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Monday, August 15, 2011

Thomas Kuhn-scientific method

Mystery abounds in our universe,Humans try to interpret it in variety of ways. Scientists have greater role in it.Perhaps no modern thinker has better convinced us of this than Thomas S. Kuhn. Was Kuhn's famous 1962 essay "The Structure of Scientific Revolutions"--intended for the now obscure International Encyclopedia of Unified Science--a radical and revolutionary manifesto liberating science from the cold language of Baconian logic? Or was it merely an essay that brought to the public arena what was often debated only in history of science conferences? Indeed, the essay was later translated into sixteen languages, and over one million copies have been sold--a very high number for such an intellectually rigorous book. Even after Kuhn's death last summer, philosophers and scientists remain divided on Kuhn's essay and the nature of Kuhn's legacy.

Science will never progress on just observing as positivist viewed.

Kuhn attacks “development-by-accumulation” views of science which hold that science progresses linearly by accumulation of theory-independent facts. Older theories give way successively to wider, more inclusive ones.

To understand the mystery around us Kuhn observes that scientists develop paradigm. Like Karl Popper, he agrees that all observation is theory laden. Scientists have a worldview or "paradigm".

The paradigm of Newton's mechanical universe is very different to the paradigm of Einstein's relativistic universe; each paradigm is an interpretation of the world, rather than an objective explanation. Darwin is also an example of a paradigm shift in biology.

Marx and his class analysis of society,

He believes that we progress intellectually through stages of development

Knowledge which does not evolve according to the four stages, according to Kuhn, may not be considered scientific.

Stages of Scientifc Development

· Pre-science

· Normal Science (most common – science is usually stable)

· Crisis and Revolution

· New Paradigm

Pre-science - Disorganized and diverse activity.

Constant debate over fundamentals.

As many theories as there are theorists.

No commonly accepted observational basis. The conflicting theories are constituted with their own set of theory-dependent observations.

Normal Science (most common – science is usually stable)

A paradigm is established which lays the foundations for legitimate work within the discipline.

Scientific work then consists in articulation of the paradigm, in solving puzzles that it throws up.

Through the paradigm learned from the text book evry secintific generation learns to solve puzzles of their generation and understand world around them

Puzzles that resist solution are seen as anomalies.

Anomalies are tolerated and do not cause the rejection of the theory.

It is necessary for normal science to be uncritical.

If all scientists were critical of a theory and spent time trying to falsify it, no detailed work would ever get done.

Crisis and Revolution - Anomalies become serious, and a crisis develops if the anomalies undermine the basic assumptions of the paradigm and attempts to remove them consistently fail.

Marxism failed to establish solutions to many prevailing problems of the then generation.

Under these circumstances the rules for the application of the paradigm become relaxed. Ideas that challenge the existing paradigm are developed.

Eventually a new paradigm will be established, but not as a result of any logically compelling justification.

In crisis there will be ‘extraordinary science’ where there will be several competing theories.
One theory will win because it will get the greatest number of supporters in the scientific community, because it is simple or may solve a social need.

New Paradigm- Each paradigm constructs “the Universe” and the meaning of concepts and observations in a completely different way.

Each paradigm comes complete with standards for the assessment of what is to count as scientific.

Different paradigms are held to be incommensurable.

The reasons for the choice of a paradigm are largely psychological and sociological.

There is no natural measure or scale for ranking different paradigms.

What is a Paradigm is ? At the core of Kuhn's thoughts is the notion of "paradigms." While Kuhn cannot claim total credit for coining the word, no intellectual work popularized the word like "Structure" did. Though one source claims that Kuhn utilizes twenty-one implicit meanings for the word during the course of his long essay, Kuhn offers an initial definition that readers can easily hold on to as legitimate. Paradigms are essentially scientific theories or ways of looking at the world that fulfill two requirements: they must be "sufficiently unprecedented to attract an enduring group of adherents away from competing modes of scientific activity," and they must be "sufficiently open-ended to leave all sorts of problems for the redefined group of practitioners to resolve".

A paradigm is a universally recognizable scientific achievement that, for a time, provides model problems and solutions to a community of practitioners.

Indeed, even in this initial definition, readers can already detect, through words such as "adherents," the manner in which Kuhn often presents his arguments. While his ideas may not be totally revolutionary in and of themselves, his language often portrays paradigms as cults and the battle between paradigms as quasi-religious wars. For science to progress at all, Kuhn argues, paradigms must emerge that serve to unify scientists behind similar goals. "Men whose research is based on shared paradigms are committed to the same rules and standards for scientific practice. That commitment and the apparent consensus it produces are prerequisites for normal science, i.e., for the genesis and continuation of a particular research tradition". Pre-paradigm eras in scientific fields are early, often random, attempts to grapple with the mystery of nature, to impose comprehensible molds on natural phenomena -- in short, to establish some sort of paradigm by which to further not only understanding, but the potential for future understanding as well. Indeed, "early fact-gathering is far more nearly random activity than the one that subsequent scientific development makes familiar".

In formulating new paradigms, Kuhn continues, social factors may affect how scientists choose to interpret the facts they directly glean from nature. A paradigm represents more than just a collection of known facts; it represents a plan of the universe through which they can at least temporarily look at the universe and further their research. In other words, once they have adopted a paradigm, they can then test the limits of its scope. Thus, while the paradigm is essentially based on observed facts, the ideas and creativity that go into articulating the paradigm may be the result of cultural or metaphysical notions. Paradigms not only supply a theory on nature, but they also dictate methodological beliefs "that permit selection, evaluation, and criticism". Once a paradigm emerges, the possibility for specialization and further development also emerges.

Textbooks, more than perhaps any other force in science, represent the bulwarks of existing paradigms. Students of science learn to deal with the world around them in the context of the paradigm they are taught. Ideally, students then grapple with the issues left unresolved within their paradigm and thus continue what Kuhn calls the enterprise of "normal science"--"an attempt to force nature into the performed and relatively inflexible box that the paradigm supplies". In dealing with nature through an existing paradigm, scientists are inherently conservative. They generally shun new theories that may shake their views of the world. According to Kuhn, however, this conservatism is not only inevitable, it is desirable: "By focusing attention upon a small range of relatively esoteric problems, the paradigm forces scientists to investigate some part of nature in a detail and depth that would otherwise be unimaginable". Normal science is essential for fact-gathering that may help confirm, clarify, or even extend paradigms. They also help to match facts with theory, and they even help to make theories more acceptable by, for instance, making them more aesthetically palatable. More fundamentally, normal science can be seen as puzzle-solving, where paradigms determine the parameters and rules for the puzzle. In other words, the paradigm sets the parameters in which scientists may view the world. Researchers must then attempt to solve the puzzles by looking for missing pieces and connecting them into a cohesive whole.

Where Paradigms Fail This period of puzzle solving, however, is often disrupted by discovery, at which point scientists must call into question the rules by which they were solving the puzzle. Restated, "Discovery commences with the awareness of anomaly, i.e. with the recognition that nature has somehow violated the paradigm-induced expectations that govern normal science". Anomaly must emerge within the context of an existing paradigm--otherwise, scientists would be unable to even recognize it.
Such anomalies occur in many ways. Gramsci’s formulation of relative autonomy was quite accidental. Since Marx view that base decide superstructure but the historical process proved different and the accident quickly became discovery, which quickly changed the expectations that scientists had with their existing scientific equipment, which eventually changed the paradigm in which Marxist operated. When discoveries create crisis situations within a scientific community and push the limits of an accepted paradigm so much so that scientists begin to deem the paradigm untenable, the community must begin to look for alternative paradigms. Quite often, these "gestalt switches," as Kuhn refers to them, from paradigm to paradigm, divide the community into defenders of the existing paradigm and proponents of a new paradigm.

This breakdown of old paradigms and emergence of new ones is often assisted by social forces. For evidence, Kuhn looks briefly at the sixteenth century debate over Copernicus' ideas. While many were beginning to recognize the discrepancy between nature and the traditional Ptolemaic perception of astronomy, the social need for calendar reform and the rise of Renaissance Neoplanotism both contributed greatly to the downfall of the Ptolemaic paradigm and the emergence of Copernicus' new paradigm.

One important aspect of Kuhn's philosophy involves the idea that "the decision to reject one paradigm is always simultaneously the decision to accept another, and the judgment leading to that decision involves the comparison of both paradigms with nature and with each other". Why is this the case? Kuhn points partly to social reasons: "To reject one paradigm without simultaneously substituting another is to reject science itself". No scientist, almost by definition, would be willing to acknowledge that no possible paradigm could explain nature. It is during these moments of crisis, though, that much of the creativity in science emerges. In attempting to articulate a new paradigm to replace a defunct one, scientists must draw on a myriad of ideas from various sources in order to reconcile fact with theory. Indeed, "like artists, creative scientists must occasionally be able to live in a world out of joint". Kuhn further suggests that it is during "periods of acknowledged crisis that scientists have turned to philosophical analysis as a device for unlocking the riddles of their field". Kuhn points towards the notion of thought experiments as a philosophical departure that facilitated the emergence of new paradigms during both Newton's and Einstein's times. The excitement and fear inherent in crisis and paradigm break-down can perhaps best be seen through the eyes of one of the greatest scientists himself. Einstein wrote of his crisis, "It was as if the ground had been pulled out from under one, with no firm foundation to be seen anywhere, upon which one could have built". This confusion often hastens the pace of discovery still further because scientists become more willing to stretch the limits of an already faltering paradigm.

Finally, Kuhn addresses the question of exactly who foments these crises. Kuhn suggests that young scientists or scientists new to the field are often the ones who instigate paradigm shifts. Unmolested by entrenched allegiances to any particular set of rules or a paradigm, these are the ones who are generally successful in challenging existing world views.

Toward a New Paradigm When crises do occur, how do scientists go about comparing two paradigms? If both ask different questions and approach nature in different ways, what makes a better paradigm? Indeed, Kuhn suggests that proponents of two competing paradigms live in different worlds, and the language each group utilizes differs so that real communication between the two camps becomes difficult. In fact, Kuhn writes, "Just because it is a transition between incommensurables, the transition between competing paradigms cannot be made a step at a time, forced by logic and neutral experience". Max Planck echoes this sentiment in his Scientific Autobiography: "a new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it". Rational judgments, however, can be made about the relative merits of two competing paradigms. New paradigms can often successfully argue that they have solved the problems that have led the previous paradigms to crisis. They may also predict phenomena that had been entirely unsuspected while the old paradigm prevailed.

According to Kuhn, perhaps more compelling and decisive than the previous two arguments for a new paradigm, "are the arguments, rarely made entirely explicit, that appeal to the individual's sense of the appropriate or the aesthetic--the new theory is said to be 'neater,' 'more suitable,' or 'simpler' than the old". In his 1992 book Dreams Of A Final Theory, Steven Weinberg, Nobel laureate for his help in the description of the electro-weak force, agrees with Kuhn when he argues, "We believe that, if we ask why the world is the way it is and then ask why that answer is the way it is, at the end of this chain of explanations we shall find a few simple principles of compelling beauty".

Indeed, Kuhn ultimately concludes that science depends on the somewhat erratic decision-making process that favors one paradigm over the other. "In short, if a new candidate for paradigm had to be judged from the start by hard-headed people who examined only relative problem-solving ability, the sciences would experience very few major revolutions.". It is difficult to think of any man who influenced the intellectual atmosphere of the last thirty years as much as Thomas Kuhn. With one essay, he managed to capture the rebellious Zeitgeist of his generation and somewhat unwittingly turn the prevalent social angst of his time against even so sacred an enterprise as science itself. His intellectual insights dispelled to a great extent the mythic aura that surrounded science in a technology-driven society.

Professor Mendelsohn remembers Kuhn's personality as "very intense." He would "pursue his points with vigor" and "not let go easily". This passion for understanding the nature of man's connection to his surroundings must be contagious. Perhaps, it is not so surprising that his ideas swept across the intellectual landscape of a generation with as much energy as it did. As Malcolm Gladwell wrote in The New Yorker, "That [Kuhn's] idea was intended to apply only to the natural sciences did not matter. It was so novel, so persuasive, and--upon the monograph's publication as a book, in 1970--so perfectly in the rebellious spirit of the times that it quickly became adopted as a kind of general theory of everything".

Kuhn's ideas were indeed truly pervasive. In philosophy, history, sociology, economics, politics, and even religion, Kuhn's theory of paradigms changed the nature of the fields. Perhaps Gladwell summed up Kuhn's legacy best when he wrote, "Kuhn will be remembered because he taught that the process of science was fundamentally human, that discoveries were the product not of some plodding, rational process but of human ingenuity intermingled with politics and personality--that science was, in the end, a social process." -- Imran Javaid

The enormous impact of Kuhn's work can be measured in the changes it brought about in the vocabulary of the philosophy of science: besides "paradigm shift", Kuhn raised the word "paradigm" itself from a term used in certain forms of linguistics to its current broader meaning. The frequent use of the phrase "paradigm shift" has made scientists more aware of and in many cases more receptive to paradigm changes, so that Kuhn’s analysis of the evolution of scientific views has by itself influenced that evolution.

For Kuhn, the choice of paradigm was sustained by, but not ultimately determined by, logical processes. Kuhn believed that it represented the consensus of the community of scientists. Acceptance or rejection of some paradigm is, he argued, a social process as much as a logical process. This means Kuhn is a relativist, although he denies this stating that a scientific theory can be assessed according to its problem solving ability.

Does science make progress through scientific revolutions? Are later paradigms better than earlier ones? No, Kuhn suggests, they are just different. The scientific revolutions which supplant one paradigm with another do not take us closer to the truth about the way the world is.

Successive paradigms are INCOMMENSURABLE. Kuhn says that a later paradigm may be a better instrument for solving puzzles than an earlier one. But if each paradigm defines its own puzzles, what is a puzzle for one paradigm may be no puzzle at all for another. So why is it progress to replace one paradigm with another which solves puzzles that the earlier paradigm does not even recognize? Kuhn used his incommensurability thesis to disprove the view the paradigm shifts are objective. Truth is relative to the paradigm.

Science does not change its paradigm over night. Younger scientists take new paradigm forward. As Kuhn put it "a new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it."

Evaluation: Kuhn showed contemporary philosophers could not ignore the history of science and the social context which science takes place. Science is a product of the society in which it is practiced.

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