Cryonics, Survival, and the Irreversibility of Death

During a recent trip back home, one of us (Adam) was invited for a tour of the facilities of the oldest and best-known cryonics organization, Alcor (located in Scottsdale, Arizona). It was a highly informative, mostly propaganda-free, visit; there was no hard sell or Kool-Aid to be found (although they do send visitors away with complimentary 3-D printed models of preservation containers or dewars). 

Around the same time, we began working on our new Australian Research Council project dealing with the way technology is changing long-held views about death and immortality. While our current focus is on digital remains of the dead, their reanimation, and notions of survival online, it is nonetheless fascinating to see the continued, and apparently growing, interest in preserving and theoretically reanimating the physical remains of the deceased. Just to mention one example, the southern hemisphere’s first known cryonic preservation occurred earlier this year. A company known as Southern Cryogenics reportedly preserved a Sydney man, who died in his eighties, in the hopes that one day “Patient One” might be reanimated using yet-to-be-invented future medical techniques.

One striking difference between the two types of technology is that at least some cryonics companies are pretty well established and stable, whereas startups promising to preserve and reanimate one’s digital remains have, thus far, been notoriously short-lived. It is still somewhat early days for the digital dead, so time will tell if some services eventually find their footing and reach the sort of relative stability of an organization like Alcor (founded in 1972).

Despite this relative stability and cryonics’ more prominent place in the mainstream public consciousness (even if still usually accompanied by a sarcastic smirk), the technology raises a number of questions, including some that, as philosophers interested in personal continuity and ethics of technology, we find intriguing and troubling. But before addressing what we find philosophically questionable about cryonics, we need to clear up some misconceptions about the practical side of the process.

What is Cryonic Preservation?

A 93-year-old, and still remarkably vibrant, William Shatner was recently asked if he would be open to cryonic preservation, and he responded with some comments about frozen heads. This is a not uncommon mistake, and the first thing we need to clarify is that current cryonic preservation methods do not involve freezing. The problem with freezing human or animal remains is that it involves the formation of ice crystals that can damage cellular structure, which would obviously not be a great development if the goal is to one day bring these beings back to life. Because reanimation (and hopefully rejuvenation, since no one wants to come back in an elderly state) is already such a high bar to clear on the back end, cryonicists want to take whatever steps they can on the front end of the process to keep that bar from getting any higher. 

Thus, instead of damaging a body (or just a head, the cheaper option that comes with its own additional obstacles to reanimation) by freezing it, cryonics companies vitrify it. That is, they bring it into a glass-like state. While gradually cooling the body and artificially maintaining respiration and blood flow to slow cellular degeneration, they remove as much water from it as possible and replace it with a kind of anti-freeze solution. Once the body has been prepared and cooled sufficiently, it can then be immersed in regularly replenished liquid nitrogen at (a molecular activity dampening) −196 °C for the long haul.

This is very likely the end of the story for a preserved corpse because a number of things would have to go very right for it to be successfully reanimated. Setting aside the myriad potential financial and social obstacles, the technological ones are massive and multi-faceted (they might include reversing aging, curing cancer and neurodegeneration, regrowing bodies, transplanting brains, and whatever it is people think they mean by “mind-uploading”). 

Nonetheless, cryonicists are heartened by several recent success stories involving the cryonic preservation of specific human tissues, the use of cryonics techniques in trauma wards, and the reanimation of nearly frozen rats and pigs. But these developments won’t get cryonicists very close to their goal, and so they usually end up relying on very speculative ideas about sophisticated future nanotechnology that could repair and rejuvenate us at the molecular level. Such a “magic bullet” may never materialize to solve all the big problems, but cryonicists are quick to point out that no one can definitively rule out the possibility. And unlike burial or cremation, cryonic preservation is the one (non-supernatural) post-mortem option that offers any chance (however small) of coming back.

So, suppose we could somehow overcome all the technical problems and bring a cryonics patient back to life. As an apocryphal French diplomat is said to have quipped: That’s all fine in practice, but will it work in theory? 

Defining Death

In fact, from both a philosophical and a legal perspective, cryonics comes with a very big catch. To be cryonically preserved, you must first be dead. Otherwise, the preservation process would itself be an act of murder (at least in jurisdictions that don’t condone assisted dying). Interestingly, similar issues arose in the 1960s, with the advent of both organ transplants and the ability to keep patients artificially ventilated after brain activity had ceased. These technologies made it necessary to define death in more precise ways than had previously been the case. In the US, the response was the Uniform Determination of Death Act (UDDA), a piece of model legislation designed to standardize the definition of death across jurisdictions. According to this definition: 

An individual who has sustained either (1) irreversible cessation of circulatory and respiratory functions or (2) irreversible cessation of all functions of the entire brain, including the brain stem, is dead.

As philosophers, of course, we can argue that legal definitions don’t necessarily get the facts right and are designed to settle practical problems rather than carve nature at the joints. (Cryonicists themselves—especially those interested in mind-uploading—gravitate toward the far more controversial information-theoretic definition of death, according to which individuals aren’t technically dead unless it would be impossible for even future technologies to retrieve the data contained in their brain structures. This definition entails that cryonics patients are still alive but raises thorny new problems about the relationship between survival and personal identity.) But even if the UDDA definition is merely conventional or comes up short in certain ways, there’s one element of it that seems rather compelling: irreversibility. 

No Going Back

In 2015, an Iowa prisoner named Benjamin Schreiber suffered a serious medical episode and had to be resuscitated. Four years later, he went to court to argue that, as he had been sentenced to life and as he had died, his sentence was over, and he should be released. The court rejected this argument on the basis that Schrieber was clearly not dead. You can “die,” in the informal sense of your pulse and breathing stopping, and nonetheless survive. But you haven’t really died in the strict sense unless you’re dead—in which case you can’t bring a lawsuit to court. 

And that’s the big philosophical problem for cryonic suspension. If death is, by definition, irreversible, then are the people in cryonic suspension alive or dead? 

Legally, of course, they have to be dead. But if they’re truly dead, and if death is irreversible, then it seems they cannot be brought back to life, and cryonics is doomed. On the other hand, if they can be resurrected one day, thanks to medical technologies we cannot even imagine yet, then it seems they are not, in fact, dead at all.

Things get even weirder when you realize that this would mean that whether someone is alive or dead right now depends not on the state of their body but on future technologies. That seems absurd for two reasons. 

Firstly, if the future is fixed—that is, if everything that is going to happen is already predetermined—then there is a fact of the matter about whether cryonics patients are alive right now. We just can’t know what the facts are until the future gets here. (It’s like saying that there’s already a “winner of the World Cup in 2026,” but we’ll have to wait until 2026 to find out who that is.) If the future is not fixed, however, it seems like whether cryonics patients are alive or not is indeterminate. They are neither alive nor dead, just in suspension, waiting for an outcome that will make them one thing or the other.

Secondly, this makes “alive” and “dead” properties that bodies have not intrinsically but relationally. Think of it this way. There are some properties you only have because of other people: “I’m the second tallest person on my soccer team” is only true because there’s someone else taller than you. As soon as the tallest player leaves, you no longer have the property of being “second tallest.” 

But we take it that “alive” or “dead” are properties that organisms, including humans, have intrinsically, not relationally. The dead are simply dead, not comparatively dead or dead in relation to others. How can whether someone is dead or not, which we take as a basic biological fact about them, depend not upon the state of the body now but upon the state of technology in the deep future?

Does it matter?

You might ask, “Isn’t this just pointless pedanticism? If this technology can bring our loved ones back someday, why would we care whether people in suspension are alive or dead right now?” To which we’d respond: firstly, the word is “pedantry,” and secondly, you’re right, at least in practical terms. We’d also choose survival, metaphysics be damned.

Even so, this discussion also points to the ways in which technology can cause us to rethink even the most basic concepts we build our lives around. We tend to think of “alive” and “dead” as binary concepts, and many of our legal and social practices in fact depend upon this. But what technology can do is show us that the underlying biological facts are messier than our everyday concepts might allow. If cryonicists are right, technology might also cause us to rethink the presumption that death is irreversible (the information-theoretic definition of death replaces it with the somewhat analogous “irretrievable”)—in which case, maybe Schreiber had a point—or that it is an intrinsic, rather than merely relational, property of organisms. Such drastic revisions to our long-standing assumptions about death seem like they could have serious implications for our legal, social, and medical practices, though they are not without philosophical supporters. 

For instance, David Hershenov argues, in a 2003 article, that irreversibility causes more trouble than it is worth in definitions of death. He thinks it is less problematic overall to bite the bullet and allow genuine cases of death to be followed by resurrection than to define death in such a way that there are cases in which it is impossible to determine when someone is dead. As messy as possible resurrection sounds for our legal, social, and medical practices, when faced with the curious case of cryonics, allowing for this possibility can actually have a conservative effect on these practices. Because resurrection after decades or centuries is so unlikely, it does not seem unreasonable to ignore the possibility until/unless it materializes, but excluding irreversibility from the way we think about death helps us avoid the immediate complications of giving up either the “alive or dead” binary or the notion of death as an intrinsic property.

Money Well Spent?

Acknowledging once again the extreme unlikelihood of cryonics paying off raises one final question we ought to address. Is it worth it? Standard responses to this question often rely on analogies with Pascal’s Wager or playing the lottery, but the most straightforward thing to say is that anyone signing up for cryonics is almost certainly wasting valuable financial resources. There’s a reason, apart from academic salaries, why neither of us has signed up at Alcor yet. But is there something wrong with people deciding to spend their money on cryonics? Maybe—but is this really a problem specific to cryonics? We often spend more money than necessary on funerals and burials without too much societal judgment. And indeed, even the most charitable amongst us occasionally throw money at all variety of frivolous nonsense without getting much grief. Some of us amass collections of outrageous hats, and others spend not insignificant portions of their annual salaries on ice cream cakes (we’re not naming names here). Admittedly, cryonics is a more significant expenditure (although there are life insurance options that make it a relatively affordable monthly expense), but in a consumerist, capitalist society, we generally accept that people are free to spend at least some of their resources as they wish. Thus, even if cryonics will almost certainly not pay off, thinking of it as a very expensive burial seems like a largely unobjectionable and non-self-deceptive approach.