Kuhn vs Popper

According to Kuhn, what is wrong with Popper’s account of the scientific method? Is Kuhn’s criticism successful?

Kuhn and Popper were two eminent Philosophers of the 20th century who dealt with the philosophy of science. These two men produced two different theories on scientific enquiry and either theory was at odds with the other, with Popper producing a method which relied on a deductive argument where as Kuhn’s theory relied more on an inductive argument. However, within this essay I will show how Kuhn’s own theory incorporates parts of Popper’s theory to produce an explanation of scientific enquiry which fits within the contemporary scientific method.

Popper’s account of the scientific method is basically an exercise in critical thinking to produce a deductive argument and his theory revolves around the concept of conjectures and refutations. This produces a process of falsifiability and falsification and this process then leads to the conjecture, which is similar to a premise, either being accepted or rejected. According to Popper “This was a theory of trial and error – of conjectures and refutations.” (Popper in Western Philosophy Anthology, p457)

The best way to demonstrate this method is to use an example. So my original conjecture is that the sun rises and sets each day and by this I mean that the sun will rise above and fall below the horizon in a 24 hour period. As I now have this conjecture my next step is to deduce that through inference I can predict that the sun will rise and set tomorrow and this theory can be tested by making observations. Consequently the next day I observe a sunrise and a sunset and this produces a further inference that the same procedure will happen again the day after and consequently for the following days. However, just because I observed the desired outcome which confirms my theory, it only corroborates my

theory as it is possible to have the desired outcome without a true premise. In other words I have not disproved that a sunrise and a sunset happen daily, I have only confirmed it and it is still theoretically possible to observe a 24 hour period without those two events.

This then leads us to a process of Faslifiability. This is basically to see if there is a possibility of showing that the conjecture can be proved wrong as it is impossible to prove that the conjecture is true. So, whilst making observations I realise that during the summer months the further north I travel the more hours of daylight I observe within a 24 hour period and when I reach the north pole I see that the sun does not rise and set within a 24 hour period. Consequently I have proved that my conjecture that the sun will rise and set within a 24 hour period to be false. So even though I have observed hundreds of sunrises and sunsets in a 24 hour period, the fact that I have observed one 24 hour period without a sunrise and sunset refutes my hypothesis as it only takes one observation to falsify my conjecture. This fact of observing a 24 hour period with no sunrise or sunset is the falsification phase of Popper’s scientific method.

So I am now in a position where my original conjecture has been proved to be false, but I can learn from my observations and alter my conjecture to accommodate this new knowledge. Instead of stating that the sun will rise above and set below the horizon in a 24 hour period I could state that the sun will rise above and set below the horizon within a twenty four hour period dependant on my position on planet Earth. This can then be corroborated by noting my position and also the time of the sunrises and sunsets around the world.

So by using Popper’s conjecture and refutation method I have started with an original conjecture that was originally corroborated but then proved to be false. I then modified the conjecture to accommodate the new knowledge and the knowledge gained corroborates the new conjecture. By using the process of falsifiability and falsification I was able to reassess the original conjecture and develop the original hypothesis.

The main reason for this change is that the original conjecture is relying on observations and induction rather than logic and deduction. This is because it is inferring that what I have observed in the past will happen again in the future and does not rely on priori knowledge, such as mathematics or geometry. However the argument is constructed on a deductive basis but as the premise is based on observations rather than deduction then the truth of the premise does not transfer strongly and there is room for doubt. Consequently there can be hundreds and thousands of observations confirming the theory but it can take just one contrary observation to falsify the premise and so consequently falsify the conclusion.

However this view of scientific enquiry has not been universally adopted and a critic of Popper’s method has been a philosopher called Thomas Kuhn. Kuhn believed that Popper’s method of conjecture and refutation only happens at times of revolution instead of being a standard practice and that for the majority of the time a scientist would practice what Kuhn would call normal science. Kuhn’s main criticism of Popper was that “Karl Popper has characterised the entire scientific enterprise in terms that apply only to its occasional revolutionary parts.” (Kuhn, 1970, OU Book 4, p162) and Kuhn developed a theory which revolves around paradigms and revolutions instead of conjecture and refutation.

So, according to Kuhn, a paradigm would be defined as a framework of knowledge which has been constructed over the history of the particular tradition and it is this framework of which a scientist would work within and contributes to the existing paradigm and is “research firmly placed upon one or more past scientific achievements” (T. Kuhn, Western Philosophy p475). This method would continue and if there was a fault or a problem within the paradigm then anomalies would arise, which over a period of time would amass and would then begin to highlight the problems within the paradigm. Two good examples of paradigms, and how a change is developed, are the Ptolemaic and Copernican astronomical systems.

With Ptolemaic astronomy the earth is placed at the centre of the universe with the planets orbiting and a fixed sphere of stars beyond the planets. This system predicted the movement of the planets and stars and was the accepted theory of the time and survived for thirteen hundred years with only minor adjustments. The Ptolemaic system was then replaced by the Copernican system of which placed the sun at the centre of the universe instead of the earth but was slow to be adopted because of the elliptical orbits and was not fully accepted until this had been incorporated. Of what these two examples show is that a paradigm provides a framework for the scientist to work within during conducting normal science, as opposed to Popper who’s method of conjecture and refutation would question the accepted knowledge of the time. However, by using Kuhn’s method the scientist would be using a system which is relying more on inference rather than deduction and the further a scientist develops a theory reliant on the paradigm the inference will get weaker. So consequently a point could be reached where the paradigm does not perform as expected and an accumulation of data happens which begins to show that there is a fault within the paradigm.

Consequently when normal science is using a paradigm which is erroneous, this would then lead to the revolutionary phase of scientific enquiry and it is this phase which is similar to Popper’s conjecture and refutation, but for Kuhn this phase will only happen if there is a new paradigm to replace the faulty one. First of all there needs to be an accumulation of data which begins to show that there are problems with the original paradigm and this can take time as there is the underdetermination of theory by data which “states that more than one theory can explain our data” (C. Chimisso, OU Book 4, p149) However when the data reaches a critical mass, change still doesn’t happen unless there is another paradigm to replace the old, mainly because the scientists require a framework to work within.

So paradigm change is reliant on two aspects, an accumulation of data showing a fault within the paradigm and a new paradigm being available to replace the old. Without either of these two qualities then a revolutionary phase cannot happen because the data is needed

to show where the fault lies and a new paradigm is needed to give direction. Also, with Kuhn’s method of scientific enquiry the issue of inference remains but the negative effect of inference, that the truth of a premise is diminished, is restricted by the use of the revolutionary phases, but these revolutionary phases only happen very rarely and science progresses in steps rather than continuously.

So in summary we have two competing theories of scientific enquiry, Popper’s conjecture and refutation and Kuhn’s paradigms and revolutions, so which one theory is the best for scientific progress?

I would argue that Kuhn’s own theory and criticisms of Popper’s theory does indeed have some merit. “Popper has described what happens in rare moments of the history of science and erroneously believed that those rare moments exemplified standard scientific practice.” (C.Chimisso, OU Book 4, p162) The three main areas which I think Kuhn’s theory is preferable to Popper are the separation of normal science and revolutions, the concept of normal science itself and the fact that paradigms change and evolve.

Even though Popper’s attempt to give scientific enquiry a logical and deductive structure is an excellent idea, this only seems to be feasible during what Kuhn believes to be the revolutionary phase. The problem with Popper’s concept is that every enquiry would be a conjecture and that would be refuted, in other words a revolution could be happening every time an experiment is performed. This act in itself would slow down scientific progress to such a degree that the scientific method becomes stagnant and does not evolve. Whereas with Kuhn, the revolutionary phase happens rarely and this gap gives the paradigm time to evolve to accommodate the new knowledge gained within the time between revolutions.

The next part of Kuhn’s theory which is attractive is the concept of normal science. This is the scientist working within the paradigm, or the framework of knowledge, that has already been provided and accepted by the scientific community. Even though in Popper’s view this is “the science student which accepts the ruling dogma of the day” (Popper,

OU Book 4, p163) the system does use knowledge that has already been tested but, admittedly, can be affected by the negative quality of inference, which is that the truth of a premise does not always transfer to the conclusion.

The last aspect of Kuhn’s theory which is attractive is the fact that paradigms can evolve and change. This allows the existing paradigm, the framework of knowledge to be altered and modified over a period of time and can actually be an answer to dogmatic thinking. A weakness for Popper is that in his theory paradigms do not exist as everything is questioned through the use of conjecture and refutation. It is the concept of the paradigm itself, a reservoir of knowledge at the disposal of the scientist that does not need to be questioned and can be relied upon, which enables science to progress forward in an orderly and cohesive direction.

So in conclusion, Popper’s concern over the effects of inference is well founded and his theory does dispel the effect of inference to a certain degree. However, Kuhn using this theory in conjunction with the concept of paradigms and normal science, demonstrates that his criticisms of Popper were well founded.

Bibliography:

Barber, A. (2011) ‘The Morality of Abortion’ in ‘Ethics’ OU course book 3, A22 Exploring Philosophy, Open University, Milton Keynes

Saul, J. (2011) ‘Philosophers on Abortion’ in ‘Ethics’ OU Website A222 Exploring Philosophy, http://learn2.open.ac.uk/course/view.php?id=200697

Thomson. J.J (1971) ‘A Defense of Abortion’ in ‘Western Philosophy an Anthology’ Cottingham J.(2008)Blackwell Publishing, Oxford