When Kuhn’s book The Structure of Scientific Revolutions (later referred as Structure) was first published in 1962, it has created an enormous impact. Different from the logical empiricists, who largely dismissed the relevance of historical and psychological aspects of science in the study of philosophy of science, Kuhn based his book on the investigation of the historical patterns in the development of science.
In this essay, I am going to focus on the detailed process of paradigm shift, which is one of the most well-known while controversial concepts in his work. During the discussion, I raise several questions and critiques toward the ambiguity, unconnectedness, and contradiction in his theory. And in the conclusion, I will try my best to reconcile the conflicts and modify Kuhn’s theory by proposing an alternative understanding toward the paradigm, which introduces a concept called PARADIGM, including the so-called paradigm shifts in Kuhn’s sense and will serve as a larger foundation of all science and scientific progress.
I
In Structure, Kuhn has offered us a brand new way of viewing science. In his sense, all the works and investigations that scientists are currently doing are within a framework — a paradigm — which he called normal science. And to understand paradigm, we can consider it as a consensus accepted by the scientists about certain core ideas, values, or methods of investigation. Within one paradigm, all scientists have reached an agreement upon, for instance, how to deal with the data, how to formulate a theory, how to test the validity and reliability of a theory, and so on. Therefore, within such a paradigm, the scientific progression is a rather coherent process. The scientists’ works share a basic foundation, which they apply to further investigate and explain the unknown phenomena. As Kuhn describes, it is a ‘puzzle-solving’ process.
Nevertheless, according to Kuhn, paradigms can be shifted, and this process begins with vast appearances or discoveries of anomalies. Anomalies can be understood as puzzles that resist solutions (within the current paradigm). Of course, as we have learned in every science class, there might be errors and mistakes in the process of scientific research. And in these cases, what we usually do is to repeat the experiment, to test the theories again and again. If it still remain unexplained, sometimes we will temporally lay it aside and continue the investigation on other topics. However, as these kinds of anomalies accumulate and finally reaching a threshold, they will lead to a crisis in the current paradigm, or the scientific field. Scientists normally will start to re-evaluate the theories under the current paradigm and deliberate the explanatory power of them. This crisis indicates that the paradigm shift is close.
Kuhn states that there are two conditions for the paradigm shift to take place. First, there needs to be anomalies over a critical mass. Second, there needs to be an alternative paradigm available. When the current paradigm fails to explain certain phenomena, solve certain puzzles, and a new paradigm seems to possess a greater explanatory power, the possibility to solve these puzzles, scientists may eventually shift to accept the alternative paradigm. And importantly, stated by Kuhn, they need to reject the former paradigm spontaneously as accepting a new one. One key concept of Kuhn is that ‘one paradigm per field per time’ (Godfrey-Smith 2003 80).
II
The process of paradigm shift is roughly introduced in the previous section. Overall, it can be summarized as following: paradigm — normal science — anomalies — new paradigm appears — paradigm shift — new paradigm. However, in order for us to further discuss the problems existing in his theory, two other essential concepts need to be introduced — incommensurability and theory-ladenness of observation.
Mainly, incommensurability is saying that there cannot be useful communication between paradigms, as there does not exist a common standard or platform upon which to compare them on the same basis. Therefore, it seems to be impossible to find out which paradigm is more superior to the other, or to accept both paradigms at a time and make them communicate their findings with each other.
The theory-ladenness of observation is directly linked to this. Some may argue that we can use ‘objective’ observational results to make the comparison. Nevertheless, can these observations be entirely objective? Here, the theory-ladenness theory suggests that there does not exist such kind of observations. All observations and data need to be examined, analyzed, and interpreted. And these processes have their foundations in the paradigm, in the common standard that scientists have all agreed upon. Therefore, through different paradigms, scientists may derive different results from the same observations, which indicates the impossibility of using ‘objective’ observations as a common basis to evaluate two paradigms at the same time.
III
Now, several problems with Kuhn’s theory are worthwhile to discuss.
I. Progress
If we strictly follow Kuhn’s idea, we can find that he believes the shift between paradigms is actually an arational process. Accepting a new paradigm will inevitably come with both gains and losses. And of course, because of the incommensurability, we cannot compare them and find which one is better or superior. This means that, by shifting in-between paradigms, the scientific field is not progressing. It is neither shifting to a ‘better’ paradigm nor one step closer to the ‘absolute truth.’ It is merely a change in worldview, a shift in the attitudes, cognitions, and objects of scientific investigation.
Then, a paradox appears. In the later chapters of Structure, Kuhn mentions the concept of progress, in which he emphasizes a special kind of efficiency of science. This efficiency can be interpreted as the problem-solving power, or more precisely, ‘the number and precision of solutions to problems in a scientific field’ (Godfrey-Smith 2003 95). Therefore, when scientists are rejecting the current paradigm and accepting a new one, they actually are progressing, in a way that they will possess higher efficiency, gaining stronger problem-solving power. And this actually is a common basis upon which we can make the comparisons between different paradigms, which is obviously contradictory to the incommensurability theory previously suggested.
This conflict is extremely hard to reconcile, and Kuhn has not offered us a clear response toward this problem of progress. It is obvious that progress can appear within a paradigm, which is suggested by all the new discoveries nowadays. However, viewing the development of science in a macro scale, is it progressing through the paradigm shifts?
II. Revolution as Consequence of Crisis
When Kuhn is describing how a paradigm shift can take place, he suggests that two conditions must both be fulfilled. First, anomalies in the normal science need to reach a critical mass. Secondly, there needs to be an alternative paradigm available. However, does this alternative paradigm appear just by chance? Or is it a necessary consequence follows by every paradigm’s end?
From Structure, it seems that Kuhn views revolutions only as the consequences of the appearance of anomalies. However, he has neglected the possibility that a new discovery comes about in the course of normal science can also positively initiate a revolution, not as a consequence of crisis. For example, the discovery of DNA in biology has led to a paradigm shift in the field of biology, especially in genetics. However, it did not appear as a consequence of any crisis. It was itself that initiated the whole revolution. Kuhn has ignored this possibility.
III. The Distinction Between Paradigmatic and Non-Paradigmatic
Following the previous problem, there is actually an essential ambiguity in Kuhn’s definition of paradigmatic components and non-paradigmatic components.
As suggested by Stephen Toulmin (1970), revisionary discoveries are far more common than the one suggested by Kuhn. However, paradigm shift does not happen all the time. It is, rather, an extremely rare occurrence. Then, what kind of discoveries on earth can be classified as paradigmatic? Is Darwin’s theory of natural selection revolutionary? Is quantum mechanics bringing a paradigm shift in physics? What about Einstein’s relativity theory? Mendel’s modern genetics? Watson’s behaviorism? The criteria for the classification is not offered by Kuhn.
IV. The ‘One Paradigm Per Field Per Time’ Rule
Finally, Kuhn states that, at one time, only one paradigm can be accepted and serve as the foundation or platform for all normal science activities to take place. However, viewing the history of science, what we find is more of a kind of co-existing relationship.
For all the examples of paradigm shift in physics, biology, and other kinds of natural sciences, we are able to, at least, observe a period of co-existence of different paradigms. Therefore, whether paradigm really ‘shifts’ is a question. Is it possibly the case that the new paradigm is instilled into the previous paradigm, serving a supplementary function? If this is the case, then, connecting to the previous discussion I, we can now consider paradigm shift as a real progress.
Using the most famous example to illustrate, Einstein’s theory of relativity, although has led to a paradigm shift in physics, has not completely replaced the classical theory of Newton. These two paradigms co-exist, and are dealing with different problems, with different objects and fields of investigation.
Therefore, the ‘one paradigm per field per time’ rule requires further examination.
All in all, Kuhn’s theory is full of ambiguity, unconnectedness, and contradiction. Although he has created a rather revolutionary view toward the development of science, this theory needs further modification.
IV
At the end, I would like to propose an idea upon how to reconcile the conflicts and modify Kuhn’s theory in accord with the historical development of science we are familiar with within the scope of my ability.
From my perspective, paradigm shift is, in nature, progressive. And different paradigms can co-exist at the same time. In this sense, paradigm shift is recognized more as a revolutionary discovery that brings new methodology, new cognition, and new attitude into a field, instead of taking the place of the original ones. It is progressive since it helps science to get greater and greater problem-solving power and efficiency.
But, does it mean there must exist an absolute truth outside there for scientists to approach? I think the answer is negative. All paradigm shifts actually take place after the adoption of the first paradigm, and this acceptation is, essentially, an arational process. It determines the bigger PARADIGM that all later scientific works need to be based upon. And all the later paradigm shifts occur within the first PARADIGM adopted, trying to make all the discoveries and theories coherent under this PARADIGM. Therefore, when this arationally chosen PARADIGM changes in the future, the truth or reality may, in accordance, change. However, this process, I believe, has never happened in our history of science. And, in reality, we do not know whether this process will ever take place in the future.
Bibliography
Godfrey-Smith, Peter. Theory and Reality: an Introduction to the Philosophy of Science. University of Chicago Press, 2003.
Kuhn, Thomas S. The Structure of Scientific Revolution. University of Chicago Press, 1996.
Toulmin, S. E. “Does the Distinction between Normal and Revolutionary Science Hold Water?” Criticism and the Growth of Knowledge, 1970, pp. 39–4