Problems as Distinct from Puzzles: Thomas Kuhn’s Crucial Innovation in Understanding the Nature of Scientific Progress
In the Structure of Scientific Revolutions, Thomas Kuhn proposes a theoretical understanding of how science develops. Prior to Kuhn’s philosophy, there had not been much exploration into theoretical accounts of scientific change. However, it was generally thought that science progressed linearly by the addition of new truths onto old truths. This linear view of scientific progress takes scientific progress to be the process of getting scientific theories to move closer to truth, but takes the correction of past mistakes to be a rare occurrence in the scientific method. Furthermore, it was generally thought that this approach to the scientific method guaranteed progress and that while there could exist better or worse scientists capable of progressing science faster or slower than others, there was no real question about if science could and would progress this way.
Thomas Kuhn was the first person to explicitly propose an alternate theory of scientific progress which profoundly diverged from the longstanding traditional linear view of scientific progress by drawing a distinction between the puzzle-solving activity of what he calls “normal science” or “normal phases” and the philosophical frame-breaking activity of what he calls “scientific revolutions” or “revolutionary phases.” I argue that Kuhn’s crucial groundbreaking insight into the nature of scientific progress is that there exists a revolutionary kind of philosophical frame-breaking activity which is just as important to scientific progress as normal science and that understanding the distinction he draws between puzzles and problems is necessary to understand the cyclical interplay between normal and revolutionary science as well as why scientific progress cannot be linear.
Kuhn’s theory rejects a strictly linear or uniform understanding of scientific progress. Kuhn begins by arguing that instead of uniform progression, science develops in phases. There are two kinds of phases: normal and revolutionary. Normal phases are phases where what Kuhn calls “normal science” occurs. Kuhn argues that his concept of normal science might resemble the linear traditional view of scientific progress which was commonplace prior to Kuhn. However, to further elucidate exactly what Kuhn means by normal science, he argues that normal science is like puzzle solving: “Under normal conditions the research scientist is not an innovator but a solver of puzzles, and the puzzles upon which he concentrates are just those which he believes can be both stated and solved within the existing scientific tradition” (Kuhn, 63). The puzzle analogy draws out some important features of normal science. Firstly, puzzle solving involves the belief that I am capable of succeeding in completing the puzzle and that my doing so will depend entirely on my own abilities. Furthermore, when I solve a puzzle, I am also going into the puzzle with the understanding that the structure of the puzzle will be mostly familiar and that the terms and methods that I must use to solve the puzzle will also be familiar to me.
If I imagine trying to solve an English crossword puzzle, I can confidently say I know that the structure of the puzzle will consist of rows and columns of boxes which I must fill with letters to spell words and that the proper word to spell will be indicated by a clue given to me by the puzzle. I also know I cannot let there be a single word on the grid which does not exist nor can I leave a word in a column or row which does not correspond to the given clue for that column or row. I know I need to use the tool of a pencil and my terms are letters and words and sometimes phrases. I also know I can access the proper solutions to the puzzle using my mental repository of knowledge, mostly of pop-culture and history. Importantly, I know that if I fail to solve the crossword puzzle, it is not because a pencil was the wrong tool or because I was not supposed to use the terms of words and letters. I also know it is not because I have misunderstood the structure of the puzzle either. If I fail to solve the crossword puzzle, it is because I personally lacked the ability (in this case a repository of memorized facts) to properly solve the puzzle. It is therefore perfectly understood by me that another person using the same tools, terms, and methods will be able to complete the puzzle if they possess a greater ability than I do. With the puzzle analogy, Kuhn wants to draw special attention to the fact that when we go into solving a puzzle, we do not take ourselves to be entering brand new completely uncharted territory.
For Kuhn, this is how normal science works. Because in normal science, we take ourselves to be mostly familiar with the structure of the problem and the terms and methods we need to solve the problem, normal science and normal periods of scientific progress are only able to accumulate puzzle-like solutions on top of each other. In periods of normal science we do not diverge from commonly-accepted terms and methods and therefore we take previously solved puzzle-like answers to be factual, objective, and true. Normal science will then take these previously solved puzzle-answers and build new puzzle-answers on top of those.
While Khun argues that normal periods are periods where science can progress, revolutionary periods are periods where scientific progress accelerates. In addition to being periods where progress is moving faster, revolutionary phases possess profound qualitative differences from phases of normal science. According to Kuhn, scientific revolutions or revolutionary science are characterized by the revision of existing commonly-accepted scientific practices and beliefs. Importantly, some of the puzzle-solutions or ideas which were, under the terms and methods of the previous period of normal science, considered achievements, will not survive the scientific revolution. This is so much so that Kuhn argues we may think we have successfully solved important scientific problems during a period of normal science but then find ourselves completely without a solution in the following revolutionary period. The idea that during scientific revolutions, not all previously accepted scientific descriptions of phenomena will be preserved is often referred to as “Kuhn loss.”
One might be inclined to interpret Kuhn’s description of revolutionary periods as suggesting that the revision of scientific practices and beliefs is good for progress, but only insofar as it adds to negative knowledge. In other words, we might think scientific revolutions are good because they show us what we previously got wrong but do not add to positive knowledge the way normal phases do. Conversely, we might be inclined to see revolutionary phases as simply a faster and better version of normal phases which does add to positive knowledge and should therefore be preferred to normal phases. However, neither of these two pictures properly capture the nature of scientific revolutions which Kuhn has in mind.
For Kuhn, a key feature of scientific progress is that it requires a cyclical interplay between normal phases and revolutionary phases. Kuhn is clear that normal phases cannot be successful in producing progress unless the relevant scientific community collectively commits to shared values, beliefs, theories, techniques, instruments and metaphysical ideas: “Normal science, the activity in which most scientists inevitably spend almost all their time, is predicated on the assumption that the scientific community knows what the world is like” (Kuhn, 65). Kuhn calls these shared commitments “disciplinary matrices” or “paradigms.” Kuhn argues that we need paradigms in order for normal science to progress: “to reject one paradigm without simultaneously substituting another is to reject science itself” (Kuhn, 64). This is so much so that in order to train a good scientist, it is important to instill in her a commitment to the prevailing paradigm so that she may contribute to the progression of normal science.
However, clinging to a paradigm, while crucial to normal science’s ability to make progress, can also be detrimental when it becomes a limiting framework. Kuhn is here identifying an important tension between the scientist’s need to conservatively cling to communal paradigmatic commitments while also desiring innovation. Therefore, revolutionary phases are not better than normal phases nor are they worse: they serve a different function and involve a different process. Importantly, in order for either kind of phase to be properly making scientific progress, it must be moving in a direction which eventually leads to the other kind of phase.
Because successful normal science requires large-scale and deeply-instilled paradigmatic commitments from an entire scientific community, these paradigms do not change unless the circumstances requiring such a change are extreme: “once it has achieved the status of paradigm, a scientific theory is declared invalid only if an alternate candidate is available to take its place” (Kuhn, 68). An important feature of normal science is that scientists do not attempt to confirm, challenge, or test the theories which guide the paradigm of this normal phase. Furthermore, if a scientist comes upon an anomaly during this normal phase, most often it will be ignored. However, Kuhn argues that if enough especially problematic anomalies, which undermine the practice of normal science, are accumulated, this can seriously threaten a paradigm: “Unanticipated novelty, the new discovery, can emerge only to the extent that his anticipations about nature and his instruments prove wrong” (Kuhn, 62).
An example of an especially problematic anomaly would be something like the case where the guiding theory behind a tool, like a commonplace piece of scientific equipment, comes to be doubted because its inadequacies are revealed. If this tool were crucial to science, it would be extremely difficult for normal science to feel as though it can continue until this anomaly is completely resolved. This introduces the idea of a problem which differs from a puzzle in that it appears to be a puzzle, but does not meet the aforementioned criteria to be a puzzle. Importantly, it will not be initially evident that this apparent puzzle is indeed actually a problem.
To elucidate the difference between the puzzle solving activity of normal science and the philosophical revolutionary frame-breaking required in the face of a problem it is worthwhile to look at another example: Nozick’s mathematical series. In this example, we can imagine Nozick writing a series of numbers on the chalkboard and asking a classroom full of students to continue the series. Being well versed students of math who know very well that mathematical series are described using mathematical functions, each student begins attempting to find the equation that will yield Nozick’s series. Only, there is no such mathematical function that could describe the series and lead you to the next number in the series because Nozick’s mathematical series is actually a list of New York train stations in increasing order. We can see how the students were led astray by the paradigm regarding mathematical series that they have been taught. It is completely sensible for a student to begin attempting to find an equation when asked to find the next number in a series because this is the accepted method of solving this kind of puzzle.
In this example, a student would have had to abandon what she thought she knew about the nature of puzzles involving series and how to go about defining them. Because of the prevailing paradigm regarding series-solving, no student thought to look at the series under a different framework, namely that the series was not defined by an equation but instead by a list of bus stops, and the puzzle remained unsolved in the context of the students’ original paradigm. This is how paradigms can inhibit progress: by restricting us to frameworks which cannot yield a solution. Similarly, paradigms can lead to incorrect solutions. Say for example that Nozick’s series, despite still being a list of bus stops, could be defined by some equation. A student might proudly calculate what this function would say is the next number in the series, but unless this is the next New York bus stop, the mathematical approach, while appearing to yield the perfectly correct result, still did not answer Nozick’s question properly. In order to figure out, we would have needed to think outside of the box and even consider that this puzzle and its solution might not be a mathematical function.
Nozick’s mathematical series example also demonstrates the positive puzzle-solving power of paradigms and illustrates why anomalies are largely ignored in normal science. Obviously, mathematical functions were not going to help us find the next number in Nozick’s series, but they do help us solve most series. If we were to abandon the prevailing paradigm which tells us to look for a defining function when we wish to solve a series, and replace it with a new paradigm which tells us to not look for functions and instead look at different city bus-stop lists, we would find success in being able to solve Nozick’s series but fail miserably at solving the vast majority of series overall. This means, despite the fact that the mathematical function paradigm of series fails to solve Nozick’s problem, it would not make sense to destroy our current paradigm regarding series in favor of this new one because it would decrease our puzzle-solving power.
However, if wide-spread confidence in the paradigmatic norms of a given normal period begins to dwindle and fail, this is what Kuhn calls a “crisis.” Such crises are what can lead out of normal science and into scientific revolutions: “novelty emerges only with difficulty, manifested by resistance, against a background provided by expectation” (Kuhn, 60). When a scientific community encounters an extreme crisis, it might revise the prevailing paradigm in such a way that gets rid of the problematic anomaly which led to the crisis and ideally resolves many still unresolved puzzles. This kind of profound revision of a prevailing paradigm of a scientific community is what Kuhn means by scientific revolution. However, Kuhn tells us that this “requires the reconstruction of prior theory and re-evaluation of prior fact, an intrinsically revolutionary process that is seldom completed by a single man and never overnight” (Kuhn, 79). Importantly, neither the decision to revise a paradigm nor the way in which the paradigm ultimately gets revised is a rational decision on the part of any individual.
For this reason, unlike normal phases, revolutionary phases are full of intellectual rational debate about different ideas and there tends to be a lot of competition and disagreement: “Because scientists are reasonable men, one or another argument will ultimately persuade many of them. But there is no single argument that can or should persuade them all. Rather than a single group conversion, what occurs is an increasing shift in the distribution of professional allegiances” (Kuhn, 78). While Kuhn says non-scientific factors, like political ones, could influence the outcomes of revolutionary phases, he is clear that the theories which prevail during this period and make their way into the next paradigm are largely the ones that show themselves, within the specific scientific community, to have a greater power to solve puzzles, more so than other competing theories discussed during the same revolutionary phase. Importantly, this revolutionary phase will need to resolve itself by the wide-spread adoption of a new, revised paradigm which will lead to a new normal phase.
Crucially, scientific progress is occurring during both revolutionary and normal phases, perhaps at different rates, but progress will nevertheless be occurring in both. In a normal phase this will take the form of the linear accumulation of puzzle-solutions within a paradigm. During a scientific phase, progress will take the form of debunking incorrect solutions which were previously held as true and the establishment of a new and improved paradigm as well as new solutions to previously unsolved puzzles. However, the phenomenon of Kuhn-loss which inevitably causes certain scientific achievements to be eliminated is why for Kuhn, scientific progress cannot be linear: because in the transition from normal to revolutionary science, scientific progress inevitably requires certain “solutions” to be removed as opposed to linearly built upon. Because the presence of extremely problematic anomalies in normal science is what leads to scientific revolutions, the new paradigm needs to resolve many of the anomalies which led the previous one to fail or it is not worth adopting this new paradigm. However, conversely, the new paradigm must retain a lot of the problem solving power of the previous paradigm. Even despite inevitable Kuhn-loss, a new paradigm will resolve more puzzles than the number and weight of the puzzle-solutions it eliminates which means scientific revolutions do lead to an increase in puzzle-solving power.
Prior to Kuhn, scientific progress was thought of as teleologically moving towards truth. Kuhn’s theory of scientific progress is not teleological and is instead an evolutionary view. Just as an evolving animal species is not moving towards some teleological ideal form of the animal species and is instead adapting to challenges in the environment. Likewise, Kuhn does not think science is moving towards some ideal or complete form and is instead constantly adapting to solve new puzzles. This is why we measure the progression of science by its ability to solve puzzles and not by its proximity to a standard of truth. Kuhn equates scientific revolutions to political ones, showing how much like in the political realm, revolution comes about when severe enough challenges make clear that the current system and prevailing status-quo is untenable, outdated, and inadequate.
Why should a change of paradigm be called a revolution? In the face of the vast and essential differences between political and scientific development, what parallelism can justify the metaphor that finds revolutions in both? One aspect of the parallelism must already be apparent. Political revolutions are inaugurated by a growing sense, often restricted to a segment of the political community, that existing institutions have ceased adequately to meet the problems posed by an environment that they have in part created. In much the same way, scientific revolutions are inaugurated by a growing sense, again often restricted to a narrow subdivision of the scientific community, that an existing paradigm has ceased to function adequately in the exploration of an aspect of nature to which that paradigm itself had previously led the way. In both political and scientific development the sense of malfunction that can lead to crisis is prerequisite to revolution. (Kuhn, 80).
In the face of a scientific community which had yet to rigorously examine its own epistemological assumptions about the methods and progression of science, Thomas Kuhn proposed an entirely new way of understanding the nature of scientific progress by introducing the idea that there is a philosophical frame-breaking activity which occurs in periods of scientific revolution that is qualitatively different from the puzzle-solving activity of normal science. By identifying and elucidating the differences between puzzles and problems, Kuhn is able to target and explain the nature of this philosophical revolutionary activity. Kuhn paints a deeply complex picture of a back and forth movement between scientific revolution and normal science which is riddled with tensions that Kuhn himself identifies. The scientist needs to learn what the scientific community takes to be its proper theories, methods, tools, values, and metaphysical commitments in order to be able to properly make progress in the context of normal science, but at the same time it is of the very nature of the paradigm that it will eventually be revised and replaced by one which is better at puzzle-solving. Nozick’s mathematical series exemplifies how a paradigm which is largely accepted can fail to properly solve all puzzles and that in order to solve these puzzles, a new framework is required. It also shows how scientific revolution is not to be desired outside of a faulty paradigm. While it is good to replace our methodological and theoretical commitments with new, better, ones, it makes no sense if the new paradigm fails to solve most puzzles as well as the old one. Neither scientific revolution nor normal science are good or desirable in and of themselves and neither is an objectively better kind of phase. Scientific Revolution relies on normal science as much as normal science relies on revolution as science would ultimately be unable to progress without the existence of both. In this sense, Kuhn shows why, in science, we need puzzles as much as we need problems and we need normal science just as much as we need scientific revolution.
Works Cited
Kuhn, Thomas S. The Structure of Scientific Revolutions
