The science and politics of genetically modified humans: will new genetic technologies be carefully controlled for their benefits--or will they inadvertently destroy civil society? Say hello to the post-human ideology.

The new human genetic technologies are arguably the most consequential technologies ever developed. Many applications have great potential to prevent disease and alleviate suffering, but others would open the door to a new, high-tech eugenics that could destabilize human biology and undermine the foundations of civil society.

Humanity needs a crash course in the science and politics of the new human genetic technologies. We need to distinguish benign applications from pernicious ones, and we need to adopt policies affirming the former and proscribing the latter. We need to repudiate eugenic political ideologies and deepen our commitment to the integrity of the human species and the dignity of all people. We need to do this on a global scale and within less than a decade.

Two new technologies are of critical concern: reproductive cloning and inheritable genetic modification.

Reproductive cloning is the creation of a genetic near-duplicate of an existing person. If I cloned myself, would the child be my son or my twin brother? In truth, he would be neither. He would be a new category of biological relationship-my clone. Opposition to reproductive cloning is nearly universal, and the United Nations has begun negotiations on an international treaty to ban it.

Inheritable genetic modification (IGM) means modifying the genes we pass to our children. Most people intuitively understand that if IGM were allowed it would change forever the nature of human life. People would quite literally have become artifacts. If cloning is the atomic bomb of the new human genetic technologies, IGM is the multi-megaton hydrogen bomb. Only the most egotistical or deluded would want to clone themselves, but if IGM were allowed even many who are appalled at the prospect of using it would feel compelled to do so, lest their children be left behind in the new techno-eugenic rat-race.

Once we begin genetically modifying our children, where would we stop? If it were acceptable to engineer one gene, why not two? If two, why not twenty, or two hundred? 1GM would put into play wholly unprecedented biological, social, and political forces that would feed back upon themselves with impacts quite beyond our ability to foresee, much less control.

People often assume that IGM is needed to enable couples to avoid passing inheritable genetic diseases such as Tay Sachs and cystic fibrosis to their children. This is not so, and those who say it is are either misinformed or seeking to mislead. Pre-implantation genetic diagnosis and other options available today allow such couples to have children completely free of the harmful genes, in all but a very small number of situations. IGM would be necessary only if a couple wished to "enhance" a child with genes that neither of them carry.

The new eugenic technologies are being actively promoted by influential scientists, writers, and others who see themselves ushering in a new epoch for human life on earth. They speak with enthusiasm of a "post-human" future in which the health, appearance, personality, cognitive ability, sensory capacity, and life-span of our children have all been genetically modified. They anticipate, with scant concern, the inevitable segregation of humanity into genetic sub-species, the "GenRich" and the "Naturals."

This new techno-eugenic vision is an integral element of an emerging socio-political ideology. It differs from conservative ideologies in its antipathy towards religion and traditional social values, from left-progressive ideologies in its rejection of egalitarian values and social welfare as a public purpose, and from Green ideologies in its enthusiastic advocacy of a technologically reconfigured and transformed natural world. It embraces a triad of ideological commitments: to science and technology as autonomous endeavors properly exempt from social control; to the priority of market outcomes; and to a political philosophy grounded in social Darwinism.

In recent months, leaders of a wide range of civil society constituencies have begun speaking out against the new techno-eugenics. Pro-choice feminists and women's health advocates charge that high-tech consumer eugenics would commodify and industrialize the process of child-bearing. Environmentalists know that genetically altered humans would have few qualms about genetically altering the rest of the natural world. Human rights and civil rights advocates worry that new eugenic technologies would stoke the fires of racial and ethnic hatred. Disability rights leaders know that a society obsessed with genetic perfection could regard the disabled as mistakes that should have been prevented. Peace and justice activists fear brutal international conflict as countries race to create genetically superior populations.

What policies do we need? We need domestic and international bans on reproductive human cloning and inheritable genetic modification, and effective, accountable regulation of all other genetic technologies. At the same time we need to affirm the many beneficial applications of genetic science--in diagnostics, therapeutics, pharmaceutical development, and other medical fileds--and to ensure that these are available to all people, regardless of economic status or geography.

Many countries have already adopted such policies. Our challenge now is to extend them world-wide. If successful, the United Nations treaty negotiations to ban reproductive cloning will be both an historic achievement and a model for international policy on IGM and other human genetic technologies.

Nothing will happen, however, unless people organize to make it happen. We need to foster new levels of awareness, organization, and engagement-in short, a new social movement--committed to affirming the integrity of the human species and opposing the new techno-eugenics and the post-human ideology. Such a movement will need to be of the same intensity, scope, and scale as the great movements of the past century that struggled on behalf of working people, anti-colonialism, civil rights, peace and justice, women's equality, and environmental protection. There is no greater challenge. Our common humanity is at stake.

Richard Hayes is executive director of the Oakland, California-based Center for Genetics and Society, which conducts research on the social implications of the new human genetic technologies.