Western society is dedicated to the moral premise that every human being has the right to his or her normal life span. "The right to life" is the first fundamental right enumerated by Thomas Jefferson in the Declaration of Independence.

Whatever our problems with health care funding, we go to great lengths to give people, however indigent and even when criminal, the medical care they need when their lives are in jeopardy. On paper, at least, we do not allow doctors to play God.

The emphasis on the right to life leads to what makes us human. On the surface, we're talking about loyalty to our own biological species. We're quite lucky that the earth's geological history has led to just one sentient biological species, divided into interchangeable races whose intellectual potentials seem absolutely equal. Imagine the political problems on a planet or dominion where different groupings of people are biologically distinct.

What makes us "human?" We can list some components: self-awareness or sentience, knowledge of our individual selves, and, particularly, the possibility of personal growth, the development of psychological surplus beyond adaptive needs. Maybe some animals, such as chimpanzees and the brightest cetaceans, enjoy these traits. Anyone who has owned a dog or cat knows that even carnivores and other animals can be "individuals." Even birds can project themselves, as I once learned from a mockingbird who insisted on demonstrating his ability to chase starlings repeatedly and then parking himself right next to me as I climbed into my car. Indeed, Albert Schweitzer once demanded respect for all life.

Human beings, however, can organize their conceptual and abstract thoughts and catalogue them in writing, and build value-adding into their cultural activities. Human beings, moreover, can cogitate over the consequences of their own personally chosen actions and deeds. Human beings understand postponing immediate pleasure or gratification in exchange for greater psychological rewards later. As far as we know today, these capacities separate us from all other species, and they seem to ridicule the idea we would battle each other over such a superficial characteristic as race.

We demand reverence for life that is potentially (or prospectively) human. The best science tells us that unborn children may have become self-aware as early as ten weeks after conception. It doesn't seem reasonable to make this claim for the zygote right after conception, much less for an unfertilized sperm or egg.

We also demand respect for life as it draws to a close, and when it is disabled. We do not take it upon ourselves to decide who is more or less "human" because of age or disability.

All of these observations lead us to consider positive laws, to protect the unborn (starting some number of weeks after conception) and the aged (and perhaps to prevent actively assisted suicides) because we resist any encroachment upon the sanctity of all human life. We see law as necessary to protect a basic human right as well as to protect a moral climate. We feel affront at demands that the state pay for abortion for the poor, or that a woman needing an organ transplant would (irresponsibly) become pregnant anyway and then demand abortion as "medical necessity."

The moral subtleties of our attitudes towards the right to life become more apparent when we consider the possibility of cloning. Suppose I were a happily married heterosexual parent and fortunate enough to raise a son who amounted to Ayn Rand's John Galt. Would I want to extract his DNA and clone ten copies of him just to glorify myself, even if I could afford it? That would destroy his specialness, his individuality.

I've heard the arguments that individual identical twins or other multiples are separate people and have their own existences. We all hear of the emotional bonds between twins, even raised apart, and of the concordances of such "traits" as sexual orientation. (That's not always true the National Institutes of Health once contemplated a bone marrow transplant to a homosexual male AIDS victim from a practicing heterosexual identical twin).

But my take on all this is that identity what makes me "me," why I've lived this culturally "self-indulgent" particular life at the end of the 20th century and was not sacrificed in some earlier war or sent through the Maoist Cultural Revolution is indeed a great mystery. We can get into reincarnation and parallel universes if we want. We can't prove anything.

Therefore, cloning someone to be a "superman" would undermine that person's own sense of who he is, undermine his own right to his own life.

Of course, there are subtler forms of genetic manipulations. Abortions (or outright infanticides) are done in some countries where there is a tremendous cultural bias for male children. Abortions in this country are done to prevent the birth of children with birth defects. Various medical technologies may soon make possible some partial sex selection even before conception. At the other end of the lifeline, there are subtle pressures in some European countries for the aged and chronically ill to accept assistance in dying. And this is not the same thing as stopping heroic resuscitative efforts for patients in hospices with terminal illnesses.

All of this brings us to a central point about the personal responsibility that derives from the right to life, almost like a mathematical corollary. To wit, we don't always own the prerogative to choose the people we will care about and remain committed to. We always deal with our obligations from what has gotten us to a certain point. I have always felt suspicious that projecting this cultural aesthetic realism, and not just an abstract loyalty to human life, is the real psychological motive behind the "right to life" movement.

True, a man or woman is supposed to fall in love with his or her "chosen" partner (unlike the situation in societies with arranged marriages), but in practice it is often difficult for many people to find partners who appeal to them and who want them. (Author George Gilder has discussed this as the "sexual princess" problem.) Moreover, having children involves a bit of pot luck. It's a bit of a lottery, even assuming the mother does everything possible in her personal behavior to have the healthiest possible baby. You may bear a future president, or a child with a tragic birth defect (or both). The moral claim on unconditional love and commitment are the same to have a real life, you have to take the chance you will have to love someone who appears to many other people to be a burden. This principle used to carry on to the extended family in earlier generations, unmarried children (often "closeted" gays and lesbians) were often expected to keep themselves available to take care of ailing family members.

Against all of this, we will later consider the right to privacy and to express oneself through one's personal choices, in a later chapter.

Intellectual honesty, however, demands certain observations straight away. Yes, if you really believe in the sanctity of human life as a paramount moral principle you'll oppose almost all abortion, but you'll also oppose capital punishment (it's playing God, too, unless your principle is protection of innocent human life and you completely trust human criminal justice). You'll even object to the conscription of young adults to serve in the armed forces and to the requirement of them to risk their own lives and appendages for the benefit and safety of others. However, some people may argue that conscription actually saves more lives than it takes; there is no such argument for elective abortion.

You may also support mandatory minimum sentences (life imprisonment without any possibility of parole) for murder, maiming someone (except in self-defense), or killing or badly injuring someone through gross negligence (reckless driving or driving while intoxicated). Such a no-exceptions policy would reinforce personal accountability and make hate-crimes laws unnecessary.

Our respect for human life heightens the need for personal honor, notably in occupations (especially the military) where people must risk their lives to provide security for others. This underlining of honor is useful in justifying the notion of natural rights and self-ownership in other areas besides just life itself. The respect for life as an absolute moral value leads many people to consider other positive laws creating an "obligation" to protect life. A good example would be good-Samaritan laws, which could create a legal nightmare because of the variety of ambiguous situations that "out and about" private citizens could encounter by pure chance. Another problematical area is triage in emergencies, when some people may be sacrificed so that others can live. Is this "playing God?"

Our higher standard of living and prolonged peacetime have increased our fundamental respect for life. Since people don't have to die as often in war, hazardous manual occupations, childbirth, or of preventable infectious disease, lifestyle habits and the commercial enterprises that support them have become moral issues. Tobacco was once legal tender in the colonies; now we look at tobacco growers and particularly tobacco companies as drug dealers and manslaughterers. Will we one day judge the food, meat and dairy industries that feed our high-fat diets in the same way? Will the workplace coffeepot go bye-bye?

The right to life leads some people to argue that people have a fundamental right to publicly funded health care as an "entitlement," at least for major or life-threatening problems. (Never mind that publicly funded single payer systems tend to pit victims of one disease against another for finite, rationable resources.) A right to health care would be a "social right," not found in the Constitution or Bill of Rights but established only through legislation, under the influence of the political process. The right-to-life claim might argue against the sometimes brutal individual competitiveness of some areas of our workplace, where people can be pressured to do without health insurance or to underuse it. But it can also support the libertarian notion that people have a right to any health care they can pay for, but perhaps not to spare parts grown in acephalic clones.