— At the Intersection of Modern Philosophy and Modern Physics —

[Essay] The Tripartite Coexistence of Worldviews: Realism, Structuralism, and Quantum Theory

— At the Intersection of Modern Philosophy and Modern Physics —

Introduction: Non-Realism Exists Without Structuralism

The basic framework of modern philosophy is often discussed in terms of the opposition between “Realism” and “Structuralism,” which serves to relativize it.

“Realism” is naively ingrained in our minds. It is the sensation that the objects before us are certainly there, and that the world remains unchanged whether we observe it or not. To relativize this, 20th-century thought produced a powerful tool known as “Structuralism.” This is the idea that meaning and value do not reside in the object itself but are determined by relationships (structure).

However, is Structuralism the only ideology capable of critiquing and relativizing Realism? In fact, there exists an even more powerful “ideology” within the realm of natural science. That is “Quantum Theory.”

While there may be debate about calling Quantum Theory—a field of physics—an “ideology,” it is an extremely important intellectual framework that defines our modern worldview. This essay discusses the possibility of a “tripartite coexistence,” where we position Quantum Theory as a third pole alongside Realism and Structuralism, allowing us to interpret the world in a more three-dimensional and flexible manner.

1. The Essence of Realism: Cartesian “Extension” and Classical Physics

First, let us organize what the “Realism” we are accustomed to actually is. The quintessence of Realism lies in the Cartesian concept of “Extension” (Res extensa).

• Boundaries and Volume: Matter has clear “boundaries,” possesses “volume,” and exclusively occupies space. It does not suddenly vanish or appear.
• Geometric Consistency: This worldview is highly compatible with Euclidean geometry and coordinate geometry.

The refinement of this realistic worldview to its limit is “Classical Physics (Newtonian Mechanics).” Classical physics deals with point masses and rigid bodies, but fundamentally presupposes Naive Realism: “Even if no one is looking, the moon is there, possessing a specific position and velocity.”

This way of thinking is extremely practical (utilitarian) in our daily lives. It is evolutionarily advantageous to believe “the object is there” and act accordingly, without consuming excessive brain resources. If we were to constantly think, like a structuralist, that “this is merely a phenomenon given meaning by social structures,” we would be too exhausted to function in daily life. Therefore, Realism should be affirmed as a “convenient intellectual tool (User Interface) acquired naturally during individual development.”

2. The Limits of Realism and Two Counterparts

However, when we begin to think deeply, Realism alone runs into “inconvenient truths.” These include contradictions in the mathematical definition of a “point (something with no magnitude)” and the complexity of social phenomena.

Here, two paths emerge to relativize Realism.

① Counter from the Humanities (Meaning): Structuralism

This posits that “truth is not inherent in the thing itself, but is an effect produced by the system (language, society, unconsciousness),” thereby dismantling the absoluteness of the subject. While powerful, it is conceptually difficult to master and can be too “circuitous” to apply constantly in daily life.

② Counter from the Sciences (Matter): Quantum Theory

This is the main subject of this essay. Quantum Theory shakes Realism to its core by questioning the very nature of physical “matter.”

• Classical Mechanics (Realism): The world is a collection of independent “points (things),” and their properties are predetermined.
• Quantum Theory (Relationalism): Properties (position or state) are not determined until observation (interaction) occurs. There are no “things,” only “probabilities” and “relationships.”

Quantum Theory shares the paradigm shift of “From Substance to Relation” with Structuralism. In a sense, Structuralism and Quantum Theory are in a complicit relationship, launching a pincer attack on the massive fortress of Realism from the “side of Meaning” and the “side of Matter,” respectively.

3. The Collapse of Space-Time Concepts: A New Worldview Presented by Quantum Theory

The most radical question Quantum Theory poses to Realism is the rewriting of “Space-Time” itself, which is the premise of existence.

When we feel “reality,” it is placed inside a “box called Space-Time.” However, modern Quantum Theory (especially findings from quantum entanglement and quantum gravity) overturns this common sense.

• Loss of Distance (Non-locality): When two particles are in a state of quantum entanglement, the observation result of one correlates “instantly” with the other, even if they are billions of light-years apart. This suggests that the concept of “distance” we believe in does not exist at a fundamental level, or that they are connected by a “backdoor (wormhole, etc.)” distinct from the space we know (The ER=EPR conjecture).
• Fluctuation of Causality: In a state of “superposition,” past and future, cause and effect, are mixed as a “fog of possibilities” until observed. Time is not an absolute entity flowing in a straight line but something that manifests as a result of interaction.

In other words, the idea is reversed: “It is not that there is an absolute stage (box) called Space-Time where matter exists, but rather, a network of relationships (entanglement) exists first, and Space-Time emerges from it like a hologram.” This aligns with the perspective of perceiving the world not as “Set-theoretic (collection of elements)” but as “Category-theoretic (arrows of relationships).”

4. Conclusion: The “Adult Wisdom” of Using Three Ideologies

We have Structuralism and Post-Structuralism as the achievements of modern philosophy. Buddhist concepts of “Emptiness (Śūnyatā)” and “Madhyamaka (Middle Way)” also occupy a similar position. However, by adding Quantum Theory, which is backed by “empirical proof from natural science,” the argument becomes much more robust.

We should be able to use (or coexist with) the following three perspectives depending on the situation:

1. Realism (Classical Mechanics): A high-efficiency “User Interface (UI)” for handling daily life and macroscopic phenomena.
2. Structuralism (Social Sciences): An “Analytical Tool” for understanding social, cultural, and linguistic biases and engaging in metacognition.
3. Quantum Theory (Modern Physics): A “Fundamental OS” for understanding the radical nature of matter and the universe (relationships, non-locality).

We do not need to assert that “Quantum Theory = Non-Realism.” There are various interpretations within Quantum Theory itself. However, in that “Quantum Theory presents the physical fact that the Realist worldview is not absolute,” it can serve as a “modern liberal art” equal to, or perhaps more powerful than, Structuralism.

We do not discard Realism, nor do we become overly cerebral with Structuralism, nor do we escape into mysticism via the strangeness of Quantum Theory. Juxtaposing these three as “theories with different effective layers” and moving freely between them—this is, perhaps, the balanced intellectual attitude required in the modern age.