If you survey our community, asking in detail about moral and ethical views on medical approaches to extending the healthy human life span, and follow up with opinions on exactly which biotechnologies should be pursued for the greatest benefit, then I suspect that you would be hard pressed to find any two people with exactly the same collection of opinions. There is a great deal of variation, even among those who primarily give their support to SENS rejuvenation research. When it comes to the technology and the prioritization, everyone has their own private SENS variant; a little added here, a little removed there. The same is true of the ethical view regarding exactly why it is that we should enable the choice of living longer for as many people as possible, as soon as possible.
For my part, I'm more or less a utilitarian, minus the part wherein one should be willing to sacrifice N to enable N+1. Ends do not blindly justify means. My utility function tends towards assigning value to time spent alive, to freedom and breadth of choice, and the absence of suffering. I think that a greater number of sentient entities, more capable sentient entities, and less suffering are all good things. The motivation really doesn't have to be any more complex than this. The most sensible approach for any individual who desires to help keep the trend of development moving in that direction is to attack the greatest causes of death, limitation, and pain in descending order. Aging is right up there at the top of the list: the greatest cause of death by far, the greatest limitation on the human condition at the present time precisely because it kills most people, and the greatest cause of suffering. We should do something about that.
The mission of healthy life extension, or healthy longevity promotion, raises a broad variety of questions and tasks, relating to science and technology, individual and communal ethics, and public policy, especially health and science policy. Despite the wide variety, the related questions may be classified into three groups. The first group of questions concerns the feasibility of the accomplishment of life extension. Is it theoretically and technologically possible? What are our grounds for optimism? What are the means to ensure that the life extension will be healthy life extension?
The second group concerns the desirability of the accomplishment of life extension for the individual and the society, provided it will become some day possible through scientific intervention. How will then life extension affect the perception of personhood? How will it affect the availability of resources for the population?
The third and final group can be termed normative. What actions should we take? Assuming that life extension is scientifically possible and socially desirable, and that its implications are either demonstrably positive or, in case of a negative forecast, they are amenable - what practical implications should these determinations have for public policy, in particular health policy and research policy, in a democratic society? Should we pursue the goal of life extension? If yes, then how? How can we make it an individual and social priority?
Quite surprisingly (at least for the proponents of healthy longevity), for decades and centuries, there has been expressed strong opposition to the very idea of life extension. The opposition has been frequent among philosophers, and even among physicians and researchers of aging. There has been a strong tendency among well-established physicians and scholars to consider aging as inexorable and therefore "normal," and to see the lifespan as fixed and immutable. Accordingly, any attempts to "meddle" with the aging process or to significantly extend longevity would be considered foolish, futile and even somehow unethical.
The apparent weight of authority of the critics and skeptics, and the wide popularity of the skeptical views, may emphasize the question: "Is increasing longevity, especially healthy longevity, really desirable, for the individual or the society?" The answer that may be given by the proponents of life extension is very simple: "Yes. People want to live longer and to live healthier." Or to put it even more bluntly, "it is better to be healthy, wealthy, wise and long-lived, than otherwise." And that may conclude the discussion. Yet, some explanations and arguments are still required. Usually, the arguments against extending longevity are standard and are refutable in standard ways. The questions and answers below may provide a short summary of such debates.
Would extending longevity enhance human suffering, or conversely, is death a solution against suffering? No. Death is not a solution against suffering. Suffering is not inevitable. Human beings have the ability to actively influence their fate and relieve suffering. And essentially, the desire to extend life does not imply a desire to prolong suffering, but a desire to prolong health (increase the healthspan).
Would extending longevity lead to extending boredom? Arguably no, as extended life also implies extended ability to learn and change. The sense of boredom does not necessarily depend on the period, and often comes and goes periodically. And generally, the feeling of boredom does not seem to be a sufficient reason to abandon the pursuit of life. And if it is (for some people) - their choices are in their hands, and should not diminish the choices and chances of others.
Would extending longevity make human life meaningless? Arguably no, as life may carry a meaning of its own, independent of death. It is difficult or even impossible to place a temporal limit on the meaning, love and enjoyment of life. Human beings are entitled to choose a prolonged existence, and that choice and pursuit alone may give their life meaning.
Would not extending longevity stop progress, make individuals and societies stagnant? Rather to the contrary, the potential for learning will be increased by longer life-spans, and such a prolonged "cultural adaptation" may be sufficient and necessary for the survival of the society. Moreover, rationally controlled development and care for the survival of the weak may be more advantageous for progress than blind and cruel Darwinian selection.
Are not aging and death from aging natural and inevitable? Does not their acceptance as natural and inevitable give comfort in facing them? Concerning the inexorable "natural" limit to the human life, however comforting a reconciliation with death may be, it should not replace an active quest for life preservation. Almost never is a particular cause of death completely "inevitable," but is always due to some identifiable material agent, and thus subject to prevention or amelioration. There is no limit "set in stone" to either the lifespan or the healthspan.
Would not the life-extending means be made available only for the rich and powerful, or some other select groups? How can we prevent this injustice? Indeed, perhaps the most frequent type of worry relates to the future availability of resources due to life extension. The common assumption is that 'there will never be enough for everybody'. Yet, in any case, the inequality of access does not seem to be a reason to hinder the emergence of new medical technologies, but only to intensify their development. The sooner they emerge, the faster they will likely become available for the people, hopefully for all.
Would not extending longevity lead to shortage of resources for the society, or "overpopulation"? It has been a persistent fear that extending longevity would lead to a shortage of resources for the global population as a whole due to its unsustainable increase. This scenario is also commonly known as 'the problem of overpopulation due to life extension'. Yet, it must be argued that the term "overpopulation" does not simply relate to the number of people on a certain territory. Rather, it indicates the degree of availability of resources, especially food, for people at that territory. And, based on the available evidence and trends of development, scarcity of resources should not be anticipated as a result of increasing longevity. It was calculated already in the 1960s by the Agricultural Economics Research Institute, Oxford, that the agricultural productivity, even at that time, would be more than sufficient to feed 45 billion people globally. Since that time the agricultural capabilities in the developed countries increased dramatically, way ahead of increases in life expectancy or population. The technological capabilities are here to feed the world.
Would not increasing life quantity mean decreasing life quality? In other words, wouldn't we have "too many old sick people"? It must be emphasized that the improvement in life quantity is commonly (though not always) inseparable from the improvement in life quality. A robust organism (similar to a robust machine) as a rule both operates efficiently and for longer periods of time. Essentially, it is the extension of the human healthspan (healthy and productive lifespan) and not just of the lifespan that is pursued in the research and development of new medical means and technologies.
The main obstacle slowing down progress in the development of anti-aging and life-extending therapies is perhaps the immense scientific difficulty of the problem itself. Aging is an extremely complex process, with many uncertainties. Hence, any potential attempts at intervention will yet require a vast amount of careful thought and effort. This does not mean that such attempts should be abandoned. On the contrary - we need to tackle the problem, "not because it is easy, but because it is hard." The payoff from its solution would be too great to abandon. But we need to admit that the problem is difficult and therefore its solution will require strong efforts. People would need to make such efforts, and they are not always willing or ready to make them. Hence one of the major bottlenecks is perhaps the general deficit in the ability or willingness of many people to invest time, effort, money and thought for the development of healthspan and lifespan extending therapies and technologies. Clearly, the more people become supportive and involved for their development, the more resources are intelligently and productively invested in it, the faster the technologies will arrive and the wider will be their availability.