4Popper is described as perhaps the greatest philosopher of the 20th century. Kuhn is said to be perhaps the most influential philosopher of science of the 20th century.
5Popper said that scientific theory which cannot be falsified is not science - at best it is metaphysics. Science advances as theories are falsified.
6Kuhn says that theories are replaced not because they have been falsified but because a new scientific paradigm becomes established and the previously existing paradigm just withers away.
7Both are concerned with the ancient argument whether the processes of science are by induction or deduction. Both are concerned with the past present and future of science. Both are concerned, in different ways, with the question of the 'truth' of science.
8Kuhn took as his first example the Copernican revolution Kuhn took as his first example the Copernican revolution. Popper engaged himself with quantum theory. Both accounts can be applied to a wide range of scientific theories and non-scientific disciplines: cosmology, physics, quantum mechanics, biology, psychoanalysis, sociology, history, metaphysics, linguistics, molecular biology, neuroscience.
9Both attracted enthusiastic supporters and both attracted vehement opponents. The question remains whether either or both or neither of the disparate accounts of the forward movement of science are 'correct', useful or mistaken.
10The Principal Antagonists Karl Popper Thomas Kuhn Logik der Forschung 1935 [The Logic of Scientific Discovery 1959]Conjectures and Refutations 1963The Structure of Scientific Revolutions 1963Second Thoughts on Paradigms 1972
11But there are many others, particularly: Imre Lakatos Paul Feyerabend
12These are all philosophers, historians or sociologists of science BUT not so many actual scientists
13Except for the remarkable Nobel physicist Richard Feynman“Philosophy of science is about as useful to scientists as ornithology is to birds” [ QED ]
14And beyond the philosophers, sociologists and psychologists of science, there are the scientists who have described, some in their Nobel Prize lectures, how they set about the problems that they faced and how they arrived at the important concrete results for which they were honoured. Here are some of them:
15NATURAL PHILOSOPHERSANAXAGORAS ARISTOTLE ROGER BACON FRANCIS BACON
16ARISTARCHUS The great heliocentric Universe [Archimedis Arenarius] SUN AND PLANETSPTOLEMY COPERNICUS GALILEOARISTARCHUS The great heliocentric Universe[Archimedis Arenarius]TYCHO BRAHE KEPLER NEWTON
23Karl Popper A Great Book is a Great Evil ? Popper 1000 pages + more thousands for critics and commentators
24Prescription or Description? Falsifying ?Verifying ?Refuting?Demarcating?Prescription or Description?
25Logik der Forschung 1935The Logic of Scientific Discovery 1959]Conjectures and Refutations 1963Forschung - ResearchEntdeckung – DiscoveryLogic?Of Research?Of Discovery?Of Scientific Method?Of Science Totality?
26Imre Lakatos and Paul Feyerabend A few notes and comments AboutImre Lakatos and Paul FeyerabendFalsification and the Methodology of Scientific Research Programmesin Criticism and the Growth of Knowledge 1970Against Method 1975A few notes and comments
27LAKATOS Lectures on Scientific Method LSE 1973 [extracts transcribed]: LAKATOS Communist Minister in Hungary. Imprisoned as revisionist. Changed name 4 or 5 times. Came to England as assistant to Popper at the LSE. British citizenship refused, ultimately stateless. Claimed to be extending Popper's ideas. Contrasted Popper0, the crude falsificationist (as seen by others), Popper1, the author of what Popper actually wrote, and Popper2, as reinterpreted by Lakatos himself.Lectures on Scientific Method LSE 1973 [extracts transcribed]:The social sciences are on a par with astrology Major theories in physics are growing entities (over years), not static entities. According to Popper, verifications do not count, only falsifications do the acme of a scientific theory is “All swans are white” because one single observation of a black swan refutes it. This is absolute nonsense. Theories grow in a sea of anomalies. Anomalies are shelved instead of being used towards rejecting the theory. [According to Popper science progresses through successive refutations] This is all logically possible, the only problem is that it has never happened in this way. The greatest victories in science were verifications, not falsifications. How Popper managed to fool them [believers in falsification] I shall never know.The fact that Popper’s philosophy survived for so long is a sociological mystery.If we follow the sceptics [Feyerabend], the demarcation problem is unsolvable there is no demarcation line; epistemologically speaking, all theories are on a par.
28FEYERABENDFEYERABEND Austrian ( ) 1943: Eastern Front - Iron Cross - Bullet in spine. 1952: At LSE with Popper as supervisor. In Against Method and Science in a Free Society Feyerabend argued that there are no methodological rules always used by scientists. Philosophy can neither succeed in providing a general description of science, nor in devising a method for differentiating products of science from non-scientific entities like myths. Against Method was dedicated to "Imre Lakatos: Friend, and fellow-anarchist”. Lakatos and Feyerabend planned to produce a joint work in which Lakatos would develop a rationalist description of science and Feyerabend would attack it.[Extracts from For and Against Method 1999 ed. and compiled by Motterlini included correspondence between Lakatos and Feyerabend ]
29Thomas Kuhn THE STRUCTURE OF SCIENTIFIC REVOLUTIONS A striking title promising a great deal: “History could produce a decisive transformation in the image of science This essay attempts to show that we have been misled ... in fundamental ways. Its aim is a sketch of the quite different concept of science that can emerge from the historical record”. The essay had a great impact introducing new concepts: "scientific revolutions" "paradigms” (from linguistics) “paradigm shifts”“normal science”With the extended edition in 1970, and specifically the Postscript (1969), the heroic tone has been lost. Some key terms: revolution, paradigm, exemplar, disciplinary matrix , had to be justified in response to often hostile criticism. Currently Kuhn’s ideas have little significance in science but are much relied upon in the social sciences where they are used loosely to advance claims for psychoanalysis and sociology to be regarded as ‘sciences’.Thomas KuhnNotes from, and on, the 1969 Postscript:Scientific community “If this book were being rewritten it would open with a discussion of the community structure of science. scientific knowledge, like language, is intrinsically the common property of a group. .., proponents of different theories are like members of different language-communities.Scientific revolutions “A [Kuhnsian] revolution need not be a large change, nor seem revolutionary. The[revolutionary] conversion experience like a gestalt switch”. Kuhnsian revolutions are said to result from the accumulation of anomalies but this does not leave room for discoveries such as DNA structure and its enormous consequences for biological research.
30Paradigms [from the Postscript] “gratuitous difficulties and misunderstandings [resulting from the 1962 book] about the concept. .. Paradigms, what they can possibly be ... [there is] no more obscure or important question. [A reader found the term used in twenty-two different ways]. ... the most novel and least understood aspect of this book. 'Paradigm' is used in two different senses. 1. Sociological – the entire constellation of the beliefs, values, techniques, and so on shared by a community. 2. concrete puzzle-solutions as models or examples of normal science.”Disciplinary matrix “What do its [a community of specialists] members share ... In my original text .. a paradigm or set of paradigms .. [but] for this the term is inappropriate. Scientists themselves would say they share a theory or set of theories. My original text makes paradigms, parts of paradigms, or paradigmatic constituents of the ‘disciplinary matrix’ ... of a particular discipline ; 'matrix' as ordered elements of the disciplinary matrix.”Exemplars [a replacement for ‘paradigms’] Normal science is puzzle-solving using knowledge embedded in shared exemplars, concrete problem-solutions used at the start of scientific education modelling one problem-solution on another.As these extracts from the Postscript show the original drive of Kuhn’s ‘new image of science’ is obscured and has lost its impact on scientific thought. Kuhn can be seen as essentially a sociologist of science.
31REFUTING THEORIES?Are theories refuted in any formal way?Were theories which prevailed for centuries refuted?Can existing theories be refuted?
32REFUTED THEORIES ?PhlogistonAstrologyWeight AristotleWave theory of lightCorpuscular theory of lightEarth-centred astronomyPtolemyMalariaWitchcraft
33How long to be verified or refuted? All is for reconsideration? Newton – 200 yearsPtolemy 1500 yearsAristotle 2000 yearsAstrology 3000 years ?Blood-letting ?General relativity how long?Big Bang how long?Present cosmology how long?Nothing’s finalAll is for reconsideration?
34Is there a uniform pattern in the very different histories of changed theories over the centuries?
35NOT REFUTATIONS BUT [examples]: Different explanations for the same set of facts (observation):Planetary movementsRotation of the earthPhlogiston – Priestley - LavoisierOr New Facts:Planck quantumInvariance of the speed of lightParticlesQuantum levelsPhotonsOr changing gestalts- changing points of view[Copernicus(Kant) – de Broglie]
36How science has advanced is a matter of record, of history, a matter of the advance of the human mind, of human society, of human cultureLimiting prescriptions for the method of science cannot be derived from the collection of scientific theories or from any single one of themIt does not follow that ‘Anything goes’ (Feyerabend’s anarchic formulation). Rather the particular examples should be examined for the light they throw on the evolution of the human mind, the innate programs of the mind (Kant) and the apparent structures of perception and language.And the relation between the emergence of theories and advances in the invention and application of tools, instruments.For example, how much science has flowed from the application of new instruments to investigate the Fraunhofer spectrum lines.
37The attempt to understand how this has been possible over 2500 years In language – In words Is it useful to describe the changes as ‘paradigm change’ or as ‘Scientific Revolutions’ (Kuhn) ?
38But if not Popper, Kuhn, Lakatos or Feyerabend ? Is there then no need or problem in considering the methods or the (continued) success (and future) of science?Preliminary questions:Understanding the terms used:Science and PseudoscienceMethod and PracticeLogic Verbal and ConcreteParadigm and Sociology of ScienceRefutation and Withering away
39What should be included? What should be excluded? DEMARCATING ?Pure ScienceApplied ScienceMathematicsApplied MathematicsTechnologyEngineeringOther ‘Sciences’?What should be included?What should be excluded?
41WHAT DO SCIENTISTS ACTUALLY DO ? How do they start to investigate? How do they then proceed?How do they confirm their finding?How does their discovery become accepted into the framework of science?
42Hadamard:In his book Psychology of Invention in the Mathematical Field, Hadamard uses introspection to describe mathematical thought processes. In sharp contrast to authors who identify language and cognition, he describes his own mathematical thinking as largely wordless, often accompanied by mental images that represent the entire solution to a problem.He surveyed 100 of the leading physicists of the day (approximately 1900), asking them how they did their work. Many of the responses mirrored his; some reported seeing mathematical concepts as colors. Einstein reported that the elements of his work consisted of visual and muscular entities, and that words or language did not seem to play any role in his mechanism of thought.
43Hadamard described the experiences of the mathematicians/theoretical physicists Carl Friedrich Gauss, Hermann von Helmholtz, Henri Poincaré and others as viewing entire solutions with “sudden spontaneousness”. The same has been reported by many others, such as G. H. Hardy, van der Waerden, Ruegg, Kekulé (dreamed of a snake seizing its own tail = the benzene ring) and Tesla.Einstein, after years of fruitless calculations, suddenly had the solution of the general theory of relativity revealed in a dream “like a giant die making an indelible impress, a huge map of the universe outlined itself in one clear vision.”“Tous les hommes de science ont dû prendre conscience de ce que leur réflexion, au niveau profond, n’est pas verbale ... Je suis moi-même surpris... à m’identifier à une molécule de protéine” [Jacques Monod Le Hasard et la nécessité]
44How some eminent scientists arrived at their results
45NEWTON’S APPLE [from the Royal Society Archives]
47The Moons of Jupiter [by telescope] The Copernican SystemPhases of VenusGalileo's observation with the telescope of the crescent, gibbous and full phases of Venus could not be explained by the Ptolemaic system and so promoted acceptance of the Copernican systemThe Moons of Jupiter [by telescope]
48DARWIN: Artificial and Natural Selection 1838 Darwin came across a pamphlet written by a politician and professional animal breeder by the name of Sir John Sebright. It was titled "The Art of Improving Breeds of Domestic Animals" (1809). In this pamphlet Darwin was struck by one particular statement which said that the weak do not survive long enough to pass on their traits.
49PLANCKh= × m2 kg / sA blackbody is an object that re-emits all of the radiant energy(light, heat) falling on it. [Kirchhoff]. Wien produced a formula to determine how much radiant energy is emitted at different frequencies for a given temperature.Planck unsuccessfully tried to derive Wien's formula on the basis of the second law of thermodynamics (entropy). Experiments had shown that Wien’s formula worked at high frequencies but failed at low frequencies.The entropy of the radiation had to depend mathematically upon its energy in the high-frequency region. Planck saw what this dependence had to be for low- frequencies in order to match the experimental results for both high and low frequencies. He guessed that the two expressions should be combined in the simplest way, and produced a formula relating the energy of the radiation to its frequency by ‘arbitrarily’ introducing a new constant (the quantum).For Planck the new constant was just a "lucky intuition." It had to be derived somehow from first principles. For this he found that he had to accept that the second law of thermodynamics was not an absolute law of nature but, following Boltzmann's interpretation, only a statistical law Planck’s constant established the ‘granulatory’ character of energy. It was, perhaps, the first ‘renormalisation’ much used in quantum mechanics! [saving mathematical equations which fail by inserting empirical experimental results]
50LORENTZIn an attempt to explain the Michelson-Morley experiment, Lorentz proposed that moving bodies contract in the direction of motion. Electrodynamic phenomena in different reference frames are described by identical equations with well defined transformation properties (cf Joseph Larmor). In 1904 Lorentz provided a detailed discussion of the increase of the inertial mass of rapidly moving objects. In 1905 Einstein used many of these concepts, mathematical tools and results to write his paper on what came to be called the theory of special relativity. The theory was originally called the Lorentz-Einstein theory.
51Against this background of scientific change what drives the individual scientist?
52NOT the Pursuit of Truth BUT the endless drive to understand ?AND to share and communicate and to make use of our understandingTo FEEL we understandA standard scientific education presents a set pattern, to be challenged – seeking one’s own understanding, not simply acquiescing in the formally presented accounts of othersThe scientific drive to understand is part of the over-riding human drive to understandAnd this drive is apparent in the development of the child
53The Scientist in the Crib Alison Gopnik Adam Meltzoff Patricia KuhlThe Explanatory Drive
55The unity (unification?) of mind over 2500-3000 years ‘Natural philosophy’ escaping from the ghetto of academic philosophy>>> neurophilosophy ?And ultimately to the structure of the human brain ?Patricia Churchland
57Roger Bacon Opus Maius 1266His Opus Maius contains treatments of mathematics and optics, alchemy and the manufacture of gunpowder, the positions and sizes of the celestial bodies, and anticipates later inventions such as microscopes, telescopes, spectacles, flying machines, hydraulics and steam ships. Bacon studied astrology and believed that the celestial bodies had an influence on the fate and mind of humans. The study of optics in part five of Opus Maius seems to draw on the works of the Muslim scientists, Alkindus (al-Kindi) and Alhazen (Ibn al-Haytham), including a discussion of the physiology of eyesight, the anatomy of the eye and the brain, and considers light, distance, position, and size, direct vision, reflected vision, and refraction, mirrors and lenses.
58Francis Bacon [New Organon and Advancement of Learning] There is therefore much ground for hoping that there are still laid up in the womb of nature many secrets of excellent use, having no affinity or parallelism with anything that is now known, but lying entirely out of the beat of the imagination, which have not yet been found out. They too no doubt will some time or other, in the course and revolution of many ages, come to light of themselves, just as the others did; only by the method of which we are now treating they can be speedily and suddenly and simultaneously presented and anticipated.
59ROBERT BOYLE [Chemist Founder of the Royal Society] Wish ListOn display at the Royal Society 350 Anniversary Exhibition