Tuesday, October 29, 2013

Do We Really Want to Live Forever?

It's easy to believe in immortality, but only as long as one doesn't think much about it.

That's the conclusion that I draw from Stephen Cave's book Immortality: The Quest to Live Forever and How It Drives Civilization (Crown Publishers, 2012), which is a thoughtful survey of the various ways to immortality, of the reasons why they are all illusions, and of the reasons why we should accept our human mortality without being crippled by fear of death.  Cave has drawn much of his reasoning from two books--Corliss Lamont's The Illusion of Immortality (first published in 1935) and Immortality (a collection of writing on the subject edited by Paul Edwards and first published in 1997). Cave's book helps me to extend and clarify what I have said in previous posts about the Darwinian assessment of the human longing for immortality. 

Some of my critics (Peter Lawler, for example) have argued that Darwinian science cannot account for the uniquely human anxiety about death and yearning for immortality.  Darwin freely admitted "that no animal is self-conscious, if by this term it is implied, that he reflects on such points, as whence he comes or whither he will go, or what is life and death, and so forth" (Descent of Man, Penguin Classics, 105).  And yet he thought that this uniquely human self-consciousness in reflecting on the meaning of life and death could be explained as emerging from the natural evolution of human cognitive capacities. 

As Cave explains it, we can see the evolutionary advantages of human self-consciousness and imagination, which promote an intense concern for our self-preservation and well-being while picturing all the threats to our lives that might lie in the future, which thereby allow us to plan how best to protect our existence.  But excessive concern for the self and excessive concern with future threats can lead us to obsess about our mortality and to fantasize about immortality in ways that blind us to the fact that worrying about death is foolish.

To reach this conclusion, we need to see that all of the ways to immortality are nonsensical and that there is wisdom in accepting human mortality.  Cave distinguishes four ways to achieve immortality and one way to achieve a wise acceptance of mortality.  He shows that all four of the ways to immortality were imagined in ancient Egypt and that the sensible acceptance of mortality is evident in a tradition of "wisdom literature" that began in ancient Sumer.

The first way to immortality is what Cave calls the Staying Alive Narrative.  We could become immortal if we could put off aging and death indefinitely.  In every civilization, there are stories about the search for the elixir of life--for some substance or technique that would keep one alive forever.  In the Gilgamesh Epic--perhaps the oldest piece of literature that has survived--Gilgamesh goes on a quest for the secret of immortal life.  In ancient Egypt, there was an elaborate system of medicine and magic directed to prolonging life and slowing aging for as long as possible.  This quest for staying alive forever continues today in the hopes of those who believe that modern science will inevitably allow us to extend life to the point of conquering death, which was one of the promises of early modern science coming from people like Francis Bacon and Rene Descartes.

This will to live forever is rooted in our evolutionary nature.  Like all living beings, human beings have evolved to preserve and reproduce themselves.  Human beings are unique, however, in that their evolved cognitive abilities for conceptual abstraction, cultural learning, and imaginative projection into the future allow them to imagine how they might achieve immortality.

While most of us today recognize the futility of the ancient quest for staying alive forever, some of us see evidence that modern science will eventually succeed in this quest.  First of all, it is evident that modern science has already extended our average lifespan.  Over the past two centuries, the scientific understanding of microbial infection has brought improvements in sanitation and medical vaccination, and the discovery of antibiotics has allowed us to fight infectious diseases.  As a consequence, life expectancy doubled in one century.  Recently, life expectancy in the most developed countries has been increasing by a few years each decade.  Projecting this trend into the future seems to some people to be the scientific way to immortality.

And yet there are lots of scientific reasons for thinking that we might be reaching the natural limit of the human lifespan.  Medical improvements might eventually allow most human beings to live to something around 122 years, which is the longest lifespan of any person on record (the Frenchwoman Jeanne Calment).  But this is not immortality.

As I argued in Darwinian Conservatism, senescence--the process of bodily decay at older ages--is probably so deeply rooted in the adaptive complexity of our bodies as shaped by natural selection that it cannot be abolished by biotechnological changes.  It is likely that aging is controlled by so many genes interacting in such complex ways that it would be hard to eliminate the genetic mechanisms for aging, and thus to greatly lengthen the life span, without disrupting other beneficial mechanisms.

A few years ago, 51 leading scientists who study aging published a statement in Scientific American declaring that there was "no truth to the fountain of youth."  They reasoned that "it is an inescapable biological reality that once the engine of life switches on, the body inevitably sows the seeds of its own destruction."  Since there is no scientifically proven way to change the process of aging, "the prospect of humans living forever is as unlikely today as it has always been."

One plausible evolutionary explanation for senescence has been offered by biologist George Williams.  Genes commonly  have more than one effect.  A gene might confer great benefits at young ages but have such harmful effects in old age that few people could live past 100.  In the environments of evolutionary history, most people probably died (from accidents and other causes) long before they could even get close to age 100.  In those conditi9ns, this gene would spread by natural selection because people would enjoy its beneficial effects in youth, in ways that would enhance their reproductive fitness, while few people would have lived long enough to experience the gene's bad effects.  The accumulation over evolutionary history of such genes that are beneficial in youth but harmful in old age might explain the aging process.  The general idea is that the evolutionary economy of nature works on the principle of trade-offs between costs and benefits.  To get youthful energy, we must accept senescent decline.  Williams suggested that we should find consolation in the thought that "senescence is the price we pay for vigor in youth."  Instead of longing to live forever, we should live the life we have as fully as we can until we reach our completion.

We cannot say that it is absolutely impossible for science to extend the human life span indefinitely, but we can say that this is highly unlikely.

Even if the indefinite extension of healthy life were made possible by medical means, this would not give us immortality, because we would still be subject to accidental causes of death.  A few years ago, aging researcher Steven Austad calculated that if we were free from aging and disease, our average lifespan would be 5,775 years.  He did this by extrapolating from the survival rates for nine-year-olds in the United States, because they are least likely to die from illness.  Living for five or six thousand years might sound pretty good, but it's not immortality.

If keeping our bodies alive forever seems improbable, then we need a backup plan.  The ancient Egyptians carefully preserved corpses through mummification so that they could reanimated in the afterlife.  This is the second way to immortality--the Resurrection Narrative--which became part of the Christian tradition through the influence of Paul in the New Testament.

To be continued . . .

1 comment:

Troy Camplin said...

We have a cognitive "error" in which we overattribute. It makes perfect sense, though, that we have this error. Better to mistake the bush for a lion than the lion for a bush. Our tendencies toward animism and anthropomorphization stem from this. So, too, our tendency to think that all order requires there to be an orderer (better to mistakenly think a hostile tribe is nearby than to mistakenly think they are not), from which we get physical and biological and economic creationism (the last called socialism). Finally, we overnarrate our lives into the future, past any realistic physical future, and into eternity.