The focus of this article is the technical plausibility of cryonics; though there are many non-technical objections, I’d like to treat the technical issue in depth before moving on to the non-technical.
Though many experts in cryogenics and other relevant fields are quoted in the media as condemning cryonics practice, none have written at greater length to explain their reasons. The closest thing to such a reason I can find is Michael Shermer’s article “Nano Nonsense and Cryonics”, but the reason he gave was one that he knew at the time of writing was contrary to scientific reality, and in response to my email asking where I could learn more he recommended three authors all of whom consider cryonics technically plausible. The only other anti-cryonics expert to respond to my email asking for more detail was John Bischof, but his replies didn’t carry the detail I was hoping for. (See my earlier blog posts A survey of anti-cryonics writing and More on anti-cryonics writing for details). Strikingly, even when the Society for Cryobiology passed their 1982 by-law barring cryonicists from membership, they produced no detail to back up their claim that “it is the Board’s scientific judgement that the prospects for re-animation of a frozen human, particularly a legally dead human, are infinitesimally low.” (see Society for Cryobiology statements on cryonics).
If cryonics really is nonsense dressed as science, this lack of detail is surprising, and in sharp contrast to pseudosciences such as homeopathy, on which volumes have been written pointing out its dodgy provenance, scientific implausibility and evidential defeat. It’s also very frustrating: I’m left trying to make a judgement call on a debate that only one side is participating in.
So this is my plea to the scientific critics of cryonics:
Please criticise cryonics.
If you thought that someone else had done it, if you thought that the article you’d want a cryonics hopeful to read had already been written, I hope that the surveys above show you that it really hasn’t. If it has, and I either haven’t found it or haven’t treated it fairly, I welcome your comments.
I’ve been trying to think about the reasons why someone like David Pegg would feel strongly enough about cryonics to take part in drafting that 1982 by-law using such strong language in his draft statements and his statements to the media on the subject, yet have nothing to say in reply to an email asking what he would recommend I read to see the other side of the argument. The only hint I currently have from critics is this remark in personal email from John Bischof:
I think the distinction is between a tissue being dead vs. alive at the time of freezing. I don’t believe there is anything I can possibly write that would further clarify that distinction.But thinking about that remark, and other suggestions that friends have made on why they don’t see the need for such an article, I’ve thought of ten reasons an expert might give for its absence, and tried to answer them.
- It’s perfectly obvious.
You are experts in your fields; what is obvious to you is not necessarily obvious to everybody. In particular, a lot of us are thinking of the brain as something a bit like a computer, and so it seems perfectly reasonable to imagine that if old bits can sometimes be read from hard drives despite being overwritten, and if Ed Felten can freeze computer RAM chips, take them out, and read the data on them, then maybe someday someone will be able to read out the state of frozen brains with future technology. Part of what is being a good teacher is understanding how others fail to grasp what is obvious to you and being able to make it obvious to them too.
- If you’re crazy enough to need persuading on this score, you’re already beyond the reach of reason.
Have you ever argued with someone who, when you finally persuaded them that everything is not fine, turned around and argued that everything was hopeless? In these instances, it’s striking that they go straight from the region where things are so good that no action is required to the region where things are so bad that no action is worthwhile, without it seems passing through the band where action is a good and worthwhile response.
In this instance, there must surely be people inbetween, who have so far only heard from one side of the argument and perhaps could be won around if they heard from you. You may be convinced despite my protestations that I’m lost to reason, but even in that case, what about the people I’m going to speak to next? I’m going to be using your relative silence on this issue to help persuade them. Please, write for those people.
- You’re asking for a scientific response to an unscientific claim
If so, that’s hardly unusual. Scientists respond to all sorts of unscientific claims; consider the response massed against creationism/”intelligent design”, or against homeopathy or vaccine scares.
Cryonics isn’t hiding in some separate magisteria; it makes claims that science is clearly best placed to evaluate. And cryonics advocates make lots of scientific claims about all sorts of things, like the extent of ischemic or freezing damage, the toxicity of their vitritification solutions, or the likely anatomical basis of memory or personality, all of which are ripe for scientific challenge.
- But the assertion that we will “someday” have the technology to reanimate is completely unfalsifiable
Falsifiability is Karl Popper’s effort to set out what distinguishes a theory that science can examine from one such as the dragon in Carl Sagan’s garage, and the linked Wikipedia article sets out some of the problems with applying this criterion. In practice, future discoveries could certainly put an end to cryonics. If, for example, we came to better understand the mechanism of memory and it were shown that freezing inevitably causes what cryonicists call information theoretic death, that would destroy the practice of cryonics at a stroke.
- It’s like trying to argue with a marshmallow
I know the feeling, and I sympathise. Sometimes for example large parts of an argument can be taken up simply with trying to pin down your counterpart to a claim that can sensibly be debated. As an atheist and skeptic, this is often how it feels arguing with religious people and other supernatural believers. I think of Sam Harris’s memorable line in his online debate with Andrew Sullivan:
I now feel like a tennis player, in mid-serve, who notices that his opponent is no longer holding a racket.From this, though, we see that people do often have some success in arguing with the marshmallow. Harris’s response is exactly one such, and it doesn’t stop there but continues for nearly a further 2000 words; and that’s just one return in a longer discussion. If cryonicists are using the tactics of marshmallow debate, you could do the world a service by calling them on it.
In addition, cryonics advocates make lots of very specific claims. Best’s “Scientific Justification of Cryonics Practice” is full of them, for example. You don’t have to write the Final Great Refutation of Cryonics; refuting any claim made by cryonics firms would be a big step forward.
- Surely the burden of proof is on cryonicists to show that it can be done?
Again, this is true of a great many things that scientists in practice put great energy into arguing against.
The burden of proof is on those who argue for the theory of heliocentrism, but in that instance the burden is not only met but overmet to a truly supendous degree, and now anyone who wants to argue against it has a tremendous burden to meet. Cryonics is of course vastly short of that standard, but you can hardly argue that cryonicists have made no effort to serve this particular ball — there are absolutely reams and reams of material arguing in favour of cryonics. If you don’t feel that it goes any way towards meeting their burden of proof, it seems like it should be possible to say a few words about why.
- Extraordinary claims require extraordinary evidence
Cryonics claims are certainly emotionally extraordinary. The idea that it might be possible to take people who are legally dead today and transport them into a second life in the unforeseeable future certainly knocks most people’s socks off. However, to require extraordinary evidence a claim has to be scientifically extraordinary — it has to be such that were it true, many settled scientific facts would need to be re-examined. If there’s any settled science that cryonics goes against, I’m not aware of it, and would very much appreciate knowing about it.
- How do you criticise “Then a miracle occurs”?
If cryonics really is like the famous “then a miracle occurs” mathematical proof, surely an expert could tell us more about which difficult but reasonable-seeming steps in cryonicists descriptions of possible future means of reanimation hides what is actually a huge chasm of difficulty that it is fantasy to posit we might one day bridge.
The ideal article I’d hope to find on the subject would:
- Explicitly address the best literature of cryonics providers
- Use probabilistic reasoning
- Discuss the question of information-theoretic death
- Discuss both bodily reanimation and scanning/WBE approaches to reanimation
But you don’t have to meet that bar to advance the debate — practically any expert writing on the subject would vastly increase the quality of the pool of anti-cryonics writing out there. If you’ve written for example blog comments that criticise technical feasibility, please turn them into articles that are designed to stand alone; if you’ve nowhere to host them I’m happy to host sufficiently good articles here. The best article I’m currently aware of is that by Chris Patil, for more on which see this discussion; I’m hoping also to get an article out of criticisms my friends have made of the Brain Emulation Roadmap.
It is incredible to me that I can beg cryonics critics for reading material in email and receive so little back. If what you say is true, then thousands of people are spending tens of millions of dollars pursuing a ridiculous dream, and new people are signing up all the time. You could save some of those people from wasting their money and their hope; though you might not believe it, you could even save me. Please, I beg you on bended knee, please actually criticise cryonics.
COMMENT POLICY As before, comments should directly address the subject of this post. If you have a comment to make about cryonics that isn’t specifically to do with what I address here, please sit on it for now; hopefully a future post will be more on topic for those thoughts.