1. Scientific Progress and Its Problems
Verification, Falsification or What?
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2. Introduction The aim of the lecture is
To present the major conceptions of scientific growth
To discuss their respective strong and weak points.
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3. Main Topics The inductivist model of science
Karl Popper’s falsificationism
Thomas Kuhn’s structural criterion of science
Imre Lakatos, sophisticated falsificationism, and research programmes
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4. Main Topics
The abandonment of the search for ‘the’ method (Feyerabend)
Larry Laudan’s research traditions
How to judge the value of a scientific theory?
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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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6. 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.
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7. Figure 1: the Inductivist Model
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8. Popper’s 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
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9. Popper’s 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 Popper’s epistemology is commonly labelled ‘critical rationalism’.
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10. Popper’s 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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11. Popper’s Falisficationism (4)
Science thus progresses by trial and error, by conjectures and refutations
Only the fittest theories survive and are tentatively and temporarily accepted
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12. Popper’s 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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13. Kuhn’s 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
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14. Kuhn’s 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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15. Kuhn’s Structural Criterion of Science (3)
The central concept of Kuhn’s epistemology is ‘paradigm’.
Masterman identifies three basic concepts within Kuhn’s notion of paradigm:
the ‘metaphysical’ paradigm,
the ‘sociological’ paradigm, and.
the ‘artefact’ paradigm.
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16. Kuhn’s 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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17. Kuhn’s 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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18. Thomas Kuhn’s 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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19. Thomas Kuhn’s 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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20. Thomas Kuhn’s Structural Criterion of Science (8)
A paradigm will never be replaced unless a ‘less problematic or better’ one comes around
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21. Thomas Kuhn’s 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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22. Thomas Kuhn’s Structural Criterion of Science (9)
This implies a conception of science as a social activity
Epistemology is an empirical science
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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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24. Lakatos, Sophisticated Falsificationism, and Research Programmes (2)
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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25. Lakatos, Sophisticated Falsificationism, and Research Programmes (3)
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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26. 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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27. 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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28. 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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29. 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
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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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31. 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
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32. Feyerabend: the Abandonment for the Search of ‘The’ Method
Feyerabend’s 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
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33. Laudan’s 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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34. Laudan’s 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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35. Laudan’s Research Traditions (3)
Contrary to Lakatos these general assumptions (hard core assumptions if you wish) may change
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36. Laudan’s 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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37. Laudan’s 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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38. Laudan’s Research Traditions (6): Nature of Empirical Problems
He distinguishes three kind of empirical problems:
solved problems
unsolved problems
anomalous problems
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39. Laudan’s 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
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40. Laudan’s Research Traditions (8): Sources of Conceptual Problems
Intra-scientific difficulties
Normative difficulties
Worldview (ontological) difficulties
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41. Laudan’s 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
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42. Laudan’s 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
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43. Larry Laudan’s 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)
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44. Larry Laudan’s 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
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45. How to Judge the Value of a Scientific Theory or Model
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?
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46. How to Judge the Value of a Scientific Theory or Model
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 model’s 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?
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47. How to Judge the Value of a Scientific Theory or Model
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?
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