Sida Liu

“If a tree falls in a forest and no one is
there to hear it, does it make a sound?”
–George Berkeley

Throughout history, humanity has struggled to understand the nature of reality. By taking a high-level overview of this process, we can gain clarity about how our understanding of reality has evolved over time. Here I’ll present my description of this process. It might be oversimplified, but it still shows some interesting patterns.

In ancient times, most people accepted the existence of an external world without question—sunrise, the growth of trees, and the beauty of nature were all self-evident. This straightforward view aligns with what we call Naive Realism, which holds that reality is what people perceive it to be.

As curiosity about the world developed, thinkers began to explore the fundamental nature of reality beyond myth. They questioned whether the world could be made of water, fire, or something else entirely. This quest for understanding marked the beginning of Metaphysics, which values reasoning as it explores fundamental questions about the essence of reality.

Over time, these speculative theories were overshadowed by a powerful idea: God was responsible for everything. This theological perspective dominated medieval thought, particularly within Christianity, where other thoughts and reasoning were often oppressed.

However, as people experienced oppression under rigid doctrines, revolutionary spirits emerged. Why should they accept teachings without using their own reasoning? This shift toward logical inquiry rekindled interest in philosophy and sparked new ways of thinking.

The focus on reason and the workings of the human mind led to intriguing discoveries, particularly about the brain. It became clear that thoughts originated in the brain rather than the heart. Upon examining the mechanisms of the brain, it seemed that it only received information through perceptions. This led philosophers like George Berkeley to propose radical ideas: perhaps nothing exists beyond our perceptions. This marked the dawn of Idealism, suggesting that it is our minds that shape reality.

Despite Berkeley’s compelling arguments, many still believed in the objective reality. They believed that while perception is crucial, it does not negate the existence of a reality independent of our minds. This viewpoint, emphasizing that experience is the only connection between the mind and the external world, laid the groundwork for Empiricism, which argues that knowledge arises only from sensory experience.

As philosophical thought progressed, a movement emerged that combined rigorous reasoning with the importance of experience as the sole means of verifying theories. This approach advocated that meaningful statements must be either empirically verifiable or true in their own right, striving to eliminate metaphysical claims that could not be tested through observation. This is Logical Empiricism, which, although it would eventually be considered obsolete due to its rigidity, at the time formed the foundation of the philosophy of science.

With the rise of modern science, the emphasis on empirical evidence took on new dimensions. Scientists recognized that relying on subjective experiences as evidence could lead to ambiguity and disputes. As a result, they turned to more objective measurements, favoring experiments that produced quantifiable results like numbers. This shift deemphasized subjective experience and contributed to what we now understand as Scientific Realism, where the existence of an external world is accepted as a foundation of scientific practice.

Today, Scientific Realism predominates in our understanding of reality. Many students of science might not even recognize that all empirical evidence was once deeply rooted in human experience. Reflecting on this historical journey, it becomes evident that Idealism represents a significant detour in our quest for understanding the reality. While it has left a lasting impact on philosophical discussions, the prevailing view is that an external world exists independently of our thoughts. The structure and functionality of the brain are indeed fascinating, but they are just part of a larger and even more fascinating reality.

Let me finish this article with an interesting question surrounding the phenomenon of a stick that appears bent when submerged in water. Someone might ask, is the stick straight or bent? If you answer that it is straight, arguing that it only looks bent in water and that touching it will confirm its straightness, they might challenge you: why do you trust your touch more than your vision? I hope you find greater enjoyment in contemplating this question after reading this article.