This blog post examines the validity and limitations of new paradigms, focusing on Thomas Kuhn’s theory of scientific revolutions.
Before Thomas Kuhn, people believed science progressed by gradually building upon past research to accumulate knowledge. This is well captured in Isaac Newton’s famous statement about standing on the shoulders of giants to see farther. However, Kuhn argued that science did not always develop by accumulating small discoveries from previous research. He believed science advanced through repeated paradigm shifts—that is, scientific revolutions. In particular, he argued that the results and methods gained during the development of normal science, based on a paradigm, make a significant contribution to scientific progress. Yet, it is questionable whether science has developed solely through scientific revolutions and the progress of normal science, as Kuhn claimed. This article will explain paradigms and normal science, then raise questions about the relationship between normal science and scientific progress. It will compare the process of scientific revolution with falsificationism to discuss why such questions are fatal.
A paradigm initially refers to the theory supported by each school of thought regarding a problem. In the early stages of scientific development, multiple schools’ paradigms compete before gradually converging into a single, universally accepted paradigm. A scientific revolution occurs when this dominant paradigm changes. Kuhn believed science developed through repeated revolutions of this kind. At this stage, a paradigm is not a concrete entity providing answers to all problems. Initially proposed as a theory explaining a few narrowly defined problems, it gradually gains persuasiveness by explaining other problems and is accepted by multiple schools. These problems include not only those already recognized but also those suggested by the paradigm itself.
Normal science refers to research conducted based on this dominant paradigm. Normal science assumes the underlying paradigm as established truth and, building upon it, seeks to pose, predict, and explain various problem situations. The problems of interest to normal science can be broadly classified into three types. The first involves the problems the paradigm initially set out to explain, interpreting and explaining results obtained through simple measurement and experimentation. The second concerns problems that can be raised by the paradigm itself, comparing results predictable through the paradigm to refine and concretize it. The third encompasses other problems the paradigm must solve, becoming increasingly specific and clear as the paradigm is used to resolve them.
In his book, Kuhn emphasizes that a paradigm is not absolute truth but rather serves as a guidebook for subsequent research. He views paradigms as determining the purpose and methods of research and aiding in finding meaning in research results. This is akin to designating a specific area to search for buried treasure and judging the value of excavated objects. Thus, Kuhn believed that even if a paradigm was flawed, the normal science built upon it contributed to scientific progress. Even if the treasure wasn’t found, one might discover minerals or at least gain the skill of digging.
However, it is questionable whether normal science, once its foundation crumbles, truly aids in forming the next paradigm and contributes more than just serving as a valuable case study of failure to scientific progress. The observational results, tools, and experimental methods acquired while developing normal science ultimately rest upon that paradigm as their foundation. When the existing paradigm is falsified and the underlying paradigm is overturned, normal science itself collapses. Can the observational results, experimental methods, and tools gained during that developmental process still be utilized without issue afterward? Can the results of research initiated from a flawed premise and the methods acquired during that process always be correct? It is impossible to know whether techniques gained from digging in the wrong ground will be suitable for digging in other ground. One cannot even be certain that the technique itself is correct, nor can one be sure that the minerals extracted from that ground are valuable. These doubts act as a fatal problem in the birth of a new paradigm. Let us discuss why questioning results obtained through previous normal science becomes a fatal problem for the birth of a new paradigm, linking the process of scientific revolution with falsificationism.
Falsificationism is the doctrine that regards propositions that withstand multiple attempts at falsification as better propositions than those that do not. A proposition is better the greater its falsifiability, yet it must not be falsified. If an existing proposition is falsified, a new proposition emerges and undergoes experiments that test both the falsifications the old proposition passed and those it failed. If the new proposition survives all these tests, it is recognized as superior to the old one. Falsificationism views accepted propositions not as truths, but as steps in the process toward truth. All propositions are merely better than their predecessors; none are irrefutable truths. Therefore, unlike inductivism, one need not agonize over whether a proposition is absolutely true. However, falsificationism inherently carries several problems. The most prominent issue is the complexity of situations. When the results of an experiment differ from those predicted based on a proposition, can we conclude the proposition is wrong? The problem may lie in the theory used for observation, or there could be issues with the assumptions of the experiment. The mere fact that the experimental results differ from the predicted results does not prove that the proposition being falsified is incorrect.
Kuhn’s paradigm is very similar to falsificationism. This is evident in the process where different paradigms emerge within each school of thought, and then converge into a single dominant paradigm. A paradigm, which initially provided answers to a few problems, must withstand the falsification attempts of numerous other problems to become the dominant paradigm. Paradigms that fail to withstand falsification disappear, while those that endure survive. Consequently, the multitude of paradigms previously proliferating among different schools vanish, leaving only one dominant paradigm accepted by many schools. This resembles falsificationism, where propositions that withstand falsification survive, while falsified propositions disappear. Furthermore, the process where a new paradigm emerges to better explain phenomena when the existing one is falsified parallels the emergence of new propositions in falsificationism. Moreover, the notion that a paradigm is not absolute truth aligns with falsificationism’s idea that while better propositions may exist, no proposition is necessarily true.
From this perspective, the process of scientific revolution carries the inherent limitations of falsificationism. The limitation of falsificationism is that when unexpected results emerge in complex situations, there is no way to determine the source of the problem. It is unclear whether the issue lies with the proposition being tested, the observational method, or other auxiliary theories. Therefore, relying on methods acquired within the established normal science becomes a fatal flaw when attempting to falsify a new paradigm. As mentioned earlier, the methods derived from normal science whose foundations have crumbled, and the observational results obtained using those methods, cannot be confidently deemed true. While a falsified and collapsed paradigm is replaced by a new one, it is difficult to accept that the achievements gained during the development of normal science based on the falsified paradigm can be utilized under the new paradigm. Moreover, falsification in complex situations cannot guarantee that the proposition being falsified is incorrect. Ultimately, falsification of a new paradigm often yields inconclusive results. This is because it remains unclear whether the problem stems from the observational methods derived from existing normal science or from the new paradigm itself. Consequently, the mode of scientific development proposed by Kuhn may prove invalid from the very moment a new paradigm emerges.
We have examined Thomas Kuhn’s argument regarding the mode of scientific development, focusing on its impact on the development of science within normal science. We then considered the validity of Kuhn’s argument by comparing the process of scientific revolution with falsificationism. The result revealed a contradiction in Kuhn’s argument: while a falsified paradigm is replaced by a new one, the achievements gained during the development of normal science based on the falsified paradigm can be utilized beyond mere failure cases. However, unlike the conventional view that scientific progress occurs gradually, the perspective that scientific development happens revolutionarily represents a valuable attempt in that it offers a new way of viewing the history of science.
