Scientific Progress and Its Problems

1
Scientific Progress and Its Problems

• Verification, Falsification or What?

2
Introduction

• The aim of the lecture is
• To present the major conceptions of scientific
  growth
• To discuss their respective strong and weak
  points.

3
Main Topics

• The inductivist model of science
• Karl Poppers falsificationism
• Thomas Kuhns structural criterion of science
• Imre Lakatos, sophisticated falsificationism, and
  research programmes

4
Main Topics

• The abandonment of the search for the method
  (Feyerabend)
• Larry Laudans research traditions
• How to judge the value of a scientific theory?

5
The Inductivist Model of Science (1)

• The facts are observed and recorded.
• The observed and recorded facts are analysed,
  compared and categorized.

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The Inductivist Model of Science (2)

• From this analysis of the facts, generalizations
  are inductively drawn as to the relations
  (empirical regularities) between them.
• Further research is inductive as well as
  deductive, employing inferences from previously
  established generalizations.

7
Figure 1 the Inductivist Model
8
Poppers Falsificationism (1)

• Not verification, but falsification
• Reason the classical problem of induction
• Observation is always affected by prior
  theoretical and conceptual commitments
• it is guided by and presupposes theory (the
  so-called searchlight theory of knowledge)
• observation is thus theory-laden

9
Poppers Falisficationism (2)

• Theories cannot be established as true in the
  light of observational evidence.
• Theories are constructed as speculative and
  tentative conjectures freely created by the human
  intellect in an attempt to overcome problems
  encountered by previous theories to give an
  adequate account of some aspects of the world.
• That is why Poppers epistemology is commonly
  labelled critical rationalism.

10
Poppers Falisficationism (3)

• Once proposed, speculative theories are to be
  rigorously and ruthlessly tested by observation
  and experiment
• Theories that conflict with empirical evidence
  must be eliminated (falsified) and replaced by
  new theories

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Poppers Falisficationism (4)

• Science thus progresses by trial and error, by
  conjectures and refutations
• Only the fittest theories survive and are
  tentatively and temporarily accepted

12
Poppers Falisficationism (5)

• A theory can never be said to be true
• Of a theory it can only be said that it is the
  best available in the sense that is better than
  anything that has come before at least for the
  time being.
• As a consequence
• there is no certainty in science
• scientific knowledge is always tentative.

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Kuhns Structural Criterion of Science (1)

• Scientists do not in fact falsify theories in the
  instant way specified by Popper
• While at the level of empirical hypotheses
  Popperian falsificationism may operate, this
  cannot be maintained at the level of broader
  theoretical structures or the evolution of
  science as a whole

14
Kuhns Structural Criterion of Science (2)

• According to Kuhn scientific evolution should be
  understood as the development of complex
  structures of theories or, as he calls them,
  paradigms

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Kuhns Structural Criterion of Science (3)

• The central concept of Kuhns epistemology is
  paradigm.
• Masterman identifies three basic concepts within
  Kuhns notion of paradigm
• the metaphysical paradigm,
• the sociological paradigm, and.
• the artefact paradigm.

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Kuhns Structural Criterion of Science (4)

• The metaphysical paradigm involves the
  ontological elements of a theory, namely those
  assumptions that affect the way in which man
  views the world and his place in it.

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Kuhns Structural Criterion of Science (5)

• The sociological paradigm refers to a concrete
  scientific achievement that functions as a model
  or framework within which scientific research is
  conducted.

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Thomas Kuhns Structural Criterion of Science (6)

• Finally, the artefact paradigm concerns a
  distinct set of tools, techniques or
  instrumentation that are considered relevant to
  he validation of scientific knowledge.

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Thomas Kuhns Structural Criterion of Science (7)

• Normal science
• Crisis
• Revolutionary science
• Gestalt switch
• New period of normal science
• New paradigm is incommensurable with previous one

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Thomas Kuhns Structural Criterion of Science (8)

• A paradigm will never be replaced unless a less
  problematic or better one comes around

21
Thomas Kuhns Structural Criterion of Science (9)

• Within this general process of development of
  science Kuhn stresses
• the importance of the scientific community
• the role of extra-scientific elements

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Thomas Kuhns Structural Criterion of Science (9)

• This implies a conception of science as a social
  activity
• Epistemology is an empirical science

23
Lakatos, Sophisticated Falsificationism, and
Research Programmes (1)

• Naïve falsificationism
• A theory is falsified by an observational
  statement that conflicts with it

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Lakatos, Sophisticated Falsificationism, and
Research Programmes (2)

• Sophisticated falsificationism
• A theory T1 is falsified if another theory T2 has
  been proposed with the following
  characteristics 
• T2 has excess empirical content over T1 that is,
  if it predicts novel facts
• T2 explains the empirical content of T1
• Some of the excess content of T2 is corroborated

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Lakatos, Sophisticated Falsificationism, and
Research Programmes (3)

• Research programmes
• Theories are part of broader structures, which
  Lakatos calls research programmes
• Within such a programme theories develop in a
  dynamic way

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Lakatos, Sophisticated Falsificationism, and
Research Programmes (4)

• A theory that is shown to be inadequate is
  replaced by a better one but typically one which
  belongs to the same family
• We have a sequence of theories, T(1), T(2), T(3)
  and so on, each of which explains more than its
  predecessor and thus supersedes it

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Lakatos, Sophisticated Falsificationism, and
Research Programmes (5)

• Such a sequence of interrelated theories is what
  Lakatos calls a scientific research programme

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Lakatos, Sophisticated Falsificationism, and
Research Programmes (6)

• The family relationship is carried on by the
  negative heuristic or hard core, which will not
  be doubted, at least during the course of the
  programme.

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Lakatos, Sophisticated Falsificationism, and
Research Programmes (7)

• Whenever observations do not fit smoothly into
  this framework and objections are raised the
  rational response is
• not to forego the hard-core assumptions
• but to protect them by a set of auxiliary
  hypotheses that
• aim at increasing the predictive power of the
  programme
• and in this way protect the hard core

30
Lakatos, Sophisticated Falsificationism, and
Research Programmes (8)

• The part of the research programme containing the
  auxiliary hypotheses is thus called the
  protective belt or positive heuristic
• It indicates what needs to be done in order to
  increase the explanatory and predictive power of
  the programme.

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Lakatos, Sophisticated Falsificationism, and
Research Programmes (9)

• When is a research programme falsified? 
• A research programme R1 is falsified when there
  is an alternative research programme R2 that
• can explain and predict as much as research
  programme R1 does
• predicts novel facts, some of which are
  corroborated

32
Feyerabend the Abandonment for the Search of
The Method

• Feyerabends key points are
• All methods have their limitations
• The method of science does not exist
• Therefore, the most reasonable position is that
  of methodological pluralism
• The importance of creativity in science anything
  goes

33
Laudans Research Traditions (1)

• Laudan argues that Lakatos criteria for
  falsifying research programmes, namely
  theoretical and empirical progressiveness, are
  too strict and do not stand the test of the
  history of science.
• In essence his position boils down to a pragmatic
  interpretation and integration of Kuhnian and
  Lakatosian concepts.

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Laudans Research Traditions (2)

• A research tradition is a set of general
  assumptions about
• the entities and the processes in a domain of
  study (ontology), and
• about the appropriate principles and methods to
  be used for investigating the problems and
  constructing the theories in that domain
  (epistemology and methodology). 

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Laudans Research Traditions (3)

• Contrary to Lakatos these general assumptions
  (hard core assumptions if you wish) may change

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Laudans Research Traditions (4) Empirical and
Conceptual Problems

• For Laudan science is
• not only about empirical problems
• but also about conceptual problems

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Laudans Research Traditions (5) Nature of
Empirical Problems

• Empirical problems are problems about the world
• Empirical problems are theory-laden as they are
  generated within a certain theoretical structure

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Laudans Research Traditions (6) Nature of
Empirical Problems

• He distinguishes three kind of empirical
  problems
• solved problems
• unsolved problems
• anomalous problems

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Laudans Research Traditions (7) Nature of
Conceptual Problems

• Internal conceptual problems when T exhibits
  certain internal inconsistencies, or when its
  basic categories of analysis are vague and
  unclear
• External conceptual problems when T is in
  conflict with another theory, T, which
  proponents of T rationally believe to be well
  founded

40
Laudans Research Traditions (8) Sources of
Conceptual Problems

• Intra-scientific difficulties
• Normative difficulties
• Worldview (ontological) difficulties

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Laudans Research Traditions (9) Core Assumptions

• The solved problem empirical or conceptual is
  the base of scientific progress (pragmatism)
• The aim of science is to maximise the scope of
  solved empirical problems, while minimising the
  scope of anomalous and conceptual problems

42
Laudans Research Traditions (10) Evaluation of
Theories

• The first and essential test for any theory is
  whether
• it provides acceptable answers to interesting
  questions
• whether, in other words, it provides satisfactory
  solutions to important problems

43
Larry Laudans Research Traditions (11)
Evaluation of Theories

• In appraising the merits of theories, it is more
  important to ask
• whether they constitute adequate solutions to
  significant problems
• than it is to ask whether they are true,
  corroborated, well confirmed or otherwise
  justifiable within the framework of contemporary
  epistemology
• This is a kind of judgemental rationalism
  (Bhaskar)

44
Larry Laudans Research Traditions (11)
Evaluation of Theories

• The overall effectiveness of a theory is
  determined by
• assessing the number and importance of the
  empirical problems, which the theory solves, and
• deducting thereof the number and importance of
  the anomalies and conceptual problems, which the
  theory generates, determine the overall
  effectiveness of a theory

45
How to Judge the Value of a Scientific Theory or
Model? A Few Rules of Thumb

• To which degree does it tackle the problems for
  which it was designed, compared to others that
  are applicable to the same problems?
• To what extent can one relax its assumptions and
  still retain a coherent model?

46
How to Judge the Value of a Scientific Theory or
Model? A Few Rules of Thumb

• To which extent events that do not conform to the
  models predictions can be explained by a
  manageable examination of its conditions?
• To which extent it is able to generate
  propositions about the real world that are not
  attainable through simple observation and common
  sense?

47
How to Judge the Value of a Scientific Theory or
Model? A Few Rules of Thumb

• To which extent does it lead to the construction
  of a new and better model?