posthuman might in itself be degrading, so that by becoming posthuman we might be harming ourselves. Another is that posthumans might pose a threat to ‘ordinary’ humans. (I shall set aside a third possible reason, that the development of posthumans might offend some supernatural being.)
The most prominent bioethicist to focus on the first fear is Leon Kass:
Most of the given bestowals of nature have their given species‐specified natures: they are each and all of a given sort. Cockroaches and humans are equally bestowed but differently natured. To turn a man into a cockroach – as we don’t need Kafka to show us – would be dehumanizing. To try to turn a man into more than a man might be so as well. We need more than generalized appreciation for nature’s gifts. We need a particular regard and respect for the special gift that is our own given nature …3
Transhumanists counter that nature’s gifts are sometimes poisoned and should not always be accepted. Cancer, malaria, dementia, aging, starvation, unnecessary suffering, and cognitive shortcomings are all among the presents that we would wisely refuse. Our own species‐specified natures are a rich source of much of the thoroughly unrespectable and unacceptable – susceptibility for disease, murder, rape, genocide, cheating, torture, racism. The horrors of nature in general, and of our own nature in particular, are so well documented4 that it is astonishing that somebody as distinguished as Leon Kass should still in this day and age be tempted to rely on the natural as a guide as to what is desirable or normatively right. We should be grateful that our ancestors were not swept away by the Kassian sentiment, or we would still be picking lice off each other’s backs. Rather than deferring to the natural order, transhumanists maintain that we can legitimately reform ourselves and our natures in accordance with humane values and personal aspirations.
If one rejects nature as a general criterion of the good, as most thoughtful people nowadays do, one can of course still acknowledge that particular ways of modifying human nature would be debasing. Not all change is progress. Not even all well‐intentioned technological intervention in human nature would be on balance beneficial. Kass goes far beyond these truisms, however, when he declares that utter dehumanization lies in store for us as the inevitable result of our obtaining technical mastery over our own nature:
The final technical conquest of his own nature would almost certainly leave mankind utterly enfeebled. This form of mastery would be identical with utter dehumanization. Read Huxley’s Brave New World, read C. S. Lewis’s Abolition of Man, read Nietzsche’s account of the last man, and then read the newspapers. Homogenization, mediocrity, pacification, drug‐induced contentment, debasement of taste, souls without loves and longings – these are the inevitable results of making the essence of human nature the last project of technical mastery. In his moment of triumph, Promethean man will become a contented cow.5
The fictional inhabitants of Brave New World, to pick the best known of Kass’s examples, are admittedly short on dignity (in at least one sense of the word). But the claim that this is the inevitable consequence of our obtaining technological mastery over human nature is exceedingly pessimistic – and unsupported – if understood as a futuristic prediction, and false if construed as a claim about metaphysical necessity.
There are many things wrong with the fictional society that Huxley described. It is static, totalitarian, caste‐bound; its culture is a wasteland. The brave new worlders themselves are a dehumanized and undignified lot. Yet posthumans they are not. Their capacities are not super‐human but in many respects substantially inferior to our own. Their life expectancy and physique are quite normal, but their intellectual, emotional, moral, and spiritual faculties are stunted. The majority of the brave new worlders have various degrees of engineered mental retardation. And everyone, save the ten world controllers (along with a miscellany of primitives and social outcasts who are confined to fenced preservations or isolated islands), are barred or discouraged from developing individuality, independent thinking, and initiative, and are conditioned not to desire these traits in the first place. Brave New World is not a tale of human enhancement gone amok, but is rather a tragedy of technology and social engineering being deliberately used to cripple moral and intellectual capacities – the exact antithesis of the transhumanist proposal.
Transhumanists argue that the best way to avoid a Brave New World is by vigorously defending morphological and reproductive freedoms against any would‐be world controllers. History has shown the dangers in letting governments curtail these freedoms. The last century’s government‐sponsored coercive eugenics programs, once favored by both the left and the right, have been thoroughly discredited. Because people are likely to differ profoundly in their attitudes towards human enhancement technologies, it is crucial that no single solution be imposed on everyone from above, but that individuals get to consult their own consciences as to what is right for themselves and their families. Information, public debate, and education are the appropriate means by which to encourage others to make wise choices, not a global ban on a broad range of potentially beneficial medical and other enhancement options.
The second fear is that there might be an eruption of violence between unaugmented humans and posthumans. George Annas, Lori Andrews, and Rosario Isasi have argued that we should view human cloning and all inheritable genetic modifications as ‘crimes against humanity’ in order to reduce the probability that a posthuman species will arise, on grounds that such a species would pose an existential threat to the old human species:
The new species, or ‘posthuman,’ will likely view the old ‘normal’ humans as inferior, even savages, and fit for slavery or slaughter. The normals, on the other hand, may see the posthumans as a threat and if they can, may engage in a preemptive strike by killing the posthumans before they themselves are killed or enslaved by them. It is ultimately this predictable potential for genocide that makes species‐altering experiments potential weapons of mass destruction, and makes the unaccountable genetic engineer a potential bioterrorist.6
There is no denying that bioterrorism and unaccountable genetic engineers developing increasingly potent weapons of mass destruction pose a serious threat to our civilization. But using the rhetoric of bioterrorism and weapons of mass destruction to cast aspersions on therapeutic uses of biotechnology to improve health, longevity, and other human capacities is unhelpful. The issues are quite distinct. Reasonable people can be in favor of strict regulation of bioweapons, while promoting beneficial medical uses of genetics and other human enhancement technologies, including inheritable and ‘species‐altering’ modifications.
Human society is always at risk of some group deciding to view another group of humans as being fit for slavery or slaughter. To counteract such tendencies, modern societies have created laws and institutions, and endowed them with powers of enforcement, that act to prevent groups of citizens from enslaving or slaughtering one another. The efficacy of these institutions does not depend on all citizens having equal capacities. Modern, peaceful societies can have large numbers of people with diminished physical or mental capacities along with many other people who may be exceptionally physically strong or healthy or intellectually talented in various ways. Adding people with technologically enhanced capacities to this already broad distribution of ability would not need to rip society apart or trigger genocide or enslavement.
The assumption that inheritable genetic modifications or other human enhancement technologies would lead to two distinct and separate species should also be questioned. It seems much more likely that there would be a continuum of differently modified or enhanced individuals, which would overlap with the continuum of as‐yet unenhanced humans. The scenario in which ‘the enhanced’ form a pact and then attack ‘the naturals’ makes for exciting science fiction, but is not necessarily the most plausible outcome. Even today, the segment containing the tallest ninety percent of the population could, in principle, get together and kill or enslave the shorter decile. That this does not happen suggests that