Stephen Cave is the author of an interesting book on the relationship between the desire for immortality and the rise of civilization. In this short op-ed, however, his argument against the plausibility of radical life extension through progress in medical technology is a bad one, amounting essentially to "it hasn't happened yet, so it won't happen."
This is the hallmark of someone who doesn't have a good appreciation of the present state of scientific knowledge. Firstly, these are the opening years in a revolutionary leap in the capabilities of biotechnology and medicine: the speed of progress is far more rapid now than it has ever been. Secondly the SENS research program is a plausible, detailed path to halt and reverse degenerative aging, and could be completed in a couple of decades given sufficient funding. The logical outcome of working SENS therapies is that in the future people will live for thousands of years - and the timeline for development means that some of those people are alive today.
But there are plenty of folk who for various reasons don't want to hear any of that, and would rather just reject it all out of hand instead of taking a serious look at the evidence:
There is a dangerous idea gaining ground in our culture. It spreads with every headline that promises a cure for cancer or celebrates the discovery of a "gene for longevity". The idea is that science and technology can make us live forever. [You] will be familiar with the prophets of this movement: men such [as] Ray Kurzweil, who promises immortality by mid-century, or Aubrey de Grey, who says we will soon be living for 1,000 years. They claim that the progress we have seen in life expectancy in past centuries can be extended, even accelerated, until ageing, disease and death are defeated for good. One problem: it's not going to happen.
The ancient Egyptians thought they had cracked it 4,000 years ago. Two millennia later, China's First Emperor was convinced an elixir was within his grasp. Since then, sages and scientists have believed they could develop a potion that would turn back the clock. You may have heard about Harvard medical professor Charles-Édouard Brown-Séquard's theory that injecting extract of dog testicles would grant eternal youth; or the double Nobel Prize-winning Linus Pauling's campaign for vitamin C as the panacea for all our ills. All these believers have had one thing in common: they are now pushing up daisies.
Believers argue that the precedent of the past is not a good guide to the future - progress, after all, has never been more rapid. But the reality is that as our population ages, we are beginning to see the full extent of the toll time takes on us. One demographer has estimated that curing all cancers, heart disease and stroke - currently the three biggest killers in developed countries - would only push up life expectancy by 15 years as our body is crumbling anyway. There are many other Malthusian monsters waiting to finish us, from our own tendency to over-indulge in sugar and salt to our microbial enemies, who evolve as rapidly as we do. Surviving is not something that can be done by drinking a magic elixir: it must be done every minute of every day. And in the end probability will always be against us.
Present day medicine does nothing to change the root causes of age-related conditions. Patching over the damage of stroke does nothing to stop the next stroke, and successfully pushing a cancer into remission does nothing to address the DNA damage that progressively raises the odds of the next cancer occurring. The only way to live much longer than we do now is to repair the cellular and molecular damage that causes these conditions to exist, and also causes people to be old. This is a new approach to medical therapies for a new age of biotechnology. People like Cave have seen radical advances in medicine in their lifetimes - why are they so resistant to the idea that radical advances continue to take place?