With respect to non-humans, e.g., carrots, mosquitoes, or squirrels, it is clear that the general rule against killing is not applicable. Neither carrots, nor mosquitoes, nor squirrels could possibly suffer anxiety over the absence of a law protecting their lives. (There are, however, good arguments against cruelty toward non-human animals, which would exclude killing them in a way that would cause them to suffer during the process. The extent to which it is ethical to use animals for food, as experimental objects to further human knowledge, and perhaps to benefit human health, is an interesting, important issue that will not be treated here.)
Of course, with respect to pets, there are strong human attachments that properly protect them from killing as well as from cruelty. Killing someone else's pet without the consent of the owner, no matter how it is done, would be to inflict a grievous injury on the owner. With respect to livestock, there are often similar attachments and, in any event, there are property issues. But with respect both to pets and to livestock, as long as cruelty is not involved, the owners are in control. Nothing in the preceding arguments would make it wrong to kill non-human animals painlessly if this were desired by the owners. It is common for people to have sick or very old pets painlessly killed so as to spare them needless suffering. It is a humane practice since there is no way for animals to anticipate and thus to dread such action. Under the preceding arguments it would certainly not be acceptable to treat humans in the same manner, even if they have deteriorated to the point where they are not fully aware of what is going on around them. (Ideas pertaining to comatose people, euthanasia, and the idea of living wills are related topics not discussed here.)
How about Martians, or, more generally, any intelligent, sentient non-humans that might be encountered in space travel? There doesn't seem to be any good reason to treat them differently from humans. (In my opinion, if extra-terrestial forms of intelligent life are ever encountered, they will almost certainly be so far advanced with respect to humans that the real question will be how they will treat us.)
What about the possibility that humans might produce intelligent robots that in some sense could be said to be self-conscious? While this is an interesting issue, I doubt that there will be any need to deal with it in the immediate future. As with the preceding one, I leave this question open.
In the preceding discussion, it was argued that the rule against killing should apply to all who are, or who in the past were, capable of fearing that they might be killed if they were not protected by law. Clearly, elderly, including senile, people are included in this group. What about those at the other end of the time-line of life? That is, how does this apply to human embryos, or to fetuses?
With respect to the indirect arguments against killing that take into account the effects on others, it is obvious that a fetus is usually greatly valued by the prospective parents, and often by other prospective relatives (I weigh in here as a proud grandfather). The strongest feelings are normally those of the mother, in whose body the fetus is developing. Harming a wanted fetus would constitute a great injury to the mother and, to a lesser extent, to other family members.
But clearly no fetus could possibly understand the implications of laws or ethical concepts. Therefore, even if we were to assume that a fetus could feel pain, or anxiety, the absence of a law against terminating the life of a fetus could not cause any fetus to feel anguish in any form. At worst, depending on the method used, and on the age of the fetus, there might be some brief pain experienced just before death.
A fetus is only a potential human being, not in the same category as, say, a six-year old child. Starting from the initial embryo, the fetus gradually acquires the basic physical organs of a human, but even when these are all in place, the fetus lacks key nervous system capabilities that exist in fully developed humans. But these missing or undeveloped facilities are not what lead to the conclusion that a fetus should not be protected by law to the extent that a person is. The essential element is that the absence of a law protecting the life of a fetus unwanted by its mother would not cause the same widespread anguish that would be caused if such protection were withdrawn from any class of people who, in the present, or past, were capable of understanding that they were, or might become, exposed to killing.
I see no way to justify the idea that a fetus itself has in any sense a "right to life". Since only the prospective family could be hurt, those outside the family, including the government, should not have a say as to whether or not a pregnancy should be terminated. Given that the mother is obviously by far the one most involved, she should be the one who makes such a decision, in consultation, as she deems appropriate, with others.
A pregnant woman has a natural protective feeling toward the new life developing within her. Doubtless this has a strong evolutionary basis. A woman's decision to abort in the face of this feeling can only be the result of a painful process driven by powerful factors, e.g.:
Sometimes, several of the above elements contribute to the decision.
If a woman decides on grounds such as those listed above that she wishes to terminate her pregnancy, what might be valid grounds for overriding that decision? The mother is obviously the one who is physically involved, undergoing all the discomfort, pain, and risk involved in nine months of pregnancy, followed by the intense pain of childbirth. She is also the one most emotionally involved. Subsequent to birth, the mother will, particularly during the early years of childhood, carry a heavy burden. The expectant father might be looking forward eagerly to parenthood, but his stake is certainly less than that of the mother. The interests of other family members, such as prospective grandparents, are obviously on a lower scale. While, particularly if she has any doubts, a woman would be well advised to get the views of the father, and perhaps of other family members, or even friends, it does not seem reasonable to give anyone the right to overrule the decision of the mother as to whether her pregnancy should be aborted.
As discussed above, a fetus is not a person capable of being hurt or disabled by the termination of pregnancy. No fetus could possibly be aware of the possibility of an abortion and thereby suffer anxiety about the possibility. Thus it is not reasonable to treat an abortion, morally or legally, as the killing of a human--much less as murder.
Some states have laws requiring a pregnant minor to notify, or even to get the consent of, her parents before getting an abortion. Along similar lines are laws requiring counseling before abortions. But there are no laws anywhere requiring notification or counseling before a thirteen-year old girl decides to go ahead and give birth. Considering the dismal future likely for a thirteen-year old mother and her child, the implication that the default should always be to allow the pregnancy to continue seems unreasonable. Bringing a child into the world is a serious matter. Proper regard for human life should make it an act that is carried out only if that child would have a reasonable chance for a decent start. Given the parental difficulties often encountered by even the most fortunate groups in our society, under the best conditions, pressuring women, or even girls, to bear children against their wills seems most reckless.
The foregoing discussion should not be taken to mean that a child born under any combination of the unfavorable circumstances mentioned above would necessarily lead a miserable life. On the contrary, there is ample evidence of the great resiliency of humans, of their ability to overcome terrible handicaps to develop into happy, valued people. But the odds against unwanted children turning out well are substantial, and pressuring women to bring children into the world under such circumstances is cruel to all concerned. Arguing to the contrary is analogous to saying that since some exceptional people with no education have had distinguished careers, it is not important to educate our children.
The principal argument made in favor of making abortions illegal is that abortion is murder. If that were true then, unless giving birth would likely result in the death of the mother, an abortion would be hard to justify . But a fetus is not an independent entity with a sense of being alive, with thoughts and fears about its future. It is a potential human, not an actual one. Its existence is a matter of concern only to the prospective parents and, to a much lesser extent, to other prospective relatives. Only if a fetus were to be aborted against the wishes of the mother should it be considered a crime--tho not murder.
But, while conceding that a fetus is not a human, so that abortion is not murder, some might argue that it is wrong to act so as to interfere with the creation of a human. We have discussed one possible justification of this position, namely that there is a societal need for a larger population. A different argument is to identify highly valued people (such as Beethoven) and point out that they would never have lived if their births had been prevented by abortion. The implication of this argument is that we should do everything possible to maximize total population, since this would increase the number of admirable people in the world. Apart from pointing out that the chances for individuals to develop their potentials are reduced by overcrowding, we might note that a larger population would also mean, not only more Beethovens, but more Hitlers.
If preventing the creation of a human is wrong, then how early in the creation process should such interference be considered immoral or criminal? The consequences of destroying an embryo and preventing it from coming into existence are the same. The human embryo is the result of the union of a sperm cell and an egg. Contraceptive devices prevent this union from occurring during sexual intercourse. If destroying an embryo is immoral, it would seem to follow that use of contraceptive devices is also immoral. Many who condemn abortion, perhaps following this line of reasoning, do indeed consider contraception immoral. (Actually, most who condemn contraception probably do so because they believe, on religious grounds, that sexual acts are moral only between married people trying to produce offspring.)
The consequences of the assumption that it is wrong to prevent the creation of a human might be carried back one more step. Consider Jack's sperm cells and Jill's ova. If any of the former unite with any of the latter, the result is a potential human. Contraception is one way to prevent this from happening, but keeping Jack and Jill apart would be equally effective. So is it immoral to refuse to invite Jack to your party when you know Jill will there?
Comments can be sent to me at unger(at)cs(dot)columbia(dot)edu