Legendary philosopher Peter Singer once imagined a scenario where a pill could double human lifespan, and argued that such a world would never be as happy as one without the medicine. Science fiction author and philosopher Russell Blackford disagrees.
In a paper for last December's Journal of Medical Ethics, Blackford blasts Singer's arguments, arguing that it's not necessarily a foregone conclusion that society would be better off without the miracle drug. The difference is that, while Singer focused on happiness, Blackford zeroes in on the notion of benevolence. And what, you ask, is the difference?
Before we can get into that, it's worth considering precisely what Singer originally imagined. As Blackford explains:
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.
Singer also stipulated that population controls would need to be put in place so that, as the human lifespan doubled, the population was halved. Thus humans, as a group, live for the same amount of total years, but half the individuals do twice the living. In any event, Singer concluded that human happiness would, both over time and at any given moment, be greater in a society that never developed the drug than it would in one that did. As such, it would be wrong to develop the medicine, even if we possessed the knowledge.
Blackford rebuts this not by question Singer's basic assumptions but instead by looking at the situation in a different way. Essentially, he feels that Singer, in keeping with his utilitarian perspective, sought to do the most possible good for the most possible people. Blackford, on the other hands, removes the second part of Singer's analysis, instead considering what would create the best possible lives. In this case, he feels that this approach would lead one to favor the exceptionally long-lived citizens of a world with the miracle drug, even if there were fewer people around to enjoy it.
This is, argues Blackford, the more benevolent policy. He introduces the notion of "total future happiness-years", which is basically the product of multiplying the human population by the human lifespan by the average level of human happiness. While Singer looked to maximize this figure by maximizing the human population, Blackford questions the importance of this product, instead simply focusing on what would most increase human happiness. In any event, both Singer and Blackford present intriguing appraisals of the human costs and benefits of living in a world with greatly increased lifespans.
But what of the miracle drug? What progress are we making on that front? For that, we turn to rogue biogerontologist and noted beard-possessor Aubrey de Grey, who recently spoke on the role of mitochondria in human aging: