Critics of pushing boundaries come from both the political right and left, he says, pointing to conservatives such as Francis Fukuyama of the President's Council on Bioethics (which in 2003 published a critical report called "Beyond Therapy: Biotechnology and the Pursuit of Happiness") and liberal activists such as Jeremy Rifkin, president of the Foundation on Economic Trends.
The Southern Baptist Theological Seminary's R. Albert Mohler Jr. is another vocal opponent of radical enhancements. It's one thing, he says, to try to give a person with bad eyesight 20/20 vision, and it's another to try to create humans whose eyesight is superhuman. The latter, he says, uses science "to redefine the species."
"From a Christian worldview perspective," he says, "there are two problems with this. First, you have the normative definition of what it means to be a human being made in the image of God." To try to exceed normal human capacities, he says, "is to open, quite literally, a Pandora's Box of moral problems."
The second problem, Mohler says, is the transhumanist desire to prolong life beyond normal aging. "The tranhumanists increasingly see death as an oddity that is to be overcome. Christians certainly do not embrace death as a good in itself, but we understand that death is a part of what it means to be human, and that, indeed, the effort to forever forestall death is itself an act of defiance that will be both unworkable and morally suspect."
Richard Sherlock takes a different view. Sherlock is a philosophy professor at Utah State University, one of only several Utah members of the World Transhumanist Association and also a practicing member of The Church of Jesus Christ of Latter-day Saints.
"We ought to be able to look at the future as an opportunity, not a threat," says Sherlock, who is also a board member of the Journal of Evolution and Technology. "I don't think you can say God has said 'this, but no more.' All these technologies are ways in which we become more like our Creator," he adds. In fact, he says, the idea of a continually advancing human "fits better within a Mormon context that sees humanity as a developing structure, aspiring to be more like God."
Not that technology doesn't present potential challenges, he says. But "we can't put our head in the sand and hope they go away. They need careful thought in light of the moral and religious traditions of the West."
"The really important question that transhumanists themselves worry about," he adds, "is how to make the future equitable."
What happens, for example, if the rich have access to nanorobots that can rid the body of cancer cells, but the poor don't? What happens if only developed countries can provide their citizens, or maybe just their wealthiest citizens, the latest in gene therapy? Hughes calls the solution "democratic transhumanism."
"Our agenda is not just 'rahrah technology,' " he says, "but the creation of a society that is egalitarian in the use of those technologies."
But even in that best of all worlds, the potential dilemmas are staggering. Take the case of Parker Jensen the Utah boy whose parents were charged with kidnapping when they refused to let their son undergo chemotherapy and think about what happens if a hospital decides that an unborn baby must undergo genetic engineering so he won't ever get cancer in the first place.
What happens when parents decide they want their children to be genetically altered to be tall? Will shortness become a disability when buildings and furniture and cars all are redesigned for the burgeoning population of tall people? Will governments decide that tallness is not in the community's best interest, since tall people take up more room? Will tallness no longer be an asset, anyway, if everyone is the same height?
And these are the easy questions. What about the scenario Hughes presents in "Citizen Cyborg": the fictitious case of a woman named Grace?
The hypothetical Grace has an auto accident that destroys the right half of her brain, at which time her remaining brain is suffused with nanoelectrodes hooked up to a computer that has the same power as the human brain. At the same time, a bath of neural growth factors and cloned neural stem cells stimulate her remaining brain cells to grow new connections to the brain prosthesis. As time goes by, the brain prosthesis assumes an increasing role in Grace's head.