Ron Bailey has provided so thorough a reply to Diana Schaub’s piece that, at least in this first blog entry, I have decided to restrict myself to commenting only on Dan Callahan’s essay.
I must begin with Callahan’s title, which he repeats in his conclusion. At the risk of inviting the reciprocal retort, I would ask Callahan to do more careful homework before straying into fields in which he is not expert. Had he done so, he would have discovered that the virtually unanimous opinion of credentialed biogerontologists is that Nature did *not* create aging through natural selection. Rather, it created organs (especially brains) that are very useful but which rely for their function on being composed of very long-lived cells, a structural feature that makes the accumulation of eventually pathogenic molecular and cellular damage inevitable. Ever since then, Nature has been striving to have its cake and eat it too by inventing more and more elaborate systems to minimize the rate of accumulation of that damage — but reducing that rate to zero is thermodynamically impossible for structures with no cellular turnover, so the result seems to be that all species with a brain and a fixed adult body size age just slowly enough that only a small minority of them die of aging in the wild rather than of starvation, predation and so on.
If my use of the word “tragedy” is the voice of youth, it is precisely that type of feature of youth that I seek to extend. I can think of no feature of my present condition more valuable to me than the willingness to aim high, and the refusal to accept the status quo as inevitable. I suspect that those who retain that attitude into old age derive great inner strength from it. Yes, St. Francis said: “Lord grant me the serenity to accept the things I cannot change, the courage to change the things I can, and the wisdom to know the difference.” But Shaw said: “The reasonable man adapts himself to the world: the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.” I say: “Long live the unreasonable man!” — and I mean to give him the chance.
Callahan’s most basic logical error comes with his discussion of the correlation between length of life and satisfaction with life. Someone’s satisfaction with life does not need to keep rising in order to justify helping them to live longer: it just needs to stay above zero. And if it dips dangerously close to zero, whatever the person’s age, if they are in even moderate health we as a society regard them as in need of help and are proud to have organizations like the Samaritans that provide such help.
Actually, maybe his next paragraph rests on an even more egregious logical error. If an extension of lifespan is not the saving of lives, because the person’s age at death will still be finite, then by inescapable extension a treatment that prevented his child from dying in infancy would also not have been saving that child’s life. The phrase “saving a life” means “giving someone the chance to live longer than they would otherwise have had the chance to live.” So, yes indeed, I must and I do claim that a death at age 2,000 would be just as tragic as at age 200, or 20, or 2.
If the fact that people have always died in old age makes such deaths not tragic, then by another inescapable extension the fact that, until 1800, at least 40% of babies had always died before their first birthday meant that those deaths were also not tragic – and, indeed, pre-industrial society pretty much took that fact of life in its stride. But in that case, what happened to make Callahan’s own child’s death tragic? Were babies less human in centuries past? No. Are frequent tragedies less tragic than rare ones (with a nod to Stalin’s aphorism that one death is a tragedy but a million deaths are a statistic)? No. What changed was that a frequent and unavoidable tragedy became a frequent and avoidable one, and thus one that it was no longer rational to rationalize out of one’s mind. And yes, sure enough, infant mortality has since become a rare and largely unavoidable tragedy — and the rarity has allowed us to continue to keep our eyes open to the fact that it is indeed a tragedy. The situation with aging is just the same: we are simply at an early stage in the process, with the realization gradually dawning that it may not be as inevitable as it has always seemed.
Callahan then tries to suggest that we have no evidence that radical life extension would be “good for us as human beings” — and this is where he embarks on the main thrust of his argument, the primacy of society over the individual. First of all, he seems to have a very curious idea of what does and does not constitute evidence for or against a proposition. If the only admissible evidence that something will happen is that it has already happened, I challenge Callahan to tell me why he believes that the sun will rise tomorrow. The true nature of evidence, of course, is that things have happened which have various features in common, and which thereby lend support to a general hypothesis that all things of a particular sort that happen in the future will have a particular property. In this case, the body of evidence is rather formidable: it is hard to find people in good health, of any age, who will volunteer to die tomorrow (and, again, if we do find such people we call the Samaritans).
But, of course, Callahan’s point is not with regard to the individual — it is with regard to “mankind.” This is where he most thoroughly misses the point. Contrary to his assertion, the possibility that we might get bored is perfectly allowed in pro-longevists’ calculations; but we regard it as just that, a possibility, and not a certainty. Callahan is the one who is guilty of the unwarranted assumption — he is so certain that “society” will be worse as a result of having the option to postpone aging indefinitely that the possibility that some people might just buck the trend is not allowed into his calculations.
Callahan’s appeal to Boulding sums up this determination to keep faith — pure faith — in the impossibility of solutions to the societal issues he raises, rather than spend a moment wondering whether such solutions might in fact emerge. It is trivial to outline any number of ways in which the structure of the economy could be adjusted to maintain turnover of personnel within a given industry by sufficiently incentivizing retraining and adult education. Of course such measures would be dramatic — they would constitute a root-and-branch redesign of current economic practice — but that is no less than we should expect in consequence of the elimination of mankind’s greatest remaining scourge. If Boulding really felt that, because he couldn’t see how this might be done, therefore the combined wisdom of the world’s economists will also not be able to do it when the time comes, then he must have had a remarkably high opinion of himself — but I rather suspect that, like Callahan, his thinking on the matter didn’t get that far.