While body hacking is sometimes presented as being new and radical, humans have been engaged in the practice (under other names) for quite some time. One of the earliest forms of true body hacking was probably the use of prosthetic parts to replace lost pieces, such as a leg or hand. These hacks were aimed at restoring a degree of functionality, so they were practical hacks.
While most contemporary body hacking seems aimed at gimmickry or rather limited attempts at augmentation, there are some serious applications that involve replacement and restoration. One example of this is the color blind person who is using a skull mounted camera to provide audio clues regarding colors. This hack serves as a replacement to missing components of the eye, albeit in a somewhat odd way.
Medicine is, obviously enough, replete with body hacks ranging from contact lenses to highly functional prosthetic limbs. These technologies and devices provide people with some degree of replacement and restoration for capabilities they lost or never had. While these sort of hacks are typically handled by medical professionals, advances in existing technology and the rise of new technologies will certainly result in more practical hacks aimed not at gimmickry but at restoration and replacement. There will also certainly be considerable efforts aimed at augmentation, but this matter will be addressed in another essay.
Since humans have been body hacking for replacement and restoration for thousands of years, the ethics of this matter are rather well settled. In general, the use of technology for medical reasons of replacement or restoration is morally unproblematic. After all, this process is simply fulfilling the main purpose of medicine: to get a person as close to their normal healthy state as possible. To use a specific example, there really is no morally controversy over the use of prosthetic limbs that are designed to restore functionality. In the case of body hacks, the same general principle would apply: hacks that aim at restoration or replacement are generally morally unproblematic. That said, there are some potential areas of concern.
One area of both moral and practical concern is the risk of body hacking done by non-professionals. That is, amateur or DIY body hacking. The concern is that such hacking could have negative consequences—that is, the hack could turn out to do more harm than good. This might be due to bad design, poor implementation or other causes. For example, a person might endeavor a hack to replace a missing leg and have it fail catastrophically, resulting in a serious injury. This is, of course, not unique to body hacking—this is a general matter of good decision making.
As with health and medicine in general, it is generally preferable to go with a professional rather than an amateur or a DIY endeavor. Also, the possibility of harm makes it a matter of moral concern. That said, there are many people who cannot afford professional care and technology will afford people an ever-growing opportunity to body hack for medical reasons. This sort of self-help can be justified on the grounds that some restoration or replacement is better than none. This assumes that the self-help efforts do not result in worse harm than doing nothing. As such, body hackers and society will need to consider the ethics of the risks of amateur and DIY body hacking. Guidance can be found here in existing medical ethics—such as moral guides for people attempting to practice medicine on themselves and others without proper medical training.
A second area of moral concern is that some people will engage in replacing fully functional parts with body hacks that are equal or inferior to the original (augmentation will be addressed in the next essay). For example, a person might want to remove a finger to replace it with a mechanical finger with a built in USB drive. As another example, a person might want to replace her eye with a camera comparable or inferior to her natural eye.
One clear moral concern is the potential dangers in such hacks—removing a body part can be rather dangerous. One approach would be to weigh the harms and benefits of such hacking. On the face of it, such replacement hacks would seem to be at best neutral—that is, the person will end up with the same capabilities as before. It is also possible, perhaps likely, that the replacement attempt will result in diminished capabilities, thus making the hack wrong because of the harm inflicted. Some body hackers might argue that such hacks have a value beyond the functionality. For example, the value of self-expression or achieving a state of existence that matches one’s conception or vision of self. In such cases, the moral question would be whether or not these factors are worth considering and if they are, how much weight they should be given morally.
There is also the worry that such hacks would be a form of unnecessary self-mutilation and thus at best morally dubious. A counter to this is to argue, as John Stuart Mill did, that people have a right to self-harm, provided that they do not harm others. That said, arguing that people do not have a right to interfere with self-harm (provided the person is acting freely and rationally) does not entail that self-harm is morally acceptable. It is certainly possible to argue against self-harm on utilitarian grounds and also on the basis of moral obligations to oneself. Arguments from the context of virtue theory would also apply—self harm is certainly contrary to developing one’s excellence as a person.
These approaches could be countered. Utilitarian arguments can be met with utilitarian arguments that offer a different evaluation of the harms and benefits. Arguments based on obligations to oneself can be countered by arguing that there are not such obligations or that the obligations one does have allows from this sort of modification. Argument from virtue theory could be countered by attacking the theory itself or showing how such modifications are consistent with moral excellence.
My own view, which I consistently apply to other areas such as drug use, diet, and exercise, is that people have a moral right to the freedom of self-abuse/harm. This requires that the person is capable of making an informed decision and is not coerced or misled. As such, I hold that a person has every right to DIY body hacking. Since I also accept the principle of harm, I hold that society has a moral right to regulate body hacking of others as other similar practices (such as dentistry) are regulated. This is to prevent harm being inflicted on others. Being fond of virtue theory, I do hold that people should not engage in self-harm, even though they have every right to do so without having their liberty restricted. To use a concrete example, if someone wants to spoon out her eyeball and replace it with a LED light, then she has every right to do so. However, if an untrained person wants to set up shop and scoop eyeballs for replacement with lights, then society has every right to prevent that. I do think that scooping out an eye would be both foolish and morally wrong; which is also how I look at heroin use and smoking tobacco.