In this blog post, we will examine the limitations of the theory of scientific revolutions presented in Thomas Kuhn’s ‘The Structure of Scientific Revolutions’ and discuss areas where it could be improved.
Thomas Kuhn’s ‘The Structure of Scientific Revolutions’ is a work that overturned the common view that scientific progress is cumulative. He argued that science develops in a revolutionary manner rather than through gradual accumulation. He explained that once a paradigm is established, normal science develops within it; when anomalies that cannot be explained by the paradigm accumulate beyond a certain level, a crisis arises; and within that crisis, a new paradigm emerges. While the process of scientific revolution proposed by Thomas Kuhn is certainly persuasive, I believe there are several limitations to applying this theory. In this paper, I aim to analyze the limitations of Thomas Kuhn’s theory and discuss areas that require refinement.
Before delving into the discussion, let us examine the structure of scientific revolutions in greater detail. First, the scientific community adopts a paradigm and conducts normal science within it. Here, a paradigm refers to an achievement that demonstrates such outstanding results as to overwhelm existing competing theories and presents problems to be solved to the research community formed around it. Normal science is the process of solving problems based on the existing paradigm, but over time, scientists encounter anomalies that are difficult to explain using existing theories. As these anomalies accumulate, a crisis arises, and amid that crisis, a new paradigm replaces the old one. A scientific revolution occurs during the process by which the new paradigm replaces the old one, and this change is not merely cumulative but has a non-cumulative nature.
Let us now examine representative examples that support Kuhn’s theory. In ‘The Structure of Scientific Revolutions’, Thomas Kuhn presents ‘Principia’, the early paradigm of electrical research, the oxygen theory of combustion, and the theory of relativity as representative examples. Newton’s ‘Principia’ fundamentally transformed the existing system of mechanics by establishing a new paradigm centered on force, mass, and universal gravitation. Furthermore, while no unified paradigm existed in 18th-century electrical research, a common framework for explaining electrical phenomena emerged around Benjamin Franklin and his work, leading to the consolidation of various theories. In chemistry, Lavoisier replaced the phlogiston theory with the theory of oxygen combustion, and in physics, Einstein’s theory of relativity opened up new areas that Newton’s classical mechanics could not explain. These examples clearly illustrate the typical process of a scientific revolution as described by Kuhn. So, does the following example fit this explanation exactly?
Let’s examine the Modern Synthesis in evolutionary biology. The Modern Synthesis is a theory that developed by integrating various research findings—such as genetics and population genetics—based on Darwin’s theory of natural selection. It once established itself as the standard theory of modern evolutionary biology and is still recognized today as a crucial theoretical foundation of the field. In that it emerged by integrating various existing research findings, the Modern Synthesis exhibits a somewhat different pattern from Kuhn’s description, in which an existing paradigm is completely discarded and a new one emerges.
Kuhn argues that when a new paradigm emerges, incommensurability arises. Incompatibility is explained in three main dimensions. First, when a paradigm shifts, the criteria for judgment change. Second, concepts and meanings change. Third, the very perspective from which the same phenomenon is viewed changes. However, when comparing the Modern Synthesis with various earlier evolutionary theories, it is difficult to argue that the meanings of concepts have changed significantly, nor is it easy to claim that the way of viewing the same natural phenomena has completely changed. This can be considered a case that differs somewhat from the three characteristics of incommensurability proposed by Kuhn.
Furthermore, cases such as the ‘Principia’ or the theory of relativity can be viewed as scientific revolutions centered on the innovative research of outstanding scientists like Newton and Einstein. In contrast, the Modern Synthesis was formed through the long-term accumulation and integration of the achievements of numerous researchers. This example demonstrates that while Kuhn’s theory can effectively explain major paradigm shifts, it has limitations in fully accounting for changes that result from the gradual accumulation of numerous studies. This issue has been consistently raised in discussions of the development of biology, and some argue that alternative explanatory approaches are necessary to understand the history of biology more accurately.
Let us also examine the case of mathematics. Mathematics is a discipline based on deductive logic. New theories develop on the foundation of previous theories, and once a theorem is proven, it is accepted as valid unless a specific error is discovered. Therefore, in mathematics, it is rare for existing theories to be completely discarded and replaced by a new paradigm, and the process of development often takes the form of continuous accumulation. In the case of such disciplines, Thomas Kuhn’s theory of scientific revolutions is difficult to apply directly.
The second limitation is that the process by which a new paradigm replaces an existing one is not necessarily radical. According to Kuhn, scientific revolutions occur relatively abruptly. However, a look at the actual history of science reveals many cases where this is not the case. It took a long time for Copernicus’s heliocentric theory to establish itself as a new paradigm replacing Ptolemy’s geocentric theory. Newton’s theory, too, was gradually accepted as the standard theory in the scientific community only after undergoing criticism from various scholars, including the Cartesian school. These examples demonstrate that it is difficult to view scientific revolutions as necessarily occurring in a radical manner.
The third limitation is that the concept of “paradigm abandonment” is unclear. Thomas Kuhn explained that when a new paradigm emerges, the existing paradigm is abandoned. However, because he did not specify the exact scope of this abandonment, the concept remains somewhat ambiguous. For example, it was once believed that light traveled through a medium called the ether; however, due to various experimental results and the development of the theory of relativity, the concept of the ether is no longer accepted in the scientific community. According to Kuhn’s explanation, the ether theory was effectively discarded by the new paradigm. If, in the future, new evidence or theories emerge that make a concept similar to the ether necessary again, how should we interpret this? Kuhn’s theory does not clearly provide criteria for determining whether a previously discarded paradigm can be reused or whether it should be viewed as an entirely new paradigm. This point demonstrates the need to define the concept of paradigm discard more specifically.
The fourth limitation is that the process by which anomalies develop into crises is not sufficiently explained. To understand this, let us first examine the concepts of anomalies and crises. Anomalies arise when new observations or research findings cannot be explained by the existing paradigm of normal science. However, scientists do not immediately abandon existing theories simply because an anomaly has been discovered. Most continue their research, viewing it as a problem to be solved in the future. So, through what process do these anomalies develop into a crisis and ultimately trigger a scientific revolution?
Kuhn explained that anomalies develop into a crisis when they combine with various factors to form a complex situation. However, a limitation of his theory is that he failed to provide a sufficient explanation of the specific conditions under which anomalies transform into a crisis. Of course, Kuhn did attempt to explain this. Through a psychological approach, he explained that the more frequently anomalies appear, the more scientists’ awareness of them is reinforced, and as a result, they develop a sense of crisis. However, I believe that simply explaining that a sense of crisis forms as the frequency of recognition increases is insufficient to fully account for the process by which anomalous phenomena lead to a scientific revolution.
So far, we have examined the limitations of Thomas Kuhn’s theory. First, we confirmed that there are cases where the structure of a scientific revolution cannot be directly applied. We also noted that the process of a scientific revolution is not necessarily radical. Third, we noted that the scope of paradigm abandonment is unclear, and finally, we examined that the explanation for how anomalies develop into a crisis is insufficient. If these limitations are addressed, Thomas Kuhn’s theory of scientific revolutions will be able to explain the process of scientific development more comprehensively and persuasively.
