I am conducting a search for the origins of life as personal research. However, I am approaching this not from the perspective of chemistry or biology, but from the standpoint of systems engineering, analyzing the mechanisms and structures by which life is constructed.
In this article, I will diverge slightly from the topic of the origin of life and consider the question of “What is life?”. I believe it’s challenging to answer what life is. Thus, the intent of this article is to reflect on the very nature of the question itself from a more detached viewpoint.
Fundamental Properties of Life
A potential characteristic of life is its structure that dynamically alters energy and matter and possesses a robust mechanism for maintaining homeostasis.
For instance, pendulums and vortices somewhat meet these criteria.
However, typically, pendulums and vortices are not considered as forms of life.
This raises the question: to what extent does something need to meet these criteria to be considered alive, and at what point is it deemed non-living?
Instead of presuming a clear threshold between life and non-life, perhaps it might be more appropriate to consider a spectrum, a “degree of life.”
If we were to measure by this degree, then compared to objects moving randomly following physical laws, pendulums and vortices would have a higher “degree of life”. However, they would have a lesser degree of life compared to cells.
In this way, using criteria like the degree of robustness in maintaining homeostasis, we can evaluate the degree of life. Of course, the robustness in maintaining homeostasis isn’t the sole factor in determining life’s degree; other characteristics must also be considered.
Incidental Properties of Life
Growth, evolution, and self-replication are sometimes cited as definitions of life. However, I believe that these properties are not essential to life but are incidental.
For example, imagine creating a cell in a test tube that neither grows nor self-replicates and, thus, does not evolve. Apart from not growing or replicating, it’s indistinguishable from regular cells. It’s hard to definitively say such an entity isn’t alive.
From this perspective, I consider growth, evolution, and self-replication as incidental traits, not essential characteristics of life.
Life and Species
Adding another perspective on evolution and self-replication, these are essential traits when considering a species. Conversely, viewing evolution and self-replication as essential to life could mean equating life with species.
For constructive discussion, it’s crucial to differentiate between species and life, or at the very least, clarify the context in which we’re speaking. Otherwise, we’d struggle to align our debates about cells that don’t grow or evolve.
Furthermore, conflating species with life ties into discussions on ethics towards living creatures and rights, including the right to life. I believe we must exercise caution when equating species with life.
This is akin to confusing a company with its workers. Indeed, workers contribute to a company. However, arguing that someone isn’t a worker unless they meet the conditions for the company’s survival is overly company-centric and lacks consideration from the workers’ perspective.
Core and Boundary
When discussing a subject as ambiguous and complex as life, it’s necessary to consider a range of entities, from those that possess all the associated characteristics of the concept to those that only have some.
This isn’t about which standard is correct to discuss. It’s desirable to debate from both perspectives. However, it’s crucial to be aware of the context in which you’re discussing. For instance, the difference is like discussing where the center of a path lies versus where the boundary between the path and the non-path is.
Both discussions revolve around the path and seem similar. But, without understanding the context, there’s a risk of major discrepancies in detail.
When thinking about subjects with inherently ambiguous boundaries, discussing just the boundary will never settle the debate. It’s also essential to talk about the core. If the core is clear, even if the boundary isn’t defined, one can debate which is closer to the center.
Is Reduction to Essential Characteristics Possible?
Suppose characteristics A, B, C, D, and E are properties that life possesses. Some life forms have all of them, while some might have only A, B, and C, and others just C, D, and E. At first glance, it might seem as if the presence of C determines whether something is alive.
However, life might not be solely based on C. There might be life forms with properties A, B, D, and E, but without C.
In this case, it’s not possible to distinctly separate life from non-life based solely on specific characteristics. It’s a situation where it’s indeterminate which properties make something alive and which properties, when absent, make something non-living.
This implies that there’s a possibility that we cannot classify based on reducing to essential properties. Reductionist classification means we can’t say something is living if it possesses certain physical structures or specific characteristics and non-living if it doesn’t. For instance, there might not be a property common to all life forms.
If we don’t bear in mind that life might be such a subject, there’s a risk of getting trapped in the maze of distinguishing between life and non-life.
Combining with the Environment
If we cannot define life based on a specific characteristic, the question arises as to how we might define it.
If one adopts a nihilistic or resigned perspective, one might think that if we can’t understand life in a reductive way, then it might be beyond our scope of understanding. In other words, one might adopt the stance that it’s essentially impossible to comprehend and we should give up.
However, there is another way to view it. Even if there isn’t a common characteristic that defines life based solely on the properties of a living organism, there might be a common characteristic in the interaction between the living organism and its environment.
For instance, defining art based solely on a piece of work is challenging. Only with the context of critics, viewers, creators, and the historical backdrop of art can the artistic position and evaluation of the work be determined.
In the art world, the belief that new, groundbreaking ideas and perspectives bring new artistic value is precisely why ready-made art pieces signed and exhibited in museums, or concerts where not a single note was played from a piano, have found their place in art history. If such historical contexts did not exist and artists presented ready-made art or silent concerts long ago, they would not have been considered art.
Similarly, life is undoubtedly established not just based on the characteristics of living organisms, but also through the interaction between the organism and its environment. The reason we might not find a common characteristic in all life when focusing on the organism alone might be because organisms have delegated crucial characteristics to their external environment.
Given this perspective, defining life shouldn’t be confined just to the characteristics of the organism alone. By expanding our view to include the environment in which the organism can live, we might be able to have a more appropriate discussion.
In Conclusion
In this article, we delved into the question, “What is life?”
First, we discussed that there isn’t a clear boundary between life and non-life. The entities that exist between non-life and life might be evaluated on a metric called “degree of life”, determining whether they are closer to life or non-life.
Next, we proposed the idea of distinguishing life from species clearly, emphasizing the need to clarify the context in which one is discussing. When thinking about species, concepts like self-replication and evolution become central. However, when discussing life rather than species, self-replication and evolution become auxiliary characteristics.
Furthermore, while searching for the boundaries of life is crucial research, if blurred boundaries are a characteristic of life, then solely focusing on these boundaries might not deepen our understanding. Therefore, I believe that rather than focusing on boundaries, it’s more appropriate to understand life using typical examples that lie in the middle.
We also touched upon the notion that even if we try to grasp characteristics in a reductive manner, we might not effectively distinguish between life and non-life. From this perspective, it’s essential to consider not only individual organisms but also their interactions with the environment.
This article consolidates my personal viewpoints on the question, “What is life?”. By firmly grasping such frameworks of thought, we can have more constructive discussions on the intricate and polysemic questions concerning life.
