About halfway through Star Wars Episode II Attack of the Clones, many viewers experienced an "Aha!" moment. Obi-Wan Kenobi is on Kamino, the home of the finest cloners in the galaxy. He looks out on the army of clones that the Kaminans have made for the Republic. The audience then realizes the ironic truth: This army will one day become the Imperial Storm Troopers.

It's ironic because the means by which the Republic is saved will eventually become the means by which it is destroyed. And that makes the cinematic Attack of the Clones a nearly perfect metaphor for our own clone wars. Just as in that galaxy far, far way, our culture is looking to cloning — specifically human cloning — as a way to defeat intractable foes: illnesses such as Parkinson's, and Alzheimer's. And, as in the movie, even if our dalliance with human cloning delivers on its promises (which is far from a certainty), the price we pay will be a lot more than we bargained for.

Now when we read the word "cloning" in the newspapers or hear it on television, it's often, at least when referring to cloning humans, preceded by one of two modifiers: reproductive or therapeutic. In both cases, we are talking about the same technology: the genetic material is removed from a human egg and is replaced by the genetic material from another person, a process known as nuclear transplantation. The egg is then stimulated to divide and finally implanted into a surrogate mother. It's nowhere near as easy as I just made it sound, but that's the process in a nutshell.

What distinguishes "reproductive" cloning from "therapeutic" cloning is merely the goals of those doing the cloning. The goal of "reproductive" cloning is, well, reproduction. It's to produce a child who is a genetic duplicate of the original cell donor. One example is an American couple known only by their first names, "Bill" and "Kathy." They are trying to become the first parents of a cloned child. As they told CNN's Connie Chung, they turned to cloning after nine years of trying and failing to have a child by other, more or less conventional, means. As "Kathy" told Chung, "I think that God really wants us to do this, that this is the next step.... I can't imagine any other reason why we haven't had a child, other than this is what we were meant to do." They are hoping that the National Academy of Sciences was right when it described "reproductive" cloning as a potential "solution for complete infertility."

But there's a lot standing between the couple and what they think of as God's will. Nuclear transplantation and implantation are the easy parts. The chances of actually giving birth to a clone are pretty slim. Earlier this year, it took 87 cloned embryos to produce the world's first cloned cat. This lack of success at bringing an embryo to term isn't an issue for "therapeutic" cloners, because their goal isn't to produce another human; it's to use that human being as a source for parts, specifically stem cells, in their medical research.

Or as columnist Charles Krauthammer, who was trained as a physician, put it in The New Republic, "the main objective ... [is] to disassemble [the four-to-seven-day-old divided cell, called a "blastocyst"] ... pull the stem cells out, grow them in the laboratory, and then try to tease them into becoming specific kinds of cells, say, kidney or heart or brain and so on." This purpose is why Krauthammer considers the expression "therapeutic cloning" to be, in his words, "misleading." What's more, the fact that "the clone is invariably destroyed in the process" makes the term "therapeutic," at least as far as the clone is concerned, more than a bit ironic.

Still, the distinction between "reproductive" and "therapeutic" cloning, while almost entirely semantic, is at the heart of our culture's deliberations over cloning. A U.S. Senate bill that would ban all forms of human cloning is stalled indefinitely. Instead, what is emerging as the consensus position is a ban on "reproductive" cloning while permitting "therapeutic" cloning. This is, as Bill Saunders of the Family Research Council has noted, an Orwellian use of semantics to defend the indefensible. What we're talking about is still human cloning.

This, of course, still leaves us with the question "what's wrong with human cloning?" The answers have to do with what it means to be human. What's more, you don't have to have to be a Christian, or believe that life begins at conception, to be morally opposed to human cloning. Neither is true of many cloning critics, including the members of the President's Council of Bioethics (PCB). Among the many ethical problems raised by human cloning, the PCB cited the following:

Human cloning is unsafe. As I noted before, the vast majority of cloned embryos never come to term. Those that do "suffer high rates of deformity and disability, both at birth and later on." What's even worse is that, as the President's Council on Bioethics (PCB) concluded, "there seems to be no ethical way to try to discover whether [reproductive] can become safe, now or in the future." The kind of experimentation needed to answer that question would involve unethical experimentation on human subjects.

Then there's the question of human identity. Forgive the cliché, but a great deal of becoming an adult is the process by which we both differentiate ourselves from our parents while maintaining our connections to them. If you think it's difficult for you, imagine doing it when you are an identical copy of one of them. Not just "you look just like your mom did at that age" but "you are your mom at that age." Then there's the burdens imposed by what the PCB described as the "constant comparisons to the life of the 'original.'"

And if that were not bad enough, there's what the PCB called "troubled family relations." Fathers and sons could also be identical twins. The same would be true for mothers and daughters. And, to put "generation-skipping" in a whole new light, grandparents could be genetic siblings to their grandchildren. Break out the creep repellent.

One last problem: "reproductive" cloning has the potential to turn children into a commodity. These children "might come to be considered more like products of a designed manufacturing process than 'gifts' whom their parents are prepared to accept as they are."

None of these concerns requires any a priori religious commitment or beliefs about when life starts. Of course, for those who believe that life begins at conception, the willful destruction of embryos in "therapeutic" cloning only reinforces the conviction that human cloning is an evil to be rejected, regardless of whatever promises its proponents hold out. But even here, a person who is neither pro-life nor a Christian can come to the same conclusion. It's possible to make what commentators like Krauthammer and Ramesh Ponnuru of National Review call a "secular case" against all human cloning.

As Krauthammer puts it, "banning the production of cloned babies while permitting the production of cloned embryos makes no sense." Eventually, somebody will implant one of these cloned embryos inside a womb. So if we really (as everybody claims) abhor the prospect of "reproductive" cloning, then it makes no sense to create an exception that will almost certainly swallow the rule.

Then there are the "consequences of delivering such unfathomable power ― and potential evil ― to the hands of fallible human beings." Once again, no specific belief system is required to understand the abuses that could arise from this technology. All that is required is an unblinkered view of history. And by "evil," we're not talking about The Boys From Brazil (the 70s movie about attempts to clone Hitler). We're talking about the human tendency to be so delighted with our cleverness and achievements that we become incapable of saying "no."

We're talking about a slow but steady slide down that slippery slope until we end up with something like this (in Krauthammer's words): "the production of headless clones ― subhuman creatures with usable human organs but no head, no brain, no consciousness to identify them with the human family." Sound extreme? It's already been done with tadpoles.

If this sounds like I've spend too much time reading The Island of Doctor Moreau or watching Sliders reruns, understand that the moral path that will lead us there is paved with a series of small, "acceptable," compromises that begin with the one we're about to make. Even if you deny that the seven-day-old human embryo is a full member of the human family, there is still something undeniably human there, enough to give us at least some qualms about treating it as a thing. (As Krauthammer puts it, "it is not nothing.") Every time we proceed despite our moral reservations, we make it easier to make the next compromise and the next, etc.

Finally, there's the "why" of human cloning. Part of it is the understandable desire to alleviate human suffering. If you will permit me one personal note, I have at least as great a stake in eradicating genetic disorders as the next person, probably more: Illnesses with proven or suspected genetic components run in my family. But there's more going on than a misdirected desire to do good. Even our popular culture can't shake the feeling that cloning and other biotechnology is so fraught with peril that the best answer is probably to stay way. (Think of a single film where cloning, or any other advanced biotechnology for that matter, was depicted as an unambiguously good thing. I can't, either.) That we are proceeding despite these misgivings says some about the state of our souls.

In his new book, Aliens in America: The Strange Truth about Our Souls, Peter Augustine Lawler comments on the spiritual and moral vision of our "new model citizens," the bourgeois bohemians or "Bobos." The Bobos, who set the tone for much of American culture, aren't concerned with matters of personal salvation, considering such a preoccupation to be "unenlightened and unhealthy." Nor do they believe in moral absolutes in sexual matters. But they are "toughly judgmental" when it comes to matters of health, such as "smoking, alcohol, obesity and seat belts."

What Lawler sees, and others don't, is that the preoccupation with health ― along with the other Bobo preoccupation, material prosperity ― flows out of their spiritual vision, or more precisely, the lack thereof. It is because they aren't concerned with matters of personal salvation, and the God that goes with such an idea, that they elevate health (and prosperity) from a means to an end to an end in itself. It stands to reason that people for whom this life is really all that matters would seek to extend and enhance that life by any means at their disposal, even if it means, as Lawler puts it, the "gradual surrender of the qualities that actually distinguish us as human beings." Or even our humanity itself.

We are at a once-in-a-lifetime moment where we can still see where our choices might lead us and have time to say "no." But that moment is coming to a close. There are economic and institutional interests that want to mask to make the choice for us by presenting us with a fait accompli. If they succeed, the next time we stop to take a look, it will be in hindsight and chances are that what will come to minds is something other than "Aha!"