Luke Parrish points me to what is clearly by far the most serious critique of cryonics ever written: a 57-page treatment by Evelina Martinenaite and Juliette Tavenier, presented as a 3rd semester project at Roskilde University in Denmark supervised by Ole Andersen.
December 22nd, 2010
Evelina Martinenaite, Juliette Tavenier
Abstract: The preservation of cells, tissues and organs by cryopreservation is a promising technology nowadays. However, the primary purpose of this science has been diverted to a doubtful technology, cryonics. Cryopreservation techniques are now being adapted with the aim of preserving people’s bodies after death in hope that in the future, medicine will be able to revive them. In this report we analyze both scientific and social issues involved with this technology. We first studied the events taking place in the cells during regular freezing. Various research experiments show that freezing causes damage to the cells. Therefore, vitrification presented by cryonics companies as an alternative, seems to be reasonable. We also looked at all the difficulties of this procedure and at the injuries that such a treatment could cause to the human body. Studies show that the vitrification procedure suppresses the injuries related to freezing but the use of cryoprotectants, although necessary, is toxic to the cells. Organs, such as kidneys, are the largest entities ever vitrified and thawed with success. By analyzing all present scientific data, we conclude that there is a limit to the size of living matter that can be cryonised effectively; therefore we conclude that it is not possible to cryonize an entire human body with the current technology without causing severe damage to it.
A brief response: Yes, cryonic preservation causes all sorts of severe damage far beyond our current ability to overcome; all the damage discussed in this paper is well understood and widely discussed by cryonics practitioners. This paper doesn't seem to quite engage with the central contention of cryonics: that so long as the information that makes up memory and personality is preserved, future technology may find a way to repair the damage caused by cryopreservation. Two distinct paths to this end are widely talked about: molecular nanotechnology, and scanning/WBE. As far as I can tell, no argument is made in the paper that human cryopreservation causes information-theoretic death, and neither of these repair options are discussed at all. As a result, this paper, while it is vastly vastly ahead of the arguments made by other critics of cryonics, is some way behind the arguments already considered and answered by cryonics advocates.
This isn't completely related to your comment, but I worry that some cryonicists (not you, as far as I can tell) have a tendency to use "future technology!" as a stopsign which gives them an excuse to not update on evidence like this. Technically, evidence like this should cause us to decrease our confidence in cryonics by some finite amount, but oftentimes such evidence gets hand-waved away with vauge stopsigns like "nanotech!" (I have a similar problem with the "well, it's better than cremation" argument, which seems to be little more than an applause light.)
There is one part of your comment that I do specifically disagree with: Though cryonics advocates have certainly addressed these arguments, I don't think a paper presenting evidence that vitrification causes "severe damage" to cell tissue can be defused by saying "no argument is made in the paper that human cryopreservation causes information-theoretic death", because "severe damage" implies that some cell tissue (and thus, information) is destroyed by the vitrification process. This is why I argued in the paragraph above that we should be updating (however slightly) on this evidence.
I'm sure there are some people out there who use the argument that way. As I've normally heard it, though, it's definitely not merely an applause light. As far as I know, we currently know of no feasible way even in principle to reverse death after cremation or long-term decay. However, we do know some ways that, in principle, we should be able to reverse freezing damage. We might turn out to be totally mistaken about that, but according to our current best information it seems very likely that we can save more of a person with future technology that is already in the pipeline provided the person is cryonically preserved.
Ergo, based on our current understanding, cryonics is better than cremation. Even if it poisons every cell in my body, at least the cells are there and can be examined in principle to reconstruct me. That's very hard to do with dead bones or ashes.
The only serious argument I can see being formed against cryonics is something that demonstrates that the likelihood of it working is so trivially better than cremation or burial that it doesn't justify the increased cost. This would require a very intense array of evidence against any future technology, including ones we haven't thought of yet, ever being able to reverse damage that must be done in order to enact cryonics on a human being. Either that, or show that some likely future technology will make reversing cremation or burial easier than reversing cryonic suspension.
I can see why this can look like an applause light. In this case, though, I think that's a result of summarizing something with a lot of passion behind it in one sentence.
That said, I'm heavily biased in favor of cryonics. If I'm missing some serious reason I should doubt it, I endeavor to be all ears!
I agree, it's not always used this way.
I think you've hit on something very important--trying to summarize something and express your passion for it at the same time can look a lot like an appluse light, especially if you aren't keeping the inferential distance in mind. Sometimes, though, the person doing the summarizing doesn't actually know the sufficient detail and evidence behind the summary, in which case the summary is pretty much always an applause light (and a mysterious answer). Related: Understanding Your Understanding.
In what direction should we update, though? The total absence of decent criticism of cryonics is to a certain extent evidence in its favour, but it doesn't tell us much about how good the criticism would be if our critics would engage properly. Now we know a little more about that. Overall this paper is about as good as I'd expect from sincere, intelligent, knowledgable people who made a real effort to engage properly with the arguments but didn't come away convinced, so my confidence in cryonics is about the same.
Shouldn't that sort of thing make one less confident given that one cryonic meme is that people who grapple with the arguments become convinced?
Interesting point! But is this proof of "at least two bio students grappled with the arguments and weren't convinced" (not surprising) or "two curious (but otherwise random) bio students grappled with the arguments and weren't convinced" (surprising, should lead to a downward revision)?
I'm not sure they would be allowed to reach a pro-cryonics position. The acknowledgments say "Finally, we would like to thank our opponent group for their pertinent and helpful comments on our work."
EDIT: OK, apparently not.
They clarify this in their reply.
It's possible that the examiners of the report are termed 'opponents'.
You think this may have been a "two groups discuss the two sides of an issue" assignment? I searched "cryonics" at the site with the full paper and found 2 other results, but they're both in Dutch. Google translates one of the titles as "People technosphere - Transhumanism and naturalness" and is about the ethical issues of uploading, and the other is about freezing stem cells.
Their English is pretty good, so I would be surprised if this were some sort of translation error where the line should be more like 'we thank our peer reviewers/copyeditors/reference-checkers/etc.' Taking it at face value, that's what it sounds like - some sort of adversarial process, likely with the others writing in favor (although it's possible the opponent group was only assigned criticism and maybe made up by criticizing multiple paper-groups?).
Someone really should ask, since apparently some of them are on Facebook.
If you look at medicine over the years, it has strongly tended to be able to cure things it used to not be able to cure. For a long time, we couldn't treat smallpox, and then we could, and now nobody suffers from smallpox. "Future technology!" invokes this trend and calling it a stopsign doesn't explain why this trend doesn't apply to cryonics.
Saying "Out of the top 10 fatal health problems, at least one will become easy to cure in the medium-term future." is quite fair given this trend. "This particular currently fatal problem will become easy to cure.", much less so.
Right, which gives us "This particular currently fatal problem has at least a one in ten chance of becoming easy to cure" unless we have some reason to think it won't be the one.
I agree, and I don't think that "stopsign!" should ever be used as a fully general counterargument; it certainly can't be used as an argument against the feasibility of cryonics. In my comment above, I was protesting against "future technology!" being used to pre-emptively end the discussion. Apologies if this was unclear.
It's not a counterargument in any case, at best it invokes an antiprediction. It's a reminder to not stop thinking where it actually is possible to figure more out, which has a pretty general applicability.
We don't need to explain why this trend doesn't apply to cryonics. The complaint is not with the trend, it is with using "future technology" as an answer to specific problems we do not know how to solve. Its not an answer at all, its like saying "we will solve it by solving it...later".
What puzzles me is why people assume the specific question (how) needs to be answered as opposed to the general question (whether).
Because people want to know if the "how" is even possible. But the fact the "how" will depend on technology that hasn't been invented yet arouses a great deal of skepticism.
Why should it? There's plenty of indirect evidence that this is technology that will be invented eventually, if there's a future at all for it to be invented in. There are already three general research paths we know of that can lead to successful reanimation: nanotech, biotech, and uploading. All three of these, in all their various incarnations, would need to fizzle and uniformly continue to produce no results in this area, for hundreds of years before cryonics will have failed. In short, the predictions we're making pretty much have to somehow contradict the laws of physics. They don't have to simply be optimistic in order to fail to happen for hundreds, perhaps thousands of years of rich scientific progress -- they have to be totally bonkers.
So we should just assume that any future technology we would like to imagine is assured of happening, given enough time?
If that is the case then I don't need to waste my time with cryonics because I am assured I will be resurrected in a Tipler Omega Point.
The argument is not that everything that seems possible is inevitable. Rather it is that this particular area of possibility-space is a generally reasonable one given a reasonably allowable timeframe for cryonics patients to be stored. Current advances in printing organs, scanning connectomes, building nanomachinery, etc. are pretty good indirect evidence of that -- provided the loss of structure isn't excessive.
For values of "later" around the 20 or 30 year mark, this is not a very convincing point. But for values of "later" in the hundreds or thousands of years, it has some weight.
Not if it's already taken into account. No double-counting (see One Argument Against An Army).
Cryonauts probably have enough information to reconstruct them to the point where childhood memories can be recovered. I don't think claiming otherwise would be a sensible critique. IMO, sceptics are better off sticking to looking at the costs.
The sections on the science seem pretty good, although they seem to focus too much on some basic and only tangential things where I would personally focus a lot more on cryobiology and what existing species with nervous systems can survive freezing (eg. nematodes).
Section 7, Discussion, is just terrible, though.
This makes zero sense to me. This is either wrong, a risible misunderstanding of free markets, or ignoring the issue of actual harms and losses.
And this would be a bad thing, why? (Also, reasoning from fictional evidence.)
He makes no such thing! This is a tissue of problems, from false choices to fallacy of composition/division.
Oy gevalt. You don't have any such guarantee right now.
Meant by whom? Obviously we aren't adapted, that's what the whole cryopreservatives thing is about! An animal as big as a human, in the evolutionary context, doesn't need to tolerate freezing.
Section 7 also entirely ignores neuropreservation and uploading (which go hand in hand, of course); page 48 is their master list, and most of the points don't apply to neuropreservation (despite their earlier including prices for it) or uploading, or are not particularly relevant (we don't need 100% thaw success rate).
I hadn't read about Isochoric preservation before:
I want to thank these people. Like, give them money, or send them a fruit basket. How do I do that?
Perhaps you could publicize their research? Cite it, link to it etc.
This I have done in spades!
I found them on Facebook and thanked them that way, but I fear that probably seemed more creepy than nice!
"Thank you for presenting strong arguments against a belief that is important to me!" is something that only makes sense on LessWrong. :)
"Thank you for seriously engaging with my beliefs" is something that makes sense much more broadly.
I do think that there is something low-status in the phrasing. "Thank you for taking my beliefs seriously enough to criticize" I would call creepy. I suspect that there is a better way to phrase this. "Thank you for the debate" is a perfectly ordinary statement, but probably not adequate for this situation.
Did they reply?
Martinenaite has now replied very politely, presenting a brief counter to the arguments I give above. I've asked her permission to share her reply.
Not yet; I'll update if they do.
I have permission to share their replies - thanks! Here's the first:
Thank you so much for taking the time to reply. I'd rather have a discussion where others can benefit than in private; would you consider adding this as a comment on my blog, or in some other public forum (eg [this post])? Or if not, do I have your permission to share this reply with others?
Whether or not you decide to take part in further public discussion on this issue, you have advanced the debate far beyond what any other critic of cryonics has achieved, so thank you!