Friday, October 07, 2016

Do We Naturally Desire Eternal Life? Or Is the Natural Limit of 115 Years Enough?

Is it natural for us to want to live forever?  If that is so, is there any way to satisfy that natural desire--perhaps through a scientific conquest of nature or through a religious transition into an immortal afterlife?

Or should we see, as I have argued, that we can satisfy our natural desire for a complete life by living out our natural life span as set by our evolved human nature?

Against both the exaggerated optimism of some proponents of biotechnology (like Lee Silver and Gregory Stock) and the exaggerated pessimism of some critics (like Leon Kass and Francis Fukuyama), I have argued (in Darwinian Conservatism and elsewhere) that our evolved human nature will always limit the uses of biotechnology, and that we can see this in how the natural human life span limits any biotechnological quest for ageless bodies.

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 impossible to eliminate the genetic mechanisms for aging, and thus to greatly lengthen the life span, without disrupting other beneficial mechanisms.

The success of modern public health and medicine in extending life expectancy over the past 150 years has been cited as evidence by many people that if we continue in this direction, eventually we can conquer death completely.  And thus the dream of early modern scientists like Francis Bacon and Rene Descartes of how modern science could make us such masters of nature that we might live forever would finally be fulfilled. 

But while we have increased the average length of life, we have not increased the maximum length of life. In contrast to the populations in previous centuries, in which few people lived past 60 or 70, most of us are living into our 80s and 90s.  And yet by age 100, 99 per cent of us will be dead; and by age 120, we will all be dead.  The maximum life span is the same today as it has been for thousands of years.  This confirms the wisdom of God's declaration in the Bible: "My spirit shall not always strive with man, for that he is also flesh: yet his days shall be an hundred and twenty years" (Genesis 6:3).

That was my argument in 2005 in Darwinian Conservatism, and now there is new research supporting that argument in the current issue of Nature (October 6, 2016).  Carl Zimmer has written an article about this for The New York Times.  Jan Vijg and his colleagues have shown that demographic data suggest that there is a natural limit to the human lifespan of about 115 years.  (This confirms the position of S. Jay Olshansky and his colleagues, whose work I cited in 2005.)  Their hypothesis is that if there is no biological limit to the human lifespan, then with improvements in public health, nutrition, and medical treatment, the age group experiencing the greatest increase in survival should be shifting to ever-older groups over time.  They found that the age with greatest improvement in survival got steadily higher over most of the twentieth century, but then it reached a plateau at about 99 in 1980.

They also looked at the age of the oldest person to die in a given year in France, Japan, the United States, and the United Kingdom.  They saw that this increased rapidly between the 1970s and the early 1990s, but then plateaued in the mid-1990s at 114.9 years.  The longest lived human being whose age could be verified was Jeanne Calment who died in France in 1997 at age 122.  But she is an extreme outlier, as indicated by the fact that no one else since 1997 has been verified as living that long.  The oldest known person living today is Emma Morano, aged 116.  This also suggests a natural human lifespan of about 115.

Here we see one of the stunning achievements of liberalism: for the first time in human history, because of the Great Enrichment of the past 150 years, human beings today in liberal social orders have a good chance of living out their natural human lifespan.

Some scientists--like James Vaupel--have raised objections to this idea that there is a natural limit to the lifespan.  The first objection is that even if the age experiencing the greatest increase in survival has plateaued in many countries, it has not yet plateaued in some countries like Japan.  The second objection is that Vijg's demographic research ignores the possibility that future medical research could find new ways to increase maximum lifespan. 

It's hard to respond to such objections that depend upon unpredictable future developments.  But one can say that so far there is no clearly confirmed way for medical science to extend the human lifespan.  One can also say that this is unlikely to happen in the future if the lifespan is controlled by too many genes.

The religious believer in immortality could object, however, that this debate is about only one way to achieve immortality--staying alive indefinitely through scientific technology.  There are two other possibilities proposed by religious believers--immortality through the separation at death of the immortal soul from the mortal body or through the resurrection of the dead body to a deathless body.  Many orthodox Christians combine both forms of immortality, because they believe that at the death of the human body the human soul lives in an afterlife, and then when Jesus returns to Earth, the dead human bodies will be resurrected and reunited with the immortal souls.

Some of my critics--like Peter Lawler--have objected that human beings will never be satisfied with living out their natural human lifespans, and that it is only the prospect of achieving the immortality of body and soul in Heaven or Hell that will satisfy the natural human desire for eternal life.

I am skeptical about whether this is possible or desirable.  Is it possible for my personal identity to live forever as an immortal soul separated from any body or as a resurrected body that never ages?  Would it be desirable to live forever if living timelessly and changelessly would not be really living a human life? Would it be desirable to live forever in an afterlife if most human beings are condemned to eternal punishment in Hell? Or should we assume, as many Christians today do, that all human beings will go to Heaven?

Should we agree with Wallace Stevens that "death is the mother of beauty"?  Does this arise from our evolved human nature as embodied minds that pass through a natural life cycle from birth to maturity to death?

Here, however, is where Leo Strauss and his students object that most human beings cannot live with "the most terrible truth" that "nothing lovable is eternal or sempiternal or deathless, or that the eternal is not lovable" (Liberalism Ancient and Modern, viii, 81, 83, 85, 92, 96, 100, 122-26, 134-35).  Insofar as liberalism embraces evolutionary science, it teaches that not only must all individual human beings die, but even the human species as a whole and the cosmic order of the Earth that makes human life possible must die.  Although this is a scientific truth of evolution, this is a deadly truth that promotes nihilism.  Only philosophers can live with this truth, and so they must hide it from everyone else.

Friedrich Nietzsche accepted evolutionary science in his middle writings--particularly, Human, All Too Human--and argued for a Darwinian aristocratic liberalism based on the truth that "everything has evolved."  Strauss and the Straussians are largely silent about this, because they agree with the Nietzsche of the later writings who saw evolutionary liberalism as a deadly nihilism that must be overcome through a new Dionysian myth that will eternalize human experience by affirming the "eternal basic text of Homo natura." Not death but eternity is the mother of beauty.

Some of these points have been developed in other posts here, here, here, here, here, here, here, here., here., here., and here.


Won Joon Choe said...

Prof. Arnhart,

I think I would have to agree with the argument you attribute to Prof. Lawler: "human beings will never be satisfied with living out their natural human lifespans, and that it is only the prospect of achieving the immortality of body and soul in Heaven or Hell that will satisfy the natural human desire for eternal life." Or at least the vast majority of human beings seek it above all else. The beginning of religious thought is linked to this longing.

Could you perchance refer us to the specific context where Prof. Lawler may have made these remarks? Thank you in advance!

CJColucci said...

If we could live not forever, but for a very long time, like 300-500 years, that would be a problem. Assuming proportionate lengths of time in youth, maturity, and old age, we would face several decades of physical limitations and senility if we got that far. And we might not get that far. If we could live in our physical prime for over a century, someone might play football for 40 years and be a mess afterward. Even if we didn't do anything that stupids, in an active life of two or three centuries, the odds that we would have a fatal fall off a ladder, slice off a limb while using a chain saw to cut wood, or get run over by a bus would be overwhelming.

Jonathan Rowe said...

I wouldn't mind living forever; but I'd definitely want some kind of finite memory of time. Human souls could be eternal in both directions. If that's true, then we've already experienced eternity; but it seems like we've only been around for a shorter period.