What Is? Life?

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What Is? Life?
by joshua brancheau

Hundreds of years ago Kant argued that the emergence and the self-organization of “organized beings” are both unexplainable “according to merely mechanical laws.”1 In 1995, Stuart Kauffman wrote that the odds against the spontaneous emergence of the complex selforganizing behavior of living systems are so high that life is impossible.2 If Galileo was right and everything in nature is written in the language of mathematics, then based on Newtonian Physics and pre-Molecular Biology, the unity of living systems would not be visible from the perspective of pure mathematics.3 What is life? And, what is the importance of establishing a definition for it? Life is unique because it seems to be a unified system directed towards a purpose. Details of the exact beginning of life are going to be impossible to determine, but at some point self-organized single-celled systems emerged from the primordial soup starting a growth pattern on this planet that has lead to the more intricate and articulate self-organized systems we know as Homo sapiens and all the eye-popping flora and fauna in-between. Whether we focus the definition of life on the smallest individual level, or we look at how all living systems function together, the definition of life needs to provide us with a means to distinguish life found on other planets, as well as the necessary requirements for a computer simulation to constitute as artificial life(Alife). I want to argue that while life necessarily requires a certain level of autonomy, even though it is a dependent autonomy, as well as the ability to adapt to a changing environment, no definition of life is sufficient without invoking the idea of teleology or purpose as a fundamental characteristic of life. By first demonstrating what makes life unique in its inexplicability, I plan to review some characteristics that would make up a good definition of life, and then relate them to the definitions found in Biology textbooks and contemporary philosophy of life.

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Why is life so unique? Kauffman says life is impossible, yet we have it here talking to you thorough my hands into your eyes at this moment! Kant maintained throughout his work that living systems cannot be explained in mechanical terms. While the separate claims he makes are often collapsed into the single recognition of the incomprehensible complexity found in the internal-causation and self-organization of living systems, Hannah Ginsborg has pointed out that there are two distinct accounts of the difficulty mechanistic science has in explaining the organization of life, and that they should be recognized as separate and not similar claims.4 Each account of life’s inability to be understood mechanically highlights a different aspect of life’s uniqueness, exploring questions about how it is caused and what is its purpose. In Kant’s earlier work he emphasizes that “it would be absurd to regard the first production of a plant or animal as a mechanical side-consequence of the universal laws of nature.”5 This puts into question the actual cause of life, how a self-organized system could naturally emerge and sustain itself in a mechanical universe. Later, in the Antinomy of

Teleological Judgment, Kant says, “some products of material nature cannot be judged as possible according to merely mechanical laws (their judging requires quite another law of causality, namely that of final causes).”6 Ginsborg wants to make clear that Kant’s use of final causes, purpose, or teleology as a distinguishing factor for living systems from the rest of the mechanical universe is understood as different from the claim that the self-organization found in living-systems cannot be explained causally in a mechanical universe (in the efficient sense, cause and effect, atoms hitting atoms). Ginsborg also wants to make sure that the way in which Kant invokes teleology in living systems is not the same as the way in which Aristotle invokes teleology in life and everything else for that matter. Kant wants us to use teleology as a regulative principle, as a presupposition

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to guide our investigations of organized being, not as an actual property of matter or the organism. Ginsborg writes, “For Kant, teleology has a merely regulative role: it is a condition of our investigating living things that we regard them in terms of purposes, but it does not follow that living things really are produced and maintained by goal-directed powers.”7 Ginsborg points out, that the biggest problem with collapsing Kant’s distinction between mechanics inability to articulate the cause and the purpose of life is that the new waves of Molecular Biology have given mechanical models for metabolism and the internal-causation of cells leading to the elimination of the more common sense understanding of Kant’s problem.8 Yet, life still displays purpose in a non-mechanical way, and Ginsborg wants to make sure this distinctive quality of life pointed out by Kant is not accidentally dismissed. These units of unity, who metabolize to remain stabilized in an unstable situation, these instances of purpose and life. How can we define life? It seems like purpose plays a big role in our understanding of life. Metabolism does too. Kant saw the need for purpose when examining life, but he did not quite understand metabolism. There are some who base their definitions for life around the processes of metabolism and the regenerative relationship metabolic-groups have with their own boundaries. The

processes of metabolism and cell regeneration are some of the mechanical processes mentioned by Ginsborg uncovered by molecular biology. Hans Jonas makes the claim that, even with the mechanics of metabolism, if God were a pure mathematician he would be unable to recognize any continuity in living systems. “[On] the lines of the general scheme underlying the

mathematical-mechanical world-picture: on the lines of teleological indifference, […], the apparent sameness and individuality of the organic whole will resolve itself—[…], as purely phenomenal, that is, fictitious.”9 Jonas’ main point is to show that mathematics and mechanics

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miss the essential points of life. Not only does the individual organism continually change its constitutive parts, but the individual organized being also moves itself to promote its continued metabolic reaction. Like Kant, Jonas is contrasting ideas of living organisms as machines with living organisms as organized lives with purpose. The metabolic units we see in the world maintain themselves for themselves. “God in his homogeneous analytical view misses the decisive point—the point of life itself: its being self-centered individuality, being for itself and in contraposition to all the rest of the world, with an essential boundary dividing ‘inside’ and ‘outside’—”10 In this sense, life is a self-bound, self-producing, self-regenerating system that defies traditional concepts of mechanics, and moves forward towards the goal of maintaining itself, and continuing itself. In contrast to Kant, Jonas is reinvoking an Aristotelian sense of teleology in life. He wants to emphasize that the purposefulness found in life is a property of its organism, rather than just a regulative principle of our investigation of living systems generally.11 When Kant opposed teleology to mechanism, he was trying to discriminate the method with which we judge living systems. Ginsborg wants to make sure we understand that Kant invokes teleology in life as a regulative principle of our judgments on living systems, one that takes into consideration the final causes of organized beings.12 Kant did not assume as Aristotle did that all matter of the universe has a purpose or goal, he just thought we should judge it like it had a goal. Jonas promotes the idea of intrinsic purpose in living systems. He bases his claims about this intrinsic property on a phenomenological reduction of organism, and an inward looking approach at the self-maintaining aspects of living systems, specifically the systems of metabolism. “[The]

teleological structure and behavior of organism is not just an alternative choice of description: it is, on the evidence of each one’s own organic awareness, the external manifestation of the

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inwardness of substance.”13 Organisms actively sustain themselves. They are aware to the extent that they can find food, and orient themselves in a position that maximizes their metabolic ingestion. We can observe this in the activity of bacteria on strands of sugar, 14 and through the entire history of human agriculture and fortification. Organisms actively situate themselves in order to maximize their survival. Evan Thompson agrees that purpose is something that not only regulates but constitutes life.15 In a broad-reaching phenomenological reduction of organized beings, Thompson has promoted a comparable model of life to that of Jonas’ metabolic-repair systems, called autopoiesis. 16 Autopoiesis is a term crafted by Humberto Maturana and Francisco Varela and it literally means self-making. Autopoiesis focuses on the individual cell as the model for life. “[A] cell produces its own components, which in turn produce it, in an ongoing circular process.”17 In order to qualify as an autopoietic system, organisms must fulfill three requirements: “(i) the system must have a semipermeable boundary; (ii) the boundary must be produced by a network of reactions that takes place within the boundary; and (iii) the network of reactions must include reactions that regenerate the components of the system.”18 Systems of bacteria and one-celled organisms are the paradigm example of autopoietic systems. Nonetheless, the general

framework of autopoietic systems is adaptable to trees, humans, rabbits, many living systems and questionably some social/ecological systems. Maturana and Varela think the systems that qualify for autopoiesis have the necessary and sufficient conditions to qualify as life.19 There are others who argue that autopoiesis does not entail a cognitive system which is a necessary condition for life. Thompson uses a phenomenological reduction on organized being, and concludes that subjective experience is necessary for the intrinsic purposiveness we find in these organisms.20 This subjective experience which creates an internally driven teleology is mind in the most

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minimal sense. Thus autopoiesis satisfies the qualification of a cognitive system, and can satisfy the necessary and sufficient conditions for life. Does this seem correct to everyone? What do we really want out of a definition for life? Autopoiesis, ecology, and genetics all look at it from different perspectives. investigation of it? The scientists, Kepa Ruiz-Mirazo, Juli Pereto, and Alvaro Moreno, published an article called, A Universal Definition of Lfe: Autonomy and Open-Ended Evolution. In it they outline conditions a definition of life should comply with as well as their own opinions about what actually constitutes the correct definition of life. They make a strict distinction between Does life actually possess purpose? or, is it just a result of our

descriptive and essentialist types of definitions. Descriptive definitions typically end up as lists that verbally illustrate the significant properties of an object or organism. Essentialist definitions try to allude to something deeper. In their words, “the second involves a completely different way of formulating the question: essentialist definitions characterize a given phenomenon in terms of its most basic dynamic mechanisms and organization.”21 The definition of life needs to be articulate the essence of life, so that it can be understood universally, rather than just listing a description of what the things we consider to be life looks like. What is the fundamental difference between what is living and what is not? A college biology textbook uses seven qualifying criteria in order to define life: cellular organization, sensitivity to the external world, growth through metabolism, development through stages, reproduction, internal regulation, and homeostasis.22 This obviously falls under the descriptive category of definitions. Mirazo, Pereto, and Moreno setup more specific criteria for the definition to fulfill and then supply their own articulation of what life is.

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Mirazo, Pereto, and Moreno claim the definition of life needs to be fully coherent with current knowledge in biology, chemistry, and physics; it needs to avoid redundancies and be selfconsistent; it needs to possess conceptual elegance and deep explanatory power, providing us with a better understanding of life; it needs to be universal in the sense that it entails all of the necessary properties of life; and it needs to be minimal yet specific, so that it includes everything that is life while excluding everything that is not.23 Based on these criteria, Mirazo, Pereto, and Moreno propose a definition of life that combines two other significant contemporarily-accepted definitions, those based on autopoiesis or metabolism, and those based on evolution, genetic heritage, and the DNA base structure of all life. Mirazo, Pereto, and Moreno say “‘a living being’ is an autonomous system with open-ended evolutionary capacities.”24 While their

extended definitions of autonomy and open-ended evolution are very technically sufficient, and provide fairly deep explanatory power for those versed in thermodynamics and dynamical systems theory, the layman would be hard pressed to apply this definition when encountered by alien life. Parts of the definition read, “[a living being is] a far-from-equilibrium system that constitutes and maintains itself establishing an organizational identity, […], with the potential to re-produce its basic functional-constitutive dynamics, bringing about an unlimited variety of equivalent systems[…]”25 Mirazo, Pereto, and Morenos’ definition fulfills their criteria to the fullest extent, but to me it seems to be less applicable than the definition really needs to be. Autopoiesis has a very easy-to-visualize base model, the interrelated network of the cell. By having this as a visual as well as conceptual model for living systems, one can investigate alien terrain with a comparative model. The characteristics of autonomy and open-ended evolution are less illustrative than autopoiesis, and where does purpose fit into their picture. Mirazo, Pereto, and Moreno consider

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autopoiesis to be an inadequate definition for life because it does not recognize the thermodynamic aspects of living systems, and more generally autopoiesis is too removed from chemical and physical science to provide an appropriate definition for biological life. On top of that, autopoiesis does not explicitly define any evolutionary patterns, and so it is inadequate in its attempt to define life.26 Thompson has a forthcoming book called Mind in Life, in which he provides a lengthy defense of autopoiesis as an adequate definition for life. He has altered and elaborated the details of Maturana and Varela’s explanations of autopoiesis, and incorporated responses to these criticisms listed above into his expanded explanation of autopoiesis. The thesis of Thompson’s book is to demonstrate the deep continuity of mind and life, where every instance of mind is an instance of life. In his book, he uses autopoiesis as his base model for defining life, and then uses a phenomenological reduction in order to instantiate mind as a product of life. In Thompson’s defense of autopoiesis, he makes sure to establish

autopoietic systems as systems that are thermodynamically open,27 shinning light on the physical nature of metabolic systems. He also elucidates aspects of sense-making and adaptability in autopoietic systems, shinning light on the broader implications of an autopoietic basis for life, namely in the directions of subjective experience and evolution. In his later work, Varela, shifted from considering autopoietic systems as machines without purpose, to adopting a Kantian approach that saw an intrinsic teleology in living systems.28 Varela saw teleology arising in two main aspects of the autopoietic entities; he called them the dynamic patterns of identity and sense-making.29 Identity is represented in the cells ability to maintain a self-enclosing boundary, segregating itself from the rest of the world. Sense-making, then, is the ability of an autopoietic system to apply value to the objects that it experiences. The minimal case of autopoiesis, a single cell, has been attacked for not having the

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capacity for sense-making, and thus weakening its claim to define life. However, with an added capacity for adaptivity, that is, the capacity to “actively regulate itself with respect to conditions of viability,”30 incorporated as a part of our understanding of autopoietic systems, sense-making becomes a fundamental part of the idea of autopoiesis and the twofold teleology remains. Thompson claims, “purposiveness is a constitutive property the whole system possesses because of the way the system is organized.”31 He bases this claim on Varela’a newer accounts of autopoietic systems. Both the ideas that Mirazo, Pereto, and Moreno put forward, and the ones Thompson puts forward, provide similar claims about what the essence of life is. They both invoke ideas of autonomous units that sustain identity through material change, and ideas of adaptability or open-ended evolution that provide the systems with a much higher rate of sustainability, and to some the only components necessary for life, DNA. Yet, only Thompson and Varela invoke any concept of teleology in their definition of life. As we have seen through the eyes of Kant, the characteristics of teleology are inextricable from a conceptualization of life. I think Thompson is correct in maintaining this thread in his exploration of a definition for life. It seems teleology or purpose is an inseparable concept from a full understanding of life. While Kant did not think, as Aristotle did, that teleology played a constitutive role in organized being. Based on our exploration of life it seems obvious that purpose does play a crucial role in living systems. Even if the purpose of life is just to flourish in the world, then life would not look too bad. Alife, and exobiology can apply the concepts of autonomy, adaptivity, and purpose to their investigations of alternative life forms. Autopoiesis provides a basic conceptual model for a minimal living system, and is flexible enough to fit systems from cells to ecosystems, and this gives a good functional picture to judge what is life.

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1

Ginsborg, Hannah. Two Kinds of Mechanical Inexplicability in Kant and Aristotle. Journal of the History of Philosophy, vol 42, no 1 (2004) pg33 Kauffman, Stuart. At Home in the Universe: the search for laws of self-organization and complexity. Oxford University Press: New York, 1995 pg44 Jonas, Hans. The Phenomenon of Life. ???. 1963 pg64

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Ginsborg, pg34 Ginsborg, pg41 6 Ginsborg, pg33 7 Ginsborg, pg60 8 Ginsborg, pg62 9 Jonas, pg78 10 Jonas, pg79 11 Jonas, pg91 12 Ginsborg, pg60 13 Jonas, pg91
4 5 14

Thompson, Evan. Mind in Life: Biology, Phenomenology, and the Sciences of Mind. Harvard University Press: Boston, MA, 2007 pg221 (unedited version)

Thompson, pg205 Thompson, pg132 17 Thompson, pg140 18 Thompson, pg145 19 Thompson, pg142 20 Thompson, pg205
15 16 21

Ruiz-Mirazo, Kepa. Juli Pereto. and Alvaro Moreno. A Universal Definition of Lfe: Autonomy and Open-Ended Evolution. pg3 Raven, Peter. and George Johnson. Biology. sixth ed. McGraw Hill: New York. 2002 pg 61

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Ruiz-Mirazo, et al, pg4 Ruiz-Mirazo, et al, pg10 25 ibid 26 Ruiz-Mirazo, et al, pg8 27 Thompson, pg140 28 Thompson, pg206 29 ibid 30 Thompson, pg208 31 Thompson, pg206
23 24

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