Most observers acknowledge that human biotechnologies are likely to create serious challenges for individuals and society. Some people, however, deny or downplay their risks and challenges, and uncritically embrace the dramatic changes they believe human biotechnologies will bring. These enthusiasts tend to oppose public oversight, and to urge the unfettered commercial development of enhancement technologies.

For the past several years, a small but influential network of mainstream scientists, bioethicists, and others has been actively promoting the unfettered development of inheritable genetic modification (changing the genes passed on to future generations) and the expanded use of selection technologies such as pre-implantation genetic diagnosis. Most of them acknowledge that these applications are likely to exacerbate existing inequalities and to create new forms of inequality. They often argue that such developments are inevitable.

"Transhumanists" are a marginal but vocal group of self-described futurists who promote human biotechnologies and other scientific advances as a means to "enhance" physical and cognitive abilities and "transcend" aspects of the human condition such as aging and dying. Their ideas are often seen as a replay of eugenics - the belief that science can and should be used to "breed" people with "superior" qualities.

Some transhumanists want to recast "eugenics" as a positive term, distinguishing their vision from past government-mandated eugenics policies. They are comfortable allowing market forces to shape these technologies and their social impact, arguing that government should have no role in developing, promoting, or regulating human biotechnologies.

Many transhumanists embrace libertarian social and political values, and some have attracted support in more mainstream libertarian circles.