Falsifiability and the demarcation problem: is the criterion defensible against Quine-Duhem holism, Kuhn's paradigms, and Lakatos's research programs?

Karl Popper, answered from the texts and cited to the page.

The position in brief

A theory is scientific iff it is falsifiable — iff it forbids certain observable states of affairs and is therefore exposed to refutation by experience.12 Non-falsifiable claims (Marxism- as-prophecy in its strong form, Freudian psychoanalysis, Adlerian individual psychology, astrology) are pseudo-science not because they are false but because they are constructed so that no possible observation can refute them.

Refutation is deductive (modus tollens); corroboration is the provisional survival of severe tests; the demarcation criterion is logical, not sociological. Bold conjectures, severe tests, error-elimination — that is the method.345

Sources

  1. Every 'good' scientific theory is a prohibition: it forbids certain things to happen. The more a theory forbids, the better it is. 4. A theory which is not refutable by any conceivable event is nonscientific. Irrefutability is not a virtue of a theory (as people often think) but a vice. 5. Every genuine test of a theory is an attempt to falsify it, or to refute it.
    Conjectures and Refutations, pp. 37–38
  2. A theory may be refuted empirically or falsified, if there exist observation statements ("basic statements", "test statements") whose truth would refute the theory; that 4 See especially Book I: Section 6, text to note 1 and the phrase "finally decidable" occurring there, as well as the term "truth value" in the subsequent paragraph. 5 See Book I: Section 34, notes 4 and 5 as well as the text to these notes.
    The Two Fundamental Problems of the Theory of Knowledge, pp. xxxi–xxxii
  3. Marxism was once a scientific theory: it predicted that capitalism would lead to increasing misery and, through a more or less mild > 7.
    Replies to My Critics, p. 25
  4. ANTHONY TROLLOPE I WHEN I received the list of participants in this course and realized that I had been asked to speak to philosophical colleagues I thought, after some hesitation and consultation, that you would probably prefer me to speak about those problems which interest me most, and about those developments with which I am most intimately acquainted.
    Conjectures and Refutations, pp. 34–35
  5. Ever since then, it can be described only as non-science — as a metaphysical dream, if you like, married to a cruel reality. Psychoanalysis is a very different case. It is an interesting psychological metaphysics (and no doubt there is some truth in it, as there is so often in metaphysical ideas), but it never was a science.
    Popper Selections, pp. 128–129

Where the argument is made

  • The Logic of Scientific Discovery (1934/1959), especially Chapter 1 ('A Survey of Some Fundamental Problems') and Chapter 4 ('Falsifiability')
  • Conjectures and Refutations (1963), especially the title essay
  • Realism and the Aim of Science (Postscript I, 1983) on the methodological refinements
  • Replies to My Critics (Schilpp 1974) on the responses to Lakatos, Kuhn, Putnam

How the argument was received

The most-attacked Popper claim. Quine-Duhem holism (Quine 1951, Duhem 1906) shows that no individual hypothesis is falsified in isolation; auxiliary hypotheses can always be adjusted to save the central theory. Kuhn's paradigms (1962) reframe science as paradigm-bound problem-solving; revolutions are not refutations but gestalt-switches. Lakatos's research programs (1978) treat falsification as a sophisticated process at the level of programs (with hard cores and protective belts), not individual theories. Feyerabend's anything-goes treats methodology as repressive.