Saturday, December 26, 2009

On Singer and radical life extension

Russell Blackford is a guest blogger for Sentient Developments.


The current (December 2009) issue of The Journal of Medical Ethics contains my paper: "Moral pluralism versus the total view: why Singer is wrong about radical life extension." There, I critique an early 1990s paper by Peter Singer, which argues that we should not proceed to develop a hypothetical life-extension drug, based on a scenario where developing the drug would fail to achieve the greatest sum of universal happiness over time. I respond that this is the wrong test. If we ask, more simply, which policy would be more benevolent, we reach a different conclusion from Singer's: even given his questionable scenario, development of the drug should go ahead. A more pluralistic account of the nature of morality than used by Singer reaches a benevolent recommendation on life-extension technology.

My paper is intended not merely to offer a better solution to the conundrums raised in Singer's original piece, but also to suggest a methodology of much wider value in applied moral philosophy.

The scenario

Singer's argument employs an imaginary scenario in which life extension would not increase, and would actually reduce, the universal sum of happiness or welfare (henceforth, I will refer simply to "happiness") over time. Singer describes a scenario in which an anti-ageing, or life-extension, pill would more-or-less double human lifespans, but the level of happiness enjoyed in the second half of a typical individual's life would be lowered to some (relatively small) extent. He also stipulates that it would be necessary to ensure that fewer people came into existence over time if the life-extending pill were developed and used. Given this scenario, he thinks, we should not go ahead with developmental work on the hypothetical life-extension pill.

More specifically, Singer imagines a scenario in which those who take the drug experience no effect during their early decades of life. However, when they reach middle age, the drug retards further ageing so dramatically as to extend an average life span from about 75 years to about 150 years. During her additional years of life, an individual's health will not be restored to youthful levels, but it will be good enough for a very worthwhile quality of life (similar to the health of people in their sixties or seventies today). An individual may find that life has lost some of its experienced "freshness", and the combination of this (should it happen) with somewhat reduced health will make her additional years less happy than her first 70 or 80 years of life - but not greatly so.

Mark Walker has questioned this scenario elsewhere, suggesting that it is unrealistic to assume that the first 70 or 80 years would typically be happier than the second for those with what he calls "superlongevity". My own approach is more fundamental, as I conclude that Singer gives the wrong recommendation even if we accept all of his stipulated facts.

A further stipulation made by Singer is that resource limitations will require population controls, whether or not the drug becomes generally available, but they will need to be more severe if the pill is developed. Fortunately, Singer tells us, the pill will allow for an increase in average child-bearing age and a lower fertility rate. Nothing in his analysis depends on the exact ingredients of a population policy; rather, his essential point is that it will be necessary to devise an appropriate policy to ensure that only half as many people are born if the life-extension drug is available. I.e., he has in mind a scenario in which the total number of people who will be born and live out their lives over a large number of years will be half what it would have been without the drug. (The fairly simple calculations involved are discussed in my article; suffice to say that Singer is more or less right here, if we adopt all his basic assumptions.)

It is easy to demonstrate that, if we adopt all these assumptions - which Singer evidently regards as constituting a plausible scenario - the total sum of happiness, over a set period of time, is greater in a society without the life-extension pill than a society with the life extension pill. Moreover, the average society-wide happiness at any given moment is higher in the society without the life-extension pill. On the other hand, typical individuals of the future will have better lives in the society with the life-extension pill than in the society without it. This may seem paradoxical, but it is actually quite easy to demonstrate that it is true so long as we make some plausible assumptions. In that case, should we go ahead with developing the drug or not?

Recommendations: Singer's ... and mine

Singer argues that should not develop the drug; I disagree. But here the argument gets complex, and I cannot, in a relatively brief blog post, do justice to the complex issues that I needed a 7000-word article to tease out properly. I agree with Singer that we should take into account the interests of future generations, not just the interests of people who are alive now, but what follows from this?

It appears that Singer wants to maximise what we could call total future happiness-years (I hope the meaning of this is transparent: in any event, it involves multiplying the number of future people by the average number of years they live, and then by their average level of happiness across an entire life). He wants to do this at all costs, even if the people who come into existence have worse lives than the smaller number of longer-lived of people who would have come into existence under a different policy. I find that very implausible. Although Singer offers thought experiments to support his approach to the question, I find them unconvincing (my article explains why in some detail).

We should, I suggest, adopt the more benevolent policy, and we should not think of benevolence as a matter of maximising total happiness-years. In a situation such as the one that concerns us, the choice of the pro-pill and anti-pill versions of Singer's life-extension scenario, we should not try to maximise the overall number of happiness-years. We should try to produce the most fortunate lives.

Moral theories

It may be that utilitarians, such as Peter Singer, are inevitably pushed toward "total-view" thinking - which attempts to maximise the total amount of happiness in the universe - rather than toward a view that we should ensure the best possible lives for those people who will come to exist in the future. As a result utilitarians can, again paradoxically given the sympathies that underly their moral theory, make policy recommendations that are not the most benevolent available.

Unfortunately, all utilitarian theories developed to date contain paradoxes or involve counterintuitive implications. If, however, we take a more pluralistic approach to the sources of our morality, such difficulties vanish. I expect that a considerable diversity of values underpins our actual moral thinking. We care, for example, about the reduction of suffering, about the lives of others going well, and about people being able to live with a certain spontaneity. We value wilderness, art and culture, the quest for knowledge, the existence of complex, creative cultures … and many other things. To at least some extent, we value all these for themselves, not solely because of their further utilitarian effects.

We do not value the largest possible sum of happiness over time ... which can, in principle, be gained by multiplying the number of sentient beings (so long as they have lives that are at least worth living). What we value, rather, is that whatever actual lives come into being should go well. Other things being equal, we value the outcomes that would be chosen, among those possible, by a benevolent decision-maker, not by a decision-maker committed to total-view utilitarianism. As shown by the way Singer has set up his life-extension scenario, these two kinds of outcomes can diverge.


It is clear to me that I should vote to go ahead and develop the life-extension pill - and so, after reflection, should you, and so should Singer. No plausible values are violated by this action; quite the opposite. Far from feeling guilt or regret at having adversely affected another person, or having destroyed or damaged anything precious, an individual who votes to develop the life-extension pill has every reason to feel virtuous. She will have helped to create a world in which lives go better than (more and different) lives would otherwise have.

I am, however, conscious that some readers will find this very truncated version of the argument unconvincing. That may, of course, be because I am wrong! However, it may also be because the issues become quite complicated, and that I really do need the considerably greater length of the full article in The Journal of Medical Ethics to explain them properly. If you have library access, I suggest you look up the original article and the other works cited there.

Otherwise, I can only promise that I will return to similar issues in future writings, perhaps here, but certainly in my own blog over at Metamagician and the Hellfire Club.

No comments:

Post a Comment