Ilia Stambler, PhD
From Ilia Stambler. A History of Life Extensionism in the Twentieth Century, 2014 (www.longevityhistory.com)
When speaking of the extension of life, or radical extension of life, the question that should immediately arise – what is it exactly that we desire to extend or preserve during life extension? What is that thing that we would wish to preserve in continuity or even in perpetuity? I would argue that the goal of life extension has been associated with a striving for stability and equilibrium, desiring to stabilize and thus perpetuate the current state of the body or personality, and the present social system. In this sense, life-extensionism may be a fundamentally conservative (or conservationist) enterprise. Therefore, the impression that life-extensionism represents a form of utopianism, a fringe or revolutionary movement, or an advocacy of a radical change of human nature – should be rejected or accepted only with profound reservations. Historically, the proponents of radical life extension may have envisioned no greater change to human nature than the extent to which maintenance of an ancient edifice changes the nature of that edifice, or the extent to which the (often high-tech) restoration and conservation of an old work of art make it a forgery. The life-extensionists may indeed have strived for a perfected society, which one might call a “utopia,” but that “utopian” society, they hoped, would uncannily resemble the one they lived in, with all or most of its institutions intact and all the near and dear ones alive and around. The life-extensionist movement may have been profoundly anti-revolutionary, if only for the simple reason that opposing the existing social system would nullify public support for longevity research. After a revolution has won, the life-extensionists may side with the winner (either opportunistically or in a firm belief, or both).
The adaptability of life-extensionists to the changing social patterns may be rapid, but paradoxically, once an adaptation had been established, it would appear that the new pattern would continue indefinitely, or only with very minor modifications. Hence, rather than speaking of life-extension generally, it may be necessary to speak of the extension of particular “life-forms” or “life patterns” – personal or social – the forms that are being perpetuated or fixated upon. We may perhaps want to select or at least discuss the patterns that we indeed wish to perpetuate. In other words, we may consider what social practices, ethical precepts or power structures may be involved in the pursuit of life-extension, or what would be the form of society in which we would wish to live long. An undesirable yet unchangeable pattern may be a dystopian prospect indeed. The question may still be raised regarding the form of society that is most conducive to longevity research or to actually increasing human longevity.
The desire to preserve constancy is difficult to fulfill, as changes in general and deteriorative changes in particular are difficult to resist. This might be one of the reasons why radical life-extensionism has not become entrenched in the public mind. The task of maintaining constancy, equilibrium or homeostasis, is daunting and goes against too many odds. Yet, the human desire to maintain constancy, in spite of all change, has been persistent as well, and in this regard life-extensionism is nothing exceptional. The inevitability of change has been acknowledged in many conceptions of social organization. But the desire for constancy and stability has been acknowledged as well. Thus according to Hegel’s classical conception of the “Zeitgeist,” or the “Spirit of the Age,” prolonged periods of stability are not tolerated, but subverted by internal oppositions. “Periods of happiness,” Hegel wrote in The Philosophy of History (1837) “are blank pages in [the History of the World], for they are periods of harmony – periods when the antithesis is in abeyance.” Civilizations are always changing, manifesting the development and realization of Spirit. But Spirit itself does not change. “Spirit is immortal; with it there is no past, no future, but an essential now … the present form of Spirit comprehends within it all earlier steps. … what Spirit is it has always been essentially; distinctions are only the development of this essential nature.” Moreover, according to Hegel, as far as human capacity for reasoning goes, constancy is always sought for. As Hegel stated in the Encyclopedia of the Philosophical Sciences (1830), “reflection is always seeking for something fixed and permanent, definite in itself and governing the particulars.” Also in Marxism, owing a great deal to Hegelianism, change and constancy are pervasive concerns. In Marxism, “social formations” constantly change, being subverted by economic developments and class struggle; that is, until the “social formation” of communism will be reached, where there will be no class struggle and which will presumably continue indefinitely. Even much earlier, transformative change has been a fundamental concept of Taoism, the “Book of Changes” being one of the most venerated texts of Chinese philosophy. Yet, Taoism also envisions the attainment by the society of the state of “Taiping” – the state of Great Peace – that will enjoy stability and harmony for eternity. (Ironically, the historical Kingdom of Taiping (1850-1864) was one of the most turbulent and violent in Chinese history.)
The recognition of the inevitability of change and the desire for perpetuation are also present in many works of cultural history, particularly the works on the history and sociology of science. Thus, in Thomas Kuhn, paradigms constantly shift, being subverted by anomalies. Yet Kuhn also points out the resilience of established paradigms. “And at least part of that achievement always proves to be permanent” (1962). (Or else, logically, the paradigmatic belief in paradigm shifts may itself pass.) Bruno Latour speaks of “reference” as “our way of keeping something constant through a series of transformations”(1999). Steven Shapin speaks of “broad European changes in attitudes to knowledge in general and to the relations between knowledge and social order.” Yet, immediately afterwards, he notices “a state of permanent crisis affecting European politics, society and culture” (1996). Michel Foucault, in The Order of Things (1966), speaks of “fixism” and “evolutionism” as “two simultaneous requirements,” and “these two requirements are complementary, and therefore irreducible.” Stability and fixity are intrinsically related to order. And the striving for stable equilibrium has been related to rationalism.
Further confirming the inexorable presence of both the concepts of change and of constancy, the American social historian Peter Burke (2005) defines “modernity” as “the assumption of fixity” and “post-modernity” as “the assumption of fluidity,” “the collapse of the traditional idea of structure,” “destabilization and decentering.” In a “modern” or “modernizing” discourse, the rhetoric of progressive change is persistent, but it may conceal a deep-seated desire for fixity and stability. And in a “post-modern” discourse, “change” is a commendation in and of itself, and “constancy” or “stability” are commonly either ignored or vilified. Yet the desire to preserve constancy cannot be easily rejected. Burke points out numerous attempts “to freeze the social structure,” to “resist change.” “Such activities,” Burke suggests, “surely deserve a place in any general theory of social change.”
On a continuum between the desire for absolute change and the desire for absolute constancy, the life-extensionists would seem to stand closer to the pole of constancy. Indeed, without some notion of constancy, the concept of life-extension, even of survival, would be meaningless. Consider such cases as the atoms of a decomposing human body merging with the Universe, or human life being transformed into the life of grave worms, as discussed by Jean Finot in The Philosophy of Long Life (1900). Many boundaries are “transcended” in such “transformations,” but one can hardly speak of “life-extension.” If extinction is determined by “a critical rate of long-term environmental change beyond which extinction is certain” (notice, any change), then life-extensionists would wish to be as far from this rate of change as possible. Or else, they would wish to design the technological armor that would make us impervious to such changes. Without work invested in maintaining constancy, spontaneous deteriorative change may be expected. Thus, in the sense of Burke’s definition, life-extensionism is a very “modern” endeavor. The rhetoric of progressive change is emphasized, but not just any change for the change’s sake, but only such change that would serve to perpetuate some existing structure. In the words of the protagonist of Giuseppe di Lampedusa’s The Leopard (1960) “If we want things to stay as they are, things will have to change.” And in the words of Lewis Carroll, “it takes all the running you can do, to keep in the same place” (1871).
The question may again arise: what is it exactly that the life-extensionists would endeavor to fix? For a religious person, the answer might be easier. The things that require preservation might be the eternal, imperishable soul maintained in a robust temple of the body, and a God-decreed social order and way of life. But for a materialist, believing in the contingent and temporal construction of physical objects, the answer may be much more difficult. Should the preservation efforts be directed to some arbitrary structure, archetype, memory, connections, the Zeitgeist? Hegel’s classical notion of the “zeitgeist” has now been generally discarded. As succinctly stated by the Austrian-British art historian Ernst Gombrich in his book In Search of Cultural History (1969), in place of the Hegelian search for expressions of the universal spirit of the age, there comes the search for connections within the surrounding culture, since “any event and any creation of a period is connected by a thousand threads with the culture in which it is embedded.” And thus, an historian may observe distinctions between specific social and ideological environments or “embedding cultures” (for example, French liberalism followed by conservatism, German fascism, Russian communism or American capitalism), even without providing exact definitions, and may detect specific adaptations.
With reference to life-extensionism, the adaptations can be clearly perceived. Even the very terms for life-extensionism have varied according to period and context – internal alchemy, gerocomia, macrobiotics, rejuvenation, experimental gerontology, anti-aging, prolongevity, life-extensionism, immortalism, transhumanism – as befits the circumstance of political correctness. And the terms for progress, within which life-extensionism has been commonly embedded, have changed as well: in place of the somewhat archaic “meliorism” and the somewhat ominously sounding “progressivism,” now the more popular terms are “making the world a better place,” “sustained human development” or “continuous evolution.” An apparent persistent opposition in life-extensionist methodologies, between what may be termed here “reductionist” vs. “holistic” approaches to life-extension, emphasizing, respectively, targeted repairs of the human machine vs. psychosomatic effects, also seems to have undergone shifts of terminological fashions. These were manifested in the dichotomies of “mechanism” vs. “vitalism,” “materialism” vs. “idealism,” “invasive/artificial therapeutics” vs. “non-invasive/natural hygiene.” The respective terms are not entirely synonymous. Moreover, “reductionist” and “holistic” methods for life-extension were often combined by the proponents. Yet, similarities and continuities between the respective terms can nonetheless be observed.
But perhaps the most salient adaptations were to what might be termed the “dominant socio-ideological order” – “liberalism” or “conservatism,” “fascism,” “communism” or “capitalism” – whose prevalence in the specific countries and periods under consideration is apparent. Though these “dominants” may seem similar to Hegelian manifestations of the “Spirit of the Age,” they are rather expressions of the “interconnected embedding culture,” not something “essential” but rather categorical and contingent. The adaptations of life-extensionism to particular contexts took various forms. These included the rhetorical support of the ruling socio-ideological order (if only to ensure that the research is not shut down by the authorities), and the positing of metaphorical socio-biological parallels between the workings of the body and the society in which the authors lived. Moreover, specific research projects were favored as compatible with the ruling socio-ideological order. But variation was only a part of the adaptation process; another was conservation. The life-extensionists did not simply “adapt” to the changing socio-ideological conditions, but sought to conserve the adaptation, sought to make their relations to the environment or “embedding culture” stable. I argue that the support of the existing ruling regime, whatever it may be, may derive from the nature of life-extensionism that seeks stability and constancy.
The life-extensionists’ inherent desire for constancy has stood in stark contrast to “apocalyptic” beliefs. Such beliefs have been present throughout the century, and they had been recently intensifying. There has existed an extensive literature expecting (and accepting) “the world as we know it” to end anytime soon. In morbid excitement, the prophets of the apocalypse have often stressed the great corruption of humanity, expressing what the novelist John Updike termed “a smug conviction that the world was doomed” (1972). Insofar as humanity was seen as inherently corrupt and self-destructive, a thorough “cleansing” appeared to be in order, through an all-out war between “the sons of light” and “the sons of darkness,” separating the bad “weeds” from the good “wheat.” Often the apocalyptists, both secular and religious, have had some very strong convictions about who the “sons of darkness” and the “weeds” are.
Historically, the life-extensionists have exhibited none of this attitude. They might find it difficult to distinguish and separate between the “weeds” and the “wheat” and would request a longer life-span to figure it out. Until then, the entire societal and personal ‘bundle’ may need to be conserved. Alternatively, many life-extensionists appear to have realized the existence of corruption and exploitation in the current society, whose perpetuation would be highly undesirable. But at the same time they also extrapolated on the manifestations of creativity, benevolence and justice, as well found in the current society, and considered them to be worth preserving indefinitely. Thus they would follow the ancient Talmudic command that “the sins will cease” but not “the sinners.” While the “apocalyptic” view largely assumed that human attempts to resist catastrophic changes are destined to failure, the life-extensionists, even though recognizing existential threats (and the threat of senescent death in the first place), valorized our ability to defend ourselves. Whatever the explanation or underlying motives, life-extensionism appears to be a profoundly anti-revolutionary, anti-catastrophic, anti-apocalyptic ideology. As the American author William Bailey emphasized in his bibliography on Human Longevity from Antiquity to the Modern Lab (1987), “Death be not proud, this heartening literature opposes Armageddon and the perniciousness of nature to say that we can extend life and enjoy many another springtime.”
The questions still remain considering what exactly the life-extensionists would desire to maintain constant, and whether anything at all can be maintained constant. An answer may be again suggested by Taoism. As the great teacher of Taoist immortalists, Lao Tse said of the Tao (the Way or Course): “How still it was and formless, standing alone, and undergoing no change. … Great, it passes on in constant flow.” Moreover, human beings should “possess the attributes of the Tao.” No wonder then that in Taoism, radical life-extension and conservation of order have always been all-pervasive aspirations. If Heraclites could not “step twice into the same river; for other waters are continually flowing in”; Lao Tse could, for the course of the flow may remain constant. It seems as if Walter Cannon’s concept of homeostasis, described in The Wisdom of the Body (1932), follows directly Lao Tse’s notion of the Tao. In Cannon, some constancy is provided by what he terms “the interesting fact that we are separated from the air which surrounds us by a layer of dead or inert material.” Yet, for Cannon, the organism is not entirely separated from the environment, but related to it through a constant flow of materials and energy: “the internal, proximate environment of the cells is made favorable by keeping the fluids on the move and constantly fresh and uniform.” A modern textbook definition of homeostasis would say the same. The materials may be exchanged, but the course and the form of their flow remain constant: “life is characterized by a continuing flow of material and energy, and a steady state is reached if all possible disturbing factors remain constant.”
A ramification of this idea can be found in the philosophy of Arthur Schopenhauer (1788-1860) who postulated that “the dead body is a mere excrement of a constant human form.” That is to say, all materials in the human body are being incessantly replaced, and only their form or arrangement is constant. Schopenhauer’s “pessimistic philosophy,” calling for reconciliation with death, was hardly compatible with life-extensionism. The life-extensionist founder of gerontology, Elie Metchnikoff took great pains to refute it, among other reasons, because he did not believe that the “form” or “ideal,” either of an individual or of a species, can exist without a material substrate (1903). Yet, the particular idea of Schopenhauer’s regarding the constancy of the human form, despite the material replacements, was approvingly cited by the German gerontologist Max Burger, the proponent of “biorhesis” or stable biological flow (1947). Indeed, various “replacement therapies” – ranging from hormones through vitamins and minerals to stem cells, artificially grown organs and bionic prostheses, while maintaining the constancy of the human form – have constituted the core of life-extensionist methodologies throughout the century, mainly in its “reductionist” and “materialistic” branches. In the “holistic” and “idealistic” branches, some essential core of human personality was believed to be able to directly control the body and resist bodily changes.
The idea of maintaining the constancy of structure and function through a continuous replacement of material components can be traced even further back to the “Paradox of the Ship of Theseus” first mentioned by Plutarch (c. 46-120 CE). The great quandary was whether a ship, all of whose parts are replaced, will retain its identity. For the life-extensionists this has been a vital issue and their implicit (and often explicit) answer has been that it would indeed remain essentially the same, since its structure and function would be preserved. And if some new components were to be added to the “Theseus’ Ship” to improve and prolong its performance, it would be essentially the same as well, since a major part of its structure and function would remain constant. However, if it were to break down into components, even though the materials would remain, the constancy of form would be lost.
Science fiction related to life-extension had a field-day with this paradox. Among many examples, in Stanislaw Lem’s “Do you exist, Mr. Johns?” (1955), the protagonist has all his biological components replaced by artificial ones, and the company that produced them claims ownership over him. The cybernetic human vehemently defends his right to an identity (that is, being identical to the former biological human), since his personal memories are uniquely his own and are only preserved in a different substrate. Even as a biological entity, all of the materials in his body were being replaced in a very short time. By analogy, he is now no more the property of the company than he was the property of the grocer who formerly supplied him with food.
Beyond science fiction, for practicing life-extensionist scientists, the “Theseus’ Ship Paradox” has been a practical concern, as it informed the search for replacement therapies. And the paradox has been resolved in a similar, positive manner. Thus Aubrey de Grey wrote in Ending Aging (2007):
“I emphasized … that the body is a machine, and that that’s both why it ages and why it can in principle be maintained. I made a comparison with vintage cars, which are kept fully functional even 100 years after they were built, using the same maintenance technologies that kept them going 50 years ago when they were already far older than they were ever designed to be.”
The main point is that for the life-extensionists, the possibility of maintaining the constancy of form has been certain.
The same valorization of the constancy of form recurs in Ray Kurzweil’s The Singularity Is Near: When Humans Transcend Biology (2005). Yet, instead of the classical notion of the “form,” Kurzweil uses the term “pattern.” Kurzweil is a world-renowned expert in pattern recognition, having pioneered several ground-breaking developments in optical character recognition, speech recognition, stock-market pattern recognition and more. The entire world, according to Kurzweil, consists of “patterns of information”: patterns of matter and energy, biological and social patterns. And there are precise procedures in information theory to determine the extent to which various patterns, material, biological or social, are similar or different (for example through the use of entropy and mutual information). Hence, for Kurzweil, the maintenance of specific patterns is a very tangible and practical task. Insofar as orderly information patterns are constantly maintained by biological systems, such patterns can be similarly (perhaps even better) maintained by machines. A dedicated life-extensionist, Kurzweil suggests the constancy of an information pattern, comprising the human body and mind, as an underlying concept for indefinite survival:
“My body is temporary. Its particles turn over almost completely every month. Only the pattern of my body and brain have continuity. … Knowledge is precious in all its forms: music, art, science, and technology, as well as the embedded knowledge in our bodies and brains. Any loss of this knowledge is tragic. … Death is a tragedy. It is not demeaning to regard a person as a profound pattern (a form of knowledge), which is lost when he or she dies. That, at least, is the case today, since we do not yet have the means to access and back up this knowledge.”
By perfecting the means of preserving our “information patterns” and eventually “backing them up,” human life can be preserved indefinitely: “We are now approaching a paradigm shift in the means we will have available to preserve the patterns underlying our existence.” And further down the line, “As we move toward a nonbiological existence, we will gain the means of ‘backing ourselves up’ (storing the key patterns underlying our knowledge, skills, and personality), thereby eliminating most causes of death as we know it.” Thus the conservation of the existing patterns is an explicit goal. Kurzweil admits that he cherishes all his memories and never discards any memorabilia, since they constitute the unique pattern of his personality. Furthermore, one might suggest, Kurzweil’s valorization of “democracy and capitalism” is a part of the overall program to conserve the “pattern” in which he exists.
It should be noted, however, that, in Kurzweil, the conserved pattern is not perceived as entirely stagnant. Rather, the underlying metaphor is that of a continuous growth, building new structures on the existing foundation or “core” and including the already existing building blocks. Kurzweil uses the analogy of an old computer file that may be preserved in a new computer, yet with many new files added to it. Similarly, our general “mind file” will be conserved, yet augmented with new extensions. The “core pattern” is not entirely unchangeable either, but it changes slowly and gradually. Still, the continuity of the pattern is maintained: “You change your pattern – your memory, skills, experiences, even personality over time – but there is a continuity, a core that changes only gradually.” Technological enhancement will not radically modify this “core”: “that’s just a surface manifestation. My true core changes only gradually.” Kurzweil uses as an epigraph to his discussion of longevity the statement by the American computer scientist Vernor Vinge (1993) that the technologically enhanced human “would be everything the original was, but vastly more.” Still, it would be “everything the original was.” Thus, the underlying desire for constancy is affirmed once again.
The assumption of constancy may also answer the frequently raised question: ‘Why would we want to prolong life?’ If human life is an absolute value now, and its value will remain the same tomorrow or in a hundred years, then all the efforts to preserve human life at any moment and for any period of time are justified. It is important to bear those philosophical considerations in mind when researching the historical motivations for life-extensionism.
Finally, and paradoxically, out of the desire for constancy, novelty arises. It is easy to dismiss the pursuit of life-extension as a “pipe dream.” Yet, many examples show that the scientific contributions of life-extensionist researchers have been considerable, and often pioneering: the first attempts at therapeutic endocrinology, blood transfusion, transplantation, cell and tissue therapy, probiotic diets, cryobiology, general hygiene, and more. These developments may have been not just due to ‘aiming high’ and in the process bound to achieve at least some results, even though most often falling short of the original aspirations. Rather, the scientific advances made by the life-extensionists may be the product of their underlying conservative bent on stability and perpetuation. As the stability of the internal milieu could not be achieved by contemporary medical technology, innovative interventions were sought. Consider, for example, such late 19th-early 20th century developments as Nikolay Pirogov’s plaster casts to fixate the bone (c. 1870), Porfiry Bakhmetiev’s preservation of animals by freezing (c. 1900), or Auguste Lumiere’s introduction into biomedicine of film and auto-chrome plates to safeguard images of the body (c. 1900). All these can be viewed as technological novelties employed in the service of maintaining constancy. And if some methods of maintaining constancy failed, such as the reductionist “endocrine” rejuvenation – new methods of maintaining homeostasis would emerge, such as improved (and still reductionist) replacement techniques or more systemic, holistic or hygienic approaches.
Many life-extensionist scientists spoke explicitly about their desire to maintain constancy through novel technological means. Thus, the British pioneer of X-ray crystallography, John Desmond Bernal (1901-1971), asserted that new technological extensions of existing human capabilities will lead to an indefinite extension of life and a greater “fixity” of human personality (1929): “This capacity for indefinite extension might in the end lead to the relative fixity of the different brains; and this would, in itself, be an advantage from the point of view of security and uniformity of conditions.” At any rate, the technologically modified man may have a better chance for self-preservation than an unmodified one, even at an early and imperfect stage of the modifying technology: “But though it is possible that in the early stages a surgically transformed man would be at a disadvantage in capacity of performance to a normal, healthy man, he would still be better off than a dead man.” The Russian pioneer of neurophysiology, Ivan Pavlov, spoke about the fundamental drive of science toward equilibration of living systems (1923): “There will be a time, even though a remote one, when mathematical analysis, based on natural science, will encompass, by magnificent mathematical equations, all existing equilibria.” And as one of the foremost twentieth century life-extensionists, the French-American pioneer of organ transplantation and tissue engineering, Alexis Carrel contended (1935): “Science has supplied us with means for keeping our intraorganic equilibrium, which are more agreeable and less laborious than the natural processes. …the physical conditions of our daily life are prevented from varying.” Thus the desire for fixity and equilibration may have been a pervasive motive in life-extensionism and often a source of new developments in biomedical science and technology. As the “philosopher of long life,” Jean Finot asserted (1900), the primary purpose of biomedical advances is not to change, but to “preserve and greatly strengthen existing life.”
References and notes
 Historically, there have been life-extensionist utopias, such as Tommaso Campanella’s The City of the Sun (1602), where “The length of their lives is generally 100 years, but often they reach 200” (http://www.gutenberg.org/files/2816/2816-h/2816-h.htm). And there have also been anti-life-extensionist utopias, such as Thomas More’s Utopia (1516), where “when any is taken with a torturing and lingering pain,” they “choose rather to die since they cannot live but in much misery” (http://www.gutenberg.org/files/2130/2130-h/2130-h.htm).
But in both cases, the utopian society is preserved in a perpetual equilibrium, and the authors’ values are hoped to triumph for all posterity.
 Georg Wilhelm Friedrich Hegel [1770-1831], The Philosophy of History, Translated by J. Sibree, Colonial Press, New York, 1900 (first published in 1837), pp. 26-27, 77.
 G.W.F. Hegel, Encyclopaedia of the Philosophical Sciences, Third and Final Edition, 1830, translated by William Wallace, first published 1873, Part II. Preliminary, “Universals apprehended in Reflection” §21n, reprinted at http://www.marxists.org/reference/archive/hegel/index.htm.
 Karl Marx and Frederick Engels, Manifesto of the Communist Party, London, 1848, http://www.anu.edu.au/polsci/marx/classics/manifesto.html.
 Thomas S. Kuhn, The Structure of Scientific Revolutions, Third Edition, The University of Chicago Press, Chicago, 1996 (first published in 1962), p. 25.
 Bruno Latour, Pandora’s Hope. Essays on the Reality of Science Studies, Harvard University Press, Cambridge MA, 1999, p. 58.
 Steven Shapin, The Scientific Revolution, The University of Chicago Press, Chicago, 1996, p. 123.
 Michel Foucault, The Order of Things, Pantheon Books, New York, 1971, reprinted by Random House / Vintage Books, New York, 1994, p. 150 (first published in 1966).
 M. Norton Wise, “Mediations: Enlightenment Balancing Acts, or the Technologies of Rationalism,” in Paul Horwich (Ed.), World Changes. Thomas Kuhn and the Nature of Science, The MIT Press, Cambridge MA, 1993, pp. 207-256.
 Peter Burke, History and Social Theory (Second Edition), Cornell University Press, Ithaca, New York, 2005, pp. 166-167, 173.
 Jean Finot, The Philosophy of Long Life (translated by Harry Roberts), John Lane Company, London and New York, 1909, first published in French as La Philosophie De La Longevite, Schleicher Freres, Paris, 1900, “The Immortal Body,” pp. 122-145.
 Reinhard Burger, Michael Lynch, “Evolution and Extinction in a Changing Environment: A Quantitative-Genetic Analysis,” Evolution, 49 (1), 151-163, 1995.
 In a recent evolutionary model, Andre C. R. Martins argued almost precisely to that effect: “when the system is completely stable, no mutation going on and no changing conditions for worse, … it is to be expected that a population that shows senescence will be driven to extinction.” However, “When conditions change, a senescent species can drive immortal competitors to extinction.” The author concludes: “We age because the world changes.” (Andre C. R. Martins, “Change and Aging: Senescence as an adaptation,” Cornell University Library, Populations and Evolution, March 23, 2011, http://arxiv.org/abs/1103.4649v1.)
Several other contemporary researchers, such as Mitteldorf, Goldsmith and Skulachev, have pondered a return to Weismann’s theory, proposing a direct evolutionary selection for senescence. A major suggested reason for such a selection is that an absence of senescence would diminish the species’ variability and diversity, hence impair its adaptability and evolvability. (Theodore C. Goldsmith, “Aging as an Evolved Characteristic – Weismann’s Theory Reconsidered,” Medical Hypotheses, 62(2), 304-308, 2004; Joshua Mitteldorf, “Ageing selected for its own sake,” Evolutionary Ecology Research, 6, 937-953, 2004; Vladimir Petrovich Skulachev, “Aging is a Specific Biological Function Rather than the Result of a Disorder in Complex Living Systems: Biochemical Evidence in Support of Weismann's Hypothesis,” Biochemistry (Moscow), 62(11), 1191-1195, Nov 1997.)
Furthermore, a link has been suggested between increasing longevity and the level of inbreeding (keeping the genome stable), even for humans. (A. Montesanto, G. Passarino, A. Senatore, L. Carotenuto, G. De Benedictus, “Spatial Analysis and Surname Analysis: Complementary Tools for Shedding Light on Human Longevity Patterns,” Annals of Human Genetics, 72(2), 253-260, 2008.)
Notably, all these authors seem to be in favor of finding effective anti-aging means for humans, suggesting that through a better understanding of the evolutionary mechanism, factors affecting longevity can be identified and manipulated.
 Giuseppe Tomasi di Lampedusa, The Leopard, translated by Archibald Colquhoun, Pantheon Books, NY, 1960, p. 40.
 Ernst Hans Josef Gombrich, In Search of Cultural History, Clarendon Press, Oxford, 1969, p. 30.
 Talmud [Gemara] – Masechet Berachoth [Tractate on Blessings], 10a, in English Babylonian Talmud, Rabbi Dr. J. H. Hertz, Rabbi Dr. I Epstein, et al. (Eds.), Talmudic Books, 2012, at http://halakhah.com/.
 It should be strongly emphasized that many transhumanists and life-extensionists are well aware of a wide variety of global existential risks – either natural threats, such as increasing solar activity, or technogenic threats, such as uncontrolled industrial pollution, or combined natural and man-made threats, such as global warming – yet they seek ways to mitigate and endure potential disasters.
(See, for example, the stated missions of the Lifeboat Foundation, http://lifeboat.com/ex/boards.)
 William G. Bailey, Human Longevity from Antiquity to the Modern Lab, Greenwood Press, Westport CN, 1987, p. ix.
 Lao-Tse. The Tao Teh King. The Tao and Its Characteristics, Translated by James Legge, 1880, reprinted at Project Gutenberg, Ch. 1. 25. 1-3, http://www.gutenberg.org/files/216/216-h/216-h.htm.
 Walter Cannon, The Wisdom of the Body, Norton, NY, 1932, pp. 27-28.
 Richard W. Jones, Principles of Biological Regulation. An Introduction to Feedback Systems, Academic Press, NY, 1973, Ch. 2, “Flow Processes in the Steady State,” p. 7.
 Schopenhauer’s exact words were: “Die Leiche ist ein blosses Exkrement der stets bestehenden menschlichen Form.” (Arthur Schopenhauers Samtliche werke, hrsg. von Dr. Paul Deussen, R. Piper & Co., Munchen, 1913, Bd. 10. Arthur Schopenhauers handschriftlicher Nachla?. Philosophische Vorlesungen: Halfte 2, Metaphysik der Natur, des Schonen und der Sitten, S. 374 – The Complete Works of Arthur Schopenhauer, edited by Dr. Paul Deussen, R. Piper & Co., Munich, 1913, Vol. 10, Arthur Schopenhauer’s hand-written papers, Philosophical Lectures, Half 2, The metaphysics of nature, of beauty and of manners, p. 374.)
This passage is quoted in Max Burger, Altern und Krankheit (Aging and Disease), Zweite Auflage, Georg Thieme, Leipzig, 1954 (1947), p. 41.
 Elie Metchnikoff, Etudy o Prirode Cheloveka (Etudes on the Nature of Man), Izdatelstvo Academii Nauk SSSR (The USSR Academy of Sciences Press), Moscow, 1961 (1903), Ch. 8. “Popytki filosofskich system borotsia s disharmoniami chelovecheskoy prirody” (Attempts of philosophical systems to combat the disharmonies of human nature), pp. 151-153.
 Max Burger, Altern und Krankheit (Aging and Disease), Zweite Auflage, Georg Thieme, Leipzig, 1954 (1947), p. 41.
 In contrast, two identically constructed “Theseus’ Ships” or “copies” would not be the same, following Aristotle’s principle that the same body cannot occupy separate places at the same time. According to Aristotle’s On the Soul, the existence of “two bodies in the same place” is impossible. And one can also infer that one body in separate places simultaneously is equally impossible. Aristotle, who equates the Soul with Vitality, establishes the immateriality of the soul precisely on this principle, since “there must be two bodies in the same place, if the soul is a body.” Rather, according to Aristotle, the soul (or vitality) is a particular faculty or form of matter.
(Aristotle [384 BCE - 322 BCE], On the Soul, translated with notes by Walter Stanley Hett, in Aristotle in Twenty-Three Volumes, William Heinemann Ltd., London, 1975 (1936), Vol. 8, Book 1, Part 5, 409b1-5, p. 53.)
The preservation of each human “copy” separately would of course be necessary unless someone embraces the notion of a “quantum mechanical body,” spoken of in some life-extensionist circles, which would allow a person to be in several places simultaneously or alternatively.
(E.g. Frank J. Tipler, The Physics of Immortality: Modern Cosmology, God, and the Resurrection of the Dead, Doubleday, NY, 1994, pp. 173, 234; Ben Goertzel and Stephan Vladimir Bugaj, The Path to Posthumanity: 21st Century Technology and Its Radical Implications for Mind, Society and Reality, Academica Press, Bethesda MD, 2006, “Physics and Immortality,” pp. 342-348; Tel Peters, Robert John Russell, and Michael Welker (Eds.), Resurrection: Theological and Scientific Assessments, William B. Eerdmans, Grand Rapids, Michigan, 2002; Deepak Chopra, Ageless Body, Timeless Mind. The Quantum Alternative to Growing Old, Harmony Books, New York, 1993, p. 288.)
The ideas about “quantum immortality” and transcending spatial confines, may be too unorthodox for a “traditional” life-extensionist wishing to defend his/her body from decay and disintegration.
 Stanislaw Lem, “Czy pan istnieje, Mr Johns?” Przekroj, Krakow, Poland, 1955, № 553 (“Do you exist, Mr. Johns?” Translated from Polish into Russian by A. Yakushev, “Sushestvuete li vy, Mister Johns?” 1960, http://samlib.ru/w/wladimir_pro/mister_djons.shtml).
 Aubrey de Grey and Michael Rae, Ending Aging. The Rejuvenation Breakthroughs That Could Reverse Human Aging in Our Lifetime, St. Martin’s Press, NY, 2007, p. 326.
 As stated by one of the pioneers in the application of Information Theory to biology, Henry Quastler (1908-1963): “The basic concepts of information theory – measures of information, of noise, of constraint, of redundancy – establish the possibility of associating precise (although relative) measures with things like form, specificity, lawfulness, structure, degree of organization. … Closely related is the problem of destruction of orderliness. In biology, this is the problem of aging and decay.”
(Henry Quastler, “The Domain of Information Theory in Biology,” Symposium on Information Theory in Biology, Gatlinburg, Tennessee, October 29-31, 1956, Edited by Hubert P. Yockey, with the assistance of Robert L. Platzman and Henry Quastler, Pergamon Press, NY, 1958, pp. 187-196.)
 Ray Kurzweil, The Singularity Is Near: When Humans Transcend Biology, Penguin Books, New York, 2005, pp. 371-372.
 Ray Kurzweil, The Singularity Is Near, 2005, p. 323.
 Ray Kurzweil, The Singularity Is Near, 2005, p. 406.
 Ray Kurzweil, The Singularity Is Near, 2005, p. 258.
 Ilia Stambler, “The unexpected outcomes of anti-aging, rejuvenation and life extension studies: an origin of modern therapies,” Rejuvenation Research, 17, 297-305, 2014 http://online.liebertpub.com/doi/abs/10.1089/rej.2013.1527.
 John Desmond Bernal, The World, the Flesh & the Devil. An Enquiry into the Future of the Three Enemies of the Rational Soul, 1929, III “The Flesh,” Reprinted at the Marxists Internet Archive Library, http://www.marxists.org/archive/bernal/works/1920s/soul/.
 I.P. Pavlov, Dvadzatiletniy opyt objektivnogo izuchenia vyshey nervnoy deyatelnosti povedenia zhivotnikh. Uslovnie reflexy (Twenty years of objective study of the high nervous activity of animal behavior. Conditioned reflexes), Gosudarstvennoe Izdatelstvo, Moscow, 1923, p. 77.
Quoted in A.L. Chizhevsky, Physicheskie Factory Istoricheskogo Processa (Physical Factors of the Historical Process), Kaluga, 1924, IV. “Vlianie geofizicheskikh i kosmicheskikh faktorov na povedenie individov i kollektivov” (The influence of geophysical and cosmic factors on the behavior of individuals and collectives, http://www.astrologic.ru/library/chizhevsky/index.htm).
 Alexis Carrel, Man, The Unknown, Burns & Oates, London, 1961 (1935), p. 180.
 Jean Finot, The Philosophy of Long Life (translated by Harry Roberts), John Lane Company, London and New York, 1909, p. 278, first published in French as La Philosophie De La Longevite, Schleicher Freres, Paris, 1900.