Philosophy of science II From positivists to Thomas Kuhn
Key concepts in the philosophy of science • Positivism • Logical positivism • Falsificationism • Paradigms • Anarchy • Social constructions
Positivism Auguste Comte (1798-1857) • Facts • Facts • More facts • Generalize from those facts • = induction
Comtes evolutionary stages Law of three phases of civilisation’s evolution • Theological • Metaphysical • Scientific The final positive stage
Logical positivism • Vienna circle 1920’s- 1930’s • Moritz Schlick, Rudolf Carnap, Otto Neurath, A. J. Ayer • Metaphysics ( = not science): • All propositions that are neither verifiable by empirical observation nor demonstrable as analytic. • Ex.: religious and ethical statements.... • Scientific method • Induction and verifiability
Alfred Ayer (1910-89) in his Language, Truth and Logic first published in 1936. The first claim of logical positivists is that a statement can only be true only if either • it is a self-evident analytic, deductive truth of the kind found in mathematics and formal logic (e.g. ‘2+2=4’) or because • the statement matches reality precisely. A consequence of this was that statements had to be verifiable to be meaningful.
Vienna circle project • Develop an exact and unbiased language for science. • logic, mathematics. • Demarcation problem • make a clear distinction between science and metaphysics (not science) • Reductionism: • Physics, the queen of science.
Falsificationism • Karl R. Popper 1902-1994 • Criticized inductivism and verifiability: • No number of cases of “A being B” can establish that “all A being B”. All such statements remain disprovable.
Principle of falsifiabillity • Scientific theory can never be accorded more than a provisional acceptance. • A theory holds until it is disproved. • Falsification, not verification is the appropriate object of the observational and experimental procedures of science. • Falsifiability is a necessary part of a scientific theory.
Popper’s hypothetico-deductive method • Enlargements of our temporary knowledge begins with the conversions of hunches or imaginative insights into hypotheses. • Then, once the conditions for falsification have been established by the application of deductive logic, such hypotheses must be tested through sustained search for negative instances.
Assignment • Try to give an examples of theories which are falsifiable and not falsifiable. • What would Popper say about a theory which is not falsifiable? • Are popperianism or/and logical positivism descriptive or normative theories of science? Argue for your answer. • What does this have to do with the problem of demarcation?
Post-Popperian theories • Both The logical positivists and popperians did not describe reality, they were creating norms about how they thought science should be practiced for the best ( most effective ) results. • Critics by • Thomas Kuhn, Imre Lakatos, Paul Feyerabend…
Thomas S. Kuhn (1922–96) • “Structure of the scientific revolution” (1962) • Paradigm theory • Prescience - normal science - crisis - revolution - new normal science - new crisis- revolution… • A theory based on study of history of science • Attempts to describe how science develops in reality
Kuhn's normal science • Grand theory as a paradigm • Praxis • community of scientists • social power-relations and structures in the scientific community • methodological school, exemplars • puzzling reality in terms of the grand theory by deduction • increasing anomalies lead to crisis
Paradigm shift • In crisis there will be ‘extraordinary science’ where there will be several competing theories • One theory will win because it will get the greatest number of supporters in the scientific community • ‘Paradigm shift is an ‘irrational’ process, such as accuracy, scope, simplicity, fruitfulness, and the ‘like’ of each paradigm
Kuhns wiew on scientific revolution • Not (unexpected) new results from research, rather a new perspective or interpretation of data.
Assignment • Exemplify the following concepts: • Paradigm • Normal-science • Exemplars • Anomalies • Paradigm in crisis • Extraordinary science • Paradigm shift • incommensurability
Imre Lakatos • ‘Criticism and the methodology of scientific research programs’ (1968 ) • Reacts to Kuhn’s views and claims that • there does exist an objective criteria where scientists can make a rational choice between two competing theories • it is due to dishonesty that some scientists do not give up their position
Lakatos’ scientific research programs • Research programs are series of theories which can be viewed in two ways • a. negative heuristic that statesa ‘untouchablehard core’ of hypothesis with a protective belt around it, protecting it from falsification • b. positive heuristic declaring that the core can be altered slightly in order to fit progression
Positive heuristic • is the good one from Lakatos point of view • The development from Copernicus to Newton is his good example • Negative heuristic is the less good one • Tyco Brahes geocentric theory is Lakatos example here
The Lakatos view ? • He revised the Popperian view after Kuhn • If the Popperian view had been practiced through history none of the progressive theories would have survived • He wanted to save the sciences from Kuhn's irrational grounds
Anarchy • Paul Feyerabend • No single correct method in science • Anything that works is fine • = epistemological anarchy
Social construction of science • “laboratory life” is disorganized • Scientific logic vs. availability of equipment, funds, careers etc.