Here I'll point out a few recent papers from the bioethics community on the topic of longevity and medical science. We are approaching the advent of therapies capable of effectively treating the underlying causes of the aging process, and for reasons we all still argue about this seems to require a lot more wailing and gnashing of teeth than, say, the prospects of developing a cure for cancer or heart disease. You won't see deep soul-searching treatises on how terrible it would be it cancer were done away with, at least not from people who like to avoid mockery, but treatments for aging appear to be fair game.
I should say here that I don't think highly of bioethics. The modern institution of bioethics is much like politics, in that it is a parasitical line of business that exists only to divert resources away from productive uses. Bioethicists as a group thrive on slowing down progress and inflicting additional costs on development: their funding comes from manufacturing problems where no problems exist, and the incentives follow on from that in a very straightforward manner. In short, bioethics is unneeded. It has no useful role. Yet, like the roil of politics, there it is, a bunch of people devoted to making vital activities such as medical development harder and more expensive. (This stands in contrast with the past of medical ethics as largely pragmatic business of formalizing triage and experiment when you cannot save everyone. Unfortunately once institutions become well established they inevitably drift in the direction of securing growth and perpetuation at the cost of their original goals. Hence bioethics).
Some truly reprehensible concepts are trafficked around in bioethics circles regarding aging, longevity, and medicine. The duty to die, the "fair innings" argument for cutting off provision of medicine to the old, suppression of research that might extend life, and so on and so forth. Meanwhile the average fellow in the street is suspicious or disinterested in living longer for entirely different reasons, but were he born a century from now, he would accept his indefinite future healthy life span without question. It's all a matter of culture. When it comes to the talking heads, there is no status quo so horrible that it won't be defended. We don't have to look far to see that; just count the hundred thousand lives lost every day to aging, and the ongoing suffering of hundreds of millions of others that is swept behind the curtains.
Of course one can also find bioethics writers, usually not of the professional sort, who write more favorably on the topic of enhanced longevity through medical science. Even so, the framing of the discussion is all too often one of rules and allowances: who should be permitted, who should be forbidden. Freedom and choice is something of a lost art as our governments grow bloated and every aspect of life is regulated by disinterested bureaucrats. In medicine particularly all that is not explicitly allowed is forbidden, and the effects of the modern biotechnology revolution are muted and suppressed by the enormous and growing costs imposed upon turning laboratory work into therapies.
The search for longevity, if not for immortality itself, has been as old as recorded history. The great strides made in the standard of living and the advances in scientific medicine, have resulted in unprecedented increases in longevity, concomitant with improved quality of life. Thanks to medical progress senior citizens, particularly octogenarians, have become the fastest growing segment of the population and the number of centenarians is increasing, even though in the last two decades, spurred by the bioethics movement, the priority assigned to the prolongation of lifespan has taken a back seat to the containment of health care costs.
Discussions of life extension ethics have focused mainly on whether an extended life would be desirable to have, and on the social consequences of widely available life extension. I want to explore a different range of issues: four ways in which the advent of life extension will change our relationship with death, not only for those who live extended lives, but also for those who cannot or choose not to. Although I believe that, on balance, the reasons in favor of developing life extension outweigh the reasons against doing so (something I won't argue for here), most of these changes probably count as reasons against doing so.
First, the advent of life extension will alter the human condition for those who live extended lives, and not merely by postponing death. Second, it will make death worse for those who lack access to life extension, even if those people live just as long as they do now. Third, for those who have access to life extension but prefer to live a normal lifespan because they think that has advantages, the advent of life extension will somewhat reduce some of those advantages, even if they never use life extension. Fourth, refusing life extension turns out to be a form of suicide, and this will force those who have access to life extension but turn it down to choose between an extended life they don't want and a form of suicide they may (probably mistakenly) consider immoral.
Biological studies have demonstrated that it is possible to slow the ageing process and extend lifespan in a wide variety of organisms, perhaps including humans. Making use of the findings of these studies, this article examines two problems concerning the effect of life extension on population size and welfare. The first - the problem of overpopulation - is that as a result of life extension too many people will co-exist at the same time, resulting in decreases in average welfare. The second - the problem of underpopulation - is that life extension will result in too few people existing across time, resulting in decreases in total welfare. I argue that overpopulation is highly unlikely to result from technologies that slow ageing. Moreover, I claim that the problem of underpopulation relies on claims about life extension that are false in the case of life extension by slowed ageing. The upshot of these arguments is that the population problems discussed provide scant reason to oppose life extension by slowed ageing.
Lastly, as for all political and philosophical fields of discussion there are bioethics debates that run right off the rails and into never-never land. At some point reality is left behind and those involved might as well be building their own sort of secular theology for all the relationship it bears to practical concerns. The paper referenced below is a particular egregious example, but there are many others that come and go on a regular basis.
The value of extending the human lifespan remains a key philosophical debate in bioethics. In building a case against the extension of the species-typical human life, Nicolas Agar considers the prospect of transforming human beings near the end of their lives into Galapagos tortoises, which would then live on decades longer. A central question at stake in this transformation is the persistence of human consciousness as a condition of the value of the transformation. Agar entertains the idea that consciousness could persist in some measure, but he thinks little is to be gained from the transformation because the experiences available to tortoises pale in comparison to those available to human beings. Moreover, he thinks persisting human consciousness and values would degrade over time, being remade by tortoise needs and environment. The value available in the transformation would not, then, make the additional years of life desirable. Agar's account does not, however, dispose of the tortoise transformation as a defensible preference. Some people might still want this kind of transformation for symbolic reasons, but it would probably be better that no human consciousness persist, since that consciousness would be inexpressible as such. Even so, it is not irrational to prefer various kinds of lifespan extension even if they involve significant modifications to human consciousness and values.