In this blog post, we will examine whether Lacatos’ research program is a sufficient basis for explaining scientists’ choice of theory.
Scientific philosophy attempts to answer questions such as what is science and what is not science, whether it is possible to determine the methodology that scientific researchers should follow when developing science, and if so, what it is, and how the history of science can be explained by a mechanism. Representative attempts to answer these questions in modern scientific philosophy include Popper’s falsificationism, Ratzinger’s research program, and Kuhn’s paradigm. They present various perspectives on science, each of which successfully answers the previous questions, but at the same time, there are enough points of criticism to be the subject of debate and revision. Lacatos’ research program tries to solve the problems of refutationalism while inheriting it to some extent. However, there are also methodological limitations. In my review of Lakatos’ research program and the limitations pointed out by Chalmers in “Modern Philosophy of Science,” I found that it did not contain any content related to the researcher’s trust in a theory that has failed many attempts to disprove. Therefore, in this article, I will briefly explain the above and, in light of this, propose another modification to Lakatos’ research program.
The key concept in Popper’s theory of falsification is that experience cannot prove that a theory is true, but it can prove that it is wrong. In other words, even if a theory explains a number of observations well, there is no guarantee that no observations will appear in the future that contradict the theory. On the other hand, if the results predicted by the theory differ from the observed results, it can be seen that the theory is wrong. The basis for scientists to endorse a theory is that attempts to disprove it have failed, so its endorsement is always tentative. Rather than simply reaffirming what is already known, evidence that something is wrong provides more information, which leads to the advancement of science. For this reason, in the theory of counter-evidence, the development of science is said to occur when a hypothesis that was predicted to be true is disproved, or when an attempt to disprove a hypothesis that was predicted to be false fails.
However, the observation results that can disprove a theory must also be true for the observation to be established (the accuracy of the experiment, the accuracy of the observation equipment, and whether the theory on which the observation is based is true, etc.). These hypotheses can also be proven false like theories, so their approval and refutation are only tentative. Also, historically, even if an observation cannot be explained by a theory, it is often considered an anomaly or an error in observation rather than a refutation of the theory. These are historical events that are difficult to explain from the perspective of refutationalism, which states that theories are discarded by refutation.
To solve this problem, Lakatos and Kun examined the historical development of science. They came to the conclusion that some theories should be understood as structures. In other words, some parts of a theory are more fundamental and are considered to be true by the scientists who study that theory. Even if there are observations that do not match the theory, the cause is thought to be due to factors other than the basic assumptions. The rest can be modified as research progresses and observations that do not match predictions are made. However, this modification must be sufficiently clear and independently verifiable. Taking the discovery of Neptune as an example, when Uranus did not follow the orbit predicted by Newtonian mechanics, researchers considered the possibility that there was another celestial body outside of Neptune that affected its motion, rather than questioning the basic principles of Newtonian mechanics.
In Lacatos’s research program, the various hypotheses that make up the theory can be understood as being divided into a solid nucleus and a protective shield. The hypothesis that is considered to be true is called the solid nucleus, and the other modifiable hypotheses are called the protective shield. Scientists consider the solid nucleus to be irrefutable, and if an observation that disproves it occurs, the protective shield is modified to protect the solid nucleus. In this process, the researcher follows two guidelines: the “negative discovery method” (not taking the nucleus as the object of refutation) and the “positive discovery method” (modifying the protective shield to explain observations and predict new phenomena). Kuhn also presents a concept similar to a research program, “paradigm,” and explains the development within such a research program as similar to the development during the “normal science” period.
The difference between Lacatos and Kuhn lies in the change of the mainstream research program or paradigm. Kuhn explained the paradigm change by giving it historical context, and he also considered the interaction between groups of scientists as an important factor. On the other hand, Lacatos evaluated the value of a research program based on the degree of success in making new predictions. In other words, research programs that can make new predictions and succeed in predictions will grow into the mainstream, while research programs that fail to disprove them will be discarded. This can be thought of as a loose form of falsification. One falsification does not immediately lead to the abandonment of a theory, but if it fails to disprove it, the theory is discarded.
The question is how long a research program must fail in its new predictions before it can be scrapped. The parallax predicted by Copernicus in the 16th century was only measurable in the 19th century. Since there may be cases where the protective shield of a regressive research program is modified and it becomes progressive, it is only possible to evaluate a particular research program as superior to competing programs by looking back at the past.
In “Contemporary Philosophy of Science,” Chalmers suggests that there are limitations to seeing Rakatos’ research program as a methodology consciously followed by scientific researchers. It is one thing to explain historical scientific development as a rule and another to determine the norms actually followed by researchers at the time. If the former explains the process of theory change, the latter explains the choices made by researchers that caused such change. Lakatos’ research program and the negative and positive discovery method were proposed as a methodology to explain the choices made by researchers as the norm for discovery, but Chalmers pointed out that the explanation has limitations.
Chalmers’ criticism is as follows. Lakatos has not presented a criterion for choosing between competing research programs. It is impossible for a researcher to immediately identify the graduality of a particular program at the time, so it is not possible to explain the researcher’s choice. In addition, the fact that scientists have achieved such changes before the Lacatos’ theory was proposed cannot be seen as the result of following the recently devised Lacatos’ methodology.
Chamath proposes a modification to the research program so that it only explains changes in theory, not the choices of researchers. Lacatos did not separate changes in theory from the choices of researchers, but he acknowledges that he cannot present a norm for choice and wants to separate the two to explain only changes in theory. He objectively expressed the amount of potential for a particular theory to develop through the concept of output. He saw that researchers did not need to understand output, but only needed to assume that science develops into higher output programs over time. He argued that researchers cannot know the norms for choosing a theory, so studying regressive theories is also rational.
However, I do not think that the Lakatosian methodology should give up explaining the choices of scientists. The criticisms presented by Chalmers can be refuted. While it is true that Lakatos failed to provide a normative choice between competing theories, if theory choice and theory change are separated, it can function as a methodology to explain the common trends followed by researchers. This cannot be a guideline to guarantee the success of an individual scientist, but it can be a methodology that includes the thinking necessary to select a successful theory.
With this guideline, we can present confidence in a hypothesis that has withstood more attempts at refutation. Among the hypotheses in a particular theory, those that have withstood more attempts at refutation and have been studied and successfully predicted for a long time are more reliable than those that have not. For example, the decision by researchers to follow Newtonian mechanics when discovering Neptune cannot be explained simply as a methodological decision. This is because the basic hypotheses of Newtonian mechanics, the inverse square law and the laws of force and acceleration, were used to make several predictions that were not contradictory. The basic hypothesis of Newtonian mechanics has been verified throughout history, and this makes researchers consider the possibility that the protective hypothesis is incorrect rather than the basic hypothesis being incorrect. This means that an unsolvable error must persist for a long period of time in order to dismiss the basic hypothesis.
This idea is difficult to apply to choices between all competing research programs, but it can affect choices when hypotheses within each research program are similar but differ in their nuclei. Researchers will tend to choose research programs whose nuclei are based on more predictions. Although old theories can be disproved, this tendency does not pose a problem in explaining the development of science.
In this article, I explain Lakatos’ theory, which explains historical events by taking a more relaxed approach to Popper’s theory of refutationalism, and discuss Chalmers’ criticism and revision of it. I also suggest that while accepting Chalmers’ revised research program, it is possible to explain the common thinking that researchers follow. This is similar to Chalmers’s criticism of the inability of scientists to accurately select the more successful theory of their time, while also acknowledging that it is impossible for scientists to consciously propose a methodology that researchers follow when scientific progress occurs. The impossibility of selecting a successful theory can lead to the impossibility of proposing a methodology that leads an individual scientist to success, but it is possible to propose the methodology that scientists have followed. One of the guidelines of this methodology is to give more credence to hypotheses that have withstood more counterevidence. This discussion is productive in that it attempts to explain more about the philosophy of science, and it is possible that in the future, we will discover more guidelines that will improve our understanding of scientists’ choices.
