In this blog post, I will reexamine the concepts of “paradigm” and “scientific revolution” as presented in Thomas Kuhn’s ‘The Structure of Scientific Revolutions’ and propose a perspective that views paradigms as provisional theories.

Definition and Formation of Paradigms

Everyone has probably heard the word “paradigm” at least once. This term is a concept popularized by Thomas S. Kuhn, a historian of science and philosopher, in his book ‘The Structure of Scientific Revolutions’ (1962). The term “paradigm” originates from the Greek word ‘paradeigma’, meaning “example, model, or specimen,” and is a concept borrowed from linguistics. In this book, Kuhn referred to a paradigm as a situation in which a particular achievement demonstrates unprecedented excellence, causing scientists to focus their research activities around that achievement and presenting problems to be solved to the research community that has been restructured around it. In this sense, Kuhn defined a paradigm as a comprehensive framework combining the scientific knowledge, theories, conventions, ways of thinking, and values that dominate a given era.

The Meaning of Paradigms and Scientific Revolutions

So how are these paradigms established? When many scientists accept a specific research result, that result becomes established as a paradigm. When a new paradigm is accepted in the presence of an existing one, this is commonly referred to as a “paradigm shift.” According to Kuhn, this shift often occurs as problems that cannot be explained by existing theories accumulate, and he referred to such shifts as “scientific revolutions.” This term is also connected to the context in which H. Butterfield used it; Butterfield, too, discussed abrupt changes in the development of science. Here, I would like to focus on the word “revolution.” In its dictionary definition, a revolution means “the act of abruptly shattering previous customs, institutions, or methods and rapidly establishing something qualitatively new.” But does a paradigm shift truly involve shattering the existing paradigm all at once and replacing it abruptly? It is highly likely that, even before the shift, many scientists or a small number of researchers had already been conducting research that contradicted the existing paradigm. This could indicate a state in which they superficially accepted the existing paradigm while, deep down, not fully believing in it. Although Kuhn stated that the previous paradigm could be disregarded once a shift occurs, this can also be interpreted to mean that, within that paradigm, adherence to it was required. Therefore, I believe the phrase “paradigm shift resulting from the fulfillment of conditions” is more appropriate than “paradigm shift caused by a scientific revolution.” When a new phenomenon or theory emerges that can be substantiated and convince other scientists, problems that could not be explained by existing theories are resolved, and that theory establishes itself as a paradigm. In other words, the shift occurs the moment the conditions for becoming a paradigm are met. Furthermore, questions arise as to whether a theory selected as a paradigm is truly an “absolute paradigm” or merely a temporary or provisional theory. If a theory were truly a paradigm that everyone considered correct, there would be almost nothing left to research beyond that theory. However, looking at actual cases of paradigm shifts, we see that someone questioned the existing paradigm and explored alternative theories, and that exploration ultimately met the necessary conditions and formed a new paradigm. Therefore, I believe it is more realistic to view a paradigm not as “a theory representing an era,” but rather as a “provisional theory” for which proof is not yet sufficient.

The Process of Paradigm Shift and Terminology: The Case of Geocentrism and Heliocentrism

Let’s examine this point through the examples of the geocentric and heliocentric models. In the past, many people believed that the Earth was stationary and the heavens moved. Since there was no way to prove otherwise, this was accepted as a matter of course, and at that time, it was a collective belief that could be called a paradigm. However, as time passed and methods of proof and logic advanced, evidence supporting the heliocentric model accumulated, leading to a paradigm shift. This example demonstrates that paradigm shifts occur through the accumulation of evidence and the fulfillment of conditions, rather than through a “revolution.” Furthermore, the term “revolution” evokes examples of political and social revolutions (e.g., the April 19th Movement, the French Revolution, the Russian Revolution) and can carry negative connotations of rejecting and destroying the existing system. A paradigm shift in science is not necessarily a process of negatively evaluating or disparaging existing theories. It is important to emphasize that it is a process in which the discovery of new facts and the expansion or revision of existing hypotheses accumulate to provide a better explanation. Of course, in some cases, the difference between a new theory and an existing one is so stark that it exhibits a drastic change worthy of being called “revolutionary.” However, my suggestion is that authors and commentators provide a more detailed explanation of the term “scientific revolution” so that it does not give rise to negative misunderstandings when general readers encounter the philosophy of science. In summary, rather than viewing a paradigm shift as a “revolution” that inevitably entails violent or negative destruction, it is more appropriate to see it as a process that occurs when new phenomena and theories solve problems that existing knowledge cannot explain and when the conditions for persuading other scientists are met. Furthermore, it better reflects the reality of ongoing scientific research to understand a paradigm not as an ultimate truth but as a theory provisionally adopted based on current evidence and conditions. Although Kuhn may have already provided various explanations, I would welcome an effort to explain the meaning of the “scientific revolution” more clearly to reduce confusion among general readers.