Past exam of the philosophy of science supplementary subject of the University of Oxford / 2017 / 3

Karl Popper's falsificationism treats theories as conjectures to be exposed to serious attempted refutation. A universal claim entails observable restrictions and can conflict with a counterexample, whereas a finite collection of favourable cases does not deductively establish the universal. This emphasizes risky tests and distinguishes surviving criticism from proof. It also avoids pretending that the problem of induction is solved merely by collecting more confirming observations.^[ref]

The main difficulty is moving from this logical asymmetry to a complete account of practice. A prediction usually has the form $(T\wedge A)\Rightarrow E$, where $A$ includes auxiliary hypotheses about apparatus, initial conditions and background physics. Observing $\neg E$ implies $\neg T\vee \neg A$, not specifically $\neg T$. This Duhem problem makes independent measurement calibration and discriminating follow-up experiments essential. An anomalous detector count can reveal a detector fault rather than a new fundamental interaction.

There are also statistical complications. Under a probability model, an unusual observation need not have zero probability; rejection at a chosen significance level is fallible. Repeated severe tests can rationally alter comparative confidence even though they do not prove a theory. A methodology that merely labels all surviving theories unrefuted misses this evidential differentiation.

Falsificationism is therefore valuable as a critical discipline, especially its opposition to adjustments that insulate a theory from every conceivable result. It is incomplete as a rule requiring immediate abandonment after any anomaly, or as a whole theory of warranted acceptance. The better reconstruction combines explicit possible failures, justified auxiliary hypotheses and comparison of competing explanations, while retaining fallibilism about the outcome.

The demarcation problem concerns what distinguishes science from pseudoscience, not merely what distinguishes true claims from false ones. Karl Popper's proposal is falsifiability: a scientific claim must exclude some possible observations, so that a test could in principle count against it. A theory that is compatible with every outcome gains no empirical credit simply by accommodating what occurred.^[ref]

This captures an important methodological defect of pseudoscience: treating every apparent counterexample as further support. But bare falsifiability is not sufficient for good science. A sharply testable lucky-number prediction can be unsupported and methodologically irresponsible. Nor does a mistaken testable theory cease to have been scientific when it is rejected. Scientific status and evidential success are different assessments.

Necessity is also more complicated than a literal one-observation refutation rule. Statistical theories permit rare outcomes, and an instrument-dependent prediction tests auxiliary hypotheses as well as the main theory. Some current research proposals have no feasible immediate test, yet belong to programmes trying to derive discriminating consequences. Their status should depend partly on whether that programme produces such tests, rather than on a permanent exemption from empirical accountability.

Thus falsifiability supplies an important constraint on empirical content but not an adequate stand-alone classification of every scientific activity. Reliable experiments, openness to criticism, comparative explanatory success and correction of failed predictions also matter. This does not make demarcation pointless: it explains why an assessment of a practice over time can be more informative than attaching a binary label to one sentence.