The Structure of Scientific Revolutions
Encyclopedia
The Structure of Scientific Revolutions (1962
), by Thomas Kuhn, is an analysis of the history of science
. Its publication was a landmark event in the history
, philosophy
, and sociology of scientific knowledge
and it triggered an ongoing worldwide assessment and reaction in — and beyond — those scholarly communities. In this work, Kuhn challenged the then prevailing view of progress in "normal science." Scientific progress
had been seen primarily as a continuous increase in a set of accepted facts and theories. Kuhn argued for an episodic model in which periods of such conceptual continuity in normal science were interrupted by periods of revolutionary science. During revolutions in science the discovery of anomalies leads to a whole new paradigm
that changes the rules of the game and the "map" directing new research, asks new questions of old data, and moves beyond the puzzle-solving of normal science. For example, Kuhn’s analysis of the Copernican Revolution emphasized that, in its beginning, it did not offer more accurate predictions of celestial events, such as planetary positions, than the Ptolemaic system, but instead appealed to some practitioners based on a promise of better, simpler, solutions that might be developed at some point in the future. Kuhn called the core concepts of an ascendant revolution its “paradigms” and thereby launched this word into widespread analogical use in the second half of the 20th century. Kuhn’s insistence that a paradigm shift
was a mélange of sociology, enthusiasm and scientific promise, but not a logically determinate procedure, caused an uproar in reaction to his work. Kuhn addressed concerns in the 1969 postscript to the second edition. For some commentators it introduced a realistic humanism into the core of science while for others the nobility of science was tarnished by Kuhn's introduction of an irrational element into the heart of its greatest achievements.
in the International Encyclopedia of Unified Science
, then as a book by University of Chicago Press
in 1962. (All page numbers below refer to the third edition of the text, published in 1996). In 1969, Kuhn added a postscript to the book in which he replied to critical responses to the first edition of the book.
Kuhn dated the genesis of his book to 1947, when he was a graduate student at Harvard University
and had been asked to teach a science
class for humanities undergraduates with a focus on historical case studies. Kuhn later commented that until then, "I'd never read an old document in science." Aristotle
's Physics was astonishingly unlike Isaac Newton
's work in its concepts of matter and motion. Kuhn concluded that Aristotle's concepts were not "bad Newton," just different.
and philosophy of science
has been described as focusing on conceptual issues: what sorts of ideas were thinkable at a particular time? What sorts of intellectual options and strategies were available to people during a given period? What types of lexicons and terminology were known and employed during certain epochs? Stressing the importance of not attributing modern modes of thought to historical actors, Kuhn's book argues that the evolution of scientific theory does not emerge from the straightforward accumulation of facts, but rather from a set of changing intellectual circumstances and possibilities. Such an approach is largely commensurate with the general historical school of non-linear history.
. For instance, at a particular stage in the history of chemistry
, some chemists began to explore the idea of atomism
. When many substances are heated they have a tendency to decompose into their constituent elements, and often (though not invariably) these elements can be observed to combine only in set proportions. At one time, a combination of water
and alcohol
was generally classified as a compound. Nowadays it is considered to be a solution, but there was no reason then to suspect that it was not a compound. Water and alcohol would not separate spontaneously, but they could be separated when heated
. Water and alcohol can be combined in any proportion
.
A chemist favoring atomic theory
would have viewed all compounds whose elements combine in fixed proportions as exhibiting normal behavior, and all known exceptions to this pattern would be regarded as anomalies whose behavior would probably be explained at some time in the future. On the other hand, if a chemist believed that theories of the atomicity of matter were erroneous, then all compounds whose elements combined in fixed proportions would be regarded as anomalies whose behavior would probably be explained at some time in the future, and all those compounds whose elements are capable of combining in any ratio would be seen as exhibiting the normal behavior of compounds. Nowadays the consensus is that the atomists' view was correct. But if one were to restrict oneself to thinking about chemistry using only the knowledge available at the time, either point of view would be defensible.
. In Ptolemy
's school of thought, cycles and epicycles
(with some additional concepts) were used for modeling the movements of the planet
s in a cosmos that had a stationary Earth at its center. As accuracy of celestial observations increased, complexity of the Ptolemaic cyclical and epicyclical mechanisms had to increase to maintain the calculated planetary positions close to the observed positions. Copernicus proposed a cosmology in which the Sun
was at the center and the Earth
was one of the planets revolving around it. For modeling the planetary motions, Copernicus used the tools he was familiar with, namely the cycles and epicycles of the Ptolemaic toolbox. But Copernicus' model needed more cycles and epicycles than existed in the then-current Ptolemaic model, and due to a lack of accuracy in calculations, Copernicus's model did not appear to provide more accurate predictions than the Ptolemy model. Copernicus' contemporaries rejected his cosmology
, and Kuhn asserts that they were quite right to do so: Copernicus' cosmology lacked credibility.
Thomas Kuhn illustrates how a paradigm shift later became possible when Galileo Galilei
introduced his new ideas concerning motion. Intuitively, when an object is set in motion, it soon comes to a halt. A well-made cart may travel a long distance before it stops, but unless something keeps pushing it, it will eventually stop moving. Aristotle had argued that this was presumably a fundamental property of nature
: for the motion of an object to be sustained, it must continue to be pushed. Given the knowledge available at the time, this represented sensible, reasonable thinking.
Galileo put forward a bold alternative conjecture: suppose, he said, that we always observe objects coming to a halt simply because some friction
is always occurring. Galileo had no equipment with which to objectively confirm his conjecture, but he suggested that without any friction to slow down an object in motion, its inherent tendency is to maintain its speed
without the application of any additional force
.
The Ptolemaic approach of using cycles and epicycles was becoming strained: there seemed to be no end to the mushrooming growth in complexity required to account for the observable phenomena. Johannes Kepler
was the first person to abandon the tools of the Ptolemaic paradigm. He started to explore the possibility that the planet Mars
might have an elliptical orbit rather than a circular
one. Clearly, the angular velocity
could not be constant, but it proved very difficult to find the formula describing the rate of change of the planet's angular velocity. After many years of calculations, Kepler arrived at what we now know as the law of equal areas.
Galileo's conjecture was merely that — a conjecture. So was Kepler's cosmology. But each conjecture increased the credibility of the other, and together, they changed the prevailing perceptions of the scientific community. Later, Newton
showed that Kepler's three laws could all be derived from a single theory of motion and planetary motion. Newton solidified and unified the paradigm shift that Galileo and Kepler had initiated.
Once a paradigm shift has taken place, the textbooks are rewritten. Often the history of science
too is rewritten, being presented as an inevitable process leading up to the current, established framework of thought. There is a prevalent belief that all hitherto-unexplained phenomena will in due course be accounted for in terms of this established framework. Kuhn states that scientists spend most (if not all) of their careers in a process of puzzle-solving. Their puzzle-solving is pursued with great tenacity, because the previous successes of the established paradigm tend to generate great confidence that the approach being taken guarantees that a solution to the puzzle exists, even though it may be very hard to find. Kuhn calls this process normal science
.
As a paradigm is stretched to its limits, anomalies — failures of the current paradigm to take into account observed phenomena — accumulate. Their significance is judged by the practitioners of the discipline. Some anomalies may be dismissed as errors in observation, others as merely requiring small adjustments to the current paradigm that will be clarified in due course. Some anomalies resolve themselves spontaneously, having increased the available depth of insight along the way. But no matter how great or numerous the anomalies that persist, Kuhn observes, the practicing scientists will not lose faith in the established paradigm for as long as no credible alternative is available; to lose faith in the solubility of the problems would in effect mean ceasing to be a scientist.
In any community of scientists, Kuhn states, there are some individuals who are bolder than most. These scientists, judging that a crisis exists, embark on what Thomas Kuhn calls revolutionary science, exploring alternatives to long-held, obvious-seeming assumptions. Occasionally this generates a rival to the established framework of thought. The new candidate paradigm will appear to be accompanied by numerous anomalies, partly because it is still so new and incomplete. The majority of the scientific community will oppose any conceptual change, and, Kuhn emphasizes, so they should. To fulfill its potential, a scientific community needs to contain both individuals who are bold and individuals who are conservative. There are many examples in the history of science in which confidence in the established frame of thought was eventually vindicated. Whether the anomalies of a candidate for a new paradigm will be resolvable is almost impossible to predict. Those scientists who possess an exceptional ability to recognize a theory's potential will be the first whose preference is likely to shift in favour of the challenging paradigm. There typically follows a period in which there are adherents of both paradigms. In time, if the challenging paradigm is solidified and unified, it will replace the old paradigm, and a paradigm shift will have occurred.
The first phase, which exists only once, is the pre-paradigm phase, in which there is no consensus on any particular theory
, though the research being carried out can be considered scientific in nature. This phase is characterized by several incompatible and incomplete theories. If the actors in the pre-paradigm community eventually gravitate to one of these conceptual frameworks and ultimately to a widespread consensus on the appropriate choice of methods
, terminology
and on the kinds of experiment
that are likely to contribute to increased insight
s, then the second phase, normal science, begins, in which puzzles are solved within the context of the dominant paradigm. As long as there is consensus within the discipline, normal science continues. Over time, progress in normal science may reveal anomalies, facts that are difficult to explain within the context of the existing paradigm. While usually these anomalies are resolved, in some cases they may accumulate to the point where normal science becomes difficult and where weaknesses in the old paradigm are revealed. Kuhn refers to this as a crisis. Crises are often resolved within the context of normal science. However, after significant efforts of normal science within a paradigm fail, science may enter the third phase, that of revolutionary science, in which the underlying assumptions of the field are reexamined and a new paradigm is established. After the new paradigm's dominance is established, scientists return to normal science, solving puzzles within the new paradigm. A science may go through these cycles repeatedly, though Kuhn notes that it is a good thing for science that such shifts do not occur often or easily.
— the new paradigm cannot be proven or disproven by the rules of the old paradigm, and vice versa. The paradigm shift does not merely involve the revision or transformation of an individual theory, it changes the way terminology is defined, how the scientists in that field view their subject, and, perhaps most significantly, what questions are regarded as valid, and what rules are used to determine the truth of a particular theory. The new theories were not, as the scientists had previously thought, just extensions of old theories, but were instead completely new world views.
Such incommensurability exists not just before and after a paradigm shift, but in the periods in between conflicting paradigms. It is simply not possible, according to Kuhn, to construct an impartial language that can be used to perform a neutral comparison between conflicting paradigms, because the very terms used are integral to the respective paradigms, and therefore have different connotations in each paradigm. The advocates of mutually exclusive paradigms are in a difficult position: "Though each may hope to convert the other to his way of seeing science and its problems, neither may hope to prove his case. The competition between paradigms is not the sort of battle that can be resolved by proofs." (SSR, p. 148). Scientists subscribing to different paradigms end up talking past one another
.
Kuhn (SSR, section XII) states that the probabilistic tools used by verificationists are inherently inadequate for the task of deciding between conflicting theories, since they belong to the very paradigms they seek to compare. Similarly, observations that are intended to falsify
a statement will fall under one of the paradigms they are supposed to help compare, and will therefore also be inadequate for the task. According to Kuhn, the concept of falsifiability is unhelpful for understanding why and how science has developed as it has. In the practice of science, scientists will only consider the possibility that a theory has been falsified if an alternative theory is available that they judge credible. If there is not, scientists will continue to adhere to the established conceptual framework. If a paradigm shift has occurred, the textbooks will be rewritten to state that the previous theory has been falsified.
In the second edition of SSR, Kuhn added a postscript in which he elaborated his ideas on the nature of scientific progress. He described a thought experiment involving an observer who has the opportunity to inspect an assortment of theories, each corresponding to a single stage in a succession of theories. What if the observer is presented with these theories without any explicit indication of their chronological order? Kuhn anticipates that it will be possible to reconstruct their chronology on the basis of the theories' scope and content, because the more recent a theory is, the better it will be as an instrument for solving the kinds of puzzle that scientists aim to solve. Kuhn remarked: "That is not a relativist's
position, and it displays the sense in which I am a convinced believer in scientific progress."
SSR is viewed by postmodern
and post-structuralist
thinkers as having called into question the enterprise of science by demonstrating that scientific knowledge is dependent on the culture
and historical circumstances of groups of scientists rather than on their adherence to a specific, definable method. In this regard, Kuhn is considered a precursor to the more radical thinking of Paul Feyerabend
. Kuhn's work has also been regarded as blurring the demarcation
between scientific and non-scientific enterprises, because it describes the mechanism of scientific progress without invoking any idealized scientific method
that is capable of distinguishing science from non-science. In the years following the publication of The Structure of Scientific Revolutions, debate raged with adherents of Karl Popper's
doctrine of falsificationism, such as Imre Lakatos
.
On the one hand, logical positivists
and many scientists have criticized Kuhn's "humanizing" of the scientific process for going too far, while the postmodernists, together with Feyerabend, have criticized Kuhn for not going far enough. SSR has also been embraced by creationists
who see creationism as an incommensurate worldview in contrast to naturalism while holding science as a valuable tool. It was also in tune with a national change in attitudes towards science in the United States at the time of the book's publication, influenced by the Cold War confrontation with the Soviet Union, beginning with the launching of the space satellite Sputnik in 1957. (Rachel Carson
's Silent Spring
was published in the same year as SSR).
The changes that occur in politics
, society
and business
are often expressed in Kuhnian terms, however poor their parallel with the practice of science may seem to scientists and historians of science. The terms "paradigm
" and "paradigm shift
" have become such notorious clichés and buzzwords that they are viewed in many circles as being effectively devoid of content. Misused and overused to the point of becoming meaningless, their use in these contexts rarely has any firm foundation in Kuhn's original definitions.
. The symposium led to the publication of the symposium's presentations plus other essays, most of them critical, which eventually appeared in an influential volume of essays that by 1999 had gone through 21 printings. Kuhn expressed the opinion that his critics' readings of his book were so inconsistent with his own understanding of it that he was "...tempted to posit the existence of two Thomas Kuhns," one the author of his book, the other the individual who had been criticized in the symposium by "Professors Popper, Feyerabend
, Lakatos
, Toulmin
and Watkins."
argued that a more realistic picture of science than that presented in SSR would admit the fact that revisions in science take place much more frequently, and are much less dramatic than can be explained by the model of revolution/normal science. In Toulmin's view, such revisions occur quite often during periods of what Kuhn would call "normal science." For Kuhn to explain such revisions in terms of the non-paradigmatic puzzle solutions of normal science, he would need to delineate what is perhaps an implausibly sharp distinction between paradigmatic and non-paradigmatic science.
Kordig maintains that there is a common observational plane. For example, when Kepler
and Tycho Brahe
are trying to explain the relative variation of the distance of the sun from the horizon at sunrise, both see the same thing (the same configuration is focused on the retina of each individual). This is just one example of the fact that "rival scientific theories share some observations, and therefore some meanings." Kordig suggests that with this approach, he is not reintroducing the distinction between observations and theory in which the former is assigned a privileged and neutral status, but that it is possible to affirm more simply the fact that, even if no sharp distinction exists between theory and observations, this does not imply that there are no comprehensible differences at the two extremes of this polarity.
At a secondary level, for Kordig there is a common plane of inter-paradigmatic standards or shared norms that permit the effective confrontation of rival theories.
In 1973, Hartry Field
published an article that also sharply criticized Kuhn's idea of incommensurability. In particular, he took issue with this passage from Kuhn:
Field takes this idea of incommensurability between the same terms in different theories one step further. Instead of attempting to identify a persistence of the reference of terms in different theories, Field's analysis emphasizes the indeterminacy of reference within individual theories. Field takes the example of the term "mass", and asks what exactly "mass" means in modern post-relativistic physics. He finds that there are at least two different definitions:
Projecting this distinction backwards in time onto Newtonian dynamics, we can formulate the following two hypotheses:
According to Field, it is impossible to decide which of these two affirmations is true. Prior to the theory of relativity, the term "mass" was referentially indeterminate. But this does not mean that the term "mass" did not have a different meaning than it now has. The problem is not one of meaning but of reference. The reference of such terms as mass is only partially determined: we don't really know how Newton intended his use of this term to be applied. As a consequence, neither of the two terms fully denotes (refers). It follows that it is improper to maintain that a term has changed its reference during a scientific revolution; it is more appropriate to describe terms such as "mass" as "having undergone a denotional refinement."
Jerry Fodor
attempts to establish that this theoretical paradigm is fallacious and misleading by demonstrating the impenetrability of perception to the background knowledge of subjects. The strongest case can be based on evidence from experimental cognitive psychology, namely the persistence of perceptual illusions. Knowing that the lines in the Muller-Lyer illusion are equal does not prevent one from continuing to see one line as being longer than the other. This impenetrability of the information elaborated by the mental modules limits the scope of interpretationalism.
In epistemology, for example, the criticism of what Fodor calls the interpretationalist hypothesis accounts for the common-sense intuition (on which naïve physics
is based) of the independence of reality from the conceptual categories of the experimenter. If the processes of elaboration of the mental modules are in fact independent of the background theories, then it is possible to maintain the realist view that two scientists who embrace two radically diverse theories see the world exactly in the same manner even if they interpret it differently. The point is that it is necessary to distinguish between observations and the perceptual fixation of beliefs. While it is beyond doubt that the second process involves the holistic relationship between beliefs, the first is largely independent of the background beliefs of individuals.
Other critics, such as Israel Sheffler, Hilary Putnam
and Saul Kripke
, have focused on the Fregean distinction between sense and reference in order to defend scientific realism
. Sheffler contends that Kuhn confuses the meanings of terms such as "mass" with their references. While their meanings may very well differ, their references (the objects or entities to which they correspond in the external world) remain fixed.
work, although it is often perceived as opening the door to the multicultural
turn in historical studies of science. Bala charges that Kuhn ignores the significant impact of Arabic and Chinese science
when he writes:
Bala argues that it is precisely Kuhn’s postmodern epistemological paradigm that obstructs recognition of non-Western influences on modern science. Bala argues that this leads Kuhn to treat different cultural scientific traditions as separate intellectual universes isolated from each other. Instead, Bala argues, we would have a different multicultural picture of science by including the contributions from Arabic, Chinese, ancient Egypt
ian and Indian traditions of philosophy
, mathematics, astronomy and physics that went into shaping the birth of modern science.
1962 in literature
The year 1962 in literature involved some significant events and new books.-Events:*January 7 - In an article in the New York Times Book Review, Gore Vidal calls Evelyn Waugh "our time's first satirist."...
), by Thomas Kuhn, is an analysis of the history of science
History of science
The history of science is the study of the historical development of human understandings of the natural world and the domains of the social sciences....
. Its publication was a landmark event in the history
History of science
The history of science is the study of the historical development of human understandings of the natural world and the domains of the social sciences....
, philosophy
Philosophy of science
The philosophy of science is concerned with the assumptions, foundations, methods and implications of science. It is also concerned with the use and merit of science and sometimes overlaps metaphysics and epistemology by exploring whether scientific results are actually a study of truth...
, and sociology of scientific knowledge
Sociology of scientific knowledge
The sociology of scientific knowledge ' is the study of science as a social activity, especially dealing "with the social conditions and effects of science, and with the social structures and processes of scientific activity."...
and it triggered an ongoing worldwide assessment and reaction in — and beyond — those scholarly communities. In this work, Kuhn challenged the then prevailing view of progress in "normal science." Scientific progress
Scientific progress
Scientific progress is the idea that science increases its problem solving ability through the application of some scientific method.-Discontinuous Model of Scientific Progress:...
had been seen primarily as a continuous increase in a set of accepted facts and theories. Kuhn argued for an episodic model in which periods of such conceptual continuity in normal science were interrupted by periods of revolutionary science. During revolutions in science the discovery of anomalies leads to a whole new paradigm
Paradigm
The word paradigm has been used in science to describe distinct concepts. It comes from Greek "παράδειγμα" , "pattern, example, sample" from the verb "παραδείκνυμι" , "exhibit, represent, expose" and that from "παρά" , "beside, beyond" + "δείκνυμι" , "to show, to point out".The original Greek...
that changes the rules of the game and the "map" directing new research, asks new questions of old data, and moves beyond the puzzle-solving of normal science. For example, Kuhn’s analysis of the Copernican Revolution emphasized that, in its beginning, it did not offer more accurate predictions of celestial events, such as planetary positions, than the Ptolemaic system, but instead appealed to some practitioners based on a promise of better, simpler, solutions that might be developed at some point in the future. Kuhn called the core concepts of an ascendant revolution its “paradigms” and thereby launched this word into widespread analogical use in the second half of the 20th century. Kuhn’s insistence that a paradigm shift
Paradigm shift
A Paradigm shift is, according to Thomas Kuhn in his influential book The Structure of Scientific Revolutions , a change in the basic assumptions, or paradigms, within the ruling theory of science...
was a mélange of sociology, enthusiasm and scientific promise, but not a logically determinate procedure, caused an uproar in reaction to his work. Kuhn addressed concerns in the 1969 postscript to the second edition. For some commentators it introduced a realistic humanism into the core of science while for others the nobility of science was tarnished by Kuhn's introduction of an irrational element into the heart of its greatest achievements.
History
The work was first published as a monographMonograph
A monograph is a work of writing upon a single subject, usually by a single author.It is often a scholarly essay or learned treatise, and may be released in the manner of a book or journal article. It is by definition a single document that forms a complete text in itself...
in the International Encyclopedia of Unified Science
International Encyclopedia of Unified Science
In 1938 a new series of publications started in USA. It was the International Encyclopedia of Unified Science . An ambitious project never completed devoted to unified science...
, then as a book by University of Chicago Press
University of Chicago Press
The University of Chicago Press is the largest university press in the United States. It is operated by the University of Chicago and publishes a wide variety of academic titles, including The Chicago Manual of Style, dozens of academic journals, including Critical Inquiry, and a wide array of...
in 1962. (All page numbers below refer to the third edition of the text, published in 1996). In 1969, Kuhn added a postscript to the book in which he replied to critical responses to the first edition of the book.
Kuhn dated the genesis of his book to 1947, when he was a graduate student at Harvard University
Harvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
and had been asked to teach a science
Science
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...
class for humanities undergraduates with a focus on historical case studies. Kuhn later commented that until then, "I'd never read an old document in science." Aristotle
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...
's Physics was astonishingly unlike Isaac Newton
Isaac Newton
Sir Isaac Newton PRS was an English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian, who has been "considered by many to be the greatest and most influential scientist who ever lived."...
's work in its concepts of matter and motion. Kuhn concluded that Aristotle's concepts were not "bad Newton," just different.
Basic approach
Kuhn's approach to the historyHistory of science
The history of science is the study of the historical development of human understandings of the natural world and the domains of the social sciences....
and philosophy of science
Philosophy of science
The philosophy of science is concerned with the assumptions, foundations, methods and implications of science. It is also concerned with the use and merit of science and sometimes overlaps metaphysics and epistemology by exploring whether scientific results are actually a study of truth...
has been described as focusing on conceptual issues: what sorts of ideas were thinkable at a particular time? What sorts of intellectual options and strategies were available to people during a given period? What types of lexicons and terminology were known and employed during certain epochs? Stressing the importance of not attributing modern modes of thought to historical actors, Kuhn's book argues that the evolution of scientific theory does not emerge from the straightforward accumulation of facts, but rather from a set of changing intellectual circumstances and possibilities. Such an approach is largely commensurate with the general historical school of non-linear history.
Historical examples
Kuhn explains his ideas using examples taken from the history of scienceHistory of science
The history of science is the study of the historical development of human understandings of the natural world and the domains of the social sciences....
. For instance, at a particular stage in the history of chemistry
History of chemistry
By 1000 BC, ancient civilizations used technologies that would eventually form the basis of the various branches of chemistry. Examples include extracting metals from ores, making pottery and glazes, fermenting beer and wine, making pigments for cosmetics and painting, extracting chemicals from...
, some chemists began to explore the idea of atomism
Atomism
Atomism is a natural philosophy that developed in several ancient traditions. The atomists theorized that the natural world consists of two fundamental parts: indivisible atoms and empty void.According to Aristotle, atoms are indestructible and immutable and there are an infinite variety of shapes...
. When many substances are heated they have a tendency to decompose into their constituent elements, and often (though not invariably) these elements can be observed to combine only in set proportions. At one time, a combination of water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
and alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
was generally classified as a compound. Nowadays it is considered to be a solution, but there was no reason then to suspect that it was not a compound. Water and alcohol would not separate spontaneously, but they could be separated when heated
Distillation
Distillation is a method of separating mixtures based on differences in volatilities of components in a boiling liquid mixture. Distillation is a unit operation, or a physical separation process, and not a chemical reaction....
. Water and alcohol can be combined in any proportion
Miscibility
Miscibility is the property of liquids to mix in all proportions, forming a homogeneous solution. In principle, the term applies also to other phases , but the main focus is usually on the solubility of one liquid in another...
.
A chemist favoring atomic theory
Atomic theory
In chemistry and physics, atomic theory is a theory of the nature of matter, which states that matter is composed of discrete units called atoms, as opposed to the obsolete notion that matter could be divided into any arbitrarily small quantity...
would have viewed all compounds whose elements combine in fixed proportions as exhibiting normal behavior, and all known exceptions to this pattern would be regarded as anomalies whose behavior would probably be explained at some time in the future. On the other hand, if a chemist believed that theories of the atomicity of matter were erroneous, then all compounds whose elements combined in fixed proportions would be regarded as anomalies whose behavior would probably be explained at some time in the future, and all those compounds whose elements are capable of combining in any ratio would be seen as exhibiting the normal behavior of compounds. Nowadays the consensus is that the atomists' view was correct. But if one were to restrict oneself to thinking about chemistry using only the knowledge available at the time, either point of view would be defensible.
The Copernican Revolution
What is arguably the most famous example of a revolution in scientific thought is the Copernican RevolutionDe revolutionibus orbium coelestium
De revolutionibus orbium coelestium is the seminal work on the heliocentric theory of the Renaissance astronomer Nicolaus Copernicus...
. In Ptolemy
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...
's school of thought, cycles and epicycles
Deferent and epicycle
In the Ptolemaic system of astronomy, the epicycle was a geometric model used to explain the variations in speed and direction of the apparent motion of the Moon, Sun, and planets...
(with some additional concepts) were used for modeling the movements of the planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
s in a cosmos that had a stationary Earth at its center. As accuracy of celestial observations increased, complexity of the Ptolemaic cyclical and epicyclical mechanisms had to increase to maintain the calculated planetary positions close to the observed positions. Copernicus proposed a cosmology in which the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
was at the center and the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
was one of the planets revolving around it. For modeling the planetary motions, Copernicus used the tools he was familiar with, namely the cycles and epicycles of the Ptolemaic toolbox. But Copernicus' model needed more cycles and epicycles than existed in the then-current Ptolemaic model, and due to a lack of accuracy in calculations, Copernicus's model did not appear to provide more accurate predictions than the Ptolemy model. Copernicus' contemporaries rejected his cosmology
Cosmology
Cosmology is the discipline that deals with the nature of the Universe as a whole. Cosmologists seek to understand the origin, evolution, structure, and ultimate fate of the Universe at large, as well as the natural laws that keep it in order...
, and Kuhn asserts that they were quite right to do so: Copernicus' cosmology lacked credibility.
Thomas Kuhn illustrates how a paradigm shift later became possible when Galileo Galilei
Galileo Galilei
Galileo Galilei , was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution. His achievements include improvements to the telescope and consequent astronomical observations and support for Copernicanism...
introduced his new ideas concerning motion. Intuitively, when an object is set in motion, it soon comes to a halt. A well-made cart may travel a long distance before it stops, but unless something keeps pushing it, it will eventually stop moving. Aristotle had argued that this was presumably a fundamental property of nature
Nature
Nature, in the broadest sense, is equivalent to the natural world, physical world, or material world. "Nature" refers to the phenomena of the physical world, and also to life in general...
: for the motion of an object to be sustained, it must continue to be pushed. Given the knowledge available at the time, this represented sensible, reasonable thinking.
Galileo put forward a bold alternative conjecture: suppose, he said, that we always observe objects coming to a halt simply because some friction
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and/or material elements sliding against each other. There are several types of friction:...
is always occurring. Galileo had no equipment with which to objectively confirm his conjecture, but he suggested that without any friction to slow down an object in motion, its inherent tendency is to maintain its speed
Speed
In kinematics, the speed of an object is the magnitude of its velocity ; it is thus a scalar quantity. The average speed of an object in an interval of time is the distance traveled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as...
without the application of any additional force
Force
In physics, a force is any influence that causes an object to undergo a change in speed, a change in direction, or a change in shape. In other words, a force is that which can cause an object with mass to change its velocity , i.e., to accelerate, or which can cause a flexible object to deform...
.
The Ptolemaic approach of using cycles and epicycles was becoming strained: there seemed to be no end to the mushrooming growth in complexity required to account for the observable phenomena. Johannes Kepler
Johannes Kepler
Johannes Kepler was a German mathematician, astronomer and astrologer. A key figure in the 17th century scientific revolution, he is best known for his eponymous laws of planetary motion, codified by later astronomers, based on his works Astronomia nova, Harmonices Mundi, and Epitome of Copernican...
was the first person to abandon the tools of the Ptolemaic paradigm. He started to explore the possibility that the planet Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
might have an elliptical orbit rather than a circular
Circular orbit
A circular orbit is the orbit at a fixed distance around any point by an object rotating around a fixed axis.Below we consider a circular orbit in astrodynamics or celestial mechanics under standard assumptions...
one. Clearly, the angular velocity
Angular velocity
In physics, the angular velocity is a vector quantity which specifies the angular speed of an object and the axis about which the object is rotating. The SI unit of angular velocity is radians per second, although it may be measured in other units such as degrees per second, revolutions per...
could not be constant, but it proved very difficult to find the formula describing the rate of change of the planet's angular velocity. After many years of calculations, Kepler arrived at what we now know as the law of equal areas.
Galileo's conjecture was merely that — a conjecture. So was Kepler's cosmology. But each conjecture increased the credibility of the other, and together, they changed the prevailing perceptions of the scientific community. Later, Newton
Isaac Newton
Sir Isaac Newton PRS was an English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian, who has been "considered by many to be the greatest and most influential scientist who ever lived."...
showed that Kepler's three laws could all be derived from a single theory of motion and planetary motion. Newton solidified and unified the paradigm shift that Galileo and Kepler had initiated.
Coherence
One of the aims of science is to find models that will account for as many observations as possible within a coherent framework. Together, Galileo's rethinking of the nature of motion and Keplerian cosmology represented a coherent framework that was capable of rivaling the Aristotelian/Ptolemaic framework.Once a paradigm shift has taken place, the textbooks are rewritten. Often the history of science
History of science
The history of science is the study of the historical development of human understandings of the natural world and the domains of the social sciences....
too is rewritten, being presented as an inevitable process leading up to the current, established framework of thought. There is a prevalent belief that all hitherto-unexplained phenomena will in due course be accounted for in terms of this established framework. Kuhn states that scientists spend most (if not all) of their careers in a process of puzzle-solving. Their puzzle-solving is pursued with great tenacity, because the previous successes of the established paradigm tend to generate great confidence that the approach being taken guarantees that a solution to the puzzle exists, even though it may be very hard to find. Kuhn calls this process normal science
Normal science
Normal Science is a concept originated by Thomas Samuel Kuhn and elaborated in The Structure of Scientific Revolutions. The term refers to the routine work of scientists experimenting within a paradigm, slowly accumulating detail in accord with established broad theory, not actually challenging or...
.
As a paradigm is stretched to its limits, anomalies — failures of the current paradigm to take into account observed phenomena — accumulate. Their significance is judged by the practitioners of the discipline. Some anomalies may be dismissed as errors in observation, others as merely requiring small adjustments to the current paradigm that will be clarified in due course. Some anomalies resolve themselves spontaneously, having increased the available depth of insight along the way. But no matter how great or numerous the anomalies that persist, Kuhn observes, the practicing scientists will not lose faith in the established paradigm for as long as no credible alternative is available; to lose faith in the solubility of the problems would in effect mean ceasing to be a scientist.
In any community of scientists, Kuhn states, there are some individuals who are bolder than most. These scientists, judging that a crisis exists, embark on what Thomas Kuhn calls revolutionary science, exploring alternatives to long-held, obvious-seeming assumptions. Occasionally this generates a rival to the established framework of thought. The new candidate paradigm will appear to be accompanied by numerous anomalies, partly because it is still so new and incomplete. The majority of the scientific community will oppose any conceptual change, and, Kuhn emphasizes, so they should. To fulfill its potential, a scientific community needs to contain both individuals who are bold and individuals who are conservative. There are many examples in the history of science in which confidence in the established frame of thought was eventually vindicated. Whether the anomalies of a candidate for a new paradigm will be resolvable is almost impossible to predict. Those scientists who possess an exceptional ability to recognize a theory's potential will be the first whose preference is likely to shift in favour of the challenging paradigm. There typically follows a period in which there are adherents of both paradigms. In time, if the challenging paradigm is solidified and unified, it will replace the old paradigm, and a paradigm shift will have occurred.
Three phases
Chronologically, Kuhn distinguishes between three phases.The first phase, which exists only once, is the pre-paradigm phase, in which there is no consensus on any particular theory
Theory
The English word theory was derived from a technical term in Ancient Greek philosophy. The word theoria, , meant "a looking at, viewing, beholding", and referring to contemplation or speculation, as opposed to action...
, though the research being carried out can be considered scientific in nature. This phase is characterized by several incompatible and incomplete theories. If the actors in the pre-paradigm community eventually gravitate to one of these conceptual frameworks and ultimately to a widespread consensus on the appropriate choice of methods
Scientific method
Scientific method refers to a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering empirical and measurable evidence subject to specific principles of...
, terminology
Terminology
Terminology is the study of terms and their use. Terms are words and compound words that in specific contexts are given specific meanings, meanings that may deviate from the meaning the same words have in other contexts and in everyday language. The discipline Terminology studies among other...
and on the kinds of experiment
Experiment
An experiment is a methodical procedure carried out with the goal of verifying, falsifying, or establishing the validity of a hypothesis. Experiments vary greatly in their goal and scale, but always rely on repeatable procedure and logical analysis of the results...
that are likely to contribute to increased insight
Insight
Insight is the understanding of a specific cause and effect in a specific context. Insight can be used with several related meanings:*a piece of information...
s, then the second phase, normal science, begins, in which puzzles are solved within the context of the dominant paradigm. As long as there is consensus within the discipline, normal science continues. Over time, progress in normal science may reveal anomalies, facts that are difficult to explain within the context of the existing paradigm. While usually these anomalies are resolved, in some cases they may accumulate to the point where normal science becomes difficult and where weaknesses in the old paradigm are revealed. Kuhn refers to this as a crisis. Crises are often resolved within the context of normal science. However, after significant efforts of normal science within a paradigm fail, science may enter the third phase, that of revolutionary science, in which the underlying assumptions of the field are reexamined and a new paradigm is established. After the new paradigm's dominance is established, scientists return to normal science, solving puzzles within the new paradigm. A science may go through these cycles repeatedly, though Kuhn notes that it is a good thing for science that such shifts do not occur often or easily.
Incommensurability
According to Kuhn, the scientific paradigms preceding and succeeding a paradigm shift are so different that their theories are incommensurableCommensurability (philosophy of science)
Commensurability is a concept in the philosophy of science. Scientific theories are described as commensurable if one can compare them to determine which is more accurate; if theories are incommensurable, there is no way in which one can compare them to each other in order to determine which is...
— the new paradigm cannot be proven or disproven by the rules of the old paradigm, and vice versa. The paradigm shift does not merely involve the revision or transformation of an individual theory, it changes the way terminology is defined, how the scientists in that field view their subject, and, perhaps most significantly, what questions are regarded as valid, and what rules are used to determine the truth of a particular theory. The new theories were not, as the scientists had previously thought, just extensions of old theories, but were instead completely new world views.
Such incommensurability exists not just before and after a paradigm shift, but in the periods in between conflicting paradigms. It is simply not possible, according to Kuhn, to construct an impartial language that can be used to perform a neutral comparison between conflicting paradigms, because the very terms used are integral to the respective paradigms, and therefore have different connotations in each paradigm. The advocates of mutually exclusive paradigms are in a difficult position: "Though each may hope to convert the other to his way of seeing science and its problems, neither may hope to prove his case. The competition between paradigms is not the sort of battle that can be resolved by proofs." (SSR, p. 148). Scientists subscribing to different paradigms end up talking past one another
Talking past each other
Talking past each other is an idiomatic expression describing a situation in which people in a discussion proceed at cross purposes. There is a mismatch....
.
Kuhn (SSR, section XII) states that the probabilistic tools used by verificationists are inherently inadequate for the task of deciding between conflicting theories, since they belong to the very paradigms they seek to compare. Similarly, observations that are intended to falsify
Falsifiability
Falsifiability or refutability of an assertion, hypothesis or theory is the logical possibility that it can be contradicted by an observation or the outcome of a physical experiment...
a statement will fall under one of the paradigms they are supposed to help compare, and will therefore also be inadequate for the task. According to Kuhn, the concept of falsifiability is unhelpful for understanding why and how science has developed as it has. In the practice of science, scientists will only consider the possibility that a theory has been falsified if an alternative theory is available that they judge credible. If there is not, scientists will continue to adhere to the established conceptual framework. If a paradigm shift has occurred, the textbooks will be rewritten to state that the previous theory has been falsified.
Kuhn's opinion on scientific progress
The first edition of SSR ended with a chapter entitled "Progress through Revolutions", in which Kuhn spelled out his views on the nature of scientific progress. Since he considered problem solving to be a central element of science, Kuhn saw that for a new candidate for paradigm to be accepted by a scientific community, "First, the new candidate must seem to resolve some outstanding and generally recognized problem that can be met in no other way. Second, the new paradigm must promise to preserve a relatively large part of the concrete problem solving activity that has accrued to science through its predecessors." And overall Kuhn maintained that the new paradigm must also solve more problems than its predecessor, which therefore entailed that the number of newly solved problems must be greater than those solved in the old paradigm.In the second edition of SSR, Kuhn added a postscript in which he elaborated his ideas on the nature of scientific progress. He described a thought experiment involving an observer who has the opportunity to inspect an assortment of theories, each corresponding to a single stage in a succession of theories. What if the observer is presented with these theories without any explicit indication of their chronological order? Kuhn anticipates that it will be possible to reconstruct their chronology on the basis of the theories' scope and content, because the more recent a theory is, the better it will be as an instrument for solving the kinds of puzzle that scientists aim to solve. Kuhn remarked: "That is not a relativist's
Relativism
Relativism is the concept that points of view have no absolute truth or validity, having only relative, subjective value according to differences in perception and consideration....
position, and it displays the sense in which I am a convinced believer in scientific progress."
Influence of SSR
In 1987, Kuhn's work was reported to be the twentieth-century book most frequently cited in the period 1976-83 in the Arts and the Humanities and the Times Literary Supplement labeled it one of "The Hundred Most Influential Books Since the Second World War." The book's basic concepts have been adopted and co-opted by a variety of fields and disciplines beyond those encompassing the history and philosophy of science.SSR is viewed by postmodern
Postmodernism
Postmodernism is a philosophical movement evolved in reaction to modernism, the tendency in contemporary culture to accept only objective truth and to be inherently suspicious towards a global cultural narrative or meta-narrative. Postmodernist thought is an intentional departure from the...
and post-structuralist
Post-structuralism
Post-structuralism is a label formulated by American academics to denote the heterogeneous works of a series of French intellectuals who came to international prominence in the 1960s and '70s...
thinkers as having called into question the enterprise of science by demonstrating that scientific knowledge is dependent on the culture
Culture
Culture is a term that has many different inter-related meanings. For example, in 1952, Alfred Kroeber and Clyde Kluckhohn compiled a list of 164 definitions of "culture" in Culture: A Critical Review of Concepts and Definitions...
and historical circumstances of groups of scientists rather than on their adherence to a specific, definable method. In this regard, Kuhn is considered a precursor to the more radical thinking of Paul Feyerabend
Paul Feyerabend
Paul Karl Feyerabend was an Austrian-born philosopher of science best known for his work as a professor of philosophy at the University of California, Berkeley, where he worked for three decades . He lived a peripatetic life, living at various times in England, the United States, New Zealand,...
. Kuhn's work has also been regarded as blurring the demarcation
Demarcation problem
The demarcation problem in the philosophy of science is about how and where to draw the lines around science. The boundaries are commonly drawn between science and non-science, between science and pseudoscience, between science and philosophy and between science and religion...
between scientific and non-scientific enterprises, because it describes the mechanism of scientific progress without invoking any idealized scientific method
Scientific method
Scientific method refers to a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering empirical and measurable evidence subject to specific principles of...
that is capable of distinguishing science from non-science. In the years following the publication of The Structure of Scientific Revolutions, debate raged with adherents of Karl Popper's
Karl Popper
Sir Karl Raimund Popper, CH FRS FBA was an Austro-British philosopher and a professor at the London School of Economics...
doctrine of falsificationism, such as Imre Lakatos
Imre Lakatos
Imre Lakatos was a Hungarian philosopher of mathematics and science, known for his thesis of the fallibility of mathematics and its 'methodology of proofs and refutations' in its pre-axiomatic stages of development, and also for introducing the concept of the 'research programme' in his...
.
On the one hand, logical positivists
Logical positivism
Logical positivism is a philosophy that combines empiricism—the idea that observational evidence is indispensable for knowledge—with a version of rationalism incorporating mathematical and logico-linguistic constructs and deductions of epistemology.It may be considered as a type of analytic...
and many scientists have criticized Kuhn's "humanizing" of the scientific process for going too far, while the postmodernists, together with Feyerabend, have criticized Kuhn for not going far enough. SSR has also been embraced by creationists
Creationism
Creationism is the religious beliefthat humanity, life, the Earth, and the universe are the creation of a supernatural being, most often referring to the Abrahamic god. As science developed from the 18th century onwards, various views developed which aimed to reconcile science with the Genesis...
who see creationism as an incommensurate worldview in contrast to naturalism while holding science as a valuable tool. It was also in tune with a national change in attitudes towards science in the United States at the time of the book's publication, influenced by the Cold War confrontation with the Soviet Union, beginning with the launching of the space satellite Sputnik in 1957. (Rachel Carson
Rachel Carson
Rachel Louise Carson was an American marine biologist and conservationist whose writings are credited with advancing the global environmental movement....
's Silent Spring
Silent Spring
Silent Spring is a book written by Rachel Carson and published by Houghton Mifflin on 27 September 1962. The book is widely credited with helping launch the environmental movement....
was published in the same year as SSR).
The changes that occur in politics
Politics
Politics is a process by which groups of people make collective decisions. The term is generally applied to the art or science of running governmental or state affairs, including behavior within civil governments, but also applies to institutions, fields, and special interest groups such as the...
, society
Society
A society, or a human society, is a group of people related to each other through persistent relations, or a large social grouping sharing the same geographical or virtual territory, subject to the same political authority and dominant cultural expectations...
and business
Business
A business is an organization engaged in the trade of goods, services, or both to consumers. Businesses are predominant in capitalist economies, where most of them are privately owned and administered to earn profit to increase the wealth of their owners. Businesses may also be not-for-profit...
are often expressed in Kuhnian terms, however poor their parallel with the practice of science may seem to scientists and historians of science. The terms "paradigm
Paradigm
The word paradigm has been used in science to describe distinct concepts. It comes from Greek "παράδειγμα" , "pattern, example, sample" from the verb "παραδείκνυμι" , "exhibit, represent, expose" and that from "παρά" , "beside, beyond" + "δείκνυμι" , "to show, to point out".The original Greek...
" and "paradigm shift
Paradigm shift
A Paradigm shift is, according to Thomas Kuhn in his influential book The Structure of Scientific Revolutions , a change in the basic assumptions, or paradigms, within the ruling theory of science...
" have become such notorious clichés and buzzwords that they are viewed in many circles as being effectively devoid of content. Misused and overused to the point of becoming meaningless, their use in these contexts rarely has any firm foundation in Kuhn's original definitions.
Criticisms of Kuhn and SSR
Kuhn's SSR was soon criticized by his colleagues in the history and philosophy of science. In 1965, a special symposium on Kuhn's SSR was held at an International Colloquium on the Philosophy of Science that took place at Bedford College, London, and was chaired by Sir Karl PopperKarl Popper
Sir Karl Raimund Popper, CH FRS FBA was an Austro-British philosopher and a professor at the London School of Economics...
. The symposium led to the publication of the symposium's presentations plus other essays, most of them critical, which eventually appeared in an influential volume of essays that by 1999 had gone through 21 printings. Kuhn expressed the opinion that his critics' readings of his book were so inconsistent with his own understanding of it that he was "...tempted to posit the existence of two Thomas Kuhns," one the author of his book, the other the individual who had been criticized in the symposium by "Professors Popper, Feyerabend
Paul Feyerabend
Paul Karl Feyerabend was an Austrian-born philosopher of science best known for his work as a professor of philosophy at the University of California, Berkeley, where he worked for three decades . He lived a peripatetic life, living at various times in England, the United States, New Zealand,...
, Lakatos
Imre Lakatos
Imre Lakatos was a Hungarian philosopher of mathematics and science, known for his thesis of the fallibility of mathematics and its 'methodology of proofs and refutations' in its pre-axiomatic stages of development, and also for introducing the concept of the 'research programme' in his...
, Toulmin
Stephen Toulmin
Stephen Edelston Toulmin was a British philosopher, author, and educator. Influenced by Ludwig Wittgenstein, Toulmin devoted his works to the analysis of moral reasoning. Throughout his writings, he sought to develop practical arguments which can be used effectively in evaluating the ethics behind...
and Watkins."
Concept of paradigm
In his 1972 work, Human Understanding, Stephen ToulminStephen Toulmin
Stephen Edelston Toulmin was a British philosopher, author, and educator. Influenced by Ludwig Wittgenstein, Toulmin devoted his works to the analysis of moral reasoning. Throughout his writings, he sought to develop practical arguments which can be used effectively in evaluating the ethics behind...
argued that a more realistic picture of science than that presented in SSR would admit the fact that revisions in science take place much more frequently, and are much less dramatic than can be explained by the model of revolution/normal science. In Toulmin's view, such revisions occur quite often during periods of what Kuhn would call "normal science." For Kuhn to explain such revisions in terms of the non-paradigmatic puzzle solutions of normal science, he would need to delineate what is perhaps an implausibly sharp distinction between paradigmatic and non-paradigmatic science.
Incommensurability of paradigms
In a series of texts published in the early 1970s, C.R. Kordig asserted a position somewhere between that of Kuhn and the older philosophy of science. His criticism of the Kuhnian position was that the incommensurability thesis was too radical, and that this made it impossible to explain the confrontation of scientific theories that actually occurs. According to Kordig, it is in fact possible to admit the existence of revolutions and paradigm shifts in science while still recognizing that theories belonging to different paradigms can be compared and confronted on the plane of observation. Those who accept the incommensurability thesis do not do so because they admit the discontinuity of paradigms, but because they attribute a radical change in meanings to such shifts.Kordig maintains that there is a common observational plane. For example, when Kepler
Johannes Kepler
Johannes Kepler was a German mathematician, astronomer and astrologer. A key figure in the 17th century scientific revolution, he is best known for his eponymous laws of planetary motion, codified by later astronomers, based on his works Astronomia nova, Harmonices Mundi, and Epitome of Copernican...
and Tycho Brahe
Tycho Brahe
Tycho Brahe , born Tyge Ottesen Brahe, was a Danish nobleman known for his accurate and comprehensive astronomical and planetary observations...
are trying to explain the relative variation of the distance of the sun from the horizon at sunrise, both see the same thing (the same configuration is focused on the retina of each individual). This is just one example of the fact that "rival scientific theories share some observations, and therefore some meanings." Kordig suggests that with this approach, he is not reintroducing the distinction between observations and theory in which the former is assigned a privileged and neutral status, but that it is possible to affirm more simply the fact that, even if no sharp distinction exists between theory and observations, this does not imply that there are no comprehensible differences at the two extremes of this polarity.
At a secondary level, for Kordig there is a common plane of inter-paradigmatic standards or shared norms that permit the effective confrontation of rival theories.
In 1973, Hartry Field
Hartry Field
Hartry H. Field is a philosopher, the Silver Professor of Philosophy at New York University. He previously taught at the University of Southern California and The Graduate Center of the City University of New York. He earned his Ph.D...
published an article that also sharply criticized Kuhn's idea of incommensurability. In particular, he took issue with this passage from Kuhn:
- "Newtonian mass is immutably conserved; that of Einstein is convertible into energy. Only at very low relative velocities can the two masses be measured in the same way, and even then they must not be conceived as if they were the same thing." (Kuhn 1970).
Field takes this idea of incommensurability between the same terms in different theories one step further. Instead of attempting to identify a persistence of the reference of terms in different theories, Field's analysis emphasizes the indeterminacy of reference within individual theories. Field takes the example of the term "mass", and asks what exactly "mass" means in modern post-relativistic physics. He finds that there are at least two different definitions:
- 1) Relativistic mass: the mass of a particle is equal to the total energy of the particle divided by the speed of light squared. Since the total energy of a particle in relation to one system of reference differs from the total energy in relation to other systems of reference, while the speed of light remains constant in all systems, it follows that the mass of a particle has different values in different systems of reference.
- 2) "Real" mass: the mass of a particle is equal to the non-kinetic energy of a particle divided by the speed of light squared. Since non-kinetic energy is the same in all systems of reference, and the same is true of light, it follows that the mass of a particle has the same value in all systems of reference.
Projecting this distinction backwards in time onto Newtonian dynamics, we can formulate the following two hypotheses:
- HR: the term "mass" in Newtonian theory denotes relativistic mass.
- Hp: the term "mass" in Newtonian theory denotes "real" mass.
According to Field, it is impossible to decide which of these two affirmations is true. Prior to the theory of relativity, the term "mass" was referentially indeterminate. But this does not mean that the term "mass" did not have a different meaning than it now has. The problem is not one of meaning but of reference. The reference of such terms as mass is only partially determined: we don't really know how Newton intended his use of this term to be applied. As a consequence, neither of the two terms fully denotes (refers). It follows that it is improper to maintain that a term has changed its reference during a scientific revolution; it is more appropriate to describe terms such as "mass" as "having undergone a denotional refinement."
Incommensurability and perception
The close connection between the interpretationalist hypothesis and a holistic conception of beliefs is at the root of the notion of the dependence of perception on theory, a central concept in SSR. Kuhn maintained that the perception of the world depends on how the percipient conceives the world: two scientists who witness the same phenomenon and are steeped in two radically different theories will see two different things. According to this view, our interpretation of the world determines what we see.Jerry Fodor
Jerry Fodor
Jerry Alan Fodor is an American philosopher and cognitive scientist. He holds the position of State of New Jersey Professor of Philosophy at Rutgers University and is the author of many works in the fields of philosophy of mind and cognitive science, in which he has laid the groundwork for the...
attempts to establish that this theoretical paradigm is fallacious and misleading by demonstrating the impenetrability of perception to the background knowledge of subjects. The strongest case can be based on evidence from experimental cognitive psychology, namely the persistence of perceptual illusions. Knowing that the lines in the Muller-Lyer illusion are equal does not prevent one from continuing to see one line as being longer than the other. This impenetrability of the information elaborated by the mental modules limits the scope of interpretationalism.
In epistemology, for example, the criticism of what Fodor calls the interpretationalist hypothesis accounts for the common-sense intuition (on which naïve physics
Naïve physics
Naïve physics or folk physics is the untrained human perception of basic physical phenomena. In the field of artificial intelligence the study of naïve physics is a part of the effort to formalize the common knowledge of human beings....
is based) of the independence of reality from the conceptual categories of the experimenter. If the processes of elaboration of the mental modules are in fact independent of the background theories, then it is possible to maintain the realist view that two scientists who embrace two radically diverse theories see the world exactly in the same manner even if they interpret it differently. The point is that it is necessary to distinguish between observations and the perceptual fixation of beliefs. While it is beyond doubt that the second process involves the holistic relationship between beliefs, the first is largely independent of the background beliefs of individuals.
Other critics, such as Israel Sheffler, Hilary Putnam
Hilary Putnam
Hilary Whitehall Putnam is an American philosopher, mathematician and computer scientist, who has been a central figure in analytic philosophy since the 1960s, especially in philosophy of mind, philosophy of language, philosophy of mathematics, and philosophy of science...
and Saul Kripke
Saul Kripke
Saul Aaron Kripke is an American philosopher and logician. He is a professor emeritus at Princeton and teaches as a Distinguished Professor of Philosophy at the CUNY Graduate Center...
, have focused on the Fregean distinction between sense and reference in order to defend scientific realism
Scientific realism
Scientific realism is, at the most general level, the view that the world described by science is the real world, as it is, independent of what we might take it to be...
. Sheffler contends that Kuhn confuses the meanings of terms such as "mass" with their references. While their meanings may very well differ, their references (the objects or entities to which they correspond in the external world) remain fixed.
Eurocentrism
More recently, criticism from a different direction has been developed by Arun Bala in his study The Dialogue of Civilizations in the Birth of Modern Science (Palgrave Macmillan, 2006). He charges that The Structure of Scientific Revolutions is itself a profoundly EurocentricEurocentrism
Eurocentrism is the practice of viewing the world from a European perspective and with an implied belief, either consciously or subconsciously, in the preeminence of European culture...
work, although it is often perceived as opening the door to the multicultural
Multiculturalism
Multiculturalism is the appreciation, acceptance or promotion of multiple cultures, applied to the demographic make-up of a specific place, usually at the organizational level, e.g...
turn in historical studies of science. Bala charges that Kuhn ignores the significant impact of Arabic and Chinese science
History of science and technology in China
The history of science and technology in China is both long and rich with many contributions to science and technology. In antiquity, independently of other civilizations, ancient Chinese philosophers made significant advances in science, technology, mathematics, and astronomy...
when he writes:
Bala argues that it is precisely Kuhn’s postmodern epistemological paradigm that obstructs recognition of non-Western influences on modern science. Bala argues that this leads Kuhn to treat different cultural scientific traditions as separate intellectual universes isolated from each other. Instead, Bala argues, we would have a different multicultural picture of science by including the contributions from Arabic, Chinese, ancient Egypt
Ancient Egypt
Ancient Egypt was an ancient civilization of Northeastern Africa, concentrated along the lower reaches of the Nile River in what is now the modern country of Egypt. Egyptian civilization coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first pharaoh...
ian and Indian traditions of philosophy
Eastern philosophy
Eastern philosophy includes the various philosophies of Asia, including Chinese philosophy, Iranian philosophy, Japanese philosophy, Indian philosophy and Korean philosophy...
, mathematics, astronomy and physics that went into shaping the birth of modern science.
See also
- American philosophyAmerican philosophyAmerican philosophy is the philosophical activity or output of Americans, both within the United States and abroad. The Internet Encyclopedia of Philosophy notes that while American philosophy lacks a "core of defining features, American Philosophy can nevertheless be seen as both reflecting and...
- Epistemological ruptureEpistemological ruptureThe notion of epistemological rupture was introduced by Gaston Bachelard. He proposed that the history of science is replete with "epistemological obstacles"--or unthought/unconscious structures that were immanent within the realm of the sciences, such as principles of division...
- ExemplarExemplarExemplar, in the sense developed by philosopher of science Thomas Kuhn, is a well known usage of a scientific theory.According to Kuhn, scientific practice alternates between periods of normal science and extraordinary/revolutionary science...
- GroupthinkGroupthinkGroupthink is a psychological phenomenon that occurs within groups of people. It is the mode of thinking that happens when the desire for harmony in a decision-making group overrides a realistic appraisal of alternatives. Group members try to minimize conflict and reach a consensus decision without...
- Night Thoughts of a Classical PhysicistNight Thoughts of a Classical PhysicistNight Thoughts of a Classical Physicist is an historical novel by historian of science Russell McCormmach, published in 1982 by Harvard University Press. Set in 1918, the book explores the world of physics in the early 20th century—including the advent of modern physics and the role of physicists...
by Russell McCormmach - a novel by a historian of science which reinforces's Kuhn's position