Why Should Killing be Illegal?

Why Should Killing be Illegal?

Stephen H. Unger
September 26, 2007

What kind of a dumb question is this? Every significant religion endorses the commandment, "Thou Shalt Not Kill", as do humanists, agnostics, and atheists. But when we look more closely, important differences in interpretation show up. Many theologians believe that "murder", rather than "kill" is the correct word in the commandment. The ranks of decent people range from those who believe that war and capital punishment are acceptable, to those who believe it wrong, under any circumstances, to kill even a mouse. Apart from disagreements as to what the scope of the rule against killing should be, some feel that there should be a fundamental justification for the rule, and that such a justification might shed light on a number of controversial issues, including abortion, capital punishment, and euthanasia.

So let us try to show why it is important to have a strongly enforced rule (or law) against killing. We need a starting point in the form of a fundamental rule that everybody agrees on. "Don't cause pain or disability" would do nicely. Of course, with respect to any moral rule, there may be complex circumstances that justify violating it. For example, it may be necessary to hurt people in the course of curing them or rescuing them, or to prevent them from causing even more pain and injury to others. In general, with respect to any rule R, the assumption is that R should be followed in the absence of a strong reason to violate it based on either R itself or on some other moral rule.

Does Killing Harm the Victim?

No, I'm not kidding! Read on. Suppose an assailant sneaks up behind a man and breaks his arm with a baseball bat. This would cause the victim pain and also disable him for a substantial period of time, clearly violating the rule against causing pain or disability. It is therefore, on the face of it, morally wrong--unless there is some circumstance that would justify it. Such a justification might be that he was about to stab an innocent person.

Instead of breaking his arm, suppose the assailant shoots him in the head with a large caliber, soft-nosed bullet, blowing his brains out and killing him instantly. Strange as it might seem, this violent act does not violate the rule against causing pain or disability! How can that be? With respect to pain, the victim, unaware of the assailant's presence, feels none prior to the trigger being pulled, and then, since he is dead, he feels nothing. Prior to the shooting he suffers no disability. Immediately afterward he is dead, and so cannot be said to suffer disability. More generally, a corpse no longer exists as a person. It is not subject to any form of harm, whether physical or psychological.

What about the loss of a future? Particularly when the victim is a healthy, young person, perhaps with all kinds of abilities, one might think, "how terrible to be robbed of a promising future". But, while others may mourn this loss, the victim is not capable of feeling it. Just as a dead man cannot feel pain, he also can't feel regret. The victim does not end up lying in a coffin bemoaning the fact that he will never play the violin again. Of course, if the victim had reason to anticipate being killed, then, prior to death, there might indeed have been a painful sense of impending loss. But absent such foreknowledge this is not a factor.

Therefore, we can conclude that, under the circumstances described, the victim of a killing is not harmed! We will have to find reasons to justify a rule against killing other than that killing harms the victim. This conclusion seems so at odds with "common sense" that, at the risk of being repetitive, an elaboration of the argument seems appropriate.

Consider the following line of reasoning:
(1) Absent some very strong justification, it is morally wrong to harm people
(2) Killing hurts people and disables them.
(3) Therefore, killing people harms them, and is morally wrong.

Sounds simple. But a closer look at (2) leads to a surprising conclusion. After death, people experience no pain, regret, or other feelings. Victims unaware of impending death suffer no anxiety prior to being killed. Killing somebody with a knife will almost certainly cause the victim to suffer severe physical pain, and perhaps psychological pain as well due to fear of impending death. No question that a live person suffers real harm in the interval before loss of consciousness and death. This would be the case to varying degrees for most forms of killing.

But not every mode of killing is accompanied by pain. As in the above example, killing might occur instantaneously with no warning, or a person might surreptitiously be given an overdose of sleeping pills sufficient to cause a painless death. Conversely, it is not hard to imagine situations where a person suffers enormous pain--well exceeding that associated with a stab wound--but is not killed. Horrible accidents involving fires or eye injuries are in this category. Thus there is no inevitable connection between pain and death. It is not as tho there is some left to right spectrum with no pain at the left end, increasing pain as we move to the right, and death associated with the most extreme pain at the right end. So it is possible that the victim of a killing suffers no harm at all.

But doesn't killing harm people in ways other than pain? Isn't harm inherent in the termination of life? This turns out to be the question leading to the surprise. If death is caused painlessly, then, prior to death, assuming the victim was never aware of what was happening, the victim, being still alive and unhurt, has suffered no harm. Once dead the victim no longer exists and so is immune from harm of any kind. Therefore, at no time has the victim been harmed in any way. (This is under the assumption that a dead person is truly incapable of any feeling and is not going to return in any form. People who believe in some form of afterlife will have to consider the matter further in the light of their particular beliefs.) So the argument that a rule against killing is justified because killing harms the victim is not valid.

Collatoral Damage

Another possible justification for a general rule against killing might be that society cannot afford the population loss that would result if there were an increase in killings. This is hardly the situation in the world today, where the human population is, if anything, too large in most places and there is concern about continued growth degrading the quality of life as a result of increased crowding and greater drain on the earth's resources. So this argument would be valid only in special circumstances--perhaps for some small tribe in the Amazon jungle. (There have been news stories recently indicating that, due to falling population numbers in Russia, the government has been taking various steps to increase the birth rate.)

A more powerful argument is based on the fact that, in most cases, killing somebody harms other people in a variety of ways. Few people are so isolated that their deaths would not impact others. A death may cause pain to children, siblings, parents, a spouse, friends, coworkers, patients, clients, employers, or customers. Where a public figure is involved, large numbers of people may grieve out of ordinary human sympathy. Even strangers may feel bad when they learn about the killing of an apparently decent ordinary individual. Apart from personal feelings, others might be harmed in more concrete ways. A family might be financially devastated by the loss of a breadwinner. A victim's employer or business partner might be a big loser. The death of a well known person, such as a musician, athlete, or politician, might be felt by many to constitute a significant societal loss.

But there is another side to consider. In some cases a death might be mourned by some and cheered by others. The reasons for cheering might be personal or material. There are doubtless some vicious people, disliked by all who know them and with no redeeming roles, whose demise would be welcomed by many and regretted by few, if any. There are also people who, for a variety of reasons, have such small contact with other people that their demise would scarcely be noticed. So basing a prohibition on killing entirely on "collateral" harm to others is not satisfying because the force of the argument varies greatly depending on the proposed victim. There would be a temptation to carve out exceptions to the rule that would be difficult to apply and subject to serious abuse. A murder trial might become a trial of the victim. Something more than the collateral damage argument is needed.

What if There is No Rule?

Since a direct validation of the don't kill rule seems difficult to find, let's try an indirect approach--a proof by contradiction. Consider the following situation: There is no general ethical or legal rule against killing, altho other laws and rules against harming people remain in effect. Nothing in the law prohibits painless killing, unanticipated by the victim. If a killing also inflicts pain, then there would be penalties, roughly proportional to the degree of pain. If a person valued by others is killed, then those suffering such loss can bring criminal charges against the killer.

Imagine living under such conditions. The life of anybody without close relations with others would be only weakly protected by law. Such an individual might justifiably be in a continuous state of dread, afraid to go to sleep for fear of being "painlessly" killed, fearing many medical procedures, afraid of strangers. For example, a 12 year old whose immediate family perished in a fire six months after they moved across the country, might experience the fear associated with membership in the unprotected group. Elderly people might worry that, if the only argument against killing is based on the effects on others, they might be perceived as not worthy of being allowed to live.

Many people would be indirectly subjected to similar anxiety. They might dread the likelihood of future entry into the exposed group. As an example, consider a 65 year old woman with no living children or siblings and no close friends. She might fear that should her husband, five years older and in poor health, die before she does, she might be considered to be in the vulnerable category. More generally, almost anybody could imagine future circumstances under which he or she might enter the unprotected category.

The point here is that, while, in any particular case, the actual killing of an individual under the circumstances described may not harm the victim, those who are, or who have good reason to think they might become, vulnerable to such treatment would, with good reason, suffer considerable anxiety.

Therefore, we need a general rule against killing, because, in the absence of such a rule, large numbers of people would, justifiably, live in dread of being killed. It is important that the rule be widely accepted and strongly enforced so that violations are infrequent enough to give people confidence that their lives are not now, or in the foreseeable future, seriously at risk.

Who Should be Protected by the General Rule?

Recall that in the introduction it was pointed out that there is much disagreement as to exactly who it is that the commandment against killing applies to. Who (or what) should not be killed? We are now in position to answer that question with respect to the arguments just presented. A beginning is made in the next paragraph, but some very interesting and important aspects of this question will be left to a subsequent essay.

Clearly all readers of this work are protected. More generally, anybody capable of understanding the concept of threats to life and the concept of protective laws and rules would also be covered. But that is not all. Membership in the protected group is permanent. Once in the group, no change in status other than death itself can end the protection. For example, an individual who becomes senile to the point where he or she cannot understand a threat to life, nevertheless remains protected. The reason is that, if a person covered by the rule could, as a result of illness or aging, lose protection, then fear of such a loss in the future would be a reasonable source of anxiety. (Some might argue that committing certain crimes should lead to the forfeiting of this protection, i.e., they might argue for capital punishment. This is a separate issue. Whether or not there should be such exceptions does not affect the fundamental arguments.) The basic idea is that nobody, with the possible exception of subjects of capital punishment, should have reason to fear that at some future time, it might become legal for them to be deliberately killed .

Click here for continuation on the subject of abortion.

Also see follow-up on application to newborns


The basic ideas embodied in this essay and in the sequel were developed in 1961 by members of a discussion group comprised of Justin Kodner, Marvin Paull, Ivan Polonsky, Maxine Polonsky, Richard Rifkin, Charlene Thiele, and the author. The aforementioned other members are, of course, not responsible for any errors or distortions in the version presented here.


Philosopher Peter Singer independently conceived of the core of the argument given here in support of making killing illegal. Along with many other interesting thoughts, he wrote about this in his book, "Practical Ethics", first published in 1979, second edition 1993, Cambridge University Press. It is very worthwhile reading (as are Singer's other works).

Comments can be sent to me at unger(at)cs(dot)columbia(dot)edu

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