Prostheses, as they are currently used, mechanically replace a limb function that was either lost or never possessed. Our understanding of prosthetics is that they are used by people whose unassisted physical abilities are limited by their lack of functioning…. the “disabled.” We might assume, therefore, that if normal functioning could be completely restored by prostheses, we would no longer describe them as disabled. Some modern prostheses are so good that they function more efficiently than regular human limbs, and yet people who have even the most advanced prosthetic limbs — paralympians with high-efficiency replacement legs, for example — are still normatively described as ‘disabled’. This suggests that our understanding of disability is defined by more than simple functionality, and that there are some deeper anthropological assumptions at work when we think about what it is to be ‘able bodied’.
This distinction becomes even less clear when we consider other technological augmentations that restore ‘normal’ functioning. Many people wear glasses, for example, and yet we do not typically think of being shortsighted as a disability in the same way as we do, say, missing a leg. To be shortsighted is to be physically impaired, so we might ask what the distinctions we make are really based on. Both prosthetic limbs and spectacles have been around for a long time, and have typically provided an imperfect — though effective — therapeutic solution. In creating limbs that work more efficiently than human limbs, however, advances in modern prosthetics may change both our understanding of disability and the nature of the distinctions between different kinds of mechanical therapies. Furthermore, thinking about the possible applications of prosthetic technology more widely reveals aspects of human culture that we perhaps usually overlook as a result of viewing them purely through the prism of their role in therapy.
In recent years, there have been several high profile examples of paralympians using high tech prostheses, and perhaps the best known of these is the South African athlete Oscar Pistorius, who has two prosthetic legs. The legs are modelled on the hind legs of the cheetah, and the modelling has been so successful that Pistorius uses up to 25% less oxygen over a distance of 400m than he would if he had regular legs. An efficiency gain of this magnitude is considerable and represents a sizeable competitive advantage over “able bodied” runners. Viewed from the perspective of pure functionality for athletic purposes, it could not be said that Pistorius is “disabled” when he used his prosthetic limbs — indeed, we could say that they enhance his athletic capacity when compared to legs of flesh, bone and muscle. Given a determination to achieve certain kinds of feats of ability, it would not necessarily be irrational for an able-bodied athlete to prefer such artificial limbs to the ones that they already possess. It would not, therefore, ultimately be irrational for somebody to decide to have their limbs removed and replaced by prosthetic ones, however odd this desire may seem to be.
The therapy/enhancement distinction is notoriously difficult to delineate in any case, given that all therapies confer an enhancement, and Pistorius’ legs are a particularly clear example of how hard it is to characterize the distinction clearly. Nonetheless, when we see Pistorius’ spoon-shaped lower legs, we “see” a disabled person — someone lacking in functionality. And certainly, when we see his lower legs, they do not look human. Perhaps, then, our definition of disability is partly characterized by appearance. If Pistorius’ legs looked and moved exactly like regular human legs, the conceptual gap would be closed by the resemblance of the prostheses to the legs that you and I have. Certainly the replication would have to be precise for this to be achieved, as less advanced prostheses modelled to look like legs or arms still do not look quite authentic. They move clumsily, and this betrays their apparently normal physiological appearance.
However much conventional prosthetics replicate normal functioning, they do not often close this gap completely. On this basis, they don’t tend to represent a desirable physical augmentation for the able-bodied. We might ask, though, if prosthetic technology were to advance so much that replacement limbs could be used as enhancements, whether there might be a corresponding rise in their desirability for some able-bodied people. It would be wrong to suggest that large numbers of people would be rushing to have their limbs replaced if ultra high-performance prosthetics were readily available, but it is not inconceivable that prosthetic limbs could be desirable to some, and there are several reasons why we should not discount the possibility.
Not everybody wants the same things from their body, and people either psychologically or neurologically driven towards developing a certain physical function sometimes devote their whole lives to achieving this. All athletes, whether able-bodied or disabled, drive themselves towards excelling in a particular way. Determination of this kind suggests that — in terms of the way they view themselves — a particular kind of ability is constitutive of the individuals that they are, and this is not limited to sport. It is also apparent in any field where it is possible to excel, for example in music, art, feats of the intellect and so on. Musicians, sportsmen and intellectuals are commonplace, however, and indeed excellence in these fields can be socially advantageous as well as personally satisfying.
I will return to the question of status later. Firstly, however, let’s consider some marginal cases where people see themselves directed towards goals not shared by many other people and which can therefore seem abnormal. One extreme example of this is the neurological condition known as Body Identity Integrity Disorder, or ‘BIID’.
People with BIID experience a separation between their physiology and their non-corporeal selves. They feel that their body, or some part of it, does not correspond to their understanding of the people that they are… that they inhabit the ‘wrong’ body. BIID is extremely rare, but it does occur. In many cases of BIID, the separation is caused by a particular limb, or a pair of limbs. This can be so distressing that there have been cases of individuals voluntarily having the offending limb amputated. For the sake of space, let us leave aside the clinical ethical dilemmas over whether or not we should allow people to have such procedures (a discussion of this can be found here, and consider just the fact that this sort of decision gets made. However unusual it might seem to wish to be an amputee, it is no more unusual to suppose that there would be people who would wish to have their limbs changed or replaced.
Of course, even if we assume there might be people who would wish to change their natural limbs for prosthetic ones, we will likely experience some doubt as to whether society would come to accept or understand this desire. Under examination, however, we will see that this will ultimately be accepted. After all, societies have come to accept, for example, that some people believe that they were born biologically the wrong sex and wish to change their gender. In the UK, it is even now possible to undergo gender reassignment through the National Health Service, paid for publicly by the taxpayer (given the satisfaction of a lengthy period of assessment, tests and living daily life as the preferred sex for a year pre-operation). While it might be hard for some of us to understand what it is like to feel this way, and while it is still rare, the desire to change one’s sex — once taboo — is now pretty thoroughly legitimated.
The desire to change limbs is not — in any obvious way — much stranger than the desire to change sex, and in view of the incidence of body identity disorder, we might reasonably suppose that at some point there might be people who would wish to appropriate prosthetic technology for their own purposes. In view of the analogous case of gender reassignment, perhaps it is a mistake to characterize the difference between body and identity as a “disorder.” Human/machine integration happens incrementally, and humans are highly capable of incorporating technological modifications of different kinds with the normative definition of the species. Certainly, where prostheses are so advanced that they could confer a distinct advantage for the user in relation to achieving a particular physical achievement, we should certainly not rule out the possibility of prosthetic technology being an elective procedure at some point.
Finally, there is one important consideration that we have only looked at briefly so far, but it is an important one to examine: the role that body modification plays in conferring social status. If you wear glasses, then you could accurately be described as having a disability. Regrettably, there is often a stigma attached to disability, but it does not apply to short or long sightedness requiring glasses. Glasses are a public signifier of a disability, and yet they exist in a different category from something like a crutch, which is also a publicly visible form of technological therapy. Indeed, far from their being an undesirable necessity, glasses are frequently an expensive, high fashion accoutrement. The “right” glasses can make you seem sexy, or rich, or intelligent, or creative, and you can choose particular glasses to make a statement about yourself that corresponds with certain personal qualities. Glasses can be considered so cool, in fact, that the nerdiness associated with them can be exploited to massive commercial advantage — a phenomenon more commonly known as ‘geek chic’.
Our attitude towards glasses shows that there is no necessary reason why different forms of prostheses cannot become socially desirable.
Anybody who saw The Empire Strikes Back as a kid will have been amazed by Luke Skywalker’s bionic hand. In the early 1980s, it seemed impossibly futuristic that someone could have a replacement hand that looked completely normal but was really a machine, but such prostheses are not so distant now. Luke had his hand chopped off, but the prosthetic that was replaced it seemed really, really cool. And it is the possibility of being “cool’ — however boneheaded it might seem — that might play a role in the appropriation of prosthetic technology for self enhancement in the future. And while Luke’s new hand looks just like a regular one, prostheses might not have to closely resemble the limbs they replace to be broadly acceptable as fine — or even attractive — to those who view them. Body adornment and modification with metal, wood, bone and paint have been used by humans for thousands of years. There are even groups today who are trying to achieve a synthesis of ancient, traditional body modification and modern technological culture. Often these modifications denote membership in a certain group, a particular level of social status, or power, or are used as a means of attraction, and it is precisely the physical difference that signifies these qualities. Prostheses are becoming more advanced and can increasingly be more effectively integrated into the body, both physiologically and neurologically. Ultimately, when they reach the point where they can be definitively considered enhancements, we may find that they are transformed — from the ultra high-tech therapy of Pistorius’ legs, to an entirely new range of choices for modifying the body and experimenting with the physiological boundaries of the species.