JOSEPH BOYLE

MEDICAL ETHICS AND DOUBLE EFFECT:THE CASE OF TERMINAL SEDATION

ABSTRACT. The use of terminal sedation to control the intense discomfort of dyingpatients appears both to be an established practice in palliative care and to run counter tothe moral and legal norm that forbids health care professionals from intentionally killingpatients. This raises the worry that the requirements of established palliative care are in-compatible with moral and legal opposition to euthanasia. This paper explains how thedoctrine of double effect can be relied on to distinguish terminal sedation from euthanasia.The doctrine of double effect is rooted in Catholic moral casuistry, but its application inlaw and morality need not depend on the particular framework in which it was developed.The paper further explains how the moral weight of the distinction between intended harmsand merely foreseen harms in the doctrine of double effect can be justified by appeal to alimitation on the human capacity to pursue good.

KEY WORDS: double-effect, euthanasia, intention, terminal sedation

The ethics of the medical profession incorporates some application ofthe moral doctrine of the double effect, particularly to govern medicaldecisions whose outcomes include shortening a patient’s life. Veryroughly: double effect provides that it can be morally good to shortena patient’s life as a foreseen and accepted but unintended side effect ofan action undertaken for a good reason, even if it is agreed that inten-tionally killing the patient or shortening the patient’s life is wrong. Themedical profession’s use of this moral doctrine has some support in legaldecisions.1

The use of terminal sedation to control the intense discomfort of dyingpatients appears to be an established procedure within palliative care.But sometimes the amount of sedative needed to control suffering hasthe effect of shortening the patient’s life. This creates worries that therequirements of appropriate palliative care mandate actions indistinguish-able from euthanasia, which is illegal and morally objectionable to manyhealth care professionals. Invoking double effect addresses these worries:the intent of the physician prescribing the life-shortening analgesics is tocontrol the suffering, not to shorten life. Evidence of physician intent canbe found in notations on the patient’s chart and in the recorded dosages

Theoretical Medicine 25: 51–60, 2004.© 2004 Kluwer Academic Publishers. Printed in the Netherlands.

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and titration of analgesics. Consequently, this action is not euthanasia butpalliative care.2

A consensus was reached among a small but representative group ofCanadian intensivists and a similar group of coroners that this applica-tion of double effect provided proper ethical guidance concerning terminalsedation. Possibly, therefore, there is consensus or the prospect of theemergence of a consensus on this application of double effect amongintensivists and other physicians, including those with oversight respon-sibility for deaths related to medical decisions.3

Whether or not the consensus reported in this study can be further valid-ated or extended, it pointedly raises the central ethical issues involved inthe prospect that this application of double effect could be an establishedpart of medical ethics – and, consequently, legally enforced. Addressingthese issues is distinct from determining the consensus of practitioners.The central issue is perhaps this: double effect is a general moral doctrine,not an ad hoc device to deal with terminal sedation or other difficult lifeand death decisions. This doctrine emerged within the casuistry of RomanCatholicism. How much of this distinctive moral view does the medicalprofession and the law implicitly accept by accepting this application ofdouble effect? To answer this question it is useful to consider further theidea of double effect and its rationale within Catholic moral theology.

The expression “double effect” was first used by St. Thomas Aquinas(1225–1274) to refer to the duality of the results of a single human action.A person performing an action that is foreseen to have a multiplicity ofresults can have very different interests in them – from serious commit-ment to bringing about a result to reluctant acceptance of a result that isunwanted but unavoidable. Since actions are purposeful, at least one ofthe results of an action must be intended, but others, although knowinglyand voluntarily caused, can be outside the agent’s intention; these latterresults I will call “accepted side effects.” Aquinas made this distinction indiscussing killing in self-defense: one who uses lethal force for defenseagainst attack need not intend the assailant’s death; that can be outside theagent’s intention.4

Following Aquinas, Roman Catholic moral theology has attributed aspecific, and very important, moral significance to this distinction betweenwhat a person intends in acting and what a person accepts as a side effectof intentionally acting for another result. The significance is this: thefactors sufficient to make simply wrong actions involving the intention ofsome result are not also sufficient to make simply wrong actions involvingaccepting, but not intending, a result of the same kind. In other words,the impermissibility of an action that is based upon the agent’s intention

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of a certain result does not render impermissible actions having a resultof that kind, if the result is not intended, but accepted as a side effect. InAquinas’s example of killing in self-defense, the moral issue was framedby the acceptance of the Augustinian prohibition of killing in self-defenseon the part of private persons, those lacking public authority to kill. Thatprohibition, Aquinas maintained, applied only to intentional killing, notto killing brought about and accepted as a side effect. Consequently, theacceptance of the Augustinian limitation on those who are permitted tokill does not imply the impermissibility of lethal self-defense, where thedeath is not intentional.

The manuals of moral theology of the nineteenth century refined andformulated Aquinas’s reasoning into a set of rules useful for giving moraladvice and conducting casuistry. These rules became know as the doctrineof double effect, or the principle of double effect. They were generallyformulated as three or four necessary conditions for the permissibilityof actions similar in some of their results to actions that are impermiss-ible because of the general categories into which they fall. Thus, theclassic formulation of the Jesuit moralist J.-B. Gury, in the mid-nineteenthcentury:

It is licit to posit a cause which is either good or indifferent from which there follows atwofold effect, one good the other evil, if a proportionately grave reason is present, and ifthe end of the agent is honorable – that is, if he does not intend the evil.5

Gury elaborated these three conditions into four, by construing thecondition of honorable intention as two. The first addressed the distinc-tion between a means and a side effect: if the bad effect – that is, theresult which would render that action simply wrong were it intended –is the means to the good effect, then it cannot be a side effect and isintended. Thus, the key requirement that the good effect be brought about“immediately,” that is, not by means of the bad effect. The second of theseextrapolated conditions – that one intend only the good effect – excludescases in which the bad effect is not brought about as a means to the goodeffect, but is nevertheless intended because it functions as an independentgoal. An example would be “bonus” effects – results that emerge as sideeffects of bringing about a goal but then recognized as independentlyuseful or beneficial and so (ordinarily) intended.

Gury’s first two conditions – that the “cause” be morally good or indif-ferent and that there be a proportionately grave reason for doing whatbrings about evil side effects – refer to the further moral considerationsthat are needed for a complete assessment of an action meeting the condi-tions for upright intention. These conditions address the two areas whereGury thought an action that cleared the intentionally focused conditions

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might still fail morally. The first area of concern arises from the possibilitythat, prior to any consideration of further results that might be intended oraccepted as side effects but not intended, some actions might be simplywrong. Perhaps his thought here is that since the movements a personchooses for the sake of self-defense have both defensive and destructiveresults, one can distinguish the chosen performance from the results andask of it whether that performance is morally permissible. In some cases,telling a lie or committing adultery, for example, the action is imper-missible on account of considerations logically prior to those concerningintended or accepted results. In the case at hand, a physician’s prescribinganalgesics, described in just that way, is morally indifferent; therefore, theresults, intentions and other circumstances of this chosen behavior willdetermine its permissibility or impermissibility. In this respect the actionis unlike acts of adultery or lying, which as so described are wrong.

This condition may be strictly redundant (and perhaps also confused)since an intended result is intrinsic to an action as a chosen performance,as the lying and adultery cases indicate. Nevertheless, this condition high-lights an important aspect of the style of moral reasoning involved indouble effect: if this condition, or either of the intentionally focusedconditions is not met, then the act is simply and indefeasibly impermiss-ible. These are absolute judgments that cannot be overturned by furtherconsiderations of the action’s particular circumstances: thus, in Aquinas’sexample of killing in self-defense, for any person who is not publiclyauthorized, intentionally killing the assailant is simply, that is, indefeasibly,wrong; nothing further one can discover about the action will reverse thatmoral judgment.6 This is the absolutism of double effect.

The second area of concern is that even if the intentional conditions aremet, and the action is not excluded as simply wrong for some prior reason,the full consideration of its circumstances might still turn up a morallyexcluding factor. The requirement of a proportionately grave reason explic-itly addresses this second area; it presupposes that bringing about as a sideeffect what would be wrong to bring about intentionally is likely harmful orotherwise morally suspect, and so in need of wider justification. Thus, therequirement is that any other considerations relevant to the moral assess-ment of the action should be brought to bear. In Aquinas’s example ofself-defense, two concerns were addressed: whether one defending oneselfhas a duty to refrain from harming the assailant, and the extent of theviolence of the defensive action. He argued that one’s duty to refrain isgenerally less pressing than the duty to protect one’s life, and only thatlevel of violence needed for the defense is justified.7

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The determination of what constitutes a proportionately grave matteris not essential for assessing what is distinctive in the doctrine of doubleeffect. That determination is likely to be as complex and as variable inoutcome as any other reasoning leading to an all-things-considered assess-ment of the morality of an action.8 But the existence of this condition, bothin the manualist formulations and in Aquinas’s reasoning in his classicstatement, underlines the fact that double effect does not imply that it ispermissible to bring about bad results if and only if they are not intended.

In the case of terminal sedation, this condition of proportionality seemsto be easily met, and the existing consensus assumes that. The need forpalliation of some dying patients is substantial and is assumed generallyto justify terminal sedation if moral and legal worries about euthanasia aresatisfactorily addressed.9

This brief survey of the Catholic sources of double effect shows whatit means, and at least roughly how it works. But the summary does notprovide a justification of the special moral significance attributed to thedistinction between what a person intends in acting and accepts as a sideeffect (hereafter the intended/accepted distinction). That is because thereappears to be no developed justification in the tradition. It seems thatAquinas and the theological tradition regarded the ethical significanceof the intended/accepted distinction of double effect as simply obvious.Aquinas’s unargued assertion that what is intended is morally per se andwhat is outside or beyond the intention is per accidens suggests as much.10

Some applications of double effect are certainly intuitively compelling,for example, those distinguishing terror bombing in warfare from carefullytargeted bombing of military targets where some civilians will likely bekilled as side effects. But such intuitive convictions are not readily gener-alized to all cases of double effect, particularly to those where peoples’normative convictions about the cases distinguished is more variable anduncertain than in the bombing cases.11 The distinction between terminalsedation and euthanasia may distinguish just such cases: some may acceptterminal sedation but regard efforts to distinguish it from euthanasia to besleight of hand; some may, for reasons independent of reasoning aboutterminal sedation, accept euthanasia as morally legitimate and so fail tosee the point of introducing double effect’s distinctions.

Moreover, people’s convictions about especially clear cases are notsufficiently focused to justify the precise significance double effectrequires the intended/accepted distinction to bear. Thus, some think thatdouble effect implies that the distinction between bad outcomes that areintended and those that are accepted is that bringing about the former is,other things being equal, morally worse than bringing about the latter.12

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This is not obviously true: the reckless or unjustified inflicting of harmas a side effect is not clearly worse than inflicting it intentionally. Moreimportantly, the implication of double effect is different: namely, that thewrongness of the former does not guarantee that of the latter.

Perhaps the moral significance of this distinction appeared obvious toolder Catholic moralists because of its analogy to the structure of divinecreative activity: God creates only good, but allows the evils of his creation– evils he does not intentionally cause but only permits as privations thatflaw his good creation.13 This analogue suggests a justification. Just asGod creates only what is good, humans should voluntarily pursue in theiractions only what is humanly good. And just as God permits the evilsflawing his creation, so humans must accept some evil consequences theyshould not intend.

The idea is that God, if he is to create some universe he has good reasonto create, must permit the evils which inevitably arise as side effects of hiscreating that universe – for example, the misuse of free will by rationalcreatures’ immoral choices. Applied to human action, the analogy suggeststhat in acting humans can and should aim exclusively at the good, but thatthere will inevitably be some bad side effects of doing that.

Independently of the suggestive theological analogy, there is a limit-ation on the human capacity to pursue the good, and that limitation isprecisely an incapacity to avoid evil side effects, not an incapacity tochoose and intend only the good.

The limitation is this: in all the situations calling for human choice,no matter what a person chooses to do, some instance of a human goodwill be harmed, destroyed or at least knowingly neglected (hereafter I willrefer to all such harms as simply “harming a good”). Thus, it is beyondhuman power to act in such a way that one’s action does nothing morethan promote human good; in all human action some instances of humangoods are promoted and served while others are, at the very least, notpromoted (as when a person leaves some of her talents undeveloped topursue a career), or, very often, more or less harmed (as one risks healthfor the sake of sports), or in some cases even destroyed (as when one kills,whether intentionally or as a side effect).

This limitation is essentially a limitation on the human capacity to avoidsome bad side effects of good choices, and not a limitation on the humancapacity to avoid choosing precisely for the sake of bad goals. In the choiceto act for some goal, namely, in an intentional action, it always remains inthe agent’s power to choose not to do it. So, when something humanly evil– harming a good – is the intended result of one’s action, one always hasthe choice of not doing that action. But one does not have a choice about

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whether or not there will be some bad side effects of whatever one choosesto do. Accepting bad side effects, therefore, is unavoidable, choosing topursue results that involve harming a good is always avoidable – thoughoften at a high price.

Since some bad side effects are inevitable, a morality based on concernfor the human good does not justify an impossible prohibition of bringingthem about. Rather, the relevant moral guidance concerning bringing aboutbad side effects addresses questions such as which bad side effects are tobe accepted and on whom the harms will fall – matters considered underthe proportionality condition of double effect. But if the underlying moralprinciple is taken to be allegiance to the human good, a person’s intentionalactions can always be aimed at the good, since one can always choose toavoid any that are not. Prohibition against intentionally harming a humangood is not an impossible prohibition.

As already noted above, the prohibitions against intentionally harminghuman goods presupposed by double effect are taken to be indefeasible orabsolute. That puts the morality in which double effect developed at oddswith much of current moral opinion. What now counts as common sensemorality largely rejects indefeasible prohibitions of actions of generallydescribed kinds; and consequentialism rejects moral absolutes as inad-equate devices for promoting the good. But if allegiance to the goodis morally basic, and if instances of goods are not commensurable ingoodness, then rational concern for the good readily justifies absoluteprohibitions of intentionally harming them. For if instances of humangoods are incommensurable in their goodness, the respect for each instanceof such goodness is required because there cannot be any good or sum ofgoods that would capture precisely the goodness of that instance. On theseassumptions, therefore, absolute prohibitions of harms to the most basicgoods alone do justice to the reality of the human good.14 But althoughdouble effect presupposes the truth of some such indefeasible norms, itsfunction in moral thought is not to justify them but rather to limit theirapplication to intentionally harming the goods of human beings.

If the preceding account of the justification of double effect’s use ofthe intended/accepted distinction is sound, then within the framework oftraditional morality as understood by the older Catholic moralists doubleeffect is a legitimate moral doctrine. Within that context, it plainly is amoral doctrine, not a specifically Catholic or religious doctrine, since itis the implication of the character of a limitation in human action andwilling joined with the implications of a kind of goods based ethical theory.Can the justification be exported from its strictly moral framework to theregulatory framework of medical ethics?

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In one respect, double effect cannot be exported as is. A person’s inten-tions in doing an action may be inferred from the action and other aspectsof its context, most importantly, how a person explains his or her actions.But a person’s intentions themselves are at least in part inaccessible toothers, and sometimes difficult even for the acting person to articulateaccurately and reflectively. Opponents of double effect argue that theseepistemological difficulties are insurmountable, indeed, that they suggestthat the basic concepts of double effect cannot be rationally applied.15

However, difficult applications of double effect can be debated with thepossibility of confident agreement, and not all applications are contro-versial. Moreover, an individual’s efforts to make upright choices willinvolve personal moral scrutiny and discussion with others that can lead tojudgments that are sufficiently confident to guide choices for many cases.16

But in the context of the regulation of behavior by law or by profes-sional ethics, the third person perspective of judges and juries becomesmore central, and concerns about people’s deepest moral orientationsless important. Here the relevant volitions are not those inaccessible ina person’s heart, but only those of which there is evidence accessible toothers besides the agent. For example, the evidence of intent in terminalsedation cases is the sum of notations on charts, dosages and titration ofanalgesics, and so on. A physician who would prefer to perform euthanasiabut who remains constrained in his or her actions by the requirements ofintent as publicly accessible indicates that he or she does not intend toend life, even if he or she wishes to do that. And that implies that thosewho cooperate with such a physician’s action, are cooperating only in acommon act of palliative care, not of euthanasia.

These considerations show that the question about the exportability ofdouble effect to medical ethics must be reformulated. The inherent limit-ations involved in using a moral doctrine for public regulatory purposesmust be recognized. The question remains: supposing they are recognized,can the moral doctrine be exported?

If there are some kinds of behavior which society or a profession judgesunacceptable, then altogether banning that behavior may be tempting. Buta general ban on behavior having certain results likely prohibits too much,for reasons already noted: for example, causing death or bodily harm isnot reasonably prohibited by medical ethics when unavoidable, and suchresults are unavoidable in some clinical conditions. However, banningintentional killing is not prohibiting too much in this way.

Furthermore, there appear to be good reasons why the medical profes-sion would want to uphold such a ban,17 and, therefore, if practitionersare confident of their ability publicly to determine intent in the relevant

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cases, then such a prohibition would be as justified as the prohibitions inthe strictly moral cases. The fact that the ban would not be justified ifapplied to the acceptance of side effects has, of itself, no tendency to callinto question the narrower exclusion of intentional killing.

The logic of double effect, therefore, has application in medical ethicsand the law, quite independently of the particular moral framework inwhich it was developed and has a natural function in moral reasoning.Double effect does not provide the justification of norms excluding inten-tionally harming a person’s good, but reminds us that when such norms aretaken as true or appropriate, whether as moral norms or social regulations,they cannot reasonably prohibit harming as a side effect. And so, the infer-ence common in debates about euthanasia is not sound: it is not the casethat the fact that we accept bringing about death or an earlier death as aside effect of choosing something else gives rational grounds for judgingintentional killing to be justified.18

NOTES

1 Vacco v. Quill, 117 Supreme Court Reporter 2293 (1997); J. Finnis, G. Grisez, and J.Boyle, “‘Direct’ and ‘Indirect’: A Reply to Critics of Our Action Theory,” The Thomist 65(2001): 1–44.2 L. Hawryluck and W. Harvey, “Analgesia, Virtue, and the Principle of Double Effect,”Journal of Palliative Care 16 supplement, October (2000): S24–S30.3 L. Hawryluck, W. Harvey, L. Lemieux-Charles, and P. Singer, “Consensus Guidelineson Analgesis and Sedation in Dying Intensive Care Patients,” BMC Medical Ethics (2002),http://www.biomedcentral.com/1472-6939/3/3.4 St. Thomas Aquinas, Summa Theologiae, II-II, q. 64, a. 7.5 J. Boyle, “Towards Understanding the Principle of Double Effect,” Ethics 90 (1980):527–538.6 Cf. n. 4, above.7 Cf. n. 4, above.8 G. Grisez, The Way of the Lord Jesus: Volume 3: Difficult Moral Questions, Appendix 1:“Human Acts and Moral Judgments,” (Quincy, IL: Franciscan Press, 1997), pp. 849–870.9 Cf. n. 2 and n. 3, above.10 Cf. n. 4, above.11 J. Boyle, “Who is Entitled to Double Effect?” The Journal of Medicine and Philosophy16 (1991): 475–494.12 Cf. n. 11, above.13 J. Boyle, “Intentions, Christian Morality and Bioethics: Puzzles of Double Effect,”Christian Bioethics 3 (1997): 87–88.14 J. Finnis, J. Boyle, and G. Grisez, “A Sounder Theory of Morality,” in NuclearDeterrence, Morality and Realism. (Oxford: Oxford University Press, 1987), pp. 275–296;See also n. 11 and n. 13, above.

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15 T. Quill, R. Dresser, and D. Brock, “The Rule of Double Effect: A Critique of ItsRole in End-of-Life Decision Making,” The New England Journal of Medicine 337 (1997):1768–1771.16 J. Finnis, G. Grisez, and J. Boyle, “‘Direct’ and ‘Indirect’: A Reply to Critics of Ouraction Theory,” The Thomist 65 (2001): 1–44; See also n. 5, above.17 D. Sulmasy and E. Pellegrino, “The Rule of Double Effect: Clearing Up the DoubleTalk,” Archives of Internal Medicine 159 (1999): 545–550; See also Vacco v. Quill, n. 1,above.18 Cf. D. Sulmasy and E. Pellegrino, “The Rule of Double Effect: Clearing Up the DoubleTalk,” n. 16, above. See also n. 14, above.

REFERENCES

Aquinas, St. Thomas. Summa Theologiae, II-II, q. 64, a. 7.Boyle, J. “Towards Understanding the Principle of Double Effect.” Ethics 90 (1980): 527–

538.Boyle, J. “Who is Entitled to Double Effect?” The Journal of Medicine and Philosophy 16

(1991): 475–494.Boyle, J. “Intentions, Christian Morality and Bioethics: Puzzles of Double Effect.”

Christian Bioethics 3 (1997): 87–88.Finnis, J., J. Boyle, and G. Grisez. “A Sounder Theory of Morality.” In Nuclear Deterrence,

Morality and Realism. Oxford: Oxford University Press, 1987, pp. 275–296.Finnis, J., G. Grisez, and J. Boyle. “‘Direct’ and ‘indirect’: A Reply to Critics of Our

Action Theory.” The Thomist 65 (2001): 1–44.Grisez, G. The Way of the Lord Jesus: Volume 3: Difficult Moral Questions. Appendix 1:

“Human Acts and Moral Judgments.” 849–870. Quincy, IL: Franciscan Press, 1997.Hawryluck, L., and W. Harvey. “Analgesia, Virtue, and the Principle of Double Effect.”

Journal of Palliative Care 16 supplement, October (2000): S24–S30.Hawryluck, L., W. Harvey, Lemieux-Charles, and P. Singer. “Consensus Guidelines on

Analgesis and Sedation in Dying Intensive are Patients.” BMC Medical Ethics, 2002,http://www.biomedcentral.com/1472-6939/3/3.

Quill, T., R. Dresser, and D. Brock. “The Rule of Double Effect: A Critique of Its Rolein End-of-Life Decision Making.” The New England Journal of Medicine 337 (1997):1768–1771.

Sulmasy, D. and E. Pellegrino. “The Rule of Double Effect: Clearing Up the Double Talk.”Archives of Internal Medicine 159 (1999): 545–550.

Vacco v. Quill. 117 Supreme Court Reporter 2293 (1997).

Department of PhilosophyUniversity of TorontoSt. Michael’s College81 St. Mary StreetToronto, OntarioCanada M55 1J4E-mail: Jboyle@chass.utoronto.ca