What is Scientific Progress: How Can Popper’s Disproversialism and Kuhn’s Paradigm Theory Coexist?

Compare Popper’s disproversialism and Kuhn’s paradigm theory and discuss how they can coexist in explaining scientific progress. Interpret the process of the Scientific Revolution through the concepts of disproversialism and paradigm shifts, and clarify the relationship between scientific progress and truth.

 

The development of science began with the synthesis of classical physics by scientists such as Galilei, Kepler, and Newton in the 16th and 17th centuries, and later, in the 19th century, Einstein, Bohr, Schrödinger, and others created a new discipline called quantum mechanics, which greatly changed people’s perception of the world. On the other hand, looking at these scientific developments from a philosophical perspective raises fundamental questions about where and how science is going. Whether there is truth in science, how science progresses, how past theories have failed or succeeded in shaping our current science, and where science should go in the future can be explored by addressing these questions. Many philosophers of science have developed their own theories on this topic, with Karl Popper’s “disproversialism” and Thomas Kuhn’s “paradigms of science” being two of the most prominent opposing theories. In this essay, I will briefly introduce Popper’s and Kuhn’s theories of disproversialism and paradigm, then explain how Kuhn’s ‘paradigm’ is right and wrong in terms of scientific progress, centering on Popper’s ‘disproversialism’, and then subordinate paradigm to disproversialism to show that Popper’s and Kuhn’s theories coexist through examples.
In order to define scientific progress, it is necessary to distinguish between science and non-science, or pseudoscience, and Popper provides a clear criterion for this: ‘critiquability’: if a hypothesis or theory is logically unassailable, it is pseudoscience. The hypothesis that God exists is not science because it cannot be disproved by any means. On the other hand, the hypothesis that “the earth’s gravitational force is uniform in magnitude at all points on the earth” can be disproved by measuring the magnitude of gravity at two points on the earth at different altitudes, which is “scientific” in Popper’s sense. In this way, Popper’s definition of ‘scientific’ does not distinguish between true and false, but rather means ‘meaningful’. Furthermore, for these hypotheses to be valuable, they must have the purpose of solving a practical problem of the time, and without this purpose, philosophical and scientific theses are nothing more than meaningless ramblings. A meaningful and disprovable conjecture is subjected to tests that attempt to disprove it, and if it proves false, it is discarded. Since no conjecture can be proven entirely true, Popper considers a conjecture to be more reliable if it has been tested many times and has not been proven false, and by repeating these tests of meaningful conjecture and disproof, science approaches the truth, the essence of all things, and this is called scientific progress.
To summarize Popper’s argument for ‘disprovationalism’, science develops in a cumulative form throughout history by repeating the process of speculation and disproof. Thomas Kuhn introduced the concept of “paradigms” to science to contrast Popper’s argument. Kuhn’s definition of a paradigm is somewhat vague in its meaning and scope, but broadly speaking, it refers to the overall characteristics of science that define an era. For example, we can think of the “heliocentrism” that was accepted as truth before Galileo as a paradigm. Just as it is not accepted now that evidence has been found to support geocentrism, a paradigm is a set of beliefs at the time and is relative, not absolute. When the existing paradigm cannot explain a problem, a new paradigm is established, which Kuhn called a “scientific revolution,” and this is where Kuhn and Popper’s arguments are most at odds. Unlike Popper, who argued that scientific knowledge is gradually accumulated by making better guesses through multiple guesses and disproving previous guesses, and that this is a step toward scientific truth, Kuhn argued that scientific revolutions are the collapse of the previous paradigm and the establishment of a new paradigm. He did not deny that scientific revolutions lead directly to scientific progress, as the new paradigm can solve more problems than the previous paradigm, but he denied that this progress leads to any truth. This is because a paradigm shift is not about continuing in one direction, but about finding a new and better direction.
However, I argue that neither Popper’s antinomianism nor Kuhn’s paradigm should be seen as opposed to each other, but rather as coexisting structures. In order to make this argument, which contrasts the theories of both scholars, convincing, I will first explain paradigms and their phenomena in terms of counterfactualism. The main difference between Kuhn’s paradigm and Popper’s is the accumulation of knowledge. A paradigm shift means the collapse of the knowledge accumulated in the previous paradigm. Kuhn’s paradigm theory also introduces the problem of Kuhn-loss, where a new paradigm may not be able to explain what the old paradigm was able to explain. These problems arise from the fact that the concept of progress in science is ill-defined. After all, new paradigms are based on research that builds on existing paradigms, so even if a paradigm shift occurs as a result of a scientific revolution, it is difficult to accept the claim that the new paradigm overthrows the old paradigm. Let’s take the duality of light, which is the foundation of quantum physics. Previously, light was considered only as a wave, but problems that could not be explained by the wave nature of light, such as the photoelectric effect (photoelectrons bounce off a metal plate only when light above a certain frequency is shone on the plate, regardless of the intensity of the light), led to the hypothesis that light is an indeterminate entity that is sometimes a wave and sometimes a particle, and the existing paradigm that light is purely a wave was faced with a crisis. It was later discovered that light is an entity that has both wave and matter properties, and this became the new paradigm. However, even after the Scientific Revolution, studies based on the particle nature of light led to the collapse of the old paradigm’s hypothesis that light is a pure wave, but the particle nature of light is often not taken into account and light is often treated as a wave, and studies on the properties of electromagnetic waves before the paradigm shift are still valid. In other words, a scientific revolution is not the collapse of an existing paradigm and the establishment of a completely new paradigm, but rather the improvement of an existing paradigm, and the degree of improvement depends on how much the existing paradigm collapses. To use the example of building a model tower, if a problem is found on the fifth floor of a tower that has been built up to the tenth floor, the tower is not completely torn down and rebuilt, but the problematic part and the part related to it, that is, the floors after the fifth floor, are torn down and rebuilt.
Let’s interpret the light example in terms of Popper’s anti-demonstrativism. The conventional paradigm of optics can be seen as a collection of hypotheses and theories that have accumulated credibility by successfully passing many tests of disproof, and the theory that light is a wave is one of them. The photoelectric effect successfully disproved the theory that light is a wave, which led to the hypothesis that light is both a wave and a particle, and then to the theory that light is composed of photons, which have both wave and particle properties, which has remained untested to this day. A paradigm shift does not mean the introduction of a completely different paradigm, but rather the modification of existing people’s perceptions by counterevidence, which is the progress of science.
The Kuhn-Ross problem is caused by a hasty determination to revolutionize science and by limiting scientific progress to explaining more things immediately. Consider two cases where a new paradigm fails to explain something that could be explained before. The first is when the new paradigm is not yet fully established. A classic example of this is the major paradigm shift in astronomy, from heliocentrism to geocentrism. Let’s first look at this through Kuhn’s paradigm theory. The epicyclic theory was able to explain various astronomical phenomena without contradiction in measurements and calculations based on the observed data at the time. However, as time went on and astronomical phenomena were observed that were difficult to explain using the theory, such as the phases of Venus, people such as Galilei and Copernicus began to doubt the theory, and a new paradigm called geodynamics emerged around them. However, the early geodynamics theory was much more complicated to calculate celestial motions than the popular theory at the time, and lacked evidence and convincing arguments. Furthermore, the errors in the celestial mechanics that geodynamics sought to correct were more accurately explained by Tycho Brahe in his revised celestial mechanics. It was only after the correctness of the geodynamic theory was proven through the theories of Kepler, Newton, and other scientists (Kepler’s laws, the law of universal gravitation, etc.) that the geodynamic theory became accepted as orthodoxy. As a result, the paradigm shifted from heliocentrism to geocentrism, but before geocentrism was fully established, Copernicus’s theory of geocentrism encountered the Kuhn-Roth problem. This is because the new paradigm, geodynamics, was less convincing than heliocentrism. Let’s rephrase this in terms of counterfactualism. At the time Copernicus argued for geodynamics, heliocentrism was still the dominant theory, so geodynamics was not yet a new “paradigm” but rather a hypothesis that tried to point out the contradictions of heliocentrism. This hypothesis was disproven by the hustle and bustle of the existing epicycles and Tycho Brahe’s revised epicycles, and the Scientific Revolution failed. Later, due to the development of physics, a more systematic geodynamic theory was reintroduced as a hypothesis, and it succeeded in disproving the geodynamic theory by explaining everything explained by the geodynamic theory without any problems and resolving the contradictions of the geodynamic theory, and only then did the geodynamic theory become a new paradigm. If a new hypothesis cannot explain phenomena that can and should be explained by the existing paradigm (i.e., that can be directly observed in real life), then it is an attempt at a scientific revolution, not a reduction in the area of explanation after the Scientific Revolution. If the new hypothesis is convincing and can disprove or overcome the old hypothesis, a paradigm shift will occur; conversely, if the new hypothesis is not convincing, there will be no scientific revolution and the old paradigm will be maintained.
The second case is when the paradigm established in the first case fails to explain what the previous paradigm was able to explain. In the days before quantum mechanics, when Newtonian mechanics was all there was to mechanics, it was assumed that any motion of an object, no matter how small, could be accurately predicted if you knew enough about the physical quantities of the object, and the motion of an atom was no exception. However, as the study of the microscopic world (the small world invisible to the naked eye) continued, quantum mechanics overturned the paradigm of classical mechanics, and the principle of indeterminacy led to the acceptance of the theory that the physical quantities of objects in the microscopic world cannot be accurately predicted or directly verified. In other words, particle motions that could be explained by classical mechanics could not be explained by the newly established quantum theory. However, in quantum mechanics, this “inexplicability” is the very essence of scientific progress and a new paradigm.
Kuhn also posited the “incommensurability” principle, which states that there is no common scale between different paradigms. For example, the Pythagorean paradigm that all things are made up of ratios of rational numbers was later challenged by the discovery that the ratio of the length of the hypotenuse of a right-angled isosceles triangle to the length of the other side cannot be represented by a rational number, leading to incommensurability between the new paradigm for number and the scale that represents the length of the hypotenuse. Kuhn argues that incommensurability precludes comparison between the two paradigms, but if we view the Scientific Revolution as an improvement in paradigms, then incommensurability becomes irrelevant. If there is an incommitment between the old paradigm and the new paradigm, it is in the areas where the old paradigm has been disproven and discarded, and new hypotheses and theories have taken its place, which are distinct from the knowledge inherited from the old paradigm. If we find that the ratio of the hypotenuse of a right-angled isosceles triangle to the length of the other side cannot be represented by a rational number, we don’t need to compare it to the Pythagoreans’ previous attempt to represent it by a rational number, and we don’t need to discard the Pythagoreans’ theories about right-angled triangles that were previously described by rational numbers. Since we don’t need to overthrow knowledge that could have explained everything just as well under the old paradigm, the uncommitted part is the knowledge that was overthrown in the course of the Scientific Revolution, and the comparison with a new paradigm that has withstood the test of disprovals and is more reliable is unnecessary.
In conclusion, if we interpret the paradigm of an era as a set of disprovable hypotheses, theories, etc. from the perspective of disprovationalism, the Scientific Revolution can be seen as the “emergence of an improved paradigm” accompanied by new theories and hypotheses that explain the contradictions discovered by disproving the existing paradigm, and this shows that the Scientific Revolution made scientific progress without considering the incommitment between paradigms. From this, we can further clarify the relationship between scientific progress and scientific truth. Truth is the essence of all things, and humans have no way of knowing for sure whether this essence exists or whether we have reached it. However, science can be seen as moving toward truth when the disprovals of old paradigms and the new paradigms that are refined by them are able to explain more than before, and describe more about the world.