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 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 states a ‘untouchable hard 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.