Reprinted from the June/July 2004 issue of Free Inquiry magazine.

Suppose you were offered a photographic memory, perfect pitch, ultraviolet-spectrum vision, heightened disease resistance, customized skin and eye color, and a one-thousand-year life-expectancy. Would you accept? Now suppose you were told that by doing so you would cease to be human. Would this make you less willing to accept? If you're like me, you'll answer "Yes" to the first question and "No" to the second. I could stand the improvements, and if they make me more than "human," so what? If you answer "Yes" to the first question but say that leaving humanness behind would actually make you more willing to accept, you may be a "transhumanist," the new breed of perfectionists who aim at collective self-improvement through direct modification of "human nature." According to Nick Bostrom, a young philosopher at Oxford and a leading transhumanist: "Transhumanists view human nature as a work-in-progress, a half-baked beginning that we can learn to remold in desirable ways. Current humanity need not be the endpoint of evolution. Transhumanists hope that by responsible use of science, technology, and other rational means we shall eventually manage to become post-human, beings with vastly greater capacities than present human beings have.1 Whereas humanists for centuries have settled for trying to perfect humanity, transhumanists want to transcend it. "Transhumanism has roots in secular humanist thinking, yet is more radical in that it promotes not only traditional means of improving human nature, such as education and cultural refinement, but also direct application of medicine and technology to overcome some of our basic biological limits." Every day, real scientific breakthroughs suggest that transhumanist hopes are no longer merely the stuff of William Gibson's science-fiction novel "Neuromancer." Life spans of laboratory mice have been doubled; transgenic animals are commonplace; jellyfish genes have been inserted into the hair follicles of mice to make them glow; a network of snail brain cells has been connected to a silicon chip, perhaps speeding the day when microchip implants can control artificial limbs, restore sight, and revive memory. Highly prominent cultural commentators like bioethicist Leon Kass, political scientist Francis Fukuyama, environmentalist Bill McKibben, and even Sun Microsystems cofounder Bill Joy have begun calling for caution, or even preemptive prohibition of human "germ-line" genetic engineering (transhumanists label such attitudes "bioconservatism"). An increasingly public debate over our "posthuman future" has ensued. Unfortunately, it has often lacked the clarity of computer-mediated vision.One obstacle to discussion is that transhumanism is not just a philosophy; it is also a grassroots movement. The movement, which has gathered force in the last ten years and coalesced around organizations like the Extropy Institute, the online magazine BetterHumans, and the World Transhumanist Association, is a motley crew of serious academics, journalists, and scientists, cyber self-help gurus, nanotech venture capitalists, polyamorists and gender-benders, cryonics freaks, and artificial intelligence geeks. Like other iconoclastic movements, organized transhumanism attracts its share of sheer goofiness. The co-founder of Extropy Institute, a Southern California body-builder and Ayn Randian named Max, had his last name changed from O'Conner to More, because "I was going to get better at everything, become smarter, fitter, and healthier." The co-mingling of serious theory and policy consideration with a grab bag of techno-utopian projects makes for easy targets for the biocons, diverting the debate from core substantive issues. Additionally, the prominence of organized transhumanism in the debate reinforces the illusion of an all-or-nothing choice between the bio-Luddites and the Borg. Grand Zarathustran dreams of becoming posthuman may leave you cold, though you might nonetheless favor some of the specific developments being proposed. You might be for life extension and gene therapy while being indifferent to whether nanotechnology will ever materialize and opposed to colonizing Mars. Unfortunately, this moderate, piecemeal approach is seldom represented by the ideological camps now squaring off. Our Genes, Our Selves?

What would it mean to become posthuman? That depends on what "being human" amounts to. There is what might be called a moral sense of humanity defined by conventional values, somewhat of the kind Captain Kirk tried repeatedly to explain to Mr. Spock on the original Star Trek. There is also a vaguely biological notion of humanity, and it is this notion that has gotten the most ink. Biocons have made the permissibility of direct intervention in the germ line a touchstone issue, and many transhumanists have followed them in framing the debate in these terms. It is bad philosophy to identify the human essence with the human genome in its present state. To do so is to buy into the antiquated notion that a creature's nature is immutable or unchanging. This intellectual vestige of the eternal, Platonic "species essence" was undermined by Darwinian biology and its insistence on the primacy of change and mutation. Incrementally changing the genome is a way of changing the species, not creating a new one.The identification of human nature with the germ line also gives too much credit to genes. It makes sense to say that what is human nature is universally or species-typically inherited; that is, somehow given or reliably present in each generation, thanks to the activities of the previous generation. But developmental and theoretical biologists now recognize that genes are not the only thing inherited in this sense. Gene transcription, protein assembly, and ontogeny are possible only in an environment of extra-genetic structures (chromatin, cellular organelles, the womb) that must be provided by the previous generation no less reliably than DNA. On this view, plenty of non-germ-line interventions count as interventions in "human nature": the introduction of new prenatal nutritional regimes, for instance. To imagine that the clear, bright line around our nature must be drawn at the boundaries of the chromosomes is to be in the grip of an outmoded gene-centered ideology.

Many of the things that appall critics (like selecting embryos by sex or chasing after earthly immortality) and thrill transhumanists (like computer implants or undermining traditional dualisms of artificial-natural and male-female) have nothing in principle to do with genomic tinkering. Anyway, significant stretches of the genome are probably "junk": self-promoting genes that contribute nothing to the phenotype, and so could be altered to no effect. Clearly, it is certain effects on people and culture that are worth caring about, not the rearrangement of our biochemistry per se. Who Teaches the Overman?

The hard task for transhumanists, then, is the one they haven't yet taken head-on: making a positive and widely appealing moral case for their particular vision of the excellent person and the good society. What can be said to those who have no desire to give up their traditional human values; delight in old-fashioned analog conversation a la Parisian café culture; aesthetic pleasure in the "natural" male and female bodies of a Balanchine ballet; surprise at the genetic lottery of no-tech conception and child-bearing; satisfaction in struggling through a mathematical problem with no calculator; or the Romantic embrace of death as integral to a whole life? "I go straight to the question of why on earth we would want to do this in the first place," says Bill McKibben. All of this enhancing and souping up presupposes a goal or an aim. What is that goal? What is it we're not intelligent enough to do now? It's not to feed the hungry-that has to do with how we share things. Fighting disease? We're making steady progress in conventional medical science with the brains that we have right now.

Maybe no answer will satisfy the Bill McKibbens. But neither should anyone settle for Max More's: it is not enough to say that humans should go for more of whatever they go for. We need to know precisely what we should want more of and why. If the question is what kinds of persons ought there to be, it won't do merely to observe that there is nothing sacrosanct about the human germ line. We need an argument for the eclipse of certain conventional values by new values. In this light, the focus on becoming biologically nonhuman can be seen as a red herring. Presumably, the fundamental point of posthumanism is that the humanness of a trait is simply irrelevant to whether it ought to be valued or pursued.

Understood as the body of intellectual and moral ideas that united Renaissance classicists, Enlightenment rationalists, and twentieth-century scientific naturalists, Western humanism was a great and necessary thing. But its moment may have passed, if only because its anthropocentrism accords too little concern to nonhuman animals and too much to human non-persons. The moment may be right for a posthumanist philosophy, if it can be articulated and ethically defended by enough clever and resourceful-you guessed it-human beings.