The following taxonomy will help to structure our thinking:
a) Biological vs. Non-biological enhancements
For example, adding an extra arm vs. going to tutoring. Within the biological enhancement sphere, there is a further division between add ons vs. alterations. For example, wearing Google glasses vs. having a permanent extra arm attached to you. Within alterations, there is an even further distinction between genetic and non-genetic enhancements.
When people speak of enhancements, many think of biological enhancements, but it is unclear whether there is any moral distinction between the two. One interesting implication from these distinctions is the regulatory regime which governs each. There are no rules regulating how much tutoring a person can get for their LSAT, but there are regimes in place to regulate biological enhancements. Drawing this regulatory distinction makes a lot of sense if biological enhancements are inherently more dangerous or raise special ethical issues. Aside from that, again, the distinction is not too useful.
To the extent the category of biological enhancements causes concern, it might be because of some features that some kinds of biological enhancements share and many non-biological ones do not, such that it is morally or ethically significant the enhancement does not share one or more of these atomistic features.
Another assumption when speaking of enhancement is that it necessarily involves some kind of modification. However, selection can also be seen as enhancement in the sense that it enhances the qualities of the person who might come into existence.
b) Choosing for ourselves vs. Choosing for others who cannot chose for themselves
Here, we should draw a further distinction between enhancing before birth vs. enhancing after birth. Among pre-birth interventions, there is a further distinction of enhancing by selection vs. enhancing by manipulation of already fertilised embryos, or foetuses.
c) Enhancements compatible with expanding life plans vs. Enhancements that will limit options
Here we contrast between the ‘swiss army knife’ enhancement vs. the specialised toolkit enhancement. This is best thought of as a continuum, with a sense of how many options are being foreclosed for the sake of a particular enhancement.
d) Reversible vs. Irreversible enhancements
On the one end might be irreversible genetic manipulation, whereas on the other it might be a nose job or boob job.
This distinction interacts with the ‘choosing for yourself vs. choosing for others who cannot choose for themselves’ category, in the sense that in deciding for the former, you are not forced to consider paternalistic concerns.
e) Enhancement vs. Treatment
Some would draw a distinction between treatments to correct disease or disability vs. enhancements to make people better than well. Arguably any attempt to defend this distinction succumbs to the baseline problem. However, this does not mean that no distinction can be drawn: there are treatments which are clearly treatments, and enhancements that are clearly enhancements. The mere existence of a grey area does not justify ignoring the distinction. This logic also shuts down the argument that one cannot stop research into human enhancements without also stopping research into treatment.
Furthermore, efforts to enhance cannot necessarily correlate with negative consequences, and efforts to heal do not necessarily correlate with positive consequences. Consider e.g. a child who is being forced to endure therapy when they would be better off learning to cope with their problem vs. a child who is being enhanced to achieve a certain dream/goal they have.
A more subtle distinction might be drawn here between enhancements to the upper bound of what people already have vs. enhancements that add beyond human nature as it now stands. Under this distinction, some may argue that enhancements which go to the former are more justifiable than the latter, arguably for three reasons: (1) the person seeking it is no less ‘human’ because the trait being sought after already exists in the human race; (2) there is no unfairness if you are just drawing from the same deck again; (3) this produces a ceiling effect.
f) Enhancements for absolute vs. positional goods
Some goods are only valuable because of their scarcity, whereas other goods are valuable irrespective of distribution. The former are positional goods whereas the latter are absolute goods. Most traits are a mix of both, and to determine how much one trait is valued for being positional vs. absolute may not be practical or possible. Arguably, there is also a question of perspective here: from what vantage point do we determine something to be absolute or positional? This leads to the possibility that all absolute goods are positional given the right circumstances.
The law may very well adopt different responses to different kinds of enhancements, but to paint with a broad brush, we can imagine the following general approaches:
a) Permit
Where the law permits the enhancement, there are a bunch of second order choices which need to be made: should the law mandate the enhancement, subsidise the enhancement, tax the enhancement or construct certain choice architecture regarding the enhancement.
b) Prohibit
Where the law prohibits enhancement, it could prohibit it flat out across the board, or impose certain caps on enhancements etc. The state might also adopt certain disgorgement remedies against those who breach the law (to the extent the enhancement is capable of being disgorged).
A difficult question here is how effectively the law would be able to monitor such breaches. Just think about how effectively doping or cheating is detected/managed at the moment.
Moral Sanctions
Society may also impose moral sanctions/norms on enhancements where the law does not permit/prohibit.
More broadly, these arguments can be characterised as harms to individuals, harms to society, and harms to human values. However, for the purposes of examining them below, they will be considered outside of these categories.
a) Safety/Risks to the Enhanced
Some enhancements may pose risks for the particular individual who seek to use them or those on whom they are imposed. Of course, many enhancements also provide benefits, the key reason they are being pursued.
However, there is a question as to what role should risk play in this debate, and in evaluating the strength of the other arguments. Medical treatments presently all carry a degree of risk, as does much of what people do in their daily lives, but this is not sufficient justification for taking the position against potentially risky enhancements. The context within which risk is raised may be relevant to the role it plays - for example, in the context of genetic germ-line modifications, it may be fair to say that if a particular enhancement is particularly risky, the risk will not only be born by the immediate enhancee, but also subsequent individuals.
b) Distribution and inequality
If enhancements are available for purchase, there is a risk that they will lead to distributional injustice and worsening inequality. This may be more acute for positional goods. One way to avoid this problem is to regulate around it e.g. subsidise or mandate it (although the latter might not be justifiable re positional goods). A more skeptical view would be to say that because it is so hard to distinguish between positional and absolute goods, enhancements should just not be allowed.
However, there is a question of whether scarce enhancements would actually cause inequality. Could it not be considered as a way of overcoming distributional injustice and reducing inequality? Instead of wealth redistribution, why not compensate individuals for bad genetic luck by directly changing it? On this view, subsidisation might be the solution, overcoming luck egalitarianism. Applied here, those with bad luck should get subsidised enhancement (although this runs into problems as to what counts as bad luck, whether a ‘separate spheres’ approach should be adopted, and how much subsidisation there should be).
An additional point is whether the inequality might be buffered by the potential for Kaldor-Hicks efficiency? This is a redux of the redistribution argument, but in the context of enhancements, the benefits produced by enhanced individuals should enable the extra value to be redistributed to those who are less fortunate and cannot obtain enhancements.
Furthermore, to an extent, there is already genetic selection in society already in terms of mate selection. This in itself already produces inequality. What then is the problem with more inequality? In this context, one might also see the argument against positional goods weaken - people often pursue positional goods now (e.g. fashion, status items etc.), so what is the problem with more positional goods?
c) The coercion of voluntary enhancements
The argument goes that, supposing enhancements were safe, costless, provided benefits to those who got them, voluntary, individualistic and state neutral, those who choose not to enhance may feel coerced into enhancing anyway. A parallel can be drawn here to doping in sports and the idea of playing ‘naked’.
However, what is the moral problem with being coerced? Why would we not want a competitive coercive dynamic to take hold if the enhancement was completely safe and costless? One potential objection might be the externalities which...