I wrote this letter, adressed to the attorney for the Alcor Life Extension Foundation, in January of 1988 to support Alcor's position in the Dora Kent case, which happily was ultimately resolved in Alcor's favor. At the time, I was a week away from leaving the Fred Hutchinson Cancer Research Center into order to join the Bristol-Myers Squibb Pharmaceutical Research Institute–Seattle (my education, positions, and research publications). Naturally, the opinions I expressed were my private professional opinions and had nothing to do with either the institution I was leaving or the institution I was joining. I have been a member of the Alcor Scientific Advisory Board since about 1996.
—James B. Lewis, PhD
January 22, 1988
Dear Mr. Ashworth:
I am writing to provide a professional opinion as to the general feasibility of cryogenic preservation as a rational gamble to obtain a chance of the future reanimation of the very recently deceased. These comments are based on reasonable extrapolations as to the capabilities of future technologies, founded upon our current knowledge of basic molecular and cellular biology. The conclusion of my arguments will be that, although reanimation of cryogenically preserved individuals is not possible with current technology, nor can it be proven that reanimation will be possible in the future, current developments most emphatically do provide a reasonable basis for supposing that such technology might be available within the next 30 to 50 years. Further, and most importantly, the nature of these probable developments is such that damage caused by current freezing techniques, which is serious enough that reanimation with current techniques is highly unlikely, is not likely to prevent reanimation with radically different future techniques. Thus the decision to pursue cryogenic preservation now is a rational gamble, and is definitely not absurd or without basis in our current scientific knowledge. Finally, whatever chance does exist would be irretrievably lost by the deterioration that would accompany autopsy or other analysis of a cryogenically preserved individual.
My professional credentials are given in the enclosed CV. Briefly, I have a PhD in Chemistry from Harvard University, and have done research in molecular biology and virology at the doctoral level for the past 16 years, the past 13 years as a principal investigator. My research has been at several of the foremost institutions in these fields, and has been funded by the National Cancer Institute, the National Science Foundation, and the American Cancer Society. Published contributions to my field, which has been primarily the study of DNA tumor viruses, are listed in the enclosed CV. My current position, which I have held for a bit more than 7 years, is as Associate Member of the Basic Sciences Faculty at the Fred Hutchinson Cancer Research Center, although I am in the process of moving to a biotechnology company. In addition, I have an appointment as an Affiliate Associate Professor in the Pathology Department of the University of Washington Medical School.
What follows is my personal professional opinion as to the current state of our knowledge of molecular and cellular biology relevant to cryogenic preservation with the goal of reanimation in the future. Currently we routinely preserve various mammalian cells by storage in liquid nitrogen, and these cells are routinely viable when thawed. All scientists, however, would agree that current technology is not capable of reviving intact organisms as complex as humans. Even if such could be done, the more fundamental problem is that the cryogenically preserved individual had already died before preservation, so would not be viable even if the technology existed to preserve and reanimate healthy individuals. The basic problem is that current preservation techniques probably inflict a substantial amount of damage to the functional integrity of complex tissues, such as human brains, and this damage can not be repaired when the tissues are thawed. Likewise, the reason people die in the first place is that one disease process or another produces very substantial damage to one or more essential life systems, so that the body no longer functions. Current medical technology does not, in general, permit the repair of such damage. Thus everyone eventually accumulates enough damage to vital systems that death is unavoidable. Similarly, because such damage can not now be repaired, complex neural tissue can not be functionally restored after storage in liquid nitrogen.
The key to our current medical and technical limitations is that human beings are very complex organisms composed of trillions of cells arranged in incredibly complex patterns, and each cell is itself a very complex structure composed of trillions of atoms arranged in incredibly complex ways. In general, once these complex patterns of atoms and cells are sufficiently disrupted, they lose the capability to repair themselves. Since all current medical technology relies on augmenting or supporting this natural self-repair capacity, cells and individuals that have suffered sufficient damage to this complex organization are irretrievably dead. However, if we could manipulate complex structures at the atomic level, this limitation would lose its force.
Such an ability would make relevant a very fundamental distinction between preservation of function and preservation of structure. Cryobiologists are currently hostile to the basic premise of cryonics because they correctly point out that current freezing techniques introduce such substantial damage to brain tissue that retrieval of function upon thawing is impossible. I have no reason to disagree on this point. However, if technology becomes capable of massive manipulation of complex structures on the atomic level, it will be possible to repair freezing-induced damage, and thus to rebuild and then reanimate. The relevant question then becomes, what degree of structure, not function, must be preserved to preserve the essential aspects of an individual's personality. Although I am not a neurobiologist, my understanding of the consensus of this field is that thoughts are likely to be represented by the specific pattern of connections made at the estimated 1,000,000,000,000,000 synapses of the human brain. Furthermore, electron microscopic examination of frozen specimens of human brain reveals that these structures are essentially preserved by current freezing techniques, even though the ability of brain cells to function is not preserved. Thus, the argument of the cryobiology community that preservation is absurd is not correct, because the functional damage caused by freezing is irrelevant to the question of whether cryogenically preserved individuals could be reanimated with radically advanced technology. This does not mean, of course, that reanimation of individual consciousness is assured, because this obviously can not be tested until such advanced technology arrives, but it does mean that reanimation is a rational gamble.
As an aside, I might add that the expectation of the ability to rebuild very complex biological structures rationalizes one of the apparently bizarre aspects of cryogenic preservation. The thought of preserving only the head and then having to "reattach" or "transplant" the reanimated head to a body at a future time makes cryonics seem especially implausible. However, the very technology that will make it possible to repair freezing damage to the brain will make it possible to rebuild a complete body, from the genetic code preserved in each cell of the individual's head, from scratch.
The crucial question is thus whether such a radically advanced control over complex structures at the atomic level is at all likely, or even possible. If it is, according to our current understanding of science, fundamentally impossible or highly unlikely, then cryonics is a fraud. However, if a reasonable possibility exists for the development of such technology, then cryonics is a rational gamble that rational individuals may decide on a personal basis to take or not to take. Such potential technical ability has been recently given the name "nanotechnology". A detailed discussion of nanotechnology is not possible here, but a lucid presentation of the principal ideas, accessible to the scientifically-literate layman, has been published (Engines of Creation, by K. Eric Drexler, Anchor/Doubleday, 1986). I will paraphrase a few of the major points here.
First of all, the manipulation of individual atoms to make complex structures at the atomic level is not forbidden according to our current understanding of the laws of physics and chemistry. This much was first pointed out back in 1959 by the eminent physicist Richard Feynman. More recently (1981) Eric Drexler pointed out in a paper published in the prestigious scientific journal, Proceedings of the National Academy of Sciences,USA, that many known biological systems are in fact already known to be molecular scale machines. Thus it should be possible to build machines (named assemblers) that will manipulate individual atoms to build complex structures, to build very small computers to direct these machines, and to enable these machines to replicate and produce trillions of copies to build and repair large structures from the atomic level on up.
Just how these assemblers will be built can not be predicted at this point in the development of science and technology (or else we would already have nanotechnolgy now or in the near future), but there are several current developments very much in the mainstream of science that give considerable cause for optimism that assemblers will be possible. First of all, is the invention of the scanning tunneling microscope, which won its inventors a share of the 1986 Nobel Prize for Physics. This machine, and a related device called the atomic force microscope, permit scientists to visualize individual atoms in structures, and in preliminary research published just last year in Nature, another first-rate scientific journal, to actually manipulate individual atoms; i.e., to physically pick up an atom and move it from one place to another. Further abilities in designing ways to handle individual atoms were recognized by the 1987 Nobel Prize in Chemistry, which included recognition for "cage" compounds that could be designed to bind specific atoms in analogous ways to the workings of enzymes and other biological molecules.
A third approach includes the reason that nanotechnology has become of substantial interest to me since I first read of these ideas nearly two years ago. The essence of molecular biology is to understand the molecular basis of life: what molecules perform what functions in the living cell and how they do it. Enormous progress over the last few decades has permitted us to understand how DNA encodes the instructions for the living cell, and how to manipulate those instructions, giving birth to the biotechnology industry. To be somewhat more explicit, DNA encodes the order of amino acids that make up the long chains of individual protein molecules. Each specific order of amino acids in each specific protein then causes that protein to fold up in three dimensions into a specific shape to make a specific molecular machine. These individual protein machines are what makes each living cell work. Although we understand how to manipulate DNA to make a specific order of amino acids, we do not yet understand how to choose the proper order to make a particular structure, which will make a machine to do a particular job. Initial work in biotechnology has been directed toward mass-producing very valuable proteins that already exist in nature, but are difficult or impossible to prepare by ordinary methods. However, a very rapidly growing new area of biotechnology is the area known as "protein engineering". As the name implies, this field of work attempts to design proteins to do specific functions that naturally-occurring proteins do not do, or do not do well. Three years ago, protein engineering was a very new and esoteric field. Now there are several journals devoted to the field and several major scientific meetings. So far, most work has been devoted to making minor modifications of naturally-occurring proteins. However, some people are beginning to try to design specific protein structures from scratch. It is, in my opinion and in the opinion of experts in this new field, not unreasonable to expect that over the next few decades (that's decades, not centuries) such work may lead to the ability to manipulate atoms to build complex, pre-designed structures; i.e., to build crude assemblers that will enable us to bootstrap our way to a mature nanotechnology.
As a molecular biologist working to understand how normal and cancerous cells work, and who is planning to learn and exploit protein engineering for designing better products in the biotechnology industry, I am vitally interested in the prospects of eventually developing nanotechnolgy. Recently, I have helped organize an informal group of both technical and nontechnical people in the Seattle area to explore the development and implications of nanotechnology. It is thus my firm belief that these immensely exciting areas of scientific investigation will have far-reaching consequences, including the possibility of reanimating cryogenically preserved individuals and providing them with healthy new versions of their own bodies. To do this, however, requires that the structures in the brain that encode memories and personality be preserved. I believe that storage in liquid nitrogen will plausibly effect this preservation, even though current techniques do damage tissue in the process of freezing. I further believe that most scientists would agree that the broad thrust of current work in several areas of science is aimed at control of complex structures with atomic precision, even though there would be very diverse opinions as to how and when this control would be achieved. What this all means is that successful reanimation of frozen brains is arguable - not assured and not absurd either — but arguable, and thus a reasonable area for individuals to decide whether or not they are interested in gambling for the possibility of a long and healthy life in the future, for themselves and/or for their loved ones.
Yours truly,
James B. Lewis, PhD
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