A Skeptic’s Guide to Cryonics

Can a case for cryonics be made on skeptical grounds? If we’d have to believe self-identified skeptics this is not only unlikely but cryonics, in fact, is a “logical” target for skeptical scrutiny. The most obvious approach for a skeptic is to demand “proof ” for cryonics. Upon closer inspection, this apparently reasonable demand is rather odd. Let’s start with a non-controversial definition of cryonics: cryonics is a form of critical care medicine that stabilizes critically ill patients at ultra-low temperatures to allow the patient to benefit from future advances in medicine. Now, what could this demand for “proof ” consist of? Does the cryonics advocate need to provide proof that future developments in medicine will indeed be capable of treating the patient? How could such a proof be even remotely possible? The most scientifically responsible answer would be to say “I don’t know.” And this answer reveals something important about cryonics. The decision to make cryonics arrangements is a form of decision making under uncertainty. Asking for “proof ” for such a decision makes little sense.

“Now wait a second,” someone might add. “It is correct that we do not have absolute knowledge about the future but, surely, science must have some kind of bearing on the question of whether it is rational to make cryonics arrangements?” This much can be admitted. And if we actually look at the science (or the history of medicine) that is relevant to make informed decisions about cryonics we find a number of encouraging observations. Medicine is increasingly recognizing the rather arbitrary nature of death. From the first clumsy attempts to restore circulation and breathing in patients with sudden circulatory arrest to today’s sophisticated protocols that employ aggressive CPR, hypothermia, and emergency cardiopulmonary bypass, our ability to resuscitate people from states in which they would have been previously been considered “dead” is moving towards ever-longer periods of circulatory arrest. In fact, in some advanced medical procedures, hypothermic circulatory arrest is deliberately induced. Such developments are backed up by histological research where it has been established that the neuroanatomical basis of identity does not just implode within 5 minutes of circulatory arrest. Observation of nature also supports the view that cessation of metabolism does not equal death.

“Well, I will admit that science and technology are constantly challenging our beliefs about death but the cryopreservation process itself causes irreparable injury to the patient,” is a common rejoinder to this argument. But this puts our skeptical friend in a rather incoherent position. Having first recognized that we cannot have absolute knowledge about the future capabilities of science, (s)he does not feel the slightest contradiction in claiming that certain kinds of damage cannot be repaired by any future medical technology.

Contemporary cryobiology now informs us that if cooling rates are not too rapid, ice formation does not explode cells from the inside, that ice-free cryopreservation (vitrification) is possible, and that mammalian brain slices can be vitrified and rewarmed with good ultrastructural preservation and viability. The situation is even better than what we might hope for because even if the damage associated with cryopreservation was substantial, it might still be possible to infer the original state from the damaged state. As we are increasingly recognizing in such diverse fields such as forensic science and paleogenetics, it is actually very, very hard to destroy information to such a degree that nothing meaningful can be inferred from what is left.

Then why has cryonics traditionally gotten such a poor reception by people who see themselves as “skeptics?” I suspect that some of it has to do with the fact that cryonics is traditionally associated with (religious) concepts such as immortality, very optimistic projections about the accelerating growth of science and technology, the technical feasibility of specific repair technologies (such as molecular nanotechnology), or mind uploading. But none of these ideas is an intrinsic part of the idea of cryonics. In its most basic form cryonics is just the recognition that what might be beyond the scope of contemporary medicine may be treatable in the future. No specific timeframe or technology is implied, or necessary. There are a lot of things that people in liquid nitrogen don’t have, but one thing they do have is time.

Contemporary science can weaken or strengthen the case for cryonics but it cannot tell with absolute certainty what our medical capabilities in the remote future will be. Saying that some kind of damage cannot be repaired by any future science is not an exercise of critical thinking but ultimately an appeal to authority. How many times do we have to revise our views about death and forecasting before we recognize that we are playing a fool’s game and that the proper, skeptical, approach is to refrain from dogmatic statements and naïve inductivism about such matters? The idea that, right here, right now, in 2013, we are at a time where we can make absolute certain claims about the future capabilities of science and technologies is preposterous. In absence of such knowledge we’d better refrain from doing harm and allow for the possibility that time will be on the side of cryonics patients.


A “Skeptic” on Cryonics: A Brief Case Study

Self-identified “skeptic” Dr. Michael Shermer wrote a column called “Nano Nonsense and Cryonics” (Scientific American, Sept. 2001) that includes a sensationalist description of cryonics with a number of factual errors:

“Cryonicists believe that people can be frozen immediately after death and reanimated later when the cure for what ailed them is found. To see the flaw in this system, thaw out a can of frozen strawberries. During freezing, the water within each cell expands, crystallizes, and ruptures the cell membranes. When defrosted, all the intracellular goo oozes out, turning your strawberries into runny mush. This is your brain on cryonics.”

Since the early days of cryonics, standard procedure has been to circulate a cryoprotectant through the circulatory system of the patient to reduce ice formation. In fact, when Shermer wrote his column the Alcor Life Extension Foundation had not only published a study that showed good histological preservation of the brain with a high concentration glycerol solution but had also introduced the newer technology of vitrification to eliminate ice formation completely. Shermer’s description of the effects of ice formation on cells is factually incorrect too, as anyone who would just casually study modern cryobiology could have discovered. Finally, one does not need to have a detailed understanding of cryonics protocols to realize that the fate of a thawed frozen brain has little to do with the resuscitation scenarios envisioned for molecular repair of the cryopreserved brain.

One can only speculate why Shermer did not inform himself about some basic facts about cryonics and cryobiology. One explanation is that there is no “cost” to being wrong about cryonics. If Shermer would make such careless statements about physics or chemistry his reputation would be much more likely to take a blow because there are numerous people who would identify these errors.

Shermer also ridicules the immortalist and transhumanist activists associated with cryonics:

“I want to believe the cryonicists. Really I do. I gave up on religion in college, but I often slip back into my former evangelical fervor, now directed toward the wonders of science and nature. But this is precisely why I’m skeptical. It is too much like religion: it promises everything, delivers nothing (but hope) and is based almost entirely on faith in the future.”

Such a perspective confuses the subculture of cryonics with the idea of cryonics itself. You can read religious aspirations into cryonics but you can also ignore them to look at the idea in its most charitable form.

Cryonics is an experimental medical procedure that allows people that cannot be sustained by contemporary medical technologies to reach a time when a treatment for their condition may be available. Such decision making under uncertainty has nothing to do with “faith” and “hope” but requires that we update our probabilities based on the available evidence from fields such as neuroscience, cryobiology, and molecular nanotechnology. While Shermer has later (rather unsuccessfully) attempted to qualify the statements made in his original article, his column is rather representative of how many critics of cryonics operate; mischaracterize its premises and procedures, avoid a discussion of the technical feasibility of molecular repair, and change the subject to psychological and philosophical issues.

Originally published as a column in Cryonics magazine September 2013