How is Double Effect Applied?

24 Apr 2014

San Francisco Philosophy Professor Thomas Anthony Cavanaugh explains the practical applications of Double Effect, citing some of the theory’s implications for political, legal and ethical questions.

Professor Cavanaugh participated in STI Experts Meeting Intention & Double Effect: Theoretical and Practical Challenges

Do people in their everyday lives rely on double effect at all?

Double effect is not at the center of everyday ethical conduct. Rather, it is a way of thinking about difficult circumstances in which, through no fault of our own, we do occasionally find ourselves. These are circumstances in which the achievement of some legitimate good cannot be realized without also bringing about a bad that we, in normal circumstances, would be obligated to avoid. So, to take a non-controversial example that shows our at least implicit reliance on double effect or something very much like it, consider chemotherapy. A physician gives drugs to a patient suffering from cancer. In addition to curing the patient of cancer, the drugs sicken, debilitate and generally make the cancer patient’s life miserable for a time. Of course, and this is the crux of double effect, this is all done with the purpose of curing the patient and the good realized, to put it in down to earth terms, outweighs the bad. So the act is a legitimate one.


Okay, so that may illustrate a somewhat common way of thinking, but some would say we simply act well when we realize more good than harm, as is the case for the physician treating the patient with cancer. Why would one need something so apparently unwieldy as double effect? Why not just measure the good and see if it outweighs the bad? In fact, isn’t that what is happening in double effect?

In part double effect does, of course, consider the goods and bads at issue. However, and this answers your question, our acts are not merely instruments by which we produce effects in the world such that we evaluate our acts entirely in terms of their productivity, as it were. Rather, our acts have meaning largely in terms of the means we employ and the ends we seek. The physician’s act is justified not solely by the outcomes. He acts as a healer insofar as he seeks his patient’s health as his end and as a physicians insofar as he employs medicine as a means to that noble end.


Okay, so you are saying that we cannot simply embrace an “end justifies the means approach” where any act if productive of enough good could be justified. Is that correct?

Yes. Consequences matter, but they are not the only thing that matters when we ask: is that a legitimate, good act? The person’s intent concerning the means he employs and the end for which he acts also play crucial roles in answering those questions about the act.


All right, So where, practically, would we see a difference between how double effect might evaluate an act and how a purely cost-benefit “end justifies the means” approach would judge an act? As you yourself acknowledge, both approaches agree about the chemotherapy example. Is that not going to happen all the time if double effect does incorporate what we can call – since it is a common way of speaking and we probably lack a better phrase – a purely cost-benefit approach?

Actually, they will often agree. I would take that to be an indication that they both incorporate

the important truth that when we act well it is at least partially due to the fact that we bring good about. Aquinas pithily says that the most basic truth we rely on when we act well is to do good and to avoid evil. Of course, given that it is such a basic truth, one would expect a lot of agreement concerning it even amongst widely divergent moral theories. For, as Aquinas says, it is the most basic moral truth. Indeed, as you note in the chemotherapy example, we do find such agreement. To answer your question, however, double effect does make a real world practical difference in a number of arenas. I will limit myself to two fora in which people rely on double effect with some frequency: in the medical and military professions. To consider one example from medicine, occasionally terminally ill patients towards the end of their lives experience pain and distress that is not treatable short of sedating them with a barbiturate. In these cases the barbiturate that relieves that patient’s pain also suppresses or depresses the patient’s breathing such that the patient will expire. This is sometimes referred to as “terminal” or “palliative” sedation. From the perspectives of public policy, law, and ethics, may one in a principled fashion accept such an act while rejecting euthanizing one’s patient at the patient’s request? Similarly, may one in a principled fashion accept terminal sedation while rejecting physician assisted suicide? One who analyzes terminal sedation employing double effect answers “yes” to both questions. For in terminal sedation the physician, patient and relevant parties involved in choosing this act seek pain and symptom relief by means of a pain and symptom-relieving drug. As they know, one cannot relieve the pain and symptoms without also bring about the patient’s death. However, they do not relieve the pain and the symptoms by killing the patient, as would be the case in euthanasia and PAS. Rather, in palliative sedation the patient, physician and nurse use drugs that actually do relieve pain and distress. So, the current wide discussion of end of life care is one important arena in which double effect plays a crucial role in distinguishing legitimate medical acts such as palliative sedation from politically, legally and ethically questionable acts such as euthanasia and physician-assisted suicide.


That does seem to be one significant real-world practical difference. You also mentioned the military’s reliance on double effect. Could you speak to that practical implication of double effect?

A basic political, legal and moral principle in the conduct of war is the principle of discrimination, or, in other words, when one wages war, one must target combatants and not target non-combatants. Accordingly, one may bomb military installations but one may not bomb civilians. Of course, this venerable principle – which we may trace back to Cicero, the first century BC Roman jurist, orator and senator – has been violated repeatedly and to the shame of those who have so violated it. Nonetheless, it is an important political, legal and moral norm. Here, of course, we encounter a natural question: does every harming of non-combatants during war violate the principle of discrimination? A double-effect analysis would hold that one violates this principle if one sets out to target and harm non-combatants. So, for example, if one proposes to terror bomb a civilian population in order to lower morale and thereby advance the war effort, one acts badly (indeed, very badly). By contrast (as for example, occurred in relieving the siege of Sarajevo in the 1990s), if one bombs a military target while knowing that it will harm nearby civilians and the good to be realized (in the case of Sarajevo, the relief of the civilians themselves) is proportionate to the harm to the civilians, then one may so act. Thus, double effect plays an important role in distinguishing legitimate tactical bombing from illegal and immoral terror bombing. Of course, as noted at the outset, it is not as if we have constant recourse to double effect. Nonetheless, it does have important application to pressing political, legal and ethical questions.


I’m still troubled that double effect makes things a little too easy. For example, what keeps a teenager who trashes his (out-of-town) parents’ house partying with his friends from saying that he had no intention either to upset them or to harm their property, that the party was an otherwise good act and that the good realized by the party really does outweigh the harm to the house and their distress, both of which he foresaw? It seems that double effect could easily lend itself to such an abuse.

Certainly, double effect can be abused. Indeed, double effect has a somewhat checkered history. Versions of it have been appropriately and roundly criticized by thinkers such as Blaise Pascal (1623-1662) and, more recently, by one of its most famous defenders, Gertrude Elizabeth Margaret Anscombe (1919-2001). Of course, one abuse of double effect would be using it as cover for an illegitimate act. So, for example, it may be the case that some people have recourse to double effect dishonestly, say to cloak an act of euthanasia as an act of terminal sedation. Another abuse of double effect would be exemplified by the teenager you mention. His act of partying with his friends while his parents are out of town is itself problematic. For him to try to separate out the damage and offense as foreseen but not intended is disingenuous on his part. Moreover, it is irrelevant. For his parents do not want him partying with his friends because it damages the house, amongst other harms. It is forbidden because of the harm, not because the harm is intended. To take a more serious example, consider what is called ‘celebratory firing’ which refers to the firing of guns into the air in celebration of a holiday like New Years. This is something of a custom in Puerto Rico, for example. There, every New Year this practice injures dozens and occasionally kills people. Those who fire off the guns certainly do not intend to harm anyone. For numerous reasons (such as the imbalance between the good of celebration and the bad of injury and death), however, double effect would not justify such an act. To consider what may be the most relevant reason double effect would not come into play here, firing guns into the air is illegal because it is dangerous (regardless of intent). So, while it is true that shooters do not intend the harm, that is not relevant here. The act is already in light of its bad effect ruled out of bounds. For double effect to come into play, we have to have an otherwise good act that in these circumstances is attended by a bad effect. So the issue is determining to what kinds of acts one may apply double effect. Very briefly (and there is a lot to talk about here, so this is not at all a complete answer), we are thinking about acts in which the concomitant bad effect is not considered part of the act, as it were. One could legitimately regard it as a concomitant or side effect. As you can imagine, this is one of the areas in discussions of double effect that generates a lot of debate. As the Latin tag would have it ‘abusus non tollit usus’, or “an abuse does not destroy legitimate use”. Double effect can be used legitimately. It does require conscientiousness and sincerity when one has recourse to it. For it always involves acts in which we are bringing about some bad outcome. The branch of morals to which double effect belongs is called ‘casuistry’ from the latin ‘casus conscientiae’ or case of conscience. The presumption being that one who analyzes an act employing double effect has a well-formed conscience troubled by the foreseen bad outcome while also concerned to realize the good at issue that cannot be separated from that concomitant bad outcome. The idea is not to “see what I can get away with.” Of course, as noted, given human nature, such an account can come to be abused by the teenager you imagine or the thinkers to whom Pascal and Anscombe objected. Ethics cannot dispense with honest selfscrutiny; neither can double effect