Imre Lakatos (1922 - 1974) ` All scientific theories are equally un-provable Falsification doesn’t work due to rescue hypotheses the "basic unit" of scientific development is not the scientific theory, such that science progresses when one theory proves to be more successful than another.

Imre Lakatos the "basic unit" is actually the research program. Science progresses when one research program becomes more productive and more useful than other and, hence, receives a greater share of social resources through funding and younger scientists looking to join. A research program is characterized by a particular set of "hard core" fundamental ideas and is deemed successful so long as it contents continue to increase.

Imre Lakatos In reality scientists do not abandon theories. They invent rescue hypotheses or ignore anomalies or refutations Popperian crucial experiments and Kuhnian revolutions turn out to be myths. What happens is progressive research replaces degenerating ones. Progressive scientific programs predict and produce dramatic, unexpected observations and results

Falsificationism Popper Science progresses toward its goal of increasing verisimilitude by advancing bold conjectures and then attempting to refute these by observations Theories cannot be verified by observation —anti-inductivism —no theory/observation distinction Theories are falsified by basic statements We choose between theories on grounds of corroboration (mark of verisimilitude)

Falsificationism Problems for Falsificationism (recap) Falsification: Some legitimate features of scientific enterprise are not falsifiable: Probabilistic Statements Existential Statements Metaphysical Commitments

Falsificationism (finale) Problems for Falsificationism 3. Basic Statements: Theories are falsified by basic statements. What warrants our acceptance of basic statements? (i) Observation?: No. Basic statements are theory laden. Accepting them requires accepting theory (ii) Decision/convention: not grounded in a rational procedure

Falsificationism (finale) ‘Whiff of Inductivism’ A Dilemma for Popper: Give up on induction —No rational criterion for choosing between competing theories —No rational grounds for continuing to use successful theories Give up the distinctive features of falsificationism

Falsificationism (finale) Problems for Falsificationism 3. Basic Statements: Theories are falsified by basic statements. What warrants our acceptance of basic statements? (i) Observation?: No. Basic statements are theory laden. Accepting them requires accepting theory (ii) Decision/convention: not grounded in a rational procedure

Scientific Research Programmes Revision versus Ad hoc Hypotheses Two questions In the light of anomalies: What should one change? Principle of least change (ii) When should one abandon a theory(in favour of another)?

Scientific Research Programmes Scientific Research Programmes (SRP) A theory is: Rules of logic and mathematics Metaphysical commitments Statements of laws Assumptions about initial conditions A SRP is a lineage of theories. SRP evolve over time Rules according to which SRP’s evolve over time.

Scientific Research Programmes Scientific Research Programmes (SRP) Parts of a SRP: Hard Core: Theoretical assertions Metaphysical commitments HC Auxiliary Belt: Initial conditions Assumptions Ad hoc hypotheses AB

Scientific Research Programmes Scientific Research Programmes (SRP) Parts of a SRP: e.g. Celestial Mechanics Hard Core: Laws of Motion Universal Gravitation Space and time HC Auxiliary Belt: Number of planets Masses of planets AB