scientific progress and its problems l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Scientific Progress and Its Problems PowerPoint Presentation
Download Presentation
Scientific Progress and Its Problems

Loading in 2 Seconds...

play fullscreen
1 / 47

Scientific Progress and Its Problems - PowerPoint PPT Presentation


  • 451 Views
  • Uploaded on

Scientific Progress and Its Problems. Verification, Falsification or What?. Introduction. The aim of the lecture is To present the major conceptions of scientific growth To discuss their respective strong and weak points. Main Topics. The inductivist model of science

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Scientific Progress and Its Problems' - liam


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
scientific progress and its problems

Scientific Progress and Its Problems

Verification, Falsification or What?

Lecture 3

introduction
Introduction

The aim of the lecture is

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

Lecture 3

main topics
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

Lecture 3

main topics4
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?

Lecture 3

the inductivist model of science 1
The Inductivist Model of Science (1)
  • The facts are observed and recorded.
  • The observed and recorded facts are analysed, compared and categorized.

Lecture 3

the inductivist model of science 2
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.

Lecture 3

popper s falsificationism 1
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

Lecture 3

popper s falisficationism 2
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’.

Lecture 3

popper s falisficationism 3
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

Lecture 3

popper s falisficationism 4
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

Lecture 3

popper s falisficationism 5
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.

Lecture 3

kuhn s structural criterion of science 1
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

Lecture 3

kuhn s structural criterion of science 2
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’

Lecture 3

kuhn s structural criterion of science 3
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.

Lecture 3

kuhn s structural criterion of science 4
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.

Lecture 3

kuhn s structural criterion of science 5
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.

Lecture 3

thomas kuhn s structural criterion of science 6
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.

Lecture 3

thomas kuhn s structural criterion of science 7
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

Lecture 3

thomas kuhn s structural criterion of science 8
Thomas Kuhn’s Structural Criterion of Science (8)
  • A paradigm will never be replaced unless a ‘less problematic or better’ one comes around

Lecture 3

thomas kuhn s structural criterion of science 9
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

Lecture 3

thomas kuhn s structural criterion of science 922
Thomas Kuhn’s Structural Criterion of Science (9)
  • This implies a conception of science as a social activity
  • Epistemology is an empirical science

Lecture 3

lakatos sophisticated falsificationism and research programmes 1
Lakatos, Sophisticated Falsificationism, and Research Programmes (1)

Naïve falsificationism

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

Lecture 3

lakatos sophisticated falsificationism and research programmes 2
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

Lecture 3

lakatos sophisticated falsificationism and research programmes 3
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

Lecture 3

lakatos sophisticated falsificationism and research programmes 4
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

Lecture 3

lakatos sophisticated falsificationism and research programmes 5
Lakatos, Sophisticated Falsificationism, and Research Programmes (5)
  • Such a sequence of interrelated theories is what Lakatos calls a scientific research programme

Lecture 3

lakatos sophisticated falsificationism and research programmes 6
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.

Lecture 3

lakatos sophisticated falsificationism and research programmes 7
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

Lecture 3

lakatos sophisticated falsificationism and research programmes 8
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.

Lecture 3

lakatos sophisticated falsificationism and research programmes 9
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

Lecture 3

feyerabend the abandonment for the search of the method
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

Lecture 3

laudan s research traditions 1
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.

Lecture 3

laudan s research traditions 2
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). 

Lecture 3

laudan s research traditions 3
Laudan’s Research Traditions (3)
  • Contrary to Lakatos these general assumptions (hard core assumptions if you wish) may change

Lecture 3

laudan s research traditions 4 empirical and conceptual problems
Laudan’s Research Traditions (4): Empirical and Conceptual Problems
  • For Laudan science is
    • not only about empirical problems
    • but also about conceptual problems

Lecture 3

laudan s research traditions 5 nature of empirical problems
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

Lecture 3

laudan s research traditions 6 nature of empirical problems
Laudan’s Research Traditions (6): Nature of Empirical Problems
  • He distinguishes three kind of empirical problems:
    • solved problems
    • unsolved problems
    • anomalous problems

Lecture 3

laudan s research traditions 7 nature of conceptual problems
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

Lecture 3

laudan s research traditions 8 sources of conceptual problems
Laudan’s Research Traditions (8): Sources of Conceptual Problems
  • Intra-scientific difficulties
  • Normative difficulties
  • Worldview (ontological) difficulties

Lecture 3

laudan s research traditions 9 core assumptions
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

Lecture 3

laudan s research traditions 10 evaluation of theories
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

Lecture 3

larry laudan s research traditions 11 evaluation of theories
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)

Lecture 3

larry laudan s research traditions 11 evaluation of theories44
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

Lecture 3

how to judge the value of a scientific theory or model a few rules of thumb
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?

Lecture 3

how to judge the value of a scientific theory or model a few rules of thumb46
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?

Lecture 3

how to judge the value of a scientific theory or model a few rules of thumb47
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?

Lecture 3