Since 1978, reproductive biologists have helped couples overcome infertility by using increasingly sophisticated techniques for generating and manipulating human embryos in the laboratory. At the same time, molecular biologists have been working to overcome human disease by deciphering the entire sequence of the human genome and constructing tools to correct genetic and cellular defects. While reproductive and molecular biologists focus on unrelated medical problems - infertility and disease - combining their technologies produces reprogenetics, which will allow us to design ourselves.

Reprogenetics will enable prospective parents to give their children genes that they themselves do not carry, thereby increasing their offspring's chances for health, longevity, happiness, and success - an appalling prospect for many bioethicists. But is reprogenetics simply a new and more powerful vehicle to repeat the abhorrent eugenic practices of the past? Or are reprogenetics and eugenics fundamentally different from one another in terms of both control and purpose?

Eugenics embodies the desire and attempts of a society's leaders to control the breeding practices of its citizens, including the forcible sterilization or murder of those deemed as carrying undesirable genes. Reprogenetics, by contrast, is concerned with the question of what genes an individual child will receive, not with the vague, unscientific goal of improving a society's gene pool. Moreover, it gives control to individual prospective parents. While eugenic practices led to a restriction of reproductive freedom and worse, reprogenetics can do the opposite. It could help parents have children with a higher likelihood of being healthy, without bringing direct harm to anyone else.

Reprogenetics can be understood as an extension of parents' fundamental motivation and desire: to protect their children and give them all possible advantages in life. Parents in affluent societies already provide environmental advantages to their children after birth; reprogenetics could allow them to pursue the same objectives before birth.

Of course, neither environmental nor genetic advantages guarantee healthier, happy, successful children. But the lack of guarantees does not prevent parents from spending $140,000 to send their children to the elite private university where I teach. If democratic societies allow people to spend money to buy environmental advantages for children, how can they prohibit parents from buying genetic advantages? If reprogenetics is used to increase chances of health, happiness and success, what could be wrong with it?

Once issues of technical safety are resolved, a fundamental objection to reprogenetics is its inherent unfairness to families unable to afford it. All modern democratic societies must balance individual autonomy and social justice. In the US, individual autonomy is of paramount importance. In most other Western countries, social solidarity looms much larger.

Most European countries try to realize it by providing equal healthcare and educational opportunities to all children. But the argument that genetic enhancements are immoral because not all children can receive them is flawed. Children are not biologically equivalent to begin with. Everyone is born with advantages or disadvantages across a whole range of physical characteristics as well as innate abilities. Life is not fair.

So, in the future the critical question will be this: "Who decides how genetic advantages are distributed?" Who decides which child will get the HIV resistance gene and who will be born susceptible to AIDS? Who will decide which child will have superior protection against cancer and heart disease?

Should the decision be left to the randomness of nature, as it is now? Should it be determined by the parents' affluence? Or should it be controlled by a benevolent state that doles out life-enhancing genes to all its newly conceived children?

Unfortunately, provision and regulation of genetic enhancement technology will not be easy. Unlike healthcare, there are almost no limits to genetic enhancements. There can always be stronger resistance to disease, greater longevity, more physical prowess, and higher mental capacity. Furthermore, the innate desire to provide for one's children is so powerful that affluent citizens may buy reprogenetics elsewhere even if their society bans or limits its use. Today, for example, Europeans travel to the US to purchase human eggs from young women chosen on the basis of their presumed genetic characteristics.

It is, however, possible to envisage an alternative scenario to that of a growing gap between "haves" and "have-nots." Although such a gap may emerge initially, the cost of reprogenetics is likely to drop sharply over time. Like computers and advanced telecommunications, it could become affordable to the majority in developed countries.

Ultimately, hyper-human genetic enhancements will become feasible, too, and the economic and social advantages that wealthy countries maintain could be expanded into a genetic advantage. The divide between wealthy and poor nations could widen further with each generation until a common humankind no longer exists. A severed humanity could be the ultimate legacy of unfettered global capitalism.