For the last several decades, a strange liberation movement has grown within the developed world. Its crusaders aim much higher than civil rights campaigners, feminists or gay-rights advocates. They want nothing less than to liberate the human race from its biological constraints. As "transhumanists" see it, humans must wrest their biological destiny from evolution's blind process of random variation and adaptation and move to the next stage as a species.
It is tempting to dismiss transhumanists as some sort of odd cult, nothing more than science fiction taken too seriously: Witness their over-the-top Web sites and recent press releases ("Cyborg Thinkers to Address Humanity's Future," proclaims one).
The plans of some transhumanists to freeze themselves cryogenically in hopes of being revived in a future age seem only to confirm the movement's place on the intellectual fringe. But is the fundamental tenet of transhumanism _ that we will someday use biotechnology to make ourselves stronger, smarter, less prone to violence and longer-lived _ really so outlandish?
Transhumanism of a sort is implicit in much of the research agenda of contemporary biomedicine. The new procedures and technologies emerging from research laboratories and hospitals _ whether mood-altering drugs, substances to boost muscle mass or selectively erase memory, prenatal genetic screening, or gene therapy _ can as easily be used to "enhance" the species as to ease or ameliorate illness.
Although the rapid advances in biotechnology often leave us vaguely uncomfortable, the intellectual or moral threat they represent is not always easy to identify. The human race, after all, is a pretty sorry mess, with our stubborn diseases, physical limitations and short lives. Throw in humanity's jealousies, violence and constant anxieties, and the transhumanist project begins to look downright reasonable.
If it were technologically possible, why wouldn't we want to transcend our current species? The seeming reasonableness of the project, particularly when considered in small increments, is part of its danger. Society is unlikely to fall suddenly under the spell of the transhumanist worldview. But it is very possible that we will nibble at biotechnology's tempting offerings without realizing that they come at a frightful moral cost.
The first victim of transhumanism might be equality. The U.S. Declaration of Independence says that all men are created equal, and the most serious political fights in the history of the United States have been over who qualifies as fully human. Women and blacks did not make the cut in 1776 when Thomas Jefferson penned the declaration. Slowly and painfully, advanced societies have realized that simply being human entitles a person to political and legal equality. In effect, we have drawn a red line around the human being and said that it is sacrosanct.
Underlying this idea of the equality of rights is the belief that we all possess a human essence that dwarfs manifest differences in skin color, beauty and even intelligence. This essence, and the view that individuals therefore have inherent value, is at the heart of political liberalism. But modifying that essence is the core of the transhumanist project. If we start transforming ourselves into something superior, what rights will these enhanced creatures claim, and what rights will they possess when compared to those left behind? If some move ahead, can anyone afford not to follow?
These questions are troubling enough within rich, developed societies. Add in the implications for citizens of the world's poorest countries for whom biotechnology's marvels likely will be out of reach, and the threat to the idea of equality becomes even more menacing.
Transhumanism's advocates think they understand what constitutes a good human being, and they are happy to leave behind the limited, mortal, natural beings they see around them in favor of something better. But do they really comprehend ultimate human goods? For all our obvious faults, we humans are miraculously complex products of a long evolutionary process, products whose whole is much more than the sum of our parts.
Our good characteristics are intimately connected to our bad ones: If we weren't violent and aggressive, we wouldn't be able to defend ourselves; if we didn't have feelings of exclusivity, we wouldn't be loyal to those close to us; if we never felt jealousy, we would also never feel love. Even our mortality plays a critical function in allowing our species as a whole to survive and adapt (and transhumanists are just about the last group I'd like to see live forever).
Modifying any one of our key characteristics inevitably entails modifying a complex, interlinked package of traits, and we will never be able to anticipate the ultimate outcome. Nobody knows what technological possibilities will emerge for human self-modification. But we can already see the stirrings of Promethean desires in how we prescribe drugs to alter the behavior and personalities of our children.
The environmental movement has taught us humility and respect for the integrity of nonhuman nature. We need a similar humility concerning our human nature. If we do not develop it soon, we may unwittingly invite the transhumanists to deface humanity with their genetic bulldozers and psychotropic shopping malls.
Francis Fukuyama is professor of international political economy at the Johns Hopkins School of Advanced International Studies and author of State-Building: Governance and World Order in the 21st Century (Ithaca: Cornell University Press, 2004).