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What is Life?


In this article, I define what life is and assert that social systems are also life by the definition. I will show in what respect societies are living things.

Image by Clker-Free-Vector-Images+Gerd Altmann from Pixabay modified by me.
An illustration of bacteriophage. A bacteriophage is a virus that infects and replicates within bacteria and archaea. It is disputed whether this sort of virus should be regarded as a life or not.

1. The functional definition of life

The biological definition of life is classified into the functional and the material. The former definition lays stress on such physiological phenomena as breath, environmental adaptability, stimulus sensitivity, growth and reproduction, and the latter on such material side as cell structure and protein.

From a philosophical viewpoint, the material definition does not seem essential. All living things on the earth are certainly made of water and hydrocarbon. However, silicon and germanium cause chemical reaction similar to that of carbon. There may be a being on an unknown planet that is made of silicon or germanium and is otherwise very similar to living things on the Earth. Does it make sense to regard it as dead material just because it includes no protein?

We do not need to imagine a SF creature to refute the protein chauvinism. Silicon and germanium are also made into a semiconductor, which conducts a program of artificial life like Tierra. Tierra consumes such resources as CPU or memory space and evolve to survive in the cyberspace. Isn’t Tierra a living thing?

It is not so essential for life to be made of protein or to be composed of cells. There are many kinds of single-celled animals and even non-celled like viroid, which is composed only of nucleic acid.

2. Three features of life systems

Therefore, what is important to define life is not what material life is made of, but what function life has. I will enumerate three functional features, which I consider are essential for life.

2.1. Open systems with the dissipative structure

An open system is a system that exchanges a substance, energy and information with environment. Life is not a statistic order like a snowy crystal that has reached equilibrium, but a dynamic order far from equilibrium that must always maintain itself through thermal dissipation. I explained that living things that grow and reproduce by means of the energy obtained from breath maintain and develop their negentropy by increasing entropy in the environment.

Information is also produced by increase in thermal entropy. Environmental adaptability and stimulus sensitivity are the functions of a living thing as an information system.

" The open system with the dissipative structure " is inadequate as a criterion for life. For example, a room automatically controlled by the air conditioner with an electric dynamo can be regarded as an open system with the dissipative structure. The dynamo generates electricity by burning oil and dissipating heat, and reduces entropy by keeping the temperature in the room constant, but this air conditioner system is not life.

2.2. Self-organization through 1/f fluctuation

Life is often said to be the phase transition that appears on the edge of chaos. It is neither dead order like monotone nor dead disorder like white noise. I have already pointed out that life has fractal structure of power law distribution. Nowadays the electric fan with 1/f fluctuation is quite common. So, it is not difficult at all to make an air conditioner with 1/f fluctuation. It is because it cannot reproduce itself that air conditioner system is not life.

2.3. Autopoiesis

Autopoiesis is self-creation, as the name shows it. I wrote that genetic information is autopoiesis, because it not only prescribes how to compose protein but also includes self-referential information to reproduce the information. Autopoiesis of genetic information does not simply reproduce itself. It has evolved through natural selection. Every life is mortal and it helps to promote evolution.

3. Three features of social systems

To sum up those three, I can define life as an autopoietic open system that self-organizes through 1/f fluctuation. Based on this definition, I dare to say that society is life. Let’s examine how social systems satisfy the three conditions.

3.1. Open systems with the dissipative structure

This is applicable to both material and information levels. At the material level, just as individual living things obtain energy by digesting food and breathing, our society obtain energy from burning fossil fuel. At the information level, just as brain manages environmental adaptability and stimulus sensitivity, leaders of social systems receive and send information to maintain and develop their systems.

Although money is often compared to blood, the universal value unit that plays the role of money in the living things is ATP. It is a transportation infrastructure that is equivalent to the blood circulation, which carries nourishment and wastes. Needless to say, it is the communication system that is equivalent to the nervous system.

3.2. Self-organization through 1/f fluctuation

Our society is neither homogeneously equal as socialists dream, nor completely free and individualistic as anarchists dream. That is to say, our social systems are neither monotone order nor white noise disorder. They form fractal order at the edge of chaos. Zipf’s law can be applied to the power spectrum and frequency of many social phenomena, for example population of cities, market indices and so on.

3.3. Autopoiesis

In society, it is social norms that are equivalent to the gene. In a gene, “information for copy" and “copy of information" produce each other and so do “justifying power" and “justification of power" in social norms. In this meaning, both biological and social systems are autopoietic.

Just as protein is produced according to genes, social action is produced according to social norms. Living things can cure illness or injury by itself and social systems can cure members of deviant behavior by punishment and recover order. However, just as living things die if illness or injury gets serious, social systems collapse, if deviant behavior is beyond control. Individual living things are mortal, but descendents inherit genes, even if ancestors die. Social systems are also mortal, but, once order is restored, the new order inherits the social norms. Of course, as genes sometimes change, social norms also change. The powerless gene and social norms have been weeded out.

4. Conclusion

Looking back upon history, you see cells that now constitute our body were once capable of living alone. So, it is not surprising that a living thing is composed of subordinate living things. This fractal self-similarity is also a trait of life.