For decades, molecular nanotechnology has occupied an ambiguous position in discussions about cryonics. The ability to manipulate matter with atomic precision would seem to provide the kind of technology required to repair severe ischemic and cryopreservation injuries. Yet detailed proposals for molecular repair have remained largely theoretical and, following the Drexler–Smalley debate, have often been dismissed as chemically implausible.

The central issue in that debate was not whether molecular manufacturing would require many reactions, specialized tools, error correction, automation, and systems integration. Eric Drexler never denied this. The dispute concerned a more fundamental question: do physics and chemistry permit reliable mechanical and positional control of molecular reactions, particularly outside the aqueous, enzyme-mediated environment of biology?

A recent series of papers from CBN Nano Technologies begins to answer that question experimentally. Researchers have developed surface-bound molecular tools, introduced inverted-mode scanning tunneling microscopy (inverted-mode STM), removed selected hydrogen and silicon atoms, deposited carbon fragments at chosen sites, and formed carbon-carbon bonds through repeated mechanical operations.

Robert Freitas and Ralph Merkle are coauthors and conceptual contributors to the three principal inverted-mode STM papers. Their involvement connects the experimental program to more than two decades of theoretical work on mechanosynthetic tools, carbon-dimer placement, reaction trajectories, failure modes, and minimum reaction sets for atomically precise manufacturing.

The experiments do not constitute a molecular assembler or demonstrate medical nanorobots. Their significance is narrower but still considerable: designed molecular tools can now perform a small but growing set of reproducible covalent operations at selected atomic sites.

From Moving Atoms to Controlled Chemistry

Scanning tunneling microscopes have been used to move atoms and molecules since the pioneering IBM experiments of the late 1980s. Subsequent work enabled atomic patterning, hydrogen removal from silicon, dopant placement, and surface reactions. The deeper challenge was not whether atoms could be moved, but whether covalent chemistry could become predictable and reproducible enough to support manufacturing.

In conventional STM, the apex atoms of a sharp metallic probe participate in both imaging and manipulation. Their exact structure and chemistry may be uncertain, and the tip can change during an experiment. This becomes a serious limitation when the probe is intended to function as a standardized chemical tool.

Inverted-mode STM reverses the arrangement. The moving mechanical probe presents a comparatively broad crystalline silicon surface. Tall, rigid molecules attached to the opposing substrate act as both imaging tips and chemical reagents. As the moving silicon probe scans across one of these stationary molecular tips, the electronic interaction between the molecule and the probe apex maps the topography of the build site, creating a sharp atomic-scale image.

This makes it possible to inspect a location, perform a reaction, examine the result, and revisit the same site with another tool. The innovation is therefore not simply improved imaging. It is an experimental platform for repeated, inspected chemical operations at the atomic scale.

The precursor paper, “Molecular Tools for Non-Planar Surface Chemistry,” introduced the molecular architecture behind this work. The tools attach to a surface through several legs while presenting a protected reactive group away from it. A rigid central structure constrains their orientation, and activation exposes the chemically active end.

Not every deposited molecule adopts the required configuration, so suitable tools must still be identified by their imaging signatures. Nevertheless, the central principle was established: a molecule can function as a localized chemical instrument.

This is important because atomically precise manufacturing would not depend on one universal nanoscale hand. Instead, much like a modern multi-tool CNC machine or a robotic assembly line, it relies on a modular repertoire of specialized tool-tips. It requires distinct tools for adding material, removing it, transferring particular groups, forming selected bonds, and verifying the results.

Three Experimental Breakthroughs

Mechanical Hydrogen Abstraction

The first dedicated inverted-mode STM paper demonstrated the removal of individual hydrogen atoms from a hydrogen-passivated silicon surface.

A molecular tool was activated by removing a protective iodine atom and aligned with a selected hydrogen atom on the silicon surface. During the transfer itself, the electrical bias was reduced to zero and the silicon probe surface was brought down mechanically to contact the localized molecular tool.At sufficiently close range, the hydrogen transferred to the molecular tool, leaving a reactive dangling bond at the chosen position.

The researchers reported successful hydrogen abstraction in 27 of 28 trials.

Hydrogen removal from silicon was not unprecedented. What was new was the combination of a designed molecular reagent, a selected atomic target, a mechanically initiated reaction, and inspection of both the altered tool and the modified surface.

Adding Carbon and Forming New Bonds

The second paper moved from subtraction to additive fabrication.

Pairs of reactive sites were prepared on the hydrogenated silicon probe apex. Activated substrate-bound tools then transferred two-carbon fragments to those selected locations on the probe, producing the intended initial structure in more than 90 percent of attempts.

Multiple carbon units could be placed in predetermined patterns. More significantly, a second carbon fragment could be added to one already present, producing a new carbon-carbon bond and a four-atom carbon structure.

The longest continuous carbon structure demonstrated was only four atoms. This is not a diamond lattice or a new bulk carbon material. But it established a sequence central to positional mechanosynthesis: deposit a fragment, retain it at a chosen site, return with another fragment, and form a larger covalently bonded product.

The yield declined as the sequence became more complicated. A reaction that succeeds 90 percent of the time is impressive chemistry but inadequate for structures requiring thousands or millions of operations unless failures can be detected, corrected, or avoided. This in situ imaging capability offers the beginnings of such a feedback process because each product can be inspected before the next operation.

A Specialized Tool for Removing Silicon

The third paper explored both carbon donation and silicon-atom abstraction on an unpassivated silicon surface.

With the original tool, either reaction could occur: the carbon fragment might be deposited, or a silicon atom might be pulled from the surface. The researchers then redesigned the molecule by changing its central atom and shortening its supporting legs.

The resulting tool strongly favored silicon abstraction. Under the reported conditions, it removed silicon in all 63 tested operations at 4 K and all 100 tested operations at 77 K, with no carbon donations observed.

This result applies to one tool, one broad target geometry, and a limited set of trajectories. Its deeper significance is that changing the molecular architecture changed the preferred chemical outcome. Selectivity could be engineered into the tool itself.

The researchers used it to remove individual silicon atoms and create small vacancy patterns. When one operation left an unwanted silicon atom on the probe's build site, they identified and removed it in a subsequent step. This is a rudimentary form of error correction: inspect the result, identify the defect, perform a corrective operation, and reinspect the site.

Operation at 77 K (-196°C) is also notable. It remains cryogenic and requires ultra-high vacuum, but it is considerably less demanding than operation near 4 K (-269°C).

Expanding the Reaction Set

Conference abstracts indicate that the next stage of the program concerns hydrogen-containing carbon groups such as C₂H and C₂H₂.

This represents more than another carbon-deposition experiment. A bare two-carbon fragment is symmetric, whereas an asymmetric group like C2​H possesses inherent chemical directionality. Controlling not just the placement coordinate, but the structural orientation of these asymmetric building blocks, is a prerequisite for constructing complex, non-planar molecular components.

Other manuscripts in preparation concern the characterization of carbon radicals and alternative methods for producing the same surface structures. The research program therefore extends beyond the manipulation experiments themselves to molecular synthesis, surface chemistry, theoretical modeling, product identification, and tool design.

From Theory to Experiment: Drexler, Freitas, and Merkle

The current research has several related intellectual origins.

In Nanosystems: Molecular Machinery, Manufacturing, and Computation (1992) Drexler described how rigid molecular machinery could position reactive groups, constrain their motion, and favor selected reaction pathways without requiring miniature hands that grasp isolated atoms.

The relationship with Freitas and Merkle is more direct. Both are coauthors of the three inverted-mode STM papers and are credited with contributing to their conceptual development. The present work is partly the experimental continuation of a research program in which they remain active participants.

Beginning in the early 2000s, Freitas, Merkle, and their collaborators studied proposed tools for transferring carbon dimers to selected sites on diamond surfaces. Their theoretical and computational work examined tool structures, reaction pathways, hydrogen abstraction, tool recharging, failure modes, and the minimum operations needed to construct increasingly complex carbon structures. They subsequently advanced this program through the Nanofactory Collaboration and patents associated with CBN Nano Technologies.

Revisiting the Drexler–Smalley debate

The Drexler–Smalley debate concerned whether chemistry permits the positional control required for molecular manufacturing. Richard Smalley argued that mechanically directed synthesis encountered “fat fingers” and “sticky fingers”: too many atoms would need to be controlled simultaneously, and a reactive fragment held by a tool could not reliably be released at its destination. Drexler replied that his proposals involved positioning bonded reactive groups, not manipulating each atom with a separate mechanical finger. Geometry, constrained motion, and competing reaction pathways would determine the result.

The inverted-mode STM experiments provide substantial support for Drexler on this central point. A molecular tool can be positioned over a selected site and used to alter a particular covalent structure. Carbon can be held during positioning and then transferred to silicon. Other tools can remove hydrogen or silicon atoms. Redesigning the tool can change the dominant reaction from mixed donation and abstraction to highly selective abstraction. In these limited systems, the “fat finger” and “sticky finger” problems have proved to be design problems rather than fundamental prohibitions.

This does not establish that a general molecular manufacturing system can now be built. The reaction repertoire remains small, the operations are serial, and the tools are altered during use. But these limitations do not show that mechanically directed positional chemistry is incoherent. They define an engineering program involving a larger reaction set, tool reloading, improved reliability, automation, error correction, parallel operation, and the construction of useful three-dimensional products. Drexler’s core claim—that physics and chemistry permit molecularly precise mechanical control—has now received significant experimental support.

Mechanosynthesis and Cryonics Revival

The cryogenic, tightly controlled conditions of inverted-mode STM may seem to limit its relevance to manufacturing or medicine. The experiments use prepared silicon surfaces, ultra-high vacuum, and liquid-helium or liquid-nitrogen temperatures.

But the conditions needed to develop or manufacture a machine (or its parts) are not necessarily those in which the finished machine must operate. Semiconductor fabrication relies on vacuum chambers, clean rooms, elevated temperatures, and carefully controlled chemistry, while the resulting devices function in ordinary environments.

For cryonics, low-temperature operation may also be less alien than it first appears. In Cryostasis Revival, Freitas proposes that the initial scanning and repair of a cryonics patient would deliberately occur at cryogenic temperatures to avoid disturbing an already fragile molecular state.

Low temperatures suppress diffusion, spontaneous reactions, autolysis, and other structural changes. A patient would be examined and stabilized without first exposing the surviving structure to normothermic biological temperatures. Premature warming could reactivate damaging processes before the tissue had been mapped or repaired.

Cryogenic operation may therefore be useful, or even necessary, during the earliest stages of revival. The first objective would not be to restore normal metabolism immediately, but to stabilize and record the information embodied in the preserved structure before controlled warming.

The present experiments establish several categories of operation relevant to molecular reconstruction: identifying atomic sites, removing selected atoms, adding fragments, forming covalent bonds, inspecting products, and correcting errors.

Future machines would not necessarily need to reproduce the exact environment or architecture of the current STM apparatus. They might be constructed under highly controlled conditions but designed to function in solid cryogenic tissue, aqueous environments, or transitional states during gradual warming.

The distance between manipulating a few atoms on silicon and repairing a human brain remains enormous. A revival system would also require sensing, computation, transport, energy management, waste removal, and the preservation or reliable inference of identity-critical neural information, topics extensively discussed in Cryostasis Revival.

One component of the broader reconstruction scenario—positionally controlled covalent chemistry using designed molecular tools—now has a stronger experimental foundation.

This is not a reason for complacency about current cryopreservation injury. The possibility of future molecular repair does not justify avoidable ischemia, ice formation, cryoprotectant toxicity, dehydration, or fracturing. Better preservation remains the most reliable way to reduce the burden on future repair technologies.

An Emerging Experimental Science

This research invites two opposite exaggerations. One is that molecular assemblers and medical nanorobots are now inevitable. The other is that the experiments are irrelevant because they are slow, cryogenic, and limited to a few atoms.

The more useful question is whether the experimental vocabulary continues to expand. Can tools be reloaded? Can more elements and functional groups be transferred? Can longer, branched, ring-shaped, or three-dimensional structures be built? Can errors be corrected automatically? Can the process be parallelized and independently replicated? Can it produce assemblers and machines intended for environments different from those required for their construction?

The answers will determine whether inverted-mode STM remains a specialized form of surface science or develops into a more general platform for atomically precise fabrication.

Researchers can now identify an atomic site, position a molecular tool, remove an atom, deposit a molecular fragment, form a bond, inspect the outcome, and attempt a correction. This is not yet molecular manufacturing, but it is credible evidence that an experimental science of positional mechanosynthesis is beginning to emerge.

References

Barrera et al. “Inverted-Mode Scanning Tunneling Microscopy for Atomically Precise Fabrication.” 2025.

Blue et al. “Towards Atom-by-Atom Fabrication: Mechanosynthetic Donation and Abstraction.” 2026.

Cowie et al. “Atomically Precise Mechanosynthesis of Carbon Structures on Hydrogenated Si(100) by Inverted-Mode STM.” 2026.

Drexler, K. Eric. Nanosystems: Molecular Machinery, Manufacturing, and Computation. 1992.

Drexler, K. Eric, and Richard E. Smalley. “Nanotechnology: Drexler and Smalley Make the Case For and Against ‘Molecular Assemblers.’” 2003.

Freitas, Robert A., Jr. Cryostasis Revival: The Recovery of Cryonics Patients Through Nanomedicine. 2022.

Freitas and Merkle. “A Minimal Toolset for Positional Diamond Mechanosynthesis.” 2008.

Huff et al., “Molecular Tools for Non‑Planar Surface Chemistry,” 2025.

McCallum et al. “(Hetero)adamantane Synthesis: A Triple Alkylation Reaction.” 2026.

Dr. R. Michael Perry was cryopreserved on April 15, 2026. This article—originally published in Physical Immortality, a short-lived journal by the Society for Venturism—perfectly captures his defining intellectual pursuits. It highlights his unwavering commitment to physical immortalism, his rigorous critique of pro-mortalist philosophy (a worldview he termed "deathism"), and his enduring optimism for radical longevity and human happiness. This profound vision of the future is explored further in his landmark book, Forever for All (2000).

By Mike Perry, Ph.D.

Sour Grapes and Sweet

In Aesop’s ancient fable, the fox seeks the juicy grapes to quench his thirst on a hot, sunny day. Finding them out of reach, however, he concludes “they must be sour.”

The thirst for longer life and better health, which would hopefully extend to a happy existence of indefinite duration, is basic to human nature. Just about everyone has been tempted by these appealing “grapes,” notwithstanding that a substantial extension of maximum human life-span, healthy or not, is quite out of reach at present, and always has been. Mortality is a basic feature of earthly life. Yet humans, who seem to be the first life forms on the planet to understand this, are not happy with it. Yes, it’s “natural,” but our instincts tell us it’s still not “okay.”

The roots of our irrepressible immortalism stretch well into prehistoric times, as is suggested, for example, by the burial of artifacts such as hunting implements with the dead. In more recent though still ancient times, the feeling flowered into major religions that promised the sought-for immortality and a happy future existence. Many of these belief systems are still with us and their adherents total perhaps about half the humans alive today. We see then how the wish for existence beyond the biological limits has survived the intractable difficulties that its practical realization has offered. In recent years, moreover, hopes for death-transcendence have taken on new life through scientific advances that offer possibilities of addressing the problem directly. The mechanisms of aging are being unraveled and eventual, full control of the aging process and known diseases is anticipated by some forward-looking people, along with other life enhancements not previously known. People can meanwhile arrange for cryopreservation in the event of death, in hopes that resuscitation technology will eventually be developed, along with the means to reverse or cure any affliction they may have suffered, including aging itself.

Not everyone, of course, can be counted among the immortality-seekers or supporters, even when the new scientific perspective is taken into account. Among those who freely reject the “grapes” of life extension are a predictable fraction who would find them sour as well. These critics defend a counterproposal of deathism, namely, that not only is one’s eventual demise inevitable and final (the grapes are out of reach) but that this should be seen in a positive light (but sour anyway, so not to worry). A recently published essay in this vein, The Immortal’s Dilemma: Deconstructing Eternal Life by George Hart, (1) offers the opinion that “life can have meaning only if it must end” and argues the case against the prospects for immortality on logical grounds. Such criticism is useful, for it points up difficulties that must be solved if immortality is ever to be realized. On the other hand, the possibility that immortality can be realized, and realized as a desirable and rewarding endeavor for an individual life (so the grapes are reachable and sweet and juicy after all) is not refuted by such arguments, as I shall maintain here. (And yes, I must confess to being one of those whose hopes rest on these grapes being in some way reachable, with emphasis, in my case, on scientific approaches to the problem.) In addition to Hart’s own critique I will also consider more briefly some other deathist arguments that have made their appearance over the centuries. But first some comments are in order about what I think immortality should encompass.

Here I am largely in agreement with Hart himself who (along with many others who have commented on the issues) is not only a materialist and a rationalist, but is also sensitized to certain difficulties of an informational nature that, I think, especially must be addressed. Thus I discount any idea of immortality “outside of time” or any supernatural or mystical process or entity taking part. A person, to exist at all, must always remain part of physical reality as revealed and understood scientifically. I also discount any idea of immortality, whether scientific or not, based on attaining a “final” mental state or a limited repertoire of states and remaining in that condition without significant change. That would amount to what is called an Eternal Return, in which one has only a finite number of subjective experiences, even if repeated endlessly—not true immortality in my view (or Hart’s, once again). An immortal life must avoid this problem of stagnation, instead becoming an endless process of personal growth which, among other things, would allow for continual recall of a growing body of past experiences. Endless personal growth would mean our immortal is continually changing—though not arbitrarily. Actually, this will cause certain arguments against immortality that easily come to mind to lose force, as we shall see, though also raising an additional, challenging problem.

It is worth remarking here that a suitable habitat for endless growth would have to exist, an expanding or already-infinite domain. Ultimately it would seem to resolve into whether information encoding memories, dispositions, and a general record of the past characteristics of the individual could be suitably recorded and organized on an ever-expanding scale. It is not known at present whether our own universe, though it appears to be expanding, could support such a process, but the possibility is not ruled out. To reasonably accommodate one immortal being, such a growth process should also extend to an entire, large population of developing immortals, so that each individual is progressing in more-or-less similar fashion. (This would also allow the addition of new, developing individuals from time to time in unending succession, though the rate of addition, as well as the growth itself, would have to be managed to be consistent with available resources. I should also add that the growth process of each person could survive temporary reversals including some losses or corruption of information, so long as overall trends were suitably robust. Basically, a subset of the information taken in by the individual should accumulate without limit and never be permanently lost or altered.) We shall return to this subject briefly later, in connection with the idea of multiple universes, which, if accepted, will be seen to further strengthen the prospects for some form of immortal habitat.

The developing immortal, then, would acquire experiences which would from then on be available for recall. Such recall would have to happen repeatedly, otherwise a given experience would drop out of consciousness forever at some point and not be part of that individual. A growing body of experiences would have to be recalled or reviewed infinitely often over infinite time to avoid stagnation. This, however, will be seen to raise a further difficulty, as Hart also notes, a problem of dilution. An experience or set of experiences might be very seldom recalled even if the recall is infinitely often, in view of the growing body of other material demanding attention. In this way substantial portions of one’s past, or ultimately all portions, may, for practical purposes be lost from consciousness and not part of the “self.” But I will argue that this problem too is manageable or at least cannot be shown not to be. Thus one could either cultivate a tolerance for an increasingly infrequent recall of a given past experience, or actually eliminate the problem by a suitable scheduling of the time spent reviewing personal archives. We shall now examine Hart’s main arguments in more detail.

Stagnation and the Death Wish

An immortal being must persist for an infinite length of time. Hart argues that, during that interval, such a being must at some point find life unbearable and wish to die, and indeed, by implication this must happen infinitely often. So, even if one always changed one’s mind later and again wanted to live, an ordeal of misery and frustration would have occurred, and moreover, must recur, over and over, infinitely often. Why is this? “It is logically possible,” he says, “and given our nature as human beings, it is also empirically possible.” On this basis he concludes that, “[g]iven an infinite period of time, what remains possible during that period of time is certain to occur.” His reasoning is that “[a] possibility that remains open by definition is certain to happen given enough time; otherwise it is meaningless to say that it remains an open possibility if it might never happen even in an infinite period of time.”

My answer to this starts with the concession that, since even an immortal being must be subject to the physical laws that govern reality, the wish to die must remain both logically and empirically possible throughout time—here I agree with Hart. Yet the conclusion that such a wish must occur (and must recur) is still fallacious, because of the assumption of personal growth which, as we noted, is necessary to avoid the problem of stagnation. A person, seen as a developing entity, would not simply be a static construct with fixed probabilities of certain things happening. With a fixed probability an event of given type, assumed independent of other events of the same type, is guaranteed to happen eventually, according to a predictable scheme. For example, suppose a devastating flood has a one percent chance of happening in any one year in a certain locale whose topography is assumed to be fixed. Then the chance of its happening in 100 years is about 64%, and the chance of its happening at least once in 1,000 years is about 99.995%, that is to say, near certainty. (For longer time intervals we come ever closer to perfect certainty.) But by taking proper precautions it would be possible to change the relevant probabilities so that an undesirable occurrence such as this becomes increasingly unlikely. People could, for instance, shore up a system of levees (slightly changing the “fixed” topography) to make a bad flood less likely, and might do so repeatedly or make other changes to further reduce the likelihood.

In the case of wanting to die, one would naturally be interested in reducing the likelihood of such a state of despondency (or reckless curiosity?). Furthermore, the sort of personal growth I envision, which would encompass the whole human—or formerly human—population, should result in ever-increasing, widespread levels of intelligence and capability to deal with problems of all sorts. This is not to say that problems will not occur and persist, and in fact, some problems could become more acute with the increasing levels of sophistication, much as we humans may be said to have more in the way of psychological problems than an earthworm. But certainly the prospect of dealing successfully with the problems cannot be ruled out. So, for example, our immortals could get happier and happier, or more and more firmly resolved to stay the course of living, or both. The likelihood, after a certain point, of a suicidal impulse ever occurring could then be vanishingly small, even though it would never drop strictly to zero.

As an illustration, we may imagine that at some future time the probability of a serious suicidal spell has been reduced to one percent per annum, and that it undergoes a further, exponential decay over time, due to the attention paid to it and the quality of research or personal dedication. With a half-life of 100 years, so that the probability reduces by half every century (though again, it never goes all the way to zero), the probability of there ever being such an episode is not 100 but only 77 percent. A half-life of 50 years will bring the probability down to 52 percent, and one of 30 years will cut it to 35 percent. Going back again to the case of the 100-year half life, the chance of at least one bad episode happening in 1,000 years is very nearly the same as its ever happening at all, or about 77 percent, but the chance of its happening after this first 1,000 years is minuscule, only about a thousandth of its ever happening at all, or .08 percent. With a 50-year half-life, the chance of a bad episode in 500 years is similarly very close to the 52 percent figure for all future time, but the chance of its happening after the 500 years is again a thousandth, in this case, .05 percent. And so on. We see then how a favorable outcome—no bad episodes at all over infinite time—becomes a near certainty with the passage of time, even though there is always some tiny chance of the contrary. (I will add that here we have assumed an exponential decay of probabilities, which makes calculations easy, but such a specific falloff is not essential; many other falloff curves will do as well.)

The same sort of argument could be applied against other “inevitable” consequences such as simple physical destruction. Developing individuals will naturally occupy larger and larger volumes of the universe, or at any rate, a larger volume in some cyberspace storing information (extending ultimately to larger spatial volumes). They thus should be able to make themselves progressively immune to such destruction, through storage of backup information and the like, even though a minuscule and diminishing probability of such destruction will always remain.

Dealing with Dilution

The second major argument Hart raises against the feasibility of immortality invokes what I have called the problem of dilution. Basically, the growing individual must eventually dwarf any previous version of itself, both informationally and, since information requires storage space, physically as well. One consequence is that, in one way or another, an immortal must develop far beyond the human level. It is easy to see how this could create problems, though we must also ask if these problems must necessarily be insoluble.

The main problem would seem to be that of a simple outweighing of earlier information and thus, of the characteristics that defined one’s identity at a particular age. The first century of the life of the individual, for example, will be represented by a finite record of, say, N bits. This archival record must occupy an increasingly small part of the total information content of the individual, say it is M bits, as growth occurs and M increases. (The N bits could also be copied repeatedly over time as insurance against loss, but would still amount to N bits of real information, so I leave it at that.) In time the N bits will be an utterly insignificant portion of the M bits, say a trillionth part or less. It is an easy conclusion that the significance to the individual of the N bits must be correspondingly tiny. In other words, the first century of your life will be as nothing to what you will have developed into—so the early person—including yourself today—will essentially be dead—even though information to reconstruct this version of you still survives. (Doing that, however, would not solve the problem long-term, because dilution would only recur as the new instance of “you” developed and accreted information. Trying to keep “you” alive by periodic recreations, on the other hand, would not work either, because of the problem of stagnation—“you” would just run through a limited repertoire of experiences before dilution once again set in and shut “you” down.)

But wait a minute—must we conclude that dilution would have to be such a problem? Surely not, if we imagine our advanced person has a certain respectful attitude toward the full collection of its past information, and the relationships between the various parts, forming a coherent whole. (This would recount both good and bad times, capture emotional as well as factual content, and be valued for lessons learned through sometimes painful mistakes along with remembered enjoyments.) A librarian does not necessarily think less of the books already on the shelves even when many more titles are acquired. This might hold all the more if the librarian is a scholar who has assembled a well-organized personal library of specially valued books that are consulted and studied from time to time. The scholar may in turn be a historian, and the “books” may include manuscripts and other memorabilia which provide information about historical periods of interest. True, if the library is extensive it may take a while before a given item in the collection is consulted once more, but that would not make it acceptable to discard that item, or necessarily lessen the item’s influence on what the scholar is doing. Finally, if we suppose that some or much of that history is personal history, our “scholar” is starting to resemble our hypothetical immortal. In short, we are not justified in assuming that an infrequent perusal of information necessarily negates the importance of that information in whatever manner it is used, including the complex activities that might be involved in expressing and experiencing one’s identity.

Today we consult books in a library by physically lifting them off the shelf and opening them up, but that is beginning to change with electronic data bases, which can be scanned much more rapidly by computer. In the future it should be possible for us to scan our own memories much more rapidly and reliably than at present, to lessen the time between scans of particular archival material. At the same time, as we grow our thought processes should also deepen, so that more in the way of processing will be required for many commonplace mental activities. This in turn would offer more opportunity for interleaving the occasional references to times past which will better anchor our sense of who we are by reminding us of where we have come from.

It seems reasonable that past versions of the self would “survive” as we remember the events of times past, that is to say, our episodic memories, and this would have importance in our continuing to persist as what could be considered the “same” albeit also a changing, developing person. But in addition to this mnemonic reinforcement I imagine there would be a more general feeling of being a particular individual, an “ambience” derived from but not referring to any specific past experiences. Ambience alone would not be sufficient, I think, to make us who we are; episodic memories would also be necessary, yet it could considerably lessen the need for frequent recall and thus alleviate the problem of dilution.

Another interesting thought is that certain items might consistently be consulted more frequently than others. (Indeed, would this not be expected?) In this way it would actually be possible to bypass the dilution effect and instead allow a fixed fraction of time for perusal of any given item, even as more items were added indefinitely. A simple way of doing this could be first to allow some fixed fraction of the time for day-to-day affairs and other non-archival work (“prime time”), and spend the rest of the time on perusal of personal archives (“archive time”). The exact apportioning of prime versus archive time is not important here, but it will be instructive to consider how the archive time itself might be subdivided. A simple, if overly simplistic, strategy would be to have half this time devoted to the first century’s records, half the remainder to the second century, and so on. (Since there would only be a finite number of centuries, there would be some unused archive time at the end, which could be spent as desired. Note, however, that in the limit of infinite total time covering infinitely many centuries, the usage of archive time would approach but not exceed 100%.) In this way, then, there would be a fixed fraction of archive time, 2–n, spent on the nth century’s records, regardless of how many centuries beyond the nth were lived or how many records accumulated. True, this way of apportioning time might not be much good beyond a few centuries; only about one trillionth the total time would be spent on the 40th century, for instance, around 1/300 sec per 100 years. (Possibly a lot could be covered even in this brief interval of about 3 million nanoseconds, however.) But the apportionment scheme could be adjusted.

A more interesting and plausible, if slightly harder-to-describe scheme would be to choose a constant c > 0 and allow the fraction c(1/(n+c–1) – 1/(n+c)) to the nth-century records. It is easy to show that the time for all centuries will add up to 100% as before, whatever positive value of c we start with. Starting with c=10 will get 10% of the total time spent on the first century, with subsequent centuries receiving a diminishing share as before, but the rate of falloff will be much slower, so that the 40th century will still receive 0.4%, or about 5 months per 100 years, that is to say, 240 million nanoseconds per minute. If we suppose that our immortal settles eventually into a routine in which 10% of the time overall is archive time, there would be 24 million nanoseconds available each minute of life for the 40th century’s memories alone, if desired, with many other centuries getting more or less comparable or greater amounts of attention, and none omitted entirely. This, I think, makes at least a plausible case that a reasonable sense of one’s personal identity could be sustained indefinitely.

In the above examples the greatest proportion of archive time falls to the earlier records, which might be fitting since these should be the most important as formative years for the prospective immortal, thus the most important for identity maintenance. (Memory recall would also naturally occur during prime time; the emphasis here could be on recent events, to maintain a balance overall.) In summary, then, we have considered ways that the problem of dilution might be successfully managed. Relatively infrequent perusal of memories might still suffice to maintain the necessary continuity with past versions of the self, or proper scheduling could stabilize the frequency of recall and bypass the dilution effect, or both. We see in any case that the problem is not what it may seem at first sight. We have no guarantee, of course, that it would not get out of bounds, but certainly some grounds for hope.

More could be said, but the difficulties are formidable, trying as we are to anticipate the possible future before it happens, and how we will deal with our problem of memory superabundance when many new options should have opened up. In that hopefully happy time a “science of personal continuation” should have taken shape to properly deal with the matter. Nay-sayers like Hart try to discount any such prospects once and for all, based on today’s perspectives with their inevitable limitations. We must look to future enlightenment to overturn such summary judgments. I will have a bit more to say on this issue, in the process addressing some other notable, pro-death thinking. But first it will be worthwhile to consider a few additional points raised in Hart’s essay. These again I think offer no fundamental, demonstrated difficulties to the idea of immortality.

Earlier we noted Hart’s bringing up the problem that the would-be immortal may at times undergo a change of feeling and wish for death. While I think we have disposed of his claim that the death wish, to remain an open possibility, would have to actually occur and recur at a serious level, it is also significant that he would allow the option of suicide, supposing such a wish did occur. And here I agree with him, if reluctantly, since a person should have that right. As an aside he seems to think of choosing to be “mortal” as an alternative different from suicide, though he does not explain how. To kill oneself with a slow-acting poison or microbe would still be suicide; would that not hold even if the process took decades and is now “natural,” as in the aging process? Choosing to age and die as we do today when aging can be reasonably controlled and prevented strikes me as a suicidal choice. But, in fairness to Hart, the delay could have significance inasmuch as the subject could undergo a change of views meanwhile, and opt for a reversal or cure. More generally, though, the rather morbid dwelling on a putative, recurring death-wish suggests that Hart may not be so happy with his own life but instead in some degree yearning for an “honorable” way out. Such an outlook is all too common among people, intelligent thinkers included. All such people should take seriously the prospect of becoming joyful geniuses—or of enhancing their already-existing genius and joyfulness—which future advances should make increasingly feasible.

True, many such people might object that doing this would make them so different it would no longer be them, they would be dead for all intents and purposes—the new person would be someone else. But I seriously doubt this would have to be so, and wish I could persuade these nay-thinkers to give more thought to the matter. A change of mind and heart need not add up to a change of person, with the old dead and gone, but can also be seen as a fulfillment of the old, which is thereby helped to become better than before, as it continues to survive, progress, and enjoy.

Morbidity and Its Remedies

The impression of morbidity in Hart’s thinking is reinforced by his opinions on very long life. “In theory you can imagine without contradiction what it would be like to be alive for a trillion or even a trillion trillion years from now. This thought experiment creates its own horror, one that is mind-numbing and nauseating.” Personally, I find the thought experiment not nauseating but exhilarating! What incomparable wonders one might explore in such long periods, what fascinating problems one might solve! What endearing relationships one might have with others of sympathetic but still differing minds, what great good one might do, with reciprocal rewards for the well-enlightened! Hart offers the thought that life ought to be like a book, which has a beginning, middle sections, and an end. In this way one’s life is “properly framed,” says he, and only in this way can it have meaning. A big problem I see with his analogy is that, while you can appreciate the “framing” and thus the meaning of a book by reading it through to the end, to do it right requires some thoughtful deliberation after you have finished the book. This is not an option you can exercise with your own life, if it too must come to a final stopping-point.

The dreary thought that one’s life needs a “conclusion” seems wrong and misguided to those of us who would like it to continue without end. (A life rightly lived is never rightly, permanently ended, we say in earnest rebuttal.) Yet it does beg the question of what meaningful activity would demand and occupy an infinite future, one in which we can and must progress indefinitely, yet continue always to respect and, in some appropriate measure, identify with our much humbler beginnings. How would an infinite existence be made worthwhile and necessary? Certainly it sounds like a tall order, but is it such an impossibility, assuming of course that the necessary technological advances will occur to at least permit escape from the biological limits that now confine us?

Indeed, from one point of view the issue seems transparently simple. Life ought to be worth living. If life is worth living, it should not come to an end, therefore one ought to be immortal. This, of course, overlooks the details of what one might be doing with one’s life as well as such other features as what sort of society would emerge if individuals were immortal. These matters are impossible to second-guess in detail, but some things can be said with reasonable confidence.

Whatever the details of a life may be, they should be such as to produce meaning and fulfillment—including, most importantly, a reason to continue, to find something always new, interesting, exciting, something from which one can learn. This applies to our limited existence today; it should apply all the more in a hoped-for immortal future. Life should be habit-forming! With the prospects for future betterment, I think it will be, both because there should be so much of interest to experience and know about, and because our means to deal with the problems of lack of interest and other negatives will itself be much greater and more refined.

Another aspect of life being worth living is that it should be worth remembering, as we have already noted, this in particular being necessary to retain a sense of continuity with one’s past to reasonably sustain one’s personal identity. Pleasure alone thus is not enough. The nature of one’s experiences should be such that thinking of them later causes enjoyment too—a requirement that, I think, should not prove too difficult in the sort of future that seems possible, even though people today often do not seem to value the remembered past.

Finally, what is worth remembering is also worth sharing. Life should be something shared with others so that all in the end will mutually benefit. Of course it must be the “right” others, which will follow if individuals are well-disposed and develop in reasonable ways.

So we see that commonsense notions that apply to life today, even with its present limitations, lead to the conclusion that immortal life, properly conducted, would be good and desirable. This is also bolstered by considering the opposite viewpoint. Could we learn to make peace with death? Could we see in it something other than final ruin and frustration? Could we find meaning in spite of (or because of) the thought of an eventual, permanent conclusion, a restitution once and for all of all our striving and cares? I think all attempts to do so must ring hollow. Knowledge of one’s mortality and its apparent inevitability is not an easy burden for the rational mind to carry. I doubt if belief in one’s impermanence can inspire much real satisfaction, except perhaps for those who view life, fundamentally, as a burden that ought to end. As one such thinker, Hart is hardly alone; a few of the others will now be worth examining, starting with the ancients.

Other Deathist Thinking

The Stoics, prominent in the early centuries c.e., insisted that fear of death, rather than death itself was the real evil, so that “man must learn to submit himself to the course of nature.” (2) Now, of course, we know that our nature is substantially malleable through our own efforts. The sort of meek submission advocated in earlier times is becoming untenable, and increasingly will be so.

The related, roughly contemporary Epicurean doctrine held that stagnation would invalidate a limitless survival. “[T]here are only a limited number of gratifications, and, once these have been experienced, it is futile to live longer.” (3) To me, this conclusion seems especially specious, even if we limit consideration to a purely intellectual discipline such as mathematics. There are infinitely mathematical truths to explore, each a separate and unique “gratification” to the rightly disposed, with no simple way to characterize them all—Gödel’s famous undecidability results establish this last property about as solidly as one could ask. Again, too, our nature is malleable thus allowing for increases in the “number of gratifications” along with other enhancements, to track the reality that obligingly refuses to be trivial.

Buddhism, also very ancient (and still quite active today) considers the “wish for continued existence” a form of “defilement.” (4) This, then, is a moral objection to immortalism, one with which we may respectfully disagree. Buddhism strongly advocates enlightenment; more enlightenment should be possible the longer one lives. In time, I conjecture, such enlightenment will lead to a recognition of the individual person as a coherent concept and something whose continued existence is to be valued and sought.

Turning to recent times, Bertrand Russell, a leading twentieth-century British philosopher, was firmly convinced of the inevitability of death, based on cosmological considerations. If nothing else, he thought, life must eventually and uniformly come to an end in the Heat Death or “running down” of the universe. Not just individuals were doomed but species, civilizations, and in short, the whole enterprise that we know as life, whether earthly or elsewhere in our cosmos, if it should exist there. Russell was not happy with this state of affairs but thought it must be accepted, arguing that “…only on the firm foundation of unyielding despair, can the soul’s habitation…be safely built.” (5) His solution was to downplay the issue. The thought that “life will die out…is not such as to render life miserable. It merely makes you turn your attention to other things.” (6) But this too rings hollow in the minds of many of us. In particular, it invites the question of whether painless, immediate suicide would not be a better alternative than prolonged and distracting efforts at “other things.” Russell does deserve credit for attempting to assess reality as it is, and make the most of what to him inspires “unyielding despair.”

It is worth remarking that Russell’s conclusions about eventual Heat Death with its apparent stifling of all life in the universe have never been ruled out but are not by any means firmly established. The recent discoveries of an apparently accelerating universal expansion have raised new, unanswered questions about the ultimate fate of the universe and any firm conclusions are premature. On the other hand, if we suppose the universe is destined to go down, taking us with it, we can ask if this is the absolute end. Barring the supernatural, many would say yes. However, suppose we accept the idea of pattern survival—that “you” could survive as a duplicate of yourself, possibly located in another universe entirely (and no one has ruled this out). Then clearly the options for survival are broadened so that even a hostile cosmology may not be able to end your existence. Life, not death, could be the ultimate outcome for any individual, who must then make the most of it rather than seeking solace in a cares-erasing oblivion. (7)

John Hick, a prominent contemporary theological philosopher, has also aired misgivings on the issue of eternal survival. His hangup is a variant of the problem of dilution. There must be a limit, he says, to how much we can identify with earlier states in which we were very different. In addition to logistical difficulties of the sort we addressed earlier, Hick considers the diary he composed as a fifteen-year-old (emphasis original): “…I know that it is my diary, and with its aid I remember some of the events recorded in it; but nevertheless I look back upon that fifteen-year-old as someone whose career I follow with interest and sympathy but whom I do not feel to be myself.” (8) This sort of dissociation is, I think, very common and perhaps a majority viewpoint among people today, though not universal. (I for one feel able to identify with my earlier person-stages, even going back to early childhood, despite the many changes.) It is noteworthy that Hick says he does not feel he can identify with his earlier self.

It is not likely that any of the arguments offered here would soon change such a viewpoint. If we must continually change so that, in time, our earlier experiences were of someone very different this might indeed prove a fatal impediment, but I do not think it must or will be so. The arguments we have already considered offer a starting point for a more hopeful outlook, but we can go a bit farther informally, something I find inspirational. Let us consider, then, what sort of beings we might be expected to develop into over a long stretch of time, in which today’s physical limitations would not apply.

Likeable, Joyful Immortals All

Clearly there are many possibilities, but I conjecture that personality types capable of and desiring very long survival will not be so varied or inscrutable as to baffle our understanding today. Instead they should basically be profoundly benevolent, desirous of benefiting others as well as themselves, and respectful of sentient creatures in general. They will acknowledge that enlightened self-interest requires a stance with a strong element of what we would call altruism. They will be intensely moral, but also joyful in the exercise and contemplation of their profound moral virtues—for an element of joy will be essential in finding life worth living, even as it is today. These joyful, good-hearted beings, then, will be the types to endure, and will refine their good natures as time progresses, so as to increasingly approximate some of our ideas of angelic or godlike personalities, as endless wonders unfold to their growing understanding.

Beings of good will who are seeking what is right and best and to develop in wonderful and rewarding ways over unlimited time, always with love, respect, and consideration for others, should not find it hard to feel a kinship with past versions of themselves which also had these attributes. Love must conquer all. The conjectured disinterest with one’s more distant past, then, will be swallowed up in the universal affection and regard for persons in general, past as well as present, which must logically extend to versions of oneself along with others. If we are good enough, then, our everlasting survival, as separate though interacting and considerate selves, becomes morally mandatory and recognizable as such by the advanced beings we shall become. So it is this high calling we must aspire to, and it may well be necessary to our survival. And, I submit, being virtuous and considerate will also make us more accepting of our earlier selves, even if they were less enlightened and rather “different,” or even, in more extreme cases, evil and horribly misguided. The bad in our earlier selves can be acknowledged when we are confident it is cured.

In the future there should be wonders aplenty for the searcher and many paths to pursue in a vast architecture of possibilities. So each of us should be able develop in interesting and unique ways, with joy accompanying our efforts, including those occasions when we reflect on where we’ve been before and how far we’ve come, something that should both comfort and inspire. Joy will thus help us maintain a reasonable sense of our identity as time goes by. If this course of development can be pursued, the rich diversity of individuals will, I submit, produce greater benefits overall than if all were subsumed in a vast collective enterprise, with individuality devalued or obliterated. As a possible precedent, we may consider how collective enterprises in our own history, and particularly totalitarian governments with centrally planned economies, have been unable to compete with more decentralized, democratic systems. The separate, developing, considerate, immortal ego, then, should have more to offer all around than some form of “nonself” or a fused consciousness.

In our advancement, of course, we should make use of whatever discoveries and technologies may be applicable. Inevitably this will involve risk but “nothing ventured, nothing gained.” In fact I think our deepening understanding will make adaptations possible that would otherwise be out of the question. The elimination of aging and biological death should be accompanied by increased understanding of the psychological difficulties connected with immortalization, with a proliferation of possible remedies. People should have numerous means to deal with various “illnesses” they may have inherited from the mortal past, along with the difficulties they encounter in the course of a hopefully unbounded future.

First published in Physical Immortality 2(4) 11-16 (4^th Q 2004)

Notes:

1. URL: https://infidels.org/kiosk/article/the-immortals-dilemma-deconstructing-eternal-life/

2. Gerald Gruman, “A History of Ideas about the Prolongation of Life.” Transactions of the American Philosophical Society 56, no. 9 (December 1966), 15.

3. Ibid., 14.

4. Hammalawa Saddhatissa, Life of the Buddha. New York: Harper and Row, 1976, 31.

5. Bertrand Russell, Why I Am Not a Christian, and Other Essays on Religion and Related Subjects. Ed. Paul Edwards. New York: Simon and Schuster, 1957, 107, as quoted in Frank J. Tipler, The Physics of Immortality: Modern Cosmology, God, and the Resurrection of the Dead. New York: Doubleday, 1994., 69.

6. Ibid., 11, as quoted in Tipler, Physics of Immortality, 70.

7. See R. Michael Perry, Forever for All: Moral Philosophy, Cryonics, and the Scientific Prospects for Immortality, Parkland, Florida: Universal Publishers, 2000.

8. John Hick, Death and Eternal Life, Louisville, Ky.: Westminster/John Knox Press, 1994, 410, as quoted in Perry, Forever for All, 470.

The scientific perspective that informs Sebastian Seung’s bestselling popular neuroscience book Connectome is so familiar to cryonicists that the bulk of this book could be mistaken for an extensive introduction to the philosophy of mind embodied in cryonics. His book offers a rigorous exposition of the view that our identity is encoded in the connections between neurons, the “connectome,” which itself is shaped by our genes and life experience. The strength of this book is not only its review of the empirical evidence that supports this outlook but its encouraging the reader to think about its implications. Readers who are intimately familiar with the argument in favor of cryonics should not assume that there is little to learn from this book. As imaging and storage technologies evolve, cryonicists can do more now than in the past to learn about their individual connectome, strengthening the likelihood of successful resuscitation.

One important element of the connectionist premise that structures Seung’s book is that it does not completely resolve competing theories about how the brain works. For example, the recognition that long-term memory (and identity) does not depend on transient electrical activity but has a more robust long-term physical basis that persists during cessation of brain activity (examples are hypothermic circulatory arrest and short periods of cardiac arrest) does not imply a single perspective on how the genome provides the neurological bases for memory formation, retention, recollection, and re-prioritization. One interesting perspective, “neural Darwinism,” which was anticipated by the economist Friedrich Hayek, proposes a theory of brain function in which a genetically determined wiring of the brain is subject to competing experiences that strengthen or weaken populations of synapses throughout life. One of the interesting implications of this theory is that consciousness can be treated as an emergent outcome of micro-events in the brain, instead of a mysterious, autonomous property of the brain (think of the curious concept of “free will”).

Seung devotes two chapters to the nature-nurture debate through a connectionist perspective. One of the unfortunate effects of the nature-nurture distinction is that it masks the obvious point that what we call “nurture” (upbringing, environment, etc.) is not exempt from biology but simply concerns the relationship between biological systems and between a biological system and its physical environment. Social scientists who have a strong “nurture”-bias should therefore not be exempted from describing “nurture” in verifiable physical terms, something that many of them do not feel the slightest obligation to do. Another unattractive feature of this debate is that it is routinely portrayed as one between genetic determinists and “environmentalists.” In reality, the debate is mostly between serious scholars who acknowledge that behavior and learning are shaped by both genetics and the environment and those who basically consider the mind a blank slate—a position that is clearly contradicted by existing science but remains popular as a premise in contemporary public policy and certain political ideologies. One of the interesting topics that Seung discusses in these chapters is whether the plasticity of the brain changes over time.

From the perspective of cryonics, the relationship between the genome and the connectome is of great importance. If some of the basic wiring of the brain that encodes personality and temperament is determined by genes and is fixed (or mostly fixed) at an early age, then some parts of the connectome might be inferred from a person’s genome, which opens up an exciting research program for cryonics. A systematic study of the field where genetics meets neurodevelopment might help in understanding the relationship between the genome and brain ultrastructure. This in turn could assist in future resuscitation attempts. To date, the assumption in cryonics has been that the complete ultrastructure of the patient must be preserved (or at least preserved in such a manner that it can be inferred), but if some of it can be inferred from the genome the repair requirements for resuscitation of cryonics patients may be relaxed. Looking for such invariable features in variable brains is an important element of a credible cryonics resuscitation research program.

The power of comparing connectomes is also recognized by Seung in a separate chapter (“Comparing”). There he reviews technologies and approaches to compare connectomes with the goal of understanding personality differences and understanding neuropathologies or “connectopathies.” This chapter is one of several in which the author reviews the existing and emerging technologies that are enabling us to produce a complete connectome, including the innovative equipment of brain preservation advocate member Kenneth Hayworth to perform serial electron microscopy. Also discussed are technologies such as diffusion MRI (dMRI), which allows for non-invasive mapping of the connectome at the macro scale using water as a probe. This technology may not be adequate to map the connectome at the cellular level but its contribution to comparative connectomics has already been recognized. It may also hold promise as a means to collect identity-critical information about an individual while alive, which again may lessen the computational challenges involved in cryonics resuscitation. One of the exciting prospects of the field of connectomics is that it can contribute to a further narrowing of the challenges involved in restoring cryonics patients to good health.

Seung closes his chapters on emerging technologies with a review of the prospects of connectomics for the treatment of neurological diseases. One of the potential treatments involves the re-programming of a person’s own (skin) cells to neurons, which can then be introduced in the brain to treat a disease or enhance brain function. Such an approach may also be used to fill the “missing gaps” in the brain of a cryonics patient (alternative technologies include molecular construction of neurons by advanced molecular nanotech­nology).

At this point, I think we can foresee a rather optimistic future for cryonics research and the prospect of resuscitation. Instead of conceptualizing cryonics as the preservation of clinically dead people in the hope that future medicine can restore these people to good health, we can envision a more complex, but more encouraging, path. The work of resuscitation and restoring identity is not something that is expected to occur exclusively in the future but rather will be an ongoing process that starts as soon as the patient is cryopreserved. And with the rise of advanced genomics and non-destructive imaging technologies, some of the initial work can be done while the person is still alive. One of the exciting aspects of being a cryonicist today is that you can take proactive steps to learn about your own connectome and other identity-relevant information.

Seung devotes no less than a whole chapter to human cryopreservation (and the associated idea of chemopreservation). The author recognizes that his own views about the connectome are so similar to the philosophy of mind that underpins cryonics that he needs to do some justice to the rationale of cryonics. One unfortunate aspect is that he situates his discussion of cryonics in the context of religion and immortality. It is undeniable that some cryonicists are motivated by visions of personal immortality but this idea is not intrinsic to cryonics (neither is mind uploading or transhumanism.) Properly conceived, cryonics is an experimental medical procedure that aims to stabilize patients at cryogenic temperatures in anticipation of future treatment. What really distinguishes cryonics from mainstream medicine is not uncertainty (which is a fact of life), but the temporal separation of stabilization and treatment. One regrettable implication of attributing religious motives to people who make cryonics arrangements is that it cheapens the use of the word ‘religious.’ Instead of referring to worship of a higher being, it is here used as a strong belief in something in the absence of conclusive evidence. But by putting the bar so low, Seung (unintentionally) classifies many aspects of life, including choosing novel experimental treatments in mainstream medicine, as “religious.”

What really distinguishes cryonics from mainstream medicine is not uncertainty (which is a fact of life), but the temporal separation of stabilization and treatment

At one point Seung writes that research aimed at demonstrating that contemporary vitrification technologies can preserve the connectome will “finally bring some science to Ettinger’s wager.” This is a remarkable statement because even the earliest arguments in favor of cryonics were never presented in the form of a pure wager. In his book The Prospect of Immortality, Robert Ettinger reviews existing evidence from cryobiology and neuroscience and argues that, combined with the expectation that medicine will continue to evolve, the choice to be cryopreserved is a rational decision. Since Ettinger’s book cryonics organizations and wealthy donors have expended a lot of money and time in perfecting preservation techniques and looking at the effects of new technologies on the structure and viability of the brain. Compared to the state of, let’s say, interventive biogerontology, the scientific progress that has been made in cryonics is not trivial. For example, it is doubtful whether the widespread adoption of vitrification in mainstream cryobiology would have been possible without sustained research into using this approach for complex organs by cryonics supporters. To my knowledge, cryonicists have always been quite eager to generate experimental knowledge to inform their decision making. Now that more advanced technologies to map the human brain are becoming available, cryonics organizations are eager to use them instead of just passively maintaining their “faith.”

Ultimately, Seung still fails to recognize that cryonics inherently involves an element of uncertainty that cannot be eliminated without it not being cryonics anymore (i.e., elimination of uncertainty makes it suspended animation). To his credit, the author recognizes that it is not necessary for a preservation technology to perfectly preserve the connectome as long as it remains possible to infer the original state (or missing information) from what has been preserved. We can speculate what the limits of such “neural archeology” will be, but I do not think anyone can make conclusive arguments. In this sense, cryonics cannot be completely moved from the realm of informed decision making into the realm of indisputable fact. An element of uncertainty will always be associated with it, even if the experimental evidence in favor of this medical procedure keeps mounting.

The author also discusses alternative preservation approaches such as chemical fixation and plastination. One drawback of existing chemical preservation technologies is that they are irreversible by contemporary techniques (literally a “dead end”) and do not permit whole organism functional recovery.

There is one formidable challenge that will inevitably arise if chemical preservation is offered as a means of personal survival. It is how to deal with the fact that if chemical fixation is delayed, perfusion impairment in the brain will prevent complete cross-linking of biomolecules. Chemopreservation requires that the procedure be started prior to, or immediately following, circulatory arrest. In absence of this, the fate of a person’s connectome is uncertain, and may even worsen during storage—a problem cryonics is exempt from. This can be mitigated by complementary immersion fixation and/or ultra-low temperature storage but this introduces all the kinds of complexities and trade-offs that have traditionally been associated with cryonics. Clinical chemopreservation also requires traditional Standby, Stabilization, and Transport (SST) procedures to bring most cases in the realm of good preservation.

One interesting consequence of thinking about preservation and evidence from a connectomics perspective is that it provides a powerful framework how to think about evidence. Obtaining a few good electron micrographs from the brain can co-exist with poor preservation in other areas. Good viability (even whole-brain tests like EEG) can co-exist with regional compromise of viability. It is not possible to present a complete connectome for each experimental or clinical case at this point in time. In that sense research aimed at complete long-term functional survival (like the CryoDAO CryoRat project) still remains an important benchmark.

The book ends with a chapter about mind uploading. One misconception about cryonics is that people seek it as a means to mind uploading, or that reviving the person in a computer is the aim of cryonics. In fact, the late Robert Ettinger became a vocal critic of mind uploading in his final years. He offered a lot of arguments for his skepticism but his main concern was that questions about the feasibility of mind uploading are ultimately empirical questions which cannot be settled by deductive reasoning and dogmatic claims about the nature of the mind or consciousness. One of the amusing aspects of the debate about mind uploading is that proponents and skeptics both accuse the other of not being consistent materialists. Interestingly enough, Seung makes an observation relevant to this debate when he writes how the idea that “information is the new soul” is implied in the mind uploading project.

Despite some misgivings about how Seung presents and conceptualizes cryonics, I am unaware of another book that offers such a clear exposition of the relationship between brain and identity that informs human cryopreservation (and chemopreservation). The most rewarding thing for me was a stronger recognition that the idea of the connectome is not just a premise but opens the door to multiple fruitful research programs aimed at personal survival.

About the Author: Sebastian Seung is Professor of Computational Neuroscience and Physics at MIT and Investigator at the Howard Hughes Medical Institute. He has made important advances in artificial intelligence and neuroscience. His research has been published in leading scientific journals and also featured in the New York Times, Technology Review, and the Economist. (From the dust jacket)

Dr. Seung was also a speaker at the Alcor-40 conference in October 2012

[This slightly revised and expanded review originally appeared in Venturist News and Views, June-July 2012, 6-7 and Cryonics, September-October 2012]

“If they could get a corpse to sit up on an operating table, they would jubilantly exclaim, “It’s alive!” And so would we. Who cares that human beings evolved from slimy materials? We can live with that, or most of us can.” Thomas Ligotti

The persistence of pessimism

When I sent out an email message soliciting contributions on the topic of philosophical pessimism and antinatalism one person declined with the reasonable response that such positions are only taken seriously by a handful of obscure philosophers. Humans have evolved to procreate and seek happiness. What is the point?

The reason why I have not been inclined to so easily dismiss the recent renaissance of philosophical pessimism is because negative and tragic views about life are woven throughout human history and culture. Most dominant religions have little positive to say about the state of humanity (after the fall) and the prospects for a life devoid of suffering on earth. Despite its relative epistemological sophistication, even Buddhism presents a picture of the universe as a source of suffering. Much can be said about pessimism, but not that its influence is outside the mainstream.

Even the antinatalist position that it is better never to have been, and that we have a moral obligation not to procreate, is not completely obscure. Who has not had the experience of talking to someone who wonders why anyone would want to bring children into this world? In fact, modern culture persists in linking intellectualism to pessimism. This perhaps should not be surprising because, as a general rule, excessive thinking comes at the expense of sensual experience. Perhaps another reason why many intellectuals are biased towards pessimism is because it provides them the opportunity to rescue us with their ideas.

Philosophical aversion to pessimism can be found among the finest thinkers in the history of philosophy, though. There is David Hume, the great empiricist thinker, and an amiable and optimistic person. Then there is Friedrich Nietzsche, who, despite a life of disease and isolation, recognized that pessimism is not an objective feature of the universe but the expression of a weak and oversensitive mind. The twentieth century witnessed a strong renaissance of the empiricism of David Hume in the form of logical positivism. These philosophers rightly abstained from putting forward a “philosophy of life,” but optimism about science and humanity’s potential is clear in their foundational writings. It is also interesting to note that the most recent forceful responses to pessimism have not come from professional philosophers but from libertarian-leaning economists who present data to prove that by many measures life is getting better all the time.

In my opinion, the most obvious question that can be raised about philosophical pessimism is whether its supporting claims are factual descriptions of reality or just expressions of temperament. Another interesting question is whether philosophical pessimism necessarily obliges us to the antinatalist position. In seeking answers to these questions we turn to the literature of contemporary antinatalism.

Jim Crawford’s Confessions of an Antinatalist is a highly readable autobiographical exposition of antinatalism. Thomas Ligotti’s book The Conspiracy Against the Human Race is more ambitious in scope and contains a wealth of historical information on pessimism, discussions of modern science, and, not surprisingly, a review of the theme of pessimism in horror literature. David Benatar’s Better Never to Have Been: The Harm of Coming into Existence is the most rigorous exposition of antinatalism to date. This book covers a lot of ground and I will confine myself to some of its main topics only.

The harm of coming into existence

In its purest form antinatalism may not be compelling but the framework that informs this position rests on a couple of reasonable premises: (1) we do not impose a harm (or withhold a benefit) by not bringing someone into this world; (2) we do impose a harm by bringing someone into the world when this person’s life will be (very) bad. Jim Crawford believes that these premises are evident. The question is then about how to determine that a person’s life is (or will be) bad, and how much consideration the interests of parents should be given.

One of the most problematic aspects about the work of Crawford and other antinatalists is that they have little patience for the argument that life is better than they think it is. In some passages it is hard to distinguish the antinatalist from the paternalist. If people think that life is much better than Crawford makes it out to be, the standard rejoinder is that these people suffer from a form of false consciousness (pessimists frequently use words like “truly” and “really”). In some passages this (quasi-Marxist) attitude borders on intolerance. A prime example can be found in Crawford’s discussion of childhood. For many people growing up was a period of great happiness and discovery. Crawford’s agitated dismissal of such accounts introduces an element of illiberalism in what is otherwise a humanistic endeavor. It is in these passages that antinatalism turns into bitter ideology.

The way the term “bias” is employed is problematic. It is used as if there is an objective perspective that can reached were it not for misleading evolutionary biases coming between the person and the universe. At times the author appears to be saying that if evolution did not select in favor of those wanting to survive we would not want to survive. This is not particularly helpful. Some of these “biases” do not cover up anything but just make us happier.

Let us assume that there is an objective, material reality that can be known through the use of reason and empirical observation. This does not mean that there is one “correct” fit between an organism and the world. A person who is manically depressed perceives the world in a different matter than a person who is not. How we are “wired” and respond to our environment is not a matter of “correct” or “incorrect.” Thinking otherwise would be hard to reconcile with an evolutionary outlook in which life is just the outcome of random interactions of organic molecules.

One argument that remains available to the pessimist would be that the probability of creating a miserable life is too high to warrant procreation. But it is at this point that the “transhumanist” can enter the debate and claim that our expected quality of life is no longer just the outcome of a “random” evolutionary process but can be brought under rational control. We should endeavor to make happy children.

In my opinion, the short response to empirical pessimism can take the following form. Pleasure and pain are both part of existence. For some sentient beings pleasure outweighs pain, for other sentient beings pain outweighs pleasure. A moral agent cannot add up, subtract, or divide these elements for life as a whole to produce an objective quality-of-existence function. The antinatalist runs into the same problems as all the utilitarians and welfare economists who have tried to define a social utility function as a guide for public policy. As Thomas Ligotti notes in his book, “…the reason for the eternal stalemate between optimists and pessimists, is that no possible formula can be established to measure proportions and types of hurt and happiness in the world. If such a formula could be established, then either pessimists or optimists would have to give in to their adversaries.” I think that the best response available to the antinatalist would be to follow David Benatar’s example and present a strictly formal argument, or simply argue that in case of doubt, we should abstain from procreation.

Escape strategies

After spending the bulk of his book persuading the reader that life is suffering, Crawford discusses what he calls “Escape Strategies.” In his treatment of Buddhism as an escape strategy he could simply have made the obvious internal critique that desire may be sufficient, but not necessary for suffering. Crawford’s treatment of Christianity is scathing, which may indicate regret because the author himself was a Christian for awhile. Why have children if there is the prospect of eternal damnation? I think that a Christian can respond by saying that following Scripture is more important than applying human morality to God’s creation.

The last escape strategy that Crawford reviews is hope, which turns into a discussion of futurism and transhumanism. The argument that many of those pursuing life extension will not be around to benefit from it is too simplistic. Unless the brain is completely destroyed at death, the neuro-anatomical basis of identity can be preserved at cryogenic temperatures for a very long time. No delusional expectations about the future are required. People in cryostasis have time. But then the author delivers a critique that I think deserves serious treatment by transhumanists (discussions about “friendly AI” do not exhaust this topic by any means). In a nutshell, we should not expect that technological progress will necessarily produce moral progress. And even if it will, accidents happen. Technologies that can be designed to produce great joy can be used to create great suffering as well. If humanity can manufacture hell without God, the case for pessimism and antinatalism may be strengthened.

There is one area of agreement between antinatalism and transhumanism that has not been widely recognized to date and that is a shared suspicion of evolution. Whereas transhumanists tend to emphasize the imperfections and suboptimal outcomes of evolution, antinatalists are deeply disturbed by it because it selects for the one thing that they associate with suffering: life and procreation.

Interestingly enough, the anticipation of dark future technologies may present a (subconscious) obstacle for many people considering cryonics. Hundreds of millions of people believe in the craziest things like astrology and psychoanalysis, but only a handful of people (around 5000) have made biostasis arrangements. This lack of interest can hardly be attributed to ignorance, and perhaps the most persuasive answer may be hidden in Crawford’s book. Cryonics basically forces people to deal with the question whether they would like to be “born again” in a far and unknown future. As a general rule, the answer seems to be “no.” Antinatalists may find additional ammunition for their position in studying the reasons for the low sign-up rate for cryonics.

Mahayana antinatalism

Antinatalists should expect a lot of obvious questions such as “are most people not glad to be alive?” or “why not kill yourself?” I fear that Crawford’s answer to the question “why not kill yourself?” risks undermining the orthodox antinatalist project. If empathic sensibility can make an enlightened antinatalist want to stick around, it is arguable that antinatalists should make an effort to remain alive in an effort to reduce the amount of (future) suffering in the universe. Antinatalists then become life extensionists. To use conventional Buddhist terminology, perhaps at some point there will be a Theravada version of antinatalism (focused primarily on non-procreation) and a Mahayana version of antinatalism (concerned with the elimination of the suffering of all sentient beings).

David Benatar runs into a similar problem when he ponders the question whether bringing new people into the world could be justified to reduce the suffering of the last remaining people. It seems to me that how an antinatalist deals with such practical moral issues depends on how the ethics of antinatalism is conceived. Do we have a “right” not to come into existence or is the objective of antinatalism to juggle with small and great suffering towards the ultimate end of its complete abolition?

If antinatalism is conceived as a strictly individualistic endeavor, concerns about the suffering of all humans can be easily dismissed. But in that case antinatalism would just collapse into individualist pessimism. Who cares about suffering, as long as it is not me! This is not the kind of sentiment that is generally found in antinatalist writings. I do not think that the question whether there might be moral reasons to remain alive, and, yes, bring into being forms of life that are benevolent but ruthless towards suffering, can be easily dismissed.

At one point Crawford observes that secular and smart people are having fewer children. This does not look good for the inevitable triumph of antinatalism. Under such scenarios antinatalism produces dysgenics, and if one believes that stupidity and evil go hand in hand, increased suffering for more people.

It is not unlikely that, in practice, antinatalism leads to more suffering because it will only be adopted by sympathetic human beings such as Crawford. The antinatalist cannot argue that the amount of suffering in the universe cannot be increased nor decreased. The whole point of antinatalism after all is that suffering can and should be decreased. But how to go about this may be more complicated than it appears. A sober assessment of the practical implications of antinatalism may require revision of the antinatalist position itself.

Confessions of an Antinatalist is a fine and humane book, but in the end it is also a book of the converted written for the already converted. Thomas Sowell has noted that in economics there are no solutions but only trade-offs. I would not be surprised if antinatalists will come to a similar conclusion at some point.

Suffering without meaning

Thomas Ligotti is a contemporary horror writer whose fiction work is marked by cosmic nihilism, alienation, and the fragile nature of reality. As a great admirer of the works of Ligotti I have been reluctant to comment on his non-fiction. Fortunately, unlike many other artists, Ligotti has little interest in “critical theory” or political lecturing. His book The Conspiracy Against the Human Race concerns the bleak fate of humanity in a deterministic and indifferent universe.

The book starts off with an introduction by obscurantist philosopher Ray Brassier, whose work would certainly qualify for the description that Ligotti gives to Schopenhauer’s oeuvre (“too overwrought in the proving to be anything more than another intellectual labyrinth for specialists in perplexity”).

Reading Ligotti’s account of why humans reject truly bleak views about life it would be interesting to see how antinatalists respond to the existence of orthodox Calvinism. Accepting a universe without free will that is ruled by an omnipotent God who has decreed that the majority of people will suffer in hell for His self-glorification seems a lot more terrifying to me. Nonetheless, hundres of millions of people have accepted this theological perspective. The existence of Reformed theology lays to rest the view that humans have an intrinsic desire to avoid doctrines that are too terrible too contemplate.

When Ligotti discusses the work of antinatalist Peter Wessel Zapfe once more we find the view that there is an objective predicament of mankind that is hidden by false consciousness. It is remarkable to see the similarities between those who argue that we do not want look our “oppression” straight in the face and those who argue that we avoid coming to terms with the horror of existence. What is often lacking here is the recognition that there is also a wealth of literature about human suffering that supports the idea that we would be happier if we did look nature straight in the face. No nonsense about “moral responsibility,” “sin,” “duty,” “the greater good” etc. Marquis de Sade, Friedrich Nietzsche, and Max Stirner are representatives of this school of thought.

What is intriguing about Ligotti’s book is that it reads like a rather delicate balancing act. On one hand, we have the detached observer (my personal favorite) who is bemused at the show business of both the optimists and pessimists. On the other hand, it is unmistakable that Ligotti feels affinity with the philosophers of cosmic horror and pessimism. His fiction does not leave much room for any other conclusion. But The Conspiracy Against the Human Race contains more than a few (unintended) suggestions for a more ironic and quietist view of life.

Hard determinism and the illusion of the self

I have a hard time relating to Ligotti’s discussion about determinism and pessimism. Hard determinism (or “hard imcompatibilism”) is just a part of the “scientific worldview” and it is not obvious to me why it should be a source of despair. Ligotti then discusses the existence of the “self.” I am inclined to think there is an important difference between free will and the self. Modern science can make sense of the world and human action without assuming free will. I am not convinced that this is possible if the concept of the self is rejected. Unlike free will, the recognition of a “self” comes at a later stage in evolution. It has been argued that our ancestors could not clearly distinguish the self from its surroundings and thus were not able to discover the laws of physics and use it to their benefit. The philosopher Hans Reichenbach developed a pragmatic case for the existence of the external world and the self in his seminal work Experience And Prediction: An Analysis of the Foundations And the Structure of Knowledge.

Why would anything that neuroscientists discover about the self and how it is constructed be a source of dread? If you believe that life is the result of random meetings of organic molecules, it stands to reason that the physical basis of consciousness and the self reflects such a process. Why would accepting such ideas make one a “heroic pessimist?” Why the pessimism at all? Ligotti even agrees. “One would think that neuroscientists and geneticists would have as much reason to head for the cliffs because little by little they have been finding that much of our thought and behavior is attributable to neural wiring and heredity rather than to personal control over the individuals we are, or think we are. But they do not feel suicide to be mandatory just because their laboratory experiments are informing them that human nature may be nothing but puppet nature. Not the slightest tingle of uncanniness or horror runs up and down their spines, only the thrill of discovery. Most of them reproduce and do not believe there is anything questionable in doing so.”

Ligotti also discussed transhumanism, but not in much depth. As a transhumanism skeptic myself, I found little to object to but it seems that Ligotti’s real target is what is called Singularitarianism. This part in the book seems something of a missed opportunity because there is substantial overlap between Ligotti’s fiction and themes that are discussed by transhumanist writers.

When Ligotti reviews near-death experiences and ego-death, the common-sense neurological explanations that were invoked in discussions of free will and the self are largely absent (a notable exception is his discussion of the possibility that a brain tumor can cause an “enlightened” state). For many critical-care physicians and neuroscientists it is a given that many people suffer (regional) cerebral ischemia during the dying process. These periods of transient oxygen deprivation can produce long term damage and a “re-wiring” of the brain, which can explain the new perspectives these people adopt. From a physicalist perspective, death of the ego is (partial) death of the brain.

In Ligotti’s book the reason for pessimism is multi-factorial. It includes the lack of meaning in an indifferent universe, the reality of hard determinism, and the illusion of the self. The works of Benatar and Crawford are more restricted in scope and mostly focus on more mundane suffering. Ligotti’s philosophical horror is much richer, but I wonder how much of it will resonate with people who embrace a scientific view of the universe.

There is a lot in Ligotti’s fine book that I have not discussed such as the extensive treatment of pessimism in horror fiction, loads of interesting philosophical and scientific references, plus illuminating discussions of obscure authors such as Peter Wessel Zappfe and Philipp Mainlander. As such, it can also be considered as an indispensable reference for philosophical pessimism and cosmic horror.

Empiricism and non-existence

David Benatar is a rigorous philosopher. His work can be situated in the analytic tradition and he makes an honest attempt to anticipate objections to his own views. When he argues for positions using mainly logical arguments he is quite persuasive. A being that does not exist can neither be harmed nor benefited. I cannot see how this argument (or tautology?) can be successfully refuted. But when Benatar attempts to argue that the quality of life of most people is much worse than they think it is, multiple challenges arise. I do not think this is the result of Benatar’s poor reasoning but the fields that he relies on – evolution, social psychology, happiness research and the study of cognitive biases – are notorious for allowing cherry picking. Ultimately Benatar also cannot escape the charge that he pays excessive attention to theories that claim that we think we are happier than we really are.

And, like Crawford, Benatar cannot completely escape the charge of illiberalism. One possible response to the charge of illiberalism is to object that it is those who procreate who are illiberal by “forcing” their optimism on the unborn. But since it is nonsense to talk about a non-existing person objecting to something, the only meaningful empirical determination if someone is being harmed is to consult the person who has come into existence unless one can predict the future with great confidence.

Benatar is on more agreeable ground when he simply derives his antinatalism from uncertainty; “some know that their baby will be among the unfortunate. Nobody knows, however, that their baby will be one of the allegedly lucky few.” It may never be completely possible to predict the future with complete certainty but with the rise of technologies such as prenatal tests and genetic engineering it should be possible to make more evidence-based decisions about the quality of a future person’s life.

Benatar believes that even if his empirical argument about the poor quality of our lives fails, his formal argument from asymmetry is still left standing. He thinks that even if there is one single painful pinprick in an otherwise good life, we still harm that person by bringing him into existence. I think that Benatar is “proving” too much here. We can agree that anyone who conceives a child cannot escape the prospect that this person will experience some harm. But from this it does not follow that the person is harmed in a meaningful moral sense without considering the expected overall quality of that life. Perhaps Benatar would respond that I have not understood his argument, and I will admit that I have a difficult time understanding why the possibility that a person’s pleasures are expected to outweigh the pains do not alter his argument. I think that both bringing into existence a life that is invariably good and a life that is generally good can be morally defended on the grounds that there will not be any post-natal moral objections from the person involved.

Of course, we are not morally obliged to do so, because we will not deprive the unborn of such a good life if we don’t have children. But since most parents have a positive interest in having children, in practice this tips the scales in favor of some (but not all!) procreation. One problem I can see with my argument is that it might permit the creation of a life form that would experience great suffering but with an unalterable survival instinct and no cognitive possibility of moral blame or regret. Some antinatalists might even claim that this is a rather accurate description of the human race as it exists today!

As an empiricist, I generally give the benefit of doubt to empirical observations when they appear to conflict with logical reasoning. I think that this preference itself can be justified on historic and pragmatic grounds. The claim that coming into existence is always a harm is not consistent with the reports of all those who have come into existence. That seems to be a non-trivial epistemological roadblock for antinatalism.

When Benatar discusses the moral duty not to have children he runs into the obvious problem of how the interests of the parents should be weighed against the interests of the child. One does not need to be an ethical egoist to believe that the interests of the parents count for something. In this case the question returns to how bad the life of most people is and, as discussed, this is a rather vulnerable part of antinatalism. Benatar attempts to answer the obvious objection that most people who have been born do not regret this or blame their parents. But when I read his thoughts on “indoctrination” I only see further evidence of the anti-liberalism in antinatalist writings.

In fairness to Benatar (who seems to identify himself as a liberal of some sorts), he does defend the legal right to procreation because he admits that there can be reasonable disagreement about his views. I think this point is particularly important for antinatalism since reasonable objections often come from the very people whose lives Benatar characterizes as very bad. Ultimately, though, one could argue that saying that something constitutes a great harm but allowing people the “right” to do so is incoherent, or at least a strange perspective on things.

Benatar highlights the importance of making a distinction between the decision to bring someone into existence and the decision to continue life. Even if we commit to the idea that it is better never to have been we can still have reasons for wanting to continue life. As a matter of fact, Benatar entertains the argument that the prospect of death itself is one of the reasons why existence is bad. Those who follow Epicurus believe that death cannot be experienced and thus cannot be a bad thing for the person. This is an extremely difficult argument to refute, but Benatar’s discussion of this topic is quite illuminating because he points out that those who hold this position may also have to commit to the view that death can never be good for a person. One only needs to imagine a person whose life is one of continuous suffering to see that this is not a plausible argument.

Benatar is less hostile to religion than Crawford and Ligotti but I do not think he can successfully escape the objection that antinatalism requires an atheist perspective. It cannot permit arguments that the “harm” of coming into existence serves a greater good which cannot be evaluated by human standards of morality. One does not have to be a scripturalist to note that Benatar is only concerned with the fate of humans and not with the interests of God. Antinatalism may not just require atheism, its conceptual framework has explicit anti-religious implications because it considers one of the defining acts of a supernatural being - the creation of sentient lifeforms - as morally suspect.

Perhaps Benatar cannot see any positive value in human suffering because his information about Creation is incomplete. Theodicies that reconcile the existence of God and the existence of Evil are not difficult to generate. As Plotinus has observed, “We are like people ignorant of painting who complain that the colours are not beautiful everywhere in the picture: but the Artist has laid on the appropriate tint to every spot.”

Meta-ethics and evolution

I am not aware that there has been much discussion of the meta-ethics that underpins the antinatalist argument. It seems to be taken for granted that the objective of moral discourse is to minimize suffering from an impartial perspective (and even then it can be questioned whether this supports antinatalism). But such a perspective of morality can be questioned. A Hobbesian might argue that the objective of morality is to facilitate mutual advantageous interaction. In such a contractarian enterprise there is little room for the interests of the unborn because they are no part of the “state of nature” and no deal needs to be struck with them. A Humean approach to morals would emphasis the spontaneous generation of conventions without appealing to objective standards of “good” or “harm.”

Furthermore, there is no god-given definition of harm. If harm is defined too narrowly, a lot of suffering will be permitted. If harm is defined to broadly the term because vacuous. One of the problems in Benatar’s argument from asymmetry is that that it fails to do justice to the perspective of the person who is being “harmed.” This problem is not eliminated by substituting logic for empirical investigation. Actually, it would be legitimate to ask whether Benatar is a rationalist who settles an empirical matter with purely logical arguments.

Mathematician and immortalist philosopher Mike Perry has observed, “Benatar’s thinking is not conducive to reproductive fitness.” Antinatalists will just remove themselves from the gene-pool by declining to procreate.

A potential response available to the antinatalist is that this scenario itself does not mean that the moral recommendations of antinatalism are incorrect. But should antinatalist arguments not incorporate arguments about its feasibility? Ought implies can and if antinatalism is not compatible with the most rudimentary notions of evolution, can it qualify as a credible moral theory? Should, as transhumanist David Pearce has suggested, the desire to eliminate suffering not be channeled in more realistic and productive directions? One provocative response to this argument that, to my knowledge, no antinatalist has produced yet is not to forgo antinatalism but to advocate coercive antinatalism and murder for the long-term greater good.

If we look at all these elements together, there is a non-trivial challenge here. Antinatalists start from arbitrary (meta) ethical premises, push logical arguments to extremes, cherry pick the scientific literature. Antinatalism is selected against by evolution, may produce dysgenics in practice, and is actively hostile towards the dominant religions. A philosophy that is neither favored by evolution nor religion has little going for it in the struggle for ideas.

Is antinatalism even possible as a practical program? Unless all organic life is terminated, complex sentient lifeforms will just re-appear to the scene again and the whole show will start again. “Non-existence is hard to do.” In reality, I think this is the biggest show-topper. Like most special plans for the world, antinatalism requires a degree of control that we may not have, cannot maintain, or (paradoxically) lose when we succeed.

Antinatalists and life extensionists

One could think that cryonicists and life extensionists should be repulsed by antinatalism. I think such a view would be mistaken. All the antinatalist authors discussed here are motivated by empathy for the suffering of all sentient life. We should also welcome the analytical and physicalist perspectives that underpin their writings. Too much (Continental) philosophy is simply an insult to the intellect and a waste of time. If a case should be made for pessimism it needs be stated in a form that is amenable to reasoned debate and empirical investigation.

Of more specific interest to life extensionists is the plausible prospect that our abilities to decrease suffering will (necessarily?) be matched by our abilities to increase suffering too. This is a possibility that should be studied in great detail by advocates of molecular nanotechnology, strong AI, and substrate-independent minds.

It is no secret that cryonicists (or any kind of biostasis advocates) are underperforming in terms of reproduction. But as Howard V. Hendrix discusses in the article “Dual Immortality, No Kids: The Dink Link between Birthlessness and Deathlessness in Science Fiction,” this may not be a coincidence. If biological immortality becomes a credible option, having children as a substitute for personal survival will lose much of its appeal.

Most rewarding for cryonicists is the unique perspective that antinatalists can bring to the debate concerning why so few people have made cryonics arrangements. The hostility of many people towards cryonics cannot be explained if people categorically believe that meaningful resuscitation (revival) is impossible. It is the prospect that cryonics may actually work that induces severe anxiety. If the antinatalists are correct in their assessment that coming into existence is always a harm, the unpopularity of cryonics might be indirect evidence for their position.

Talking with antinatalists

Is antinatalism distinctly subversive? Most antinatalists waste little time reminding their readers how controversial their ideas are. They think that they have uncovered the greatest taboo of all time. As an empirical matter, this is doubtful. Antinatalist ideas can be freely discussed in modern (Western) countries, something that cannot be said about a number of other controversial ideas. Antinatalists are also quick to point out that their pessimism should not be dismissed as an expression of weakness and depression. But then the antinatalists commit a similar error by too easily viewing optimism as a defense mechanism or a form of bias. But is it completely unreasonable to look for the neurophysiologic and genetic basis of pessimism and optimism? The uncompromising naturalism in the work of the antinatalists supports such an inquiry.

Jim Crawford: Confessions of an Antinatalist (Nine Banded Books 2010)

Thomas Ligotti: The Conspiracy Against the Human Race: A Contrivance of Horror (Hippocampus Press 2010)

David Benatar: Better Never to Have Been: The Harm of Coming into Existence (Oxford University Press 2006)

This article is a revised and expanded version of an article originally published in Cryonics, 2nd Quarter, 2010.

Thanks to Dr. Michael Perry for discussing some of the topics in this review and proofreading an earlier version of this document.

The goal of human cryopreservation standby and stabilization procedures is to preserve the structure and viability of the brain after medico-legal pronouncement of death. To achieve this goal we employ three different techniques: cardiopulmonary support (CPS), rapid induction of cooling (hypothermia), and pharmacological intervention.

The primary purpose of the medication protocol is to reduce or eliminate injury from cerebral ischemia. Ischemia is interruption of the delivery of adequate amounts of both oxygen and nutrients to the brain. The better we protect the brain from ischemic injury, the better the patient’s chances of future revival. This introduction will familiarize the reader with the different classes of medications we use, and some of the issues associated with administering them.

While these stabilization medications protocols have traditionally been formulated for the use of cryonics, it cannot be emphasized enough that any non-elective (out-of-hospital) biostasis procedure that entails a delay between circulatory arrest and start of procedures (such as “chemopreservation”) can benefit from pharmaceutical stabilization.

The effects of ischemia and interrupted blood flow affect both cryoprotectant and chemical fixative perfusion.

Although virtually all the medications ultimately are given to help mitigate the effects of circulatory arrest, many of them are pharmaceuticals with other uses in mainstream medicine. Therefore, EMT’s, paramedics and nurses may be familiar with many of them. The most important differences are the number used, the different context and rationale of use, and (sometimes) different dosages.

Anesthetics

Although the human brain accounts for only 2% of total body mass it accounts for about 20-25% of total oxygen consumption. Therefore, the first priority is to reduce cerebral oxygen consumption to make the brain more tolerant to the limited blood flow (mechenical) chest compressions produce. This can be achieved by inducing deep anesthesia. Because we prefer to use medications that are not scheduled drugs and which also confer anti-ischemic benefits, the current anesthetic of choice is propofol. Naturally, this medication should be given just before, or immediately after, starting CPS. The choice of propofol is a typical example of the sort of trade off that sometimes needs to be made in human cryopreservation. Propofol produces transient hypotension which is undesirable in the context of trying to restore optimal cerebral blood flow. This effect can be mitigated by the administration of vasopressive medications like phenylephrine (see below).

Antithrombotics

The formation of blood clots during after circulatory arrest cases is problematic for a variety of reasons. It may frustrate our attempt to provide adequate CPS, cause incomplete or sub-optimal blood washout, and complicate perfusion of the cryoprotectant solution. For this reason, heparin has been a core stabilization medication since the start of doing standby, stabilization, and transport (SST).

Recent experimental research within the research community (most notably at Advanced Neural Biosciences) has identified sodium citrate as the most potent anti-coagulant - with additional anti-ischemic benefits due to its chelating of calcium (a driver of ischemic injury).

Because anticoagulant agents like heparin and sodium citrate only prevent blood clotting, after termination of mechanical CPS, a fibrinolytic, streptokinase, is added to the washout solution to dissolve existing blood clots.

Vasopressors

In human cryopreservation vasopressors are used to increase blood pressure and selectively shift blood flow to the vital organs (including the brain). The current vasopressors of choice are vasopressin and phenylephrine. Because avoiding some of the side effects of these medications is not as high a priority in human cryopreservation as in conventional medicine, protocol and dosages may differ somewhat from current practice in cardiopulmonary resuscitation. It is hard to overestimate the importance of restoring adequate cerebral blood flow in the human cryopreservation patient.

Because they are rapidly metabolized, vasopressors needs to be given intermittently at short intervals, or continuously infused, instead of administering just one single bolus. Ideally, the quality of chest compressions and oxygenation of the brain are measured to validate stabilization procedures in general, and to make informed decisions about the use of vasoactive medications, in particular. One way to do this is to measure expired end tidal-CO2 (ETCO2).

Cerebroprotective Agents

In the ideal case, circulation and ventilation are restored immediately after pronouncement of medico-legal death, in conjunction with the administration of medications and induction of (surface) cooling. Although this protocol is fairly aggressive compared to that which is usually employed by paramedics in out-of-the-hospital resuscitation from cardiac arrest, it is usually inadequate to completely meet the metabolic demands of the patient. This is especially true if the patient has already experienced some ischemic injury prior to pronouncement and/or the standby team is not able to start the stabilization protocol immediately, or if the patient is febrile at the time of pronouncement.

No (or inadequate) blood flow fails to provide (enough) energy to maintain ion gradients across cell membranes, leading to depolarization. The depolarization of presynaptic membranes overactivates the neurotransmitter glutamate, causing increased calcium ion (Ca++) influx. In the absence of adequate energy production, excessive Ca++ leads to a cascade of damaging events including pathological activation of various enzymes, inflammatory mediators, generation of harmful free radicals and apoptosis (programmed cell death), producing a harmful positive feedback-loop in which one event amplifies and accelerates others.

The agents that are used in human cryopreservation to mitigate ischemia, reperfusion injury, and compromised (micro)circulation in the brain include a variety of medications and chemicals to target different parts of the damaging cascade.

Ischemia-reperfusion induced free radical generation is mitigated by a licensed antioxidant cocktail called Vital-Oxy. Vital-Oxy contains antioxidants like D-alpha tocopherol (Vitamin E), melatonin and the free radical spin trapping agent alpha Phenyl t-Butyl Nitrone (PBN). Vital-Oxy also includes the anti-inflammatory drug carprofen. In a preferred formulation, the (viscous) Vital-Oxy is diluted with magnesium sulfate solution to further enhance its neuroprotective properties.

In abbreviated versions of the protocol the low molecular weight superoxide scavenger 4-Hydroxy-Tempo (TEMPOL) is administered. The antibiotic minocycline also has neuroprotective properties (see below).

This multi-modal approach in treating cerebral ischemia has been developed and proven to be effective in recovering dogs after 17 minutes of normothermic cardiac arrest at Critical Care Research, a California-based resuscitation research company.

Buffers

Human blood normally has a pH of 7.4, which is kept in a very tight range in a healthy human being. But after a (prolonged) period of ischemia, and/or inadequate circulation and ventilation, the typical patient becomes acidotic. This is a serious concern because this condition damages cells, releases destructive enzymes, accelerates blood clotting, and induces clumping of red blood cells (agglutination). Acidosis can also reduce the effectiveness of heparin or some vasopressors like phenylephrine because the drug is effective only within a certain pH range, or acidosis degrades the drug and inactivates it.

To prevent and treat acidosis a buffer is given. The current buffer of choice in human cryopreservation is tromethamine (THAM) because it does not have some of the side effects (like cell swelling) of sodium bicarbonate. In the ideal human cryopreservation case, pH is meticulously monitored and additional buffer is administered if acidosis is observed.

Volume Expanders and Oncotic Agents

Intravenous access is not only necessary to administer medications but also to administer fluids to address electrolyte imbalances and replace volume (in the dehydrated patient). Hydroxyethyl starch (given as Hetastarch) is currently the volume expander of choice in cryonics to address reduced blood volume (hypovolemia), which often occurs as a result of dehydration during the dying phase.

Another medication employed in fluid resuscitation is mannitol. Mannitol has been proven effective in ischemia induced cerebral edema by promoting movement of fluid from the cells to the vascular space. Other advantages of mannitol are reduction of blood viscosity (improving perfusion) and its free radical scavenging properties. Some cryonics organizations use the glycerol polymer decaglycerol (also used as the Z-1000 ice blocker in the M22 vitrification solution). Decaglycerol is used to osmotically inhibit cerebral edema and often co-administered with THAM as one solution.

Both of these fluids are given in fairly large volumes (compared to most of the medications), so a basic understanding of fluid balance and electrolytes is desirable to make informed decisions for the patient.

Antibiotics

Microbial overgrowth can be an issue during long (normothermic) transport times. Minocycline is a broad spectrum bacteriostatic antibiotic that also doubles as a neuroprotectant. Minocycline is free radical scavenging molecule with desirable tissue- and brain penetration and a variety of neuroprotective properties including inhibition of metalloproteinases, inducible nitric oxide (iNOS), PARP, mitochondrial cytochrome c release and, apoptosis.

Administration of antibiotics and the use of sterile technique have sometimes been perceived as redundant and expensive for treating cryonics patients. One answer to this objection is that the guiding philosophy of stabilization is to provide a level of care and commitment at least equal to, or better than, the care the patient received before pronouncement of legal death. It’s also important to note that antibiotics and sterile technique are not only used to treat the patient, but also to protect the stabilization team members from infection.

Antacids

Antacids are used to neutralize the pH of stomach contents to prevent erosion of the stomach wall by hydrochloric acid at low temperatures - an observation that goes back to the small animal hypothermic revival experiments by cryobiologist Audrey U. Smith and colleagues. Erosion of the stomach wall can lead to contamination of the circulatory system with stomach contents and abdominal swelling during later perfusion.

A solution of aluminum hydroxide and magnesium hydroxide (previously sold as Maalox) has traditionally been used for this purpose. Unlike the other medications, antacids are directly delivered to the stomach through a gastric tube or the gastric channel of the i-Gel airway.

General Issues

The fairly large number and volume of the medications raise the obvious question of what the preferred sequence should be. The most important consideration is that the sequence should reflect medical priorities. For example, propofol is administered as the first medication to prevent (hypothetical) CPS-induced return of consciousness and reduce cerebral metabolic demand. Ideally, the administration of propofol is quickly followed by a vasoactive medication to mitigate profofol-induced hypotension. The other high-priority medication is sodium citrate to aggressively mitigate blood clotting and protect the brain against the harmful effects of calcium overload.

The second consideration is to give the small volume medications first, and the larger volume medications later, so that most of the medications can be given in the shortest period of time. Naturally, there can be a conflict between the two. When not desirable to delay the administration of a drug, a small portion of the total volume can be given rapidly and the rest can be administered (as a drip) later. Ideally, several lines are used so there is no conflict between small and large volume administration.

Although the medications currently used in human cryopreservation reflect years of research, review, and experience, it needs to be stressed that this does not completely release the biostasis technician from using medical common sense. For example, a normally hydrated infant may have different fluid (and medical) needs than a severely dehydrated large adult. A patient may have already been heavily pre-medicated with some of the medications in our protocol (heparin for example). If prompt cardiopulmonary support is not possible (for example after one hour of circulatory arrest), it may be questionable and wasteful to administer many medications to mitigate early-stage ischemic injury.

These kinds of issues stress the importance of comprehensive data collection, detailed reporting, and systematic analysis. The more we learn about the different effects of our protocol in different situations, the better we may be able to refine it to suit a particular patient’s needs. In this respect human cryopreservation is not unlike conventional medicine; one size doesn’t fit all.

This is a revised and updated version of an earlier exposition of cryonics stabilization medications from spring, 2006. An extensive review of cryonics stabilization medications can be found here.

Robert Ettinger, the “father of cryonics,” was cryopreserved on July 23, 2011. While Ettinger’s book Man into Superman (1972) is considered an important contribution to transhumanism, he increasingly came to recognize that most people do not desire a hard break with the past and resist radical transformation. During the last years of his life he became a vocal critic of “mind uploading” as a means of personal survival and spent a considerable amount of time refining his arguments why mind uploading is not likely to work. This document organizes excerpts from his last book Youniverse and mailing list messages on the topic of substrate-independent minds. In the afterword, I make a brief attempt to place his contributions in a broader philosophical context.

The title of this document refers to a message that Robert Ettinger sent to the Cryonics Institute mailing list on July 21, 2011. In response to the claim that the human mind is a machine, and that the function of any machine can be duplicated by a machine built of another material, Ettinger asked, “Can you build a locomotive out of helium?”

Mind Uploading

“A large and burgeoning group of scientists, including some of the brightest, believe that—in principle—computers will fairly soon be able to think in the fullest sense of the word. They will be living, conscious entities with feelings and subjective experiences.

“A corollary—many believe—is that your persona could be uploaded into a computer and you could then live an incomparably bigger and better life as a simulation or emulation.

“I think the uploading thesis is probably wrong, although (as usual) it’s too soon to be sure. But the issue is a significant part of modern philosophy, and potentially has enormous practical importance.

“…I am among the radicals in the expectations for AI. But intelligence is not life. It is by no means proven that life as we know it with subjective experience can exist on an arbitrary substrate, such as silicon.” (Youniverse)

Information

“One extreme school of thought holds that information and its processing constitute everything that is important. In particular, you are essentially just a collection of information, including a program for processing that information. Your ‘hardware’—the nervous tissue that embodies and handles the information—is only secondary.

“My conclusion will be that it is not necessarily possible—even in principle—for consciousness to exist on an inorganic substrate, and in fact that it is unlikely.

“Sometimes the doubters are accused of dualism—the increasingly discredited belief that the living and inanimate worlds, or the material and the spiritual worlds, are separate.

“This certainly is not true of me or of many others who question the information paradigm. I am a thoroughgoing materialist and reductionist. I will not feel in the least dehumanized if it turns out the information paradigm is right…I have strong doubts, but they are based entirely on the evidence, or lack thereof.

“The most radical of the ‘strong AI’ people believe that all thinking is information processing, and all information processing is thinking; and they appear to believe that consciousness is just an expression of complexity in thinking.

“People who talk this way must be admired for boldness and strength of conviction, but I think not for clarity of thought.

“The point is, all physical phenomena, all interactions, involve information processing in some sense. But that isn’t all they do. A computer, or a person with pencil and paper, could figure out—describe or predict—what the atoms do, and that would be an analog of the information processing part of the phenomenon; but only the actual, physical atoms can form an oxygen molecule. And to anthropomorphize or analogize ‘feelings’ and ‘thoughts’ into these phenomena is simply unjustified. It amounts to declaring, by fiat, that thinking and feeling are inherent in information processing; but saying so doesn’t make it so.” (Youniverse)

Turing Tests and Zombies

“Alan Turing was a brilliant mathematician and computer pioneer. He played an extraordinary part in winning World War II through his work in cryptography for British Intelligence. He also showed many of the potential capabilities of general computers. But one of the works for which he is most famous is badly flawed or has been badly misused—the ‘Turing test’ for intelligence / consciousness.

“Again, I am a firm materialist and reductionist: I readily concede the possibility that a machine could (conceivably) have life and consciousness. But I deny that we can assume that (inorganic) machines have this potential; and with still more help from Turing I think I can make the case persuasive.

“‘Uploaders’ or ‘upmorphists’ or patternists generally maintain that our identity resides in our information content. Their most extreme position is patently absurd—that ‘we’ literally persist, in some degree, if any of the information about us is preserved, even our writings or biographical data. (Shades of Woody Allen! ‘I don’t want to live on in my works; I want to live on in my apartment.’) Anyone who believes this needs more help than I can provide.

“Turing ingeniously showed that a strip of paper tape marked in squares, with zeroes or ones marked on the squares according to certain rules, along with a simple mechanism for moving the tape and making or erasing marks, could be a universal information processor—i.e., it could accomplish any information processing task that any digital computer (serial or parallel) could do, given enough time. It could even produce any result that a quantum computer might, albeit at a teeny-tiny fraction of the speed.

“You certainly can’t claim that a paper tape (even when it is moving) is alive or conscious! Yet that tape, in theory, could produce any response that a person could to a particular stimulus—if by ‘response’ we mean a signal sent to the outside world, suitably coded. It could converse with perfect fidelity to an individual’s character, and over a teletype could fool that person’s husband or wife.

“My original objection to the uploading assumption was simply that we don’t know anything about consciousness or feeling, hence it is premature to assume that it can exist other than where we know it exists, viz., in organic brains. It is entirely possible that meat machines (as opposed to machines of silicon or metal etc.) have some unique quality that allows the emergence of feeling and consciousness. Until we can isolate and define the mechanisms of feeling—of the subjective condition—we must reserve judgment as to the possibility of inorganic people. (Youniverse)

“Uploaders tend to put faith in the Turing Test for human intelligence, and to believe that zombies cannot exist. Let’s take a quick look.

“Communicating (say) by email, a testor tries to determine whether the testee is a human or a computer program. Passing the test supposedly proves the testee is human or equivalent. But the test is clearly worthless, since it produces both false positives and false negatives. As much as 50 years ago Eliza, a program pretending to be a psychiatrist, fooled many people—false positives. And of course a child or a retarded person could perform below par and produce a false negative. The Turing test is baloney.

“In similar vein, uploaders tend to believe that something which outwardly behaves like a person must be a person. They reject the possibility of zombies, systems that by their actions appear to be sentient but are not. Yet it is often easy to fool people, and, as already noted, programs have fooled people even though no one claims the programs were alive.” (Cryonics Institute Mailing List, September 9, 2010).”

Imperfect Simulations

“..any simulation created in the foreseeable future will be imperfect, because it will necessarily reflect current theories of physics, and these are known to be incomplete and almost certainly in error to some extent or in some domains. Whether this would necessarily result in material deviations of the simulation from the course of nature, and in particular whether it would preclude feeling, we don’t yet know. But we do know that the simulation would be wrong, which in itself is enough to justify withholding judgment on the possibility of living computers.” (Youniverse)

Analog Failures

“The uploading thesis depends on the assumption that any organic process in the brain can be duplicated by analog in some other medium but this not only isn’t obvious; it’s nonsense.

“For example, suppose a certain process depends on magnetism, and all you have to work with are the mechanical forces transmitted by rigid bodies. Can you make an electric motor out of tinker toys? Can you build a synchrotron out of wooden boards and nails? Uploaders think a computer (of the electronic variety) can be a person: how about a Babbage mechanical computer made of rods and gears? Presumably, any kind of information processing and storage can be done by a collection of rods and gears but could rods and gears conceivably be conscious? I doubt it; not all media are created equal. So it is entirely possible that organic brains have potentialities not realizable anywhere else in the universe.” (Youniverse)

“Just ask yourself what consciousness is—what physical condition or process constitutes consciousness. You don’t know, hence you cannot know that a simulation fills the bill.” (Cryonics Institute Mailing List, September 16, 2010)

Petitio Principii

“It seems to me that all the computer-metaphor people… keep making the same error over and over again—assuming as a premise the very hypothesis they are trying to establish. When the premise is the same as the conclusion, naturally the conclusion follows from the premise. They refer repeatedly to ‘all computational devices’ etc., implying that the brain is just that—another computational device—when in fact that is precisely what is at issue: Is the brain possibly something more than a computational device? The computer metaphor is plausible (and I am not in the least uncomfortable with it) but plausibility isn’t proof.” (Youniverse)

The Map is not the Territory

“Adherents of the ‘information paradigm,’ I believe, are deceived in part by glibness about ‘information’ and hasty ways of looking at it.

“Apprently it needs to be said again and again: a description of a thing or a process—no matter how accurate and how nearly complete—is not the same as the thing or the process itself. To assume that isomorphism is enough is just that—an assumption, not self-evidently permissible.

“Even though (for example) a computer program can in principle describe or predict the behavior of a water molecule in virtually all circumstances, a water molecule for most purposes cannot be replaced by its description or program. If you pile up 6.02 x 10²³ computers with their programs, you will not have 18 grams of water, and you will have a hard time drinking it or watering your plants.” (Youniverse)

“Eliezer Yudkowsky (and other uploaders) claim that mapping a system results in a map that effectively has the same properties as the original. Well, look again at one of my counter-examples. I write down with pencil and paper the quantum description of a hydrogen atom in its ground state. It could hardly be more obvious that the marks on paper do not constitute a hydrogen atom. And if you put side by side two papers describing two hydrogen atoms, they will not combine to form a hydrogen molecule. In principle, of course (the math is difficult) you could write down expressions corresponding to the formation of hydrogen molecules from hydrogen atoms, but you will still have just marks on paper.

Once more, a simulation is just a coded description of a thing, not the thing itself.” (Cryonics Institute Mailing List, September 18, 2010)

Identity

“The term ‘identical’ is used in different ways by different people. To some, two systems are identical if they differ only in location, e.g. two hydrogen atoms in ground state. But I have pointed out that a difference in location necessarily implies other differences as well, such as gravitational fields. Hence my position is that, if the question arises, are A and B identical, then they are not.

“If two systems differ in spatial or temporal location, then they may be identical to most observers for most purposes, but survival of one does not imply survival of the other. Suppose you, as you are now according to local observation, also exist at a great distance in space or time (either past or future), just by accident. I see no reason for the survival of B to imply the survival of A.” (Cryonics Institute Mailing List, September 16, 2010)

Afterword

Robert Ettinger presented a number of distinct arguments (no fewer than fifteen, by his own count!) against mind uploading and I cannot pretend to have presented them all in this document. I think there are a number of core positions associated with Ettinger’s argument that can be stated quite succinctly, however.

1. Whether mind uploading is possible is ultimately an empirical question and cannot be settled conclusively by analogies or thought experiments.

2. A description of a material object is not necessarily the same as the object.

3. A simulation must be erroneous because the program necessarily is based on our incomplete knowledge about physics.

4. Consciousness may be substrate-dependent.

5. A copy of a person may not constitute personal survival.

The common denominator that runs through Ettinger’s critique of substrate-independent minds is a thorough empiricism about knowledge. Ettinger does not categorically rule out the feasibility of mind uploading but takes people to task for dogmatic claims on these topics in absence of empirical corroboration.

Ettinger was particularly irritated by the claim that materialism commits a person to the acceptance of mind uploading. He could not see how a rejection of the soul excludes the view that certain materials are uniquely suitable, or even exclusively suitable, for a certain function. One might add that it is even conceivable that the mind is substrate-independent but that existing organic chemistry provides the most versatile basis for advanced consciousness and survival.

Most of the issues that Ettinger was concerned about may be resolved by the time he will be resuscitated but it is possible that some of the issues that are at stake in this debate are ultimately un-falsifiable or even pseudo-problems. For example, how could we settle the question of whether a copy is “really you?” Obviously, a copy of something will always confirm that (s)he is really him- or herself but that is of little help in resolving the question. Similarly, we may never be able to conclusively verify (or falsify) that a computer has consciousness or feelings. Is it even conceivable that new super-intelligent life forms will replace humans without being conscious or having feelings. Evolution selects for fitness, and whether this implies consciousness is an open question.

So who is right, Robert Ettinger or his critics? I think what captures Ettinger’s perspective the best is to say that if you expect an answer right now, you have not paid close attention to his argument.

This document was circulated in late 2011 as a tribute to Robert Ettinger after his cryopreservation at the Cryonics Institute.

In contemporary medicine, terminally ill patients can be declared legally dead using two different criteria: whole brain death or cardio-respiratory arrest. Although many people would agree that a human being without any functional brain activity, or even without higher brain function, has ceased to exist as a person, not many people realize that most patients who are currently declared legally dead by cardio-respiratory criteria have not yet died as a person. Or to use conventional biomedical language, although the organism has ceased to exist as a functional, integrated whole, when a patient is declared legally dead using cardio-respiratory criteria, the neuroanatomy of the person is still intact

It might seem odd that contemporary medicine allows deliberate destruction of the properties that make us uniquely human (our capacity for consciousness) unless one considers the significant challenge of keeping a brain alive in a body that has ceased to function as an integrated whole. But what if we could put the brain “on pause” until a time when medical science has become advanced enough to treat the cause of death, reverse aging, and restore the patient to health?

Metabolic Arrest

Putting the brain on pause is not as far fetched as it seems. The brain of a patient undergoing general anesthesia has ceased being conscious. But because we know that the brain that represents the person is still there in a viable body, we do not think of such a person as “temporarily dead.”

One step further than general anesthesia is hypothermic circulatory arrest. Some medical procedures, such as complicated neurosurgical interventions, require not only cessation of consciousness but also complete cessation of blood flow to the brain. In these cases the temperature of the patient is lowered to such a degree (≈16 degrees Celsius) that the brain can tolerate a period without any circulation at all. Considering the fact that parts of the human brain can become irreversibly injured after no more than five minutes without oxygen at normal body temperature, the ability of the brain to survive for at least an hour at these temperatures without any oxygen is quite remarkable.

Again, because we know that in such cases the neuroanatomical basis that represents the person is still there in a viable body, we do not think of such a person as “temporarily dead.” These examples illustrate that the medical community already recognizes and accepts the fact that a medical procedure that produces loss of consciousness, and even loss of circulation, does not constitute irreversible death.

Unfortunately, general anesthesia and hypothermic circulatory arrest cannot be used to pause the brain long enough to find a treatment for a person who has been declared legally dead by cardio-respiratory criteria. A person under general anesthesia may require tens, if not hundreds, of years of artificial circulation to keep the brain viable until medical science is able to return him to health. Leaving financial considerations aside, artificial circulation of an organ, let alone such a vulnerable organ as the brain, will produce progressive brain injury over time, and ultimately, destruction of the person.

Hypothermic circulatory arrest eliminates the need for metabolic support of the brain, but only for a limited period of time. Current research into hypothermic circulatory arrest indicates that the brain might tolerate up to 3 hours of complete circulatory arrest if the temperature is lowered close to the freezing point of water (0 degrees Celsius). This is not nearly long enough to put the brain on pause to allow the patient to reach a time where his current untreatable medical condition may be treatable. In light of these limitations, it is understandable that no serious attempts are currently being made to continue long-term care for a patient whose body has stopped functioning as an integrated organism.

But if low temperatures can extend the period that the brain can survive without circulation, much lower temperatures should be able to extend this period even further. At -196 degrees Celsius molecular activity has become so negligible that it can be said that the brain has been put on pause in the literal sense of the word. This allows the patient to be “transported” to a time when more advanced medical technologies are available, even if this would require hundreds of years. Advocates of human cryopreservation (i.e, “cryonics) argue that long-term care at cryogenic temperatures offers a rational alternative to the current practice of burial and cremation of persons no longer treatable by contemporary medicine.

Contrary to popular views of cryonics, cryonics is not about preserving dead people but about long-term care of critically ill patients. The objection that cryonics is an attempt to resuscitate dead people reflects a misunderstanding of the rationale behind cryonics. The arguments supporting human cryopreservation are not radically different than the already established arguments behind general anesthesia and hypothermic circulatory arrest; it merely introduces lower temperatures and longer care. Therefore, the difference between contemporary medicine and cryonics is quantitative, not qualitative, in nature. Likewise, the relationship between cryonics and religion is not qualitatively different than that between contemporary medicine and religion. In both cases medical technology is used to preserve life.

Vitrification

But does the procedure of cooling a patient to cryogenic temperatures not cause injury in itself? Most of the human body consists of water and lowering the body below the freezing point of water will produce massive ice formation. For this reason, patients who present for cryonics are protected from ice damage by using a cryoprotective agent to reduce, or even eliminate, ice formation. Modified cardiopulmonary bypass technologies are used to circulate the solution throughout the body. When enough water is replaced with the cryoprotective agent, the patient is maintained at cryogenic temperatures for long-term care. Historically the cryoprotective agents that were used in cryonics are mainstream cryoprotective agents such as DMSO and glycerol. High concentrations of glycerol or DMSO can significantly reduce ice formation, but cannot eliminate it altogether.

A better alternative to conventional cryoprotection is vitrification. Vitrification offers the prospect of cooling an organ to cryogenic temperatures without ice formation. Although vitrification of pure water requires extremely high cooling rates, these cooling rates can be greatly reduced if high concentrations of cryoprotective agents and “ice blockers” are added. Ice blockers are synthetic variants of naturally occurring anti-freeze proteins used by hibernating animals to protect themselves from freezing injury. The vitrification agent is introduced within a so-called “carrier solution” which includes molecules to prevent cell swelling, support metabolism, maintain physiological pH, and prevent oxidative damage. The vitrification agent is introduced in a gradual fashion to prevent excessive volume changes in cells. During the final stages of cryoprotectant perfusion the temperature is dropped below zero degrees Celcius to protect the cells from toxicity caused by high concentrations of the vitrification agent.

The current generation of vitrification agents can preserve the fine details (ultra-structure) of the brain without requiring impractical cooling rates. Although electrical activity has recently been demonstrated in vitrified rabbit brain slices, reversible vitrification of the whole human brain without loss of cellular viability is currently not possible. The current research objective, therefore, is to improve on these vitrification agents to allow for reproducible vitrification and recovery of organs with complete long-term viability. Such a breakthrough would not only lead to cryogenic organ banking for transplantation and research but would remove the most fundamental obstacle to true suspended animation of humans.

Brain death and cryonics

Although a vitrified patient cannot be rewarmed and restored to health with contemporary technologies, the extremely low temperatures at which a patient is maintained permit possible resuscitation of a patient in the future without any risk of deterioration during long-term care. In this sense it compares favorably to procedures such a hypothermic circulatory arrest which allow for only a few hours to treat a patient. This not only offers the option to treat patients who cannot be treated with contemporary medical technologies, it also offers the possibility to treat medical conditions where successful resuscitation is possible but higher brain function will be lost if care is resumed at normal body temperature.

A good example of this is cardiac arrest. Patients who have suffered more than 5-7 minutes of cardiac arrest can often be resuscitated, but some of the most vulnerable cells in the brain (such as hippocampal CA1 neurons) will die within days of the insult. There are currently no effective medical interventions or neuroprotective agents that will prevent such damage. As a result, today’s medicine can restore viability to such patients, but only by losing some, or most, higher brain functions.

If one believes that the objective of medical care is not just to preserve life in the sense of integrated biological function, but also to preserve the person, then one would agree that such patients might be better served by interventions that place them under long-term care in the form of cryonics. Although there is no guarantee that such patients will be restored to full functionality in the future, the near-certainty of higher brain death is an alternative that many people would prefer to avoid.

Conclusion

Cryonics does not involve the freezing of dead people. Cryonics involves placing critically ill patients that cannot be treated with contemporary medical technologies in a state of long-term low temperature care to preserve the person until a time when treatments might be available. Similar to such common medical practices as general anesthesia and hypothermic circulatory arrest, cryonics does not require a fundamental paradigm shift in how conventional medicine thinks about biology, physiology, and brain function. Although current cryopreservation methods are not reversible, under ideal circumstances the fine structure that encodes a person’s personality is likely to be preserved. Complete proof of reversible vitrification of human beings would be sufficient, but is not necessary, for acceptance of cryonics as a form of long-term critical care medicine. The current alternative is death; or for persons who are at risk of suffering extensive brain injury, loss of personhood.

For very old and fragile patients, meaningful resuscitation would require reversal of the aging process. Obviously, the objective of cryonics is not to resuscitate patients in a debilitated and compromised condition, but to rejuvenate the patient. Ongoing research in fields such as bio-gerontology, nanomedicine, and artificial intelligence inspire optimism that such treatment will be available in the future. In 2022, the nanotechnology expert Robert Freitas published an extensive book-length exposition how such revival attempts will look like, titled “Cryostasis Revival: The Recovery of Cryonics Patients through Nanomedicine.”

The fortunate thing for cryonics patients is that even if fundamental breakthroughs in these fields will be the result of long and painstaking research, the cold temperatures allow them time — a lot of time.

The First Minutes After “Death”

As currently practiced, cryonics procedures can only be started after legal death has been pronounced by a medical professional. To prevent brain injury between pronouncement of legal death and long-term care in liquid nitrogen all major cryonics organizations offer standby services to ensure that the time of circulatory arrest is minimized. In ideal circumstances the cryonics organization of which the patient is a member will deploy a standby team consisting of cryonics professionals to stabilize the patient immediately after pronouncement of legal death.

A mechanical device is used to restart blood circulation and ventilate the patient. Because the objective of this intervention is not to resuscitate but to stabilize the patient this is called cardiopulmonary support (CPS). At the same time the patient is lifted into a portable ice bath to induce hypothermia to slow metabolism. A number of medications are also given to support blood flow to the central organs, reverse and prevent blot clotting, restore physiological pH, prevent edema, and protect the brain from ischemic injury. After completion of CPS, the patient is further cooled by replacing the blood with an hypothermic organ preservation solution, similar to mainstream organ preservation solutions like Viaspan.

At the cryonics organization the patient’s blood is replaced with the vitrification agent to prevent ice formation during cooldown to liquid nitrogen temperature for long-term care. More recently, cryonics organizations have replaced transport to the cryonics organization at cold temperature (near 0 degrees Celsius) with a procedure called field cryoprotection (FCP) in which the cryoprotection part is done at a remote location (or even a vehicle) as well, followed by transport on dry ice (-78.5 Celsius) to the facility for further cooling and long-term care.

An earlier version of this article was published in 2007 for Pharmaciae Sacrum, the study association of pharmacy students in Groningen, the Netherlands.

The Greek philosopher Epicurus famously wrote:

Death is nothing to us, since when we exist death is not present, and when death is present we no longer exist.

Epicurus addressed subjective experience. We can now add a scientific corollary: reports of “death” are often premature and greatly exaggerated.

For most of history, aging and death were incomprehensible and final.
There was nothing actionable to do about it.

That has changed.

Here we do not treat death as binary, inevitable, sacred, or morally necessary.

We now have

• Demonstrated vitrification of mammalian organs

• Structural preservation of the brain

• Continued progress in cryoprotectant design

• Imaging methods that verify preservation outcomes

• Molecular strategies to characterize and repair damage at nanometer scale

• Rapid progress in AI and deep learning

• A growing experimental literature on biostasis technologies

The proposition

You are not irreversibly dead until the physical basis of your identity has been erased.

If that physical substrate can be preserved or inferred, death need not be final.

This publication explores that preservation challenge.

Topics

• Metabolic arrest and hypometabolism

• Cryoprotection and vitrification

• Cerebral ischemia and neuroprotection

• The chemistry of death

• Structural preservation of neural tissue

• Revival technologies

• Philosophy of mind

• Rejuvenation technologies

• Biostasis providers and protocols

The tone of this publication is:

• Empirically grounded

• Technically serious

• Skeptical of hype

• Skeptical of resignation

• Open to uncomfortable conclusions

If you are looking for simplistic promises, this is not the place.
If you are looking for miserabilism or dystopian fatalism, this is also not the place.

Some posts will be technical.
Some will be philosophical.
Most will live in the uncomfortable territory between.

Continuity

This publication continues the original Depressed Metabolism cryonics blog.

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biostasis.com

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