Transcript No Slide Title

EUROPEAN SOCIETY FOR THE STUDY OF COGNITIVE SYSTEMS
London 5-6 July 2010
THE SCIENTIFIC MIND
Falsifying Paradigms
Popper and Kuhn Revisited
Robin Allott
EUROPEAN SOCIETY FOR THE STUDY
OF COGNITIVE SYSTEMS
London 5-6 July 2010
THE SCIENTIFIC MIND
Falsifying Paradigms
Popper and Kuhn Revisited
Robin Allott
Popper 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.
Popper said that scientific theory which cannot be
falsified is not science - at best it is metaphysics.
Science advances as theories are falsified.
Kuhn 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.
Both 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.
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.
Both 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.
The Principal Antagonists
Karl Popper
Thomas Kuhn
Logik der Forschung 1935 [The
The Structure of Scientific Revolutions 1963
Logic of Scientific Discovery 1959]
Second Thoughts on Paradigms 1972
Conjectures and Refutations 1963
But there are many others, particularly:
Imre Lakatos
Paul Feyerabend
These are all philosophers, historians or
sociologists of science
BUT not so many actual scientists
Except for the remarkable Nobel physicist
Richard Feynman
“Philosophy of science is about as useful to
scientists as ornithology is to birds” [ QED ]
And 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:
NATURAL PHILOSOPHERS
ANAXAGORAS
ARISTOTLE
ROGER BACON
FRANCIS BACON
SUN AND PLANETS
PTOLEMY
COPERNICUS
GALILEO
KEPLER
NEWTON
ARISTARCHUS
The great heliocentric
Universe
[Archimedis Arenarius]
TYCHO BRAHE
CHEMISTRY
ROBERT BOYLE
PRIESTLEY
LAVOISIER
CAVENDISH
ELECTROMAGNETISM
FARADAY
HERTZ
CLERK MAXWELL
EVOLUTIONARY GENETICS
CHARLES DARWIN
Double Helix
GREGOR MENDEL
CRICK
WATSON
ROSALIND FRANKLIN
DNA X-Ray
NUCLEAR SCIENCE
ENRICO FERMI
NEUROSCIENCE
RITA LEVI-MONTALCINI
Karl Popper
A Great Book is a Great Evil ?
Popper 1000 pages + more thousands for critics and commentators
Falsifying ?
Verifying ?
Refuting?
Demarcating?
Prescription or Description?
Logik der Forschung 1935
The Logic of Scientific Discovery 1959]
Conjectures and Refutations 1963
Forschung - Research
Entdeckung – Discovery
Logic?
Of Research?
Of Discovery?
Of Scientific Method?
Of Science Totality?
About
Imre Lakatos and Paul Feyerabend
Falsification and the Methodology of Scientific
Research Programmes
Against Method 1975
in Criticism and the Growth of Knowledge 1970
A few notes and comments
LAKATOS
LAKATOS 1923-1974. 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 100-200 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.
FEYERABEND
FEYERABEND Austrian (1924-1994) 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 fellowanarchist”. 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 1968-1974.]
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 Thomas Kuhn
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’.
Notes 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 languagecommunities.
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.
Paradigms [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.
REFUTING THEORIES?
Are theories refuted in any formal way?
Were theories which prevailed for centuries refuted?
Can existing theories be refuted?
REFUTED THEORIES ?
Phlogiston
Astrology
Weight Aristotle
Wave theory of light
Corpuscular theory of light
Earth-centred astronomy
Ptolemy
Malaria
Witchcraft
How long to be verified or
refuted?
Newton – 200 years
Ptolemy 1500 years
Aristotle 2000 years
Astrology 3000 years ?
Blood-letting ?
General relativity how long?
Big Bang how long?
Present cosmology how long?
Nothing’s final
All is for reconsideration?
Is there a uniform pattern in the very different histories of
changed theories over the centuries?
NOT REFUTATIONS BUT [examples]:
Different explanations for the same set of facts (observation):
Planetary movements
Rotation of the earth
Phlogiston – Priestley - Lavoisier
Or New Facts:
Planck quantum
Invariance of the speed of light
Particles
Quantum levels
Photons
Or changing gestalts- changing points of view
[Copernicus(Kant) – de Broglie]
How science has advanced is a matter of record, of history,
a matter of the advance of the human mind, of human society, of
human culture
Limiting prescriptions for the method of science cannot be derived
from the collection of scientific theories or from any single one of
them
It 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.
The 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) ?
But 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 Pseudoscience
Method and Practice
Logic Verbal and Concrete
Paradigm and Sociology of Science
Refutation and Withering away
DEMARCATING ?
Pure Science
Applied Science
Mathematics
Applied Mathematics
Technology
Engineering
Other ‘Sciences’?
What should be included?
What should be excluded?
WHAT 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?
Hadamard:
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.
Hadamard 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]
How some eminent scientists arrived at
their results
NEWTON’S APPLE
[from the Royal Society Archives]
The Copernican System
The Moons of Jupiter
[by telescope]
Phases of Venus
Galileo'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 system
DARWIN: 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.
PLANCK
h= 6.626068 × 10-34 m2 kg / s
A 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 lowfrequencies 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]
LORENTZ
In 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.
Against this background of scientific change what
drives the individual scientist?
NOT the Pursuit of Truth
BUT the endless drive to understand ?
AND to share and communicate and to make use of our
understanding
To FEEL we understand
A standard scientific education presents a set pattern, to be
challenged – seeking one’s own understanding, not simply
acquiescing in the formally presented accounts of others
The scientific drive to understand is part of the over-riding
human drive to understand
And this drive is apparent in the development of the child
The Scientist in the Crib
Alison Gopnik Adam Meltzoff Patricia Kuhl
The Explanatory Drive
The Past and the Future
The unity (unification?) of mind over 2500-3000 years
‘Natural philosophy’ escaping from the ghetto of
academic philosophy
>>> neurophilosophy ?
Patricia Churchland
And ultimately to the structure of the human brain ?
From the Past looking to the Future
Roger Bacon Opus Maius 1266
His 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.
Francis 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.
ROBERT BOYLE [Chemist Founder of the Royal Society]
Wish List
On display at the Royal Society 350 Anniversary
Exhibition
NEWTON
A Child on the Sea-shore
HEISENBERG
The Great Edifice of Science
ANAXAGORAS
Anaxagoras c. 500 BC – 428 BC Pre-Socratic Greek philosopher.