For the complete text, including illustrations, introductory quote, footnotes, and commentary on the reaction to the originally published article see Billions and Billions.
There is no right to life in any society on Earth today, nor has there been at any former time… : We raise farm animals for slaughter; destroy forests; pollute rivers and lakes until no fish can live there; kill deer and elk for sport, leopards for the pelts, and whales for fertilizer; entrap dolphins, gasping and writhing, in great tuna nets; club seal pups to death; and render a species extinct every day. All these beasts and vegetables are as alive as we. What is (allegedly) protected is not life, but human life.
And even with that protection, casual murder is an urban commonplace, and we wage “conventional” wars with tolls so terrible that we are, most of us, afraid to consider them very deeply… That protection, that right to life, eludes the 40,000 children under five who die on our planet each day from preventable starvation, dehydration, disease, and neglect.
Those who assert a "right to life" are for (at most) not just any kind of life, but for--particularly and uniquely—human life. So they too, like pro-choicers, must decide what distinguishes a human being from other animals and when, during gestation, the uniquely human qualities--whatever they are--emerge.
Despite many claims to the contrary, life does not begin at conception: It is an unbroken chain that stretches back nearly to the origin of the Earth, 4.6 billion years ago. Nor does human life begin at conception: It is an unbroken chain dating back to the origin of our species, hundreds of thousands of years ago. Every human sperm and egg is, beyond the shadow of a doubt, alive. They are not human beings, of course. However, it could be argued that neither is a fertilized egg.
In some animals, an egg develops into a healthy adult without benefit of a sperm cell. But not, so far as we know, among humans. A sperm and an unfertilized egg jointly comprise the full genetic blueprint for a human being. Under certain circumstances, after fertilization, they can develop into a baby. But most fertilized eggs are spontaneously miscarried. Development into a baby is by no means guaranteed. Neither a sperm and egg separately, nor a fertilized egg, is more than a potential baby or a potential adult. So if a sperm and egg are as human as the fertilized egg produced by their union, and if it is murder to destroy a fertilized egg--despite the fact that it's only potentially a baby--why isn't it murder to destroy a sperm or an egg?
Hundreds of millions of sperm cells (top speed with tails lashing: five inches per hour) are produced in an average human ejaculation. A healthy young man can produce in a week or two enough spermatozoa to double the human population of the Earth. So is masturbation mass murder? How about nocturnal emissions or just plain sex? When the unfertilized egg is expelled each month, has someone died? Should we mourn all those spontaneous miscarriages? Many lower animals can be grown in a laboratory from a single body cell. Human cells can be cloned… In light of such cloning technology, would we be committing mass murder by destroying any potentially clonable cells? By shedding a drop of blood?
All human sperm and eggs are genetic halves of "potential" human beings. Should heroic efforts be made to save and preserve all of them, everywhere, because of this "potential"? Is failure to do so immoral or criminal? Of course, there's a difference between taking a life and failing to save it. And there's a big difference between the probability of survival of a sperm cell and that of a fertilized egg. But the absurdity of a corps of high-minded semen-preservers moves us to wonder whether a fertilized egg's mere "potential" to become a baby really does make destroying it murder.
Opponents of abortion worry that, once abortion is permissible immediately after conception, no argument will restrict it at any later time in the pregnancy. Then, they fear, one day it will be permissible to murder a fetus that is unambiguously a human being. Both pro-choicers and pro-lifers (at least some of them) are pushed toward absolutist positions by parallel fears of the slippery slope.
Another slippery slope is reached by those pro-lifers who are willing to make an exception in the agonizing case of a pregnancy resulting from rape or incest. But why should the right to live depend on the circumstances of conception? If the same child were to result, can the state ordain life for the offspring of a lawful union but death for one conceived by force or coercion? How can this be just? And if exceptions are extended to such a fetus, why should they be withheld from any other fetus? This is part of the reason some pro-lifers adopt what many others consider the outrageous posture of opposing abortions under any and all circumstances--only excepting, perhaps, when the life of the mother is in danger.
By far the most common reason for abortion worldwide is birth control. So shouldn't opponents of abortion be handing out contraceptives and teaching school children how to use them? That would be an effective way to reduce the number of abortions. Instead, the United States is far behind other nations in the development of safe and effective methods of birth control--and, in many cases, opposition to such research (and to sex education) has come from the same people who oppose abortions.