What is a Scientific Paradigm?

In what follows I will define a scientific paradigm.  I will describe Kuhn’s conception of normal science as puzzle solving based on a scientific paradigm.  I offer an account of two scientific theories that exemplify normal science.  I will detail Kuhn’s main points in favour of his format of normal science.  Finally, I criticise normal science for providing no motivation for scientists to generate new knowledge and for frequently blinding them to new discoveries.  I argue that in this sense Kuhn’s analysis is inadequate.

Although the conception of a paradigm is central to Kuhn’s analysis of science, he fails (at least in ‘The Structure Of Scientific Revolutions’) to provide a complete and unambiguous definition.  The paradigm can be conceived either as a disciplinary matrix or in a narrower sense as an exemplar.  A disciplinary matrix is a set of rules, principles, assumptions and exemplars that determine scientific research.  He grouped these rules into four spheres: symbolic generalisations; metaphysical, ontological elements and models; values; exemplars (the original narrower meaning of paradigm).  Symbolic generalisations refer to the formalised schemes with which the relevant scientists work, for instance the equation F = ma.  Metaphysical, ontological elements and models cover the entities forming the world that is the subject of science such as atoms, as well as analogies and metaphors scientists might employ.  Values consist of Kuhn’s five-fold criteria for what constitutes ‘good’ science and basis for theory choice: consistency (internal-external), plausibility, simplicity, explanatory power and usefulness.  Finally, exemplars refer to the concrete problem solutions through which the student of science learns conceptual things about nature and through this process the tacit knowledge gained from doing science rather than by acquiring rules for doing it.  Thus, a paradigm, in the disciplinary matrix sense, is the background of unquestioned theory, or the set of beliefs scientists hold.  Kuhn asserts that scientific paradigms embody two characteristics.  Firstly, the paradigm’s achievement was sufficiently unprecedented to attract an enduring group of adherents away from competing modes of scientific activity.  Second, the paradigm is sufficiently open-ended to leave all sorts of problems for the redefined group of practitioners to resolve.  The paradigm is a sign of the maturity of science.  It means there is no need for scientists to start anew at first principles and research can be guided.  A scientific revolution is the successive transition from one paradigm to another.

Paradigms relate closely to normal science.  Paradigms become more successful than their competitors at solving the few problems practitioners have come to recognise as acute.  Kuhn refers to all paradigm-based activities as puzzle solving; this implies there is a solution within the given paradigm.  Normal science is puzzle solving by nature, it consists in the actualisation of the promise of the scientific paradigm’s success discoverable in selected and still incomplete examples.  This is an actualisation achieved by extending the knowledge of the facts the paradigm displays as particularly revealing, by increasing the extent of the match between those facts and the paradigm’s predictions, and by further articulation of the paradigm itself.  The paradigm focuses scientists upon a small range of relatively esoteric problems forcing them to investigate some part of nature in incredible detail and depth.  Normal science possesses a built in mechanism that ensures the relaxation of the restrictions bounding research whenever the paradigm from which they derive ceases to function effectively. Normal science is science conducted in the framework of one paradigm that is accepted and respected within the scientific community.  It is a method driven, rule governed, systematic, and orderly form of scientific activity.  The activity of normal science is determined by different commitments resulting from accepting the paradigm.  Kuhn identifies four sorts of commitments: conceptual, theoretical, instrumental, and methodical.  Conceptual commitments relate to those concepts that can be acceptably employed to formulate scientific problems and their solutions.  Theoretical commitments ask what laws and entities are to be used in the scientific problem and its solution.  Instrumental commitments refer to the instruments used by the scientists, and methodical commitments to allowable methods for problem solving.  For example, in classical Newtonian mechanics conceptual commitments would be the scientists’ conceptions of time and space, theoretical commitments would be laws such as F = ma, instrumental commitments would be the measuring devices utilized by the scientists, and methodical commitments regard the method of solving a differential equation involving F = ma to get to the solution of the puzzles of motion.

Kuhn classifies normal scientific activities into three categories.  First, determination of significant fact, this is through observation or prediction and derivation from theory.  Second, matching of the facts with the theory, that is, matching a collection of data devoid of intrinsic interest with the theory the scientists are interested in.  Third, the articulation of the theory or paradigm is where the theoretical and experimental aspects of science mix.  In particular, the determination of significant fact involves measuring constants, predicting parameters having pragmatic or intrinsic value, for instance the position of stars.  Matching of facts with theory involves verifying facts and collecting data with no particular pragmatic value but that which can be directly compared with the predictions of a paradigm.  The articulation of theory/paradigm involves extending the testing limits of applicability of the paradigm, like finding out if the laws of thermodynamics are applicable to heat phenomena produced by mechanics.

Kuhn claims that normal science is based on a paradigm, is dogmatic and is objectively progressive.  Paradigms and not individuals drive normal science.  The paradigm directs the scientists to perform certain experiments, make certain observations, modify their theories in a particular way, to make particular choices between competing theories and hypotheses etc.  The dogmatic nature of normal science manifests in the way that students are taught the paradigm without being encouraged to question it, or even seriously consider alternatives.  The failure of a scientist to solve a scientific puzzle reflects on the competence of the researcher, not the soundness of the paradigm.  So, although paradigms often accumulate anomalies, normal scientific activity is directed towards removing those anomalies and not towards refuting the paradigm.  Kuhn equates progress with cumulativeness, that is, since scientists accumulate solutions to scientific puzzles, normal science must be progressive.

Perhaps Lorentz (1853-1928) and Brahe (1546-1601) give some of the best examples of Kuhn’s conservative scientific practice of normal science.  Brahe proposed a version of the geostatic system in which, like Ptolemy, the sun moved round the earth, but the other planets orbited the sun.  In this way Brahe was able to capture the explanatory features of Copernicus’ theory without having to attribute any motion to the earth, which had sparked objections on physical, astronomical and religious grounds.  Lorentz (in line with most physicists of his day) believed light and other EM radiation propagated in an aether at rest with respect to absolute space.  In response to the null result obtained by the Michelson-Morley experiment, Lorentz postulated that all physical objects contract in their direction of motion.  Lorentz also introduced time dilation, and so obtained the Lorentz transformations that figure in Einstein’s special theory of relativity.  Of course, unlike Einstein, Lorentz worked in the classical framework of absolute space and time.  The work of Copernicus and Einstein is not normal science, their theories are part of what Kuhn calls revolutionary science.  Revolutionary science comes after normal science.  Kuhn argues that neither science nor the development of knowledge can be understood if research is viewed exclusively through revolutions it occasionally produces.  Though testing of basic commitments occurs only in extraordinary science, it is normal science that discloses both the points to test and the manner of testing.  Further, it is normal science that professionals are trained in, not the extraordinary practice of science.  Kuhn contends it is normal science rather than extraordinary science that most (almost) distinguishes science from other enterprises.

Apparent from this conception of normal science being based on a paradigm, that is, either as a disciplinary matrix or an exemplar (and hence a model of reality) is that normal science forces nature into the framework of the given paradigm.  This is unsuccessful.  Within normal scientific activity there is no motivating factor for scientists to discover new facts and generate new knowledge, in fact, they are frequently blinded to new facts, this is one of the reasons scientific discovery is so difficult and rare.  Discoveries are rare because the expectations generated by the paradigm obscure our vision.  Also, the normal science format is intolerant of new ideas – normal science does not aim at novelty, novelty signals the end of normal science.  It is not aimed at discovering anything that may threaten the paradigm.  As earlier considered, anomalies are not thought of as refutations but simply as the fodder of puzzle solving.  Kuhn suggests motivation is grounded in the individual scientist’s conviction that, if only he is skilful enough, he will succeed in solving a puzzle that no one else before has solved, or solved so well.  This analysis does seem to jar with the ‘traditional’ perspective that the motivation for scientists doing normal science/research is passion, or some abstract yet noble goal such as serving humankind or discovering truth.  If normal science were just about puzzle solving one would be inclined to think that after some reflection, the process would appear trivial and meaningless.  It is also worth highlighting that Kuhn has abandoned traditional confirmation theory, no longer is there a focus on the past predictive track record of the theories but future prospects and expected fertility of those theories.  Whilst I cannot call this an outright argument against Kuhn, many philosophers of science hold that following Kuhn and allowing values a place in science rather than going for the traditional attempted objectivity (even if these values encroach on science anyway) of confirmation theory somehow generates a lower quality of evidence and scientific theory.

To conclude, a scientific paradigm is an exemplar, a solution to a scientific problem used in the education of scientists.  Another definition, a later and wider definition, of scientific paradigm is a disciplinary matrix consisting of exemplars but also symbolic generalisations, metaphysical ontological elements and models, and values.  Normal science is based on a paradigm, and as such is a puzzle solving activity.  The activity of normal science is determined by different commitments resulting from accepting the paradigm.  Kuhn identifies four sorts of commitments: conceptual, theoretical, instrumental, and methodical. Kuhn classifies normal scientific activities into three categories: determination of significant fact, matching of the facts with the theory, and articulation of the theory or paradigm.  As well as being paradigm-based, normal science is dogmatic and objectively progressive.  Lorentz and Brahe came up with scientific theories that seemed to solve the same puzzles as the revolutionary science of Einstein and Copernicus, but remained true to the original paradigm i.e. the classical framework.  They exemplify Kuhn’s normal scientific practice.  According to Kuhn, normal science is necessary because without it neither science nor the development of knowledge can be understood, it discloses both the points to test and the manner of scientific testing, and fundamentally it is normal science that professionals are trained in.  However, Kuhn’s conception of normal science is not entirely successful.  It lacks a motivating factor and actually makes new discoveries difficult and rare.  Kuhn tries to ground motivation as being intrinsic in the solving of (or attempt to solve) scientific puzzles.  I do not think this kind of motivation would stand up to prolonged reflection.  In fact simply these criticisms, I think, are enough to label Kuhn’s working of normal science as inadequate.



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