or knowingly to help the patient die, which would be necessary to support a conviction for assisting in suicide. Moreover, the general refusal of jurors to convict physicians charged with assisted suicide or homicide for contributing to the consensual deaths of their suffering, terminally ill patients indicates that many ordinary persons disagree with the prohibition against all intentional direct killing, incorporated in both the rule of double effect and current criminal law. 

The rule of double effect has many shortcomings as an ethical guide for either clinical practice or public policy. First, the rule originated in the context of a particular religious tradition. 

American society incorporates multiple religious, ethical, and professional traditions, so medicine must accommodate various approaches to assessing the morality of end-of-life practices. Many persons and groups reject the position that death should never be intentionally hastened when unrelievable suffering is extreme and death is desired by the patient. 

Yet the rule’s absolute prohibition against deliberately taking human life seems to apply even to a competent, terminally ill patient who seeks to end suffering through the cessation of life-sustaining therapy. 

Second, the analysis of intention used in the rule of double effect is problematic, difficult to validate externally, and inconsistent with other analyses of human intention. Even philosophers and theologians sympathetic to the distinction between intended and foreseen consequences have failed to find an unambiguous way to draw the distinction in many difficult cases. Moreover, according to modern psychology, human intention is multilayered, ambiguous, subjective, and often contradictory. 

The rule of double effect does not acknowledge this complexity; instead, intention is judged according to the presence or absence of a clear purpose. Clinicians familiar with the requirements of the rule may learn to express their intentions in performing ambiguous acts such as providing terminal sedation or withdrawing life support in terms of foreseen but unintended consequences; at the same time, other clinicians may reasonably interpret these acts as clear violations of the rule. 

Third, in most moral, social, and legal realms, people are held responsible for all reasonably foreseeable consequences of their actions, not just the intended consequences. Physicians are not exempt from this expectation. This understanding of moral responsibility encourages people to exercise due care in their actions and holds them responsible for that which is under their control 

The important moral question is whether the risk of foreseeable harm is justified by an action’s good effects. It is the principle of proportionality that determines when the risk of undesirable consequences is justified. 

Fourth, autonomy is a central tenet of Western medical ethics and law. 

Those who give considerable weight to patients’ rights to determine their own care believe that the patient’s informed consent to an action that may cause death is more fundamental than whether the physician intends to hasten death. From this perspective, the crucial moral considerations in evaluating any act that could cause death are the patient’s right to self-determination and bodily integrity, the provision of informed consent, the absence of less harmful alternatives, and the severity of the patient’s suffering. 

Finally, the rule of double effect has had both desirable and undesirable effects on clinical conduct. The rule has reassured clinicians that prescribing high-dose opioids for pain in terminally ill patients is morally permissible, and that is all to the good 

More controversially, the rule has reinforced absolute societal and professional prohibitions against directly and intentionally causing death. 

Unfortunately, the rule of double effect has also had negative effects on clinical practice, particularly when patients are making decisions that include death as a likely consequence. Concern about violating the rule’s absolute prohibition against intentionally causing death may account for the reluctance of some physicians to honor their patients’ requests to withdraw life-sustaining therapy.. 

Furthermore, the unwillingness of some physicians to provide adequate medication for pain relief, particularly if the medication could contribute to an earlier death, may reflect their failure to accept the rule’s simplistic account of intention in such situations. 


For clinicians and others who believe in an absolute prohibition against actions that intentionally cause death, the rule of double effect may be useful as a way of justifying adequate pain relief and other palliative measures for dying patients. But the rule is not a necessary means to that important end. Furthermore, the rule’s absolute prohibitions, unrealistic characterization of physicians’ intentions, and failure to account for patients’ wishes make it problematic in many circumstances. In keeping with the traditions of medicine and broader society, we believe that physicians’ care of their dying patients is properly guided and justified by patients’ informed consent, the degree of suffering, and the absence of less harmful alternatives to the treatment contemplated. 

Timothy E. Quill, M.D. 

University of Rochester School of Medicine Rochester, NY 14607 

Rebecca Dresser, J.D. 

Case Western Reserve University Cleveland, OH 44106 

Dan W. Brock, Ph.D. 

Brown University Providence, RI 02912 

Dr. Quill’s views do not necessarily reflect those of the University of Rochester or its Department of Medicine. 

Address reprint requests to Dr. Quill at the Department of Medicine, Genesee Hospital, 224 Alexander St., Rochester, NY 14607. 

We are indebted to James Childress, Ph.D., for his contribution to early drafts of the manuscript. 

Critique of the Double Effect

Monday, December 11th 
National Public Radio, All Things Considered 

To hear a tape of this show, go to: 

NPR’s Elizabeth Arnold moderates a discussion between Dr. Timothy Quill, Professor of Medicine and Psychiatry at the University of Rochester School of Medicine and Dentistry, and Dr. Daniel Salmasey, Director of the Center for Clinical Bioethics and Associate Professor of Medicine at the Georgetown University Medical Center. They take up the doctrine of “double effect” that holds that an effect that would be morally wrong is it were caused intentionally permissible if unintended, even if forseen. The principle has guided physicians for centuries in the cases of giving drugs to patients for the relief of distressing symptoms while at the same time running the risk of hastening their deaths. Dr. Quill’s critique of the Rule of Double Effect appears in this week’s (Dec. 11) issue of New England Journal of Medicine. 


ELIZABETH ARNOLD, HOST: And I’m Elizabeth Arnold. Imagine this scene at the bedside: you’re a physician and your patient, who’s dying of cancer, is in extreme pain. Your patient is having some trouble breathing, but the chief complaint is pain. A powerful drug is available for you to use — one that will certainly control the pain and make your patient comfortable — but one that also runs the risk of shortening your patient’s life. Do you use the drug in that way? 

This is an ethical dilemma physicians and patients have struggled with for centuries, often under the guidance of the ethical principle known as “double effect” 

Historically, the principle grew out of Roman Catholic moral theology and holds that an effect that would be morally wrong if it were caused intentionally is permissible if unintended, even if it’s foreseen. In other words, in the case of your patient with cancer, if your intent is to control your patient’s pain, you can go ahead and use the powerful drug, even if you run the risk of shortening your patient’s life by so doing. In today’s issue of the New England Journal of Medicine, the principle of double effect is the subject of a critique written by Dr. Timothy Quill, professor of medicine and psychiatry at the University of Rochester School of Medicine and Dentistry. He joins us from Chicago. Dr. Quill, welcome. 


ARNOLD: And with me here in Washington is Dr. Daniel Salmasey, director of the Center for Clinical Bioethics and associate professor of medicine at Georgetown University Medical Center. Dr. Salmasey, welcome to you 


ARNOLD: Timothy Quill, let’s start with you. Explain to us your reservations about this principle. 

QUILL: Well, for the particular clinical situation that you were describing, actually the double effect is quite helpful. It allows the physician to progressively increase pain medicine, perhaps even use sedation, as long as his or her intent is to relieve the patient’s suffering, even if it might contribute to an earlier death. And this has liberated us, I think, to not be fearful about using whatever dose of pain medicine is needed. But take a slightly different scenario. Let’s say that that patient is near death and starts talking about wanting to die — being ready to die — in fact, wanting to go to sleep to die. All of a sudden, if they start talking about wanting to die, and that is their intent in taking higher doses of pain medicine, then it creates a more difficult dilemma for the clinician because they’re not supposed to intend to help somebody to die. 

So the double effect rule places a premium of importance on the physician’s intentions, but really a much lesser role of the patient’s will, their informed consent, which is a much more important consideration. 

ARNOLD: Dr. Salmasey? 

SALMASEY: Well, I agree 100 percent with Dr. Quill that the situation you described is one in which narcotics should be used judiciously and appropriately for patients in those circumstances. But I think that one of the problems I have with the paper, and Dr. Quill’s other comments sort of allude to that, is that the paper in some ways generalizes the use of this principle, somewhat outside of the bounds in which it’s typically intended to be used. 

So for instance, desire to die is not a symptom that a drug controls. And so, I wouldn’t think that we should, under those circumstances, be giving people drugs because it’s their desire to die, and that the principle of double effect would actually not allow it under those circumstances. 

If he’s talking about, for instance, giving people who have no real symptoms, but simply say that it’s now a point where I think I’m going to be dying in the next six months and I want to take a large dose of drugs so that I can die quickly, then I think that’s the same as physician-assisted suicide. And that would be stopped by the principle of double effect anyway, because the intention that’s shared in both cases is that the patient should die. 

ARNOLD: Dr. Quill, same as physician-assisted suicide? 

QUILL: I don’t think suicide is the right term for any of these circumstances, but I think the focus needs to be on the patient’s will; their informed consent; the adequacy of palliative care; the nature and severity of their suffering. And if a person starts talking about wanting to die, it seems to me we have an obligation to listen to them and try to respond to them. 

ARNOLD: Dr. Quill, in your article, you talk about the difficulty in evaluating a physician’s intention. Is it really that — that difficult to distinguish between intending to kill someone and not intending to? 

QUILL: Well, the double effect makes a distinction between a death that is intended and one that is merely foreseen, but not intended. And it’s OK if death is foreseen, but not intended, but not if it is done intentionally. And that works in circumstances of usual pain management, where we are taking the risk of providing high doses of pain medicine, but it is neither the doctor’s intent nor the patient’s intent to help a patient to die. We accept that risk and we use amounts that seem to be in proportion to their suffering. Severe suffering, we take more risk with higher doses. 

But the whole equation begins to change when the patient starts talking about wanting to die because then what does it mean when you start giving very high doses to someone in that same circumstance who wants to die — and can you still say that you’re not intending to help them to die, when that’s their purpose in taking — that’s one of their purposes in taking their — this higher dose of medicine? 

So in fact, all — we know — what we know about intentions from psychology is that they are complex; they’re multi-layered; at times, ambiguous. And the double effect thinks of intentions in black and white terms. They’re either present or absent. And that is very problematic in the real world of clinical medicine. 

ARNOLD: Do you agree with that, Dr. Salmasey? 

SALMASEY: Well, I certainly agree that it’s very difficult to get inside somebody’s mind and read their intentions. I mean, there’s no question about that. But I’m troubled by this sort of obfuscation about intentions that sometimes seems to come across in comments from Dr. Quill and within the paper. There’s a great quote from Samuel Johnson who once said that, you know, “the fact of dusk does not mean there’s no difference between night and day”; And if you’re giving — when I give morphine to patients, I think part of the problem is that most — I’m giving more than most of the clinicians around me who aren’t, I think, giving enough of the drug to patients to relieve their pain. And my intention in doing — in doing that is to relieve their pain. If I give them 10 milligrams or 20 milligrams of morphine and they’ve never had some before, that’s perfectly all right and it’s better than giving them two. And I may slightly increase the possibility that they may die more quickly that way. 

On the other hand, if I walk up to you, Elizabeth, and you know, inject three grams of morphine over 10 seconds into your veins, any clinician worth his salt would say that that’s, you know, way over the amount that’s appropriate for treating you if you had a stubbed toe, and that this is problematic and they would question what my intentions are. And it would seem very obvious that my intentions were not simply to relieve your pain in that circumstance. So while there is some ambiguity, and I think we ought to give good clinicians the benefit of the doubt using their judgment, we still ought to reserve the possibility of being able to judge people’s intentions on the basis of their actions. And sometimes, it’s very clear. 

ARNOLD: What about the patient’s autonomy? Certainly, there are limits to that, aren’t there? If a patient comes to you with a headache and asks for an MRI, presumably you’d say no. If a dying patient asks you to shoot them, presumably you’d say no 

QUILL: Sure, there are many limits to that. The patient’s informed consent and autonomy is just — is one element of many. Another element is the nature and extent of their suffering. How severe is it? How effective are our means to relieve it? And the third is, and this is one element of the double effect rule with which I am in complete sympathy, and that is that the intervention has to be proportionate to the situation. 

So again, with small amounts of pain, you may take the risks of small amounts of pain medicine, but with severe suffering at the very end — severe pain — you may take the risk of very, very large doses of pain medicine. So proportionality is — and the nature of suffering — are also key elements, as well as autonomy. It’s not simply a matter of autonomy. 

SALMASEY: I — I think that we also want to be careful that we’re using the right medication to treat the right symptom, or the right modality of treatment for the proper symptom. Suffering is much broader as a concept than pain, and Dr. Quill and I will certainly agree on that. Not all people who have pain are suffering, and not all suffering is — has pain as its root cause. So when the patient’s problem is pain, I’m going to give them a narcotic or other drug that’s designed to treat their pain. If their problem is depression, I’m not going to use narcotics to treat that depression. I’ll use an anti-depressant. If their problem is existential angst, or as the Dutch say, “tiredness of life”; I’m not sure that we have a drug that treats those sorts of things. 

Maybe what the patient needs in those circumstances is somebody who’s going to not abandon them — be at the bedside with them; remind them that they have dignity and value and meaning, even as the bonds that keep them and us together are slowly dissolving. I mean, that’s the kind of thing that the patient may really be asking for, and that’s the kind of treatment we ought to be giving people. 

And I worry sometimes that with all the talk about physician- assisted suicide and euthanasia, we’re — we’re really jumping the gun. There’s so much more work we have to do in making the care of the dying better that we ought to be putting much more of our energy into doing that, rather than focusing on this particular case of one modality of euthanasia or assisted suicide. 

ARNOLD: Dr. Quill? 

QUILL: Yeah, in general, I actually agree with that. I think we need to improve care of the dying. We need to improve access to hospice programs and good pain management. Those are all things that we need to devote — and I think we are beginning to devote resources to this as a culture. But we also need to learn how to really listen to people who are getting good care — have access to these things — but still are suffering in ways that are very extreme at the very end. And they achieve a readiness for death. They are ready to die. 

And again, if they’re on life supports, for example, we deal with that conversation very explicitly. We say — the message we give to clinicians is: “listen to your patient because generally they know what they need. Listen to them very carefully. Assess them for depression and other things, but listen to them” 

If they’re not on life support, suffering in otherwise exactly the same way, the message is very different, and I think the message should be the same: “listen to that patient.” Try to find every alternative you can to help them keep living, but if there are no alternatives and the suffering is extreme, I think we have to be much more creative and open- minded in our response. There’s nothing magical about assisted suicide as a response, but there is something very important about not abandoning such patients and really searching with them for acceptable solutions. So if not assisted suicide, then what? And we’re beginning to open