https://blogs.scientificamerican.com/bra...lly-exist/
EXCERPT: . . . Even today, scientists have no satisfactory or universally accepted definition of life. While pondering this problem, I remembered my brother’s devotion to K’Nex roller coasters and my curiosity about the family cat. Why do we think of the former as inanimate and the latter as alive? In the end, aren’t they both machines? Granted, a cat is an incredibly complex machine capable of amazing behaviors that a K’Nex set could probably never mimic. But on the most fundamental level, what is the difference between an inanimate machine and a living one? Do people, cats, plants and other creatures belong in one category and K’Nex, computers, stars and rocks in another? My conclusion: No. In fact, I decided, life does not actually exist.
[...] Formal attempts to precisely define life date to at least the time of ancient Greek philosophers. ... In the 17th century, German chemist George Erns Stahl and other researchers began to describe a doctrine that would eventually become known as vitalism. ... Subsequent experiments revealed vitalism to be completely untrue—the inorganic can be converted into the organic both inside and outside the lab. Instead of imbuing organisms with “some non-physical element,” other scientists attempted to identify a specific set of physical properties that differentiated the living from the nonliving. Today, in lieu of a succinct definition of life ... widely used biology textbooks include a rather bloated list of such distinguishing characteristics...
[...] It’s almost too easy to shred the logic of such lists. No one has ever managed to compile a set of physical properties that unites all living things and excludes everything we label inanimate. There are always exceptions. Most people do not consider crystals to be alive, for example, yet they are highly organized and they grow. Fire, too, consumes energy and gets bigger. In contrast, bacteria, tardigrades and even some crustaceans can enter long periods of dormancy during which they are not growing, metabolizing or changing at all, yet are not technically dead.
[...] Why is defining life so frustratingly difficult? Why have scientists and philosophers failed for centuries to find a specific physical property or set of properties that clearly separates the living from the inanimate? Because such a property does not exist. Life is a concept that we invented. On the most fundamental level, all matter that exists is an arrangement of atoms and their constituent particles. These arrangements fall onto an immense spectrum of complexity, from a single hydrogen atom to something as intricate as a brain. In trying to define life, we have drawn a line at an arbitrary level of complexity and declared that everything above that border is alive and everything below it is not. In truth, this division does not exist outside the mind. There is no threshold at which a collection of atoms suddenly becomes alive, no categorical distinction between the living and inanimate, no Frankensteinian spark. We have failed to define life because there was never anything to define in the first place.
I nervously explained these ideas to Gerald Joyce on the phone, anticipating that he would laugh and tell me they were absurd. After all, this is someone who helped NASA define life. But Joyce said the argument that life is a concept is “perfect.” He agrees that the mission to define life is, in some ways, futile. The working definition was really just a linguistic convenience. “We were trying to help NASA find extraterrestrial life,” he says. “We couldn’t use the word ‘life’ in every paragraph and not define it.”
Carol Cleland, a philosopher at the University of Colorado Boulder who has spent years researching attempts to deliniate life, also thinks that the instinct to precisely define life is misguided—but she is not yet ready to deny life's physical reality. “It’s just as premature to reach the conclusion that there is no intrinsic nature to life as it is to define life,” she says. “I think the best attitude is to treat what are normally taken as the definitive criteria of life as tentative criteria.”
[...] Recognizing life as a concept in no way robs what we call life of its splendor. It's not that there's no material difference between living things and the inanimate; rather, we will never find some clean dividing line between the two because the notion of life and non-life as distinct categories is just that—a notion, not a reality. Everything about living creatures that fascinated me as a boy are equally wondrous to me now, even with my new understanding of life. I think what truly unites the things we say are alive is not any property intrinsic to those things themselves; rather, it is our perception of them, our love of them and—frankly—our hubris and narcissism. [...] Truthfully, that which we call life is impossible without and inseparable from what we regard as inanimate. (MORE - details)
EXCERPT: . . . Even today, scientists have no satisfactory or universally accepted definition of life. While pondering this problem, I remembered my brother’s devotion to K’Nex roller coasters and my curiosity about the family cat. Why do we think of the former as inanimate and the latter as alive? In the end, aren’t they both machines? Granted, a cat is an incredibly complex machine capable of amazing behaviors that a K’Nex set could probably never mimic. But on the most fundamental level, what is the difference between an inanimate machine and a living one? Do people, cats, plants and other creatures belong in one category and K’Nex, computers, stars and rocks in another? My conclusion: No. In fact, I decided, life does not actually exist.
[...] Formal attempts to precisely define life date to at least the time of ancient Greek philosophers. ... In the 17th century, German chemist George Erns Stahl and other researchers began to describe a doctrine that would eventually become known as vitalism. ... Subsequent experiments revealed vitalism to be completely untrue—the inorganic can be converted into the organic both inside and outside the lab. Instead of imbuing organisms with “some non-physical element,” other scientists attempted to identify a specific set of physical properties that differentiated the living from the nonliving. Today, in lieu of a succinct definition of life ... widely used biology textbooks include a rather bloated list of such distinguishing characteristics...
[...] It’s almost too easy to shred the logic of such lists. No one has ever managed to compile a set of physical properties that unites all living things and excludes everything we label inanimate. There are always exceptions. Most people do not consider crystals to be alive, for example, yet they are highly organized and they grow. Fire, too, consumes energy and gets bigger. In contrast, bacteria, tardigrades and even some crustaceans can enter long periods of dormancy during which they are not growing, metabolizing or changing at all, yet are not technically dead.
[...] Why is defining life so frustratingly difficult? Why have scientists and philosophers failed for centuries to find a specific physical property or set of properties that clearly separates the living from the inanimate? Because such a property does not exist. Life is a concept that we invented. On the most fundamental level, all matter that exists is an arrangement of atoms and their constituent particles. These arrangements fall onto an immense spectrum of complexity, from a single hydrogen atom to something as intricate as a brain. In trying to define life, we have drawn a line at an arbitrary level of complexity and declared that everything above that border is alive and everything below it is not. In truth, this division does not exist outside the mind. There is no threshold at which a collection of atoms suddenly becomes alive, no categorical distinction between the living and inanimate, no Frankensteinian spark. We have failed to define life because there was never anything to define in the first place.
I nervously explained these ideas to Gerald Joyce on the phone, anticipating that he would laugh and tell me they were absurd. After all, this is someone who helped NASA define life. But Joyce said the argument that life is a concept is “perfect.” He agrees that the mission to define life is, in some ways, futile. The working definition was really just a linguistic convenience. “We were trying to help NASA find extraterrestrial life,” he says. “We couldn’t use the word ‘life’ in every paragraph and not define it.”
Carol Cleland, a philosopher at the University of Colorado Boulder who has spent years researching attempts to deliniate life, also thinks that the instinct to precisely define life is misguided—but she is not yet ready to deny life's physical reality. “It’s just as premature to reach the conclusion that there is no intrinsic nature to life as it is to define life,” she says. “I think the best attitude is to treat what are normally taken as the definitive criteria of life as tentative criteria.”
[...] Recognizing life as a concept in no way robs what we call life of its splendor. It's not that there's no material difference between living things and the inanimate; rather, we will never find some clean dividing line between the two because the notion of life and non-life as distinct categories is just that—a notion, not a reality. Everything about living creatures that fascinated me as a boy are equally wondrous to me now, even with my new understanding of life. I think what truly unites the things we say are alive is not any property intrinsic to those things themselves; rather, it is our perception of them, our love of them and—frankly—our hubris and narcissism. [...] Truthfully, that which we call life is impossible without and inseparable from what we regard as inanimate. (MORE - details)