In this article, I will be evaluating the compatibility of Karl Popper’s and Thomas Kuhn’s ideas on scientific method and progress.
Sir Karl Popper was a 20th century scientific philosopher who’s notability in the field of science stems from his theoretical analysis of how science progresses. Popper rejected the traditional scientific view of observational induction. The customary notion that scientific theory can only be validated through observation. Instead, Popper advocated methods of empirical falsification in which scientific theories and hypothesis could only be proven to be false. In this method, the longer the period that a scientific model is valid, the more likely it is to be true; even though it may never be proven to be true.
Thomas Kuhn was also a scientific philosopher and physicist who developed the notion that scientific progress undergoes “paradigm shifts”. His theory on the structure of scientific process states that scientific advancement occurs in a cycle. Progress appears when a paradigm shifts, leading to new paradigms and greater advancements. Kuhn like popper dismissed the traditional scientific framework that existed previously but unlike Popper suggested that scientific progress happens in stages and cycles rather occurring continually as presumed before.
Sir Karl Popper’s theory of scientific progress is a direct result of his dismay at conventional scientific methods of induction. Popper suggests that unless theories can be proven to be true through methods of deduction; they must be labelled as false. Poppers primary problem with induction is its insistence that singular statements such as the analysis of observations or practical’s; from the viewpoint of induction are viewed to be universal. Popper strengthens his argument by stating that the “people who say of a universal statement that we know its truth from experience usually mean that the truth of this universal statement can somehow be reduced to the truth of singular one” (Popper 1972:29) this describes Induction as “superfluous” which then consequently results in logical inconsistencies.
Popper and his theory of falsification is based on the imperative that no scientific rule can ever absolutely be certified and that a generalised inference from a scientific observation; regardless of the number of times repeated will never become scientific truth. Furthermore, Popper states that to claim Induction produces inferences based on observation is a myth which has been accepted not only in scientific circle but also psychology and even in everyday human interaction. The theory of inductions; core criteria is to differentiate truth form falsehood. However, the framework that is used in Popper’s view; is in fact unable to scientifically produce theoretical or observational truth. Because of this Popper is left with the opinion that induction only provides probable assumption rather certain hypotheses and therefore Popper agrees with Hume that “it is impossible to justify a law by observation or experiment, since it transcends experiment”. (Klemke Hollinger and Rudge 1998:45)
In contrast Thomas Kuhn’s notion of scientific progress is associated with the historical analysis of science rather than the concepts of Induction and deduction. To fully comprehend Kuhn’s theory on scientific method and progress it is essential to understand Kuhn’s notion of paradigms. Kuhn defines a paradigm as an accepted framework and common law which is subjected to further articulation until a new paradigm emerges. For Kuhn “paradigms gain their status because they are more successful than their competitors in solving a few problems that the group of practitioners has come to recognize as acute” (Kuhn 1970:23). Therefore, Science can only progress when paradigms shift leading to an assumed greater accuracy in the paradigm’s prediction and articulation due to the acceptance of the scientific community.
So, it follows that scientist do not in fact intend to produce new theories that advance scientific knowledge but instead they become intolerant towards previous theories and paradigm’s that attempt to explain scientific phenomena. In his book “The structure of scientific Revolution” Kuhn reiterates that each paradigm has a distinct perspective in regards to explaining a specific scientific theory and function. Therefore, in a similar fashion to Karl popper who stated that it is impossible to produce absolute scientific truth but only the greater probability of truth; Kuhn states that contrasting paradigms investigate scientific method through differing frameworks and consequently ask different question and are therefore provided with a different answer.
However, unlike Popper who suggests that the longer a scientific theory is around the more probable its chances of being true; because of its ability to compete and defeat new emerging hypotheses. Kuhn claims that Paradigms and scientific methodology abide by incompatible standards and are therefore considered to be “incommensurable”. Though, such a view has often been intensively critiqued by some segments of the scientific community for being relativistic and claiming that there is no such phenomenon as progress in scientific knowledge because different theories of scientific method are incomparable to another.
Popper’s promotion of a deductive approach towards scientific methodology and philosophy is characterised by his theory of falsification. Popper holds the view that science can only progress through trial and error. During this process, scientific conclusions are compared with one another to achieve higher levels of logical deduction. For Popper, there are four core criterions which need to be used to test a scientific theory; these include logical comparisons of scientific conclusions to test the internal consistencies of the theory. Second, the theory must be investigated to ensure that it is empirical rather than rhetorical. The third principle requests that scientific theories must be compared with other pre-existing theories to determine whether it deserves to be labelled as a scientific advancement. Finally, the fourth and last of Popper’s principles is the notion that; scientific theory must be accessed through its own conclusion by means of empirical application.
For Popper, if these four-key principles are appropriated then scientific progress can be measured through the theory of falsification because as (Pitt, J.C. 1985:12) states “if a theory passes such criteria and has been verified, then the theory has for the time being passed the test” however “if the conclusion has been falsified then their falsification also falsifies the theory which it was logically deduced from”. In addition to this, Popper sees it noteworthy to distinguish between falsifiability and falsification. Falsifiability can be described as the framework and regulation for a system of statements whilst falsification can be explained as the method by which a hypothesis should be more falsifiable than the previous theory that it has replaced.
Popper’s deductive form of scientific method can be contrasted with Kuhn’s theory of scientific revolution using paradigms. Inductive and deductive methods can be criticised for neglecting the historical evidence of how science has progressed. Since the origins of civilisation in Mesopotamia, science has been advancing through numerous important and still relevant theories which at the time could not be inducted, deducted or even explained. This progress can be more appropriately explained by the theory of scientific revolution; which states that a scientific theory can only be replaced with another and if this does not occur then the existing theory is for the time the closest thing to scientific truth.
I will now elaborate Kuhn’s notion of scientific paradigms by providing a more detailed explanation of Kuhn’s varying stages of scientific progress. As explained previously Kuhn viewed scientific progress to occur in a cycle rather than being continuous. For Kuhn, Scientific progress occurs in five key stages beginning with an era of pre-science characterised by disagreements on central theories. The first stage: Pre-science can only be transformed into to Kuhn’s second stage of progress which is defined as “normal science” only when scientific institutions and establishments agree upon a single unitary paradigm. Kuhn explains “normal science” as a process involving a detailed attempt to improve sciences relationship with nature. During this phase Kuhn describes normal science as an era of “puzzle solving” with the aim of one day being able to complete the jigsaw.
Another important factor leading to scientific progress for Kuhn; is the emergence of anomalies in scientific observations and experiments. The discovery of an anomaly leads to the recognition of the fact that nature has in a sense desecrated the existing paradigm and the rules that govern “normal science”. Due to such a discovery, science “continues with a more or less extended exploration of the anomaly. And it closes only when the paradigm theory has been adjusted so that the anomalous has become the expected” (Kuhn1972:53). Such acceptance of an anomaly then produces Kuhn’s third stage of scientific progress; “crisis” which is characterised as a period of competing paradigms in which new theories emerge from the long-lasting crisis which has “penetrated so deep that it led to a scientific revolution” (Kuhn 1970:67).
The fourth and arguably the most significant stage of scientific progress is the emergence of a “scientific revolution” which Kuhn compares to the emergence of political revolution. In this stage, there is an increasing sense that existing scientific theories have ceased to effectively tackle the problems posed by the new emerging paradigm. Kuhn claims that just like a political revolution a scientific revolution’s success “necessitates the partial relinquishment of one set of institutions for another” (Kuhn 1970:93). Finally, once a scientific revolution has taken place; the emergence of a new dominant paradigm creates the fifth and final stage of the stages of scientific progress which is the introduction of a “new science. However, for Kuhn the progress of scientific progress does not stop at the emergence of a “new science”. Kuhn holds the view that “new science” will eventually turn into the norm and become a theory of “normal science” which will then eventually culminate in the production of a new paradigm due to the anomalies that existed in the previous theory.
After much reading on Karl Popper and Thomas Kuhn’s notion of scientific progress I have struggled to find much significant compatibility between the two theories on social progress. Probably the only absolute resemblance between the two scientific philosophers is the rejection of previous models and explanations of scientific progress; although being for differing reasons.
In summary Karl Popper’s idea of scientific progress revolves around the notion that the scientific method of deduction is the only logical means by which a scientific observation can be falsified. Since the positive confirmation of a phenomenon is a baseless practice in determining whether a theory is true. Popper states that the only method that allows us to achieve scientific progress is through trial and error. Since only the most upstanding scientific theories survive the test of time.
Conversely, Thomas Kuhn asserts that the emergence of scientific progress can only take place when existing frameworks of scientific method and theory are replaced with new emerging Paradigm’s due to sciences natural property of progressing through revolutionary cycles.
Kuhn’s concept of scientific progress has been mainly praised for considering the history of scientific advancement and for developing a correlation between scientific development and the emergence of new scientific method. However, both sets of ideas have been criticised for differing reasons. Popper’s account of scientific progress can be accused of not explaining the progress that science has made for much of human history without using the framework of falsification and deductive methods, Whilst Kuhn has been critiqued for having a relativistic approach and not providing a specific account of the idea of progress.
Klemke,E.D. Hollinger,R. and Rudge,W.S.(1998) Introductory readings in the Philosophy of science. Amherst, New York: Prometheus Books.
Kuhn, T. (1957) The Copernican Revolution: Planetary Astronomy in the Development of Western Thought. Harvard: University Press.
Kuhn, T.S. (1970) The structure of scientific progress. London: International Encyclopaedia of Unified Science
Kuhn, T (1972). The Essential Tension: Selected Studies in Scientific Tradition and Change. University of Chicago Press.
Pitt, J.C. (1985) Change and progress in modern science. Boston: Reidel publishing company.
Popper, K. (1972) The logic of scientific discovery. London: Hutchingson of London.
Popper, K. (1972) Conjectures and Refutations: The Growth of Scientific Knowledge. London: Routledge publishing.
Popper, K. (1994) The Myth of the Framework: In Defence of Science and Rationality. New York: Routledge publishing.