Questions: Popper's Falsificationism

Question 1

Astronomers observe that Uranus's orbit deviates from Newtonian predictions. A strict Popperian might argue Newton's theory is falsified; actual scientists instead predicted an unknown planet (Neptune). What philosophical tension does this example reveal?

• A. It shows that Newton's theory was not falsifiable, because it could always accommodate new observations
• B. It shows that the Duhem-Quine problem is real — theories are tested alongside auxiliary assumptions, so a failed prediction can be resolved by revising an auxiliary hypothesis rather than the core theory
• C. It shows that Popper's method was correct — scientists should have abandoned Newton after the first anomaly
• D. It shows that falsifiability is irrelevant to actual scientific practice and should be abandoned

Answer: (B)

The Neptune case is the classic illustration of the Duhem-Quine problem that Popper acknowledged but struggled to fully answer. Newton's theory predicts planetary orbits given initial conditions and assumed bodies — revising the auxiliary assumption (how many planets exist) rather than the core theory was scientifically legitimate. Popper's response was that scientists must commit in advance to which auxiliary assumptions are fixed; critics like Kuhn and Lakatos argued this was too simplistic as a description of actual science.

Question 2

A scientist conducts ten experiments, each confirming a theoretical prediction. Popper would say this makes the theory:

• A. Confirmed — repeated successful predictions raise the probability that the theory is true
• B. Verified — ten confirmations are sufficient to establish the theory as scientific fact
• C. Corroborated — the theory has survived ten attempts to falsify it, which is not the same as increasing its probability of truth
• D. Well-supported inductively — Popper accepted induction for well-tested theories

Answer: (C)

Popper explicitly rejected the concept of confirmation and replaced it with corroboration. A corroborated theory has survived attempts to falsify it — that is all we can say. It does not become more probably true with each successful test; Popper accepted Hume's argument that induction cannot logically justify universal claims. We hold corroborated theories provisionally as our best current conjectures, knowing they remain falsifiable.

Question 3

According to Popper, a scientific theory becomes more strongly confirmed — and thus more probably true — the more successful predictions it makes.

• T. True
• F. False

Answer: False

This is the core misconception about Popper. He rejected confirmation in favor of corroboration, and he accepted Hume's problem of induction as unanswerable. Surviving tests does not increase a theory's probability of truth — it only shows the theory has not yet been falsified. The theory remains a conjecture we provisionally accept, not a fact we have established. Popper's asymmetry runs in one direction only: falsification is logically decisive; confirmation is not.

Question 4

On Popper's account, an unfalsifiable claim such as 'most events have a cause' is necessarily false or meaningless.

• T. True
• F. False

Answer: False

Popper's demarcation criterion distinguishes scientific from non-scientific claims — not true from false, or meaningful from meaningless. An unfalsifiable claim may be true, profound, or philosophically important; it simply cannot be tested empirically in the way science requires. Popper was careful to say that metaphysical claims fall outside science without thereby dismissing them. His target was the pretense of scientific status, not the claim's truth or meaning.

Question 5

Why does Popper argue that logical asymmetry between verification and falsification makes falsifiability the right demarcation criterion for science?

Model answer: No finite number of confirming observations can logically entail a universal generalization — this is Hume's problem of induction, which Popper accepted as unanswerable. But a single counterexample can definitively refute a universal theory by modus tollens: if theory T implies observation O, and O is false, then T is false. Since falsification is logically decisive and verification is not, Popper proposed falsifiability — the existence of possible observations that would contradict the theory — as the mark of a genuinely empirical, scientific claim.

The key is the logical asymmetry: universal statements are asymmetric with respect to confirmation and refutation. 'All swans are white' cannot be proven true by any finite list of white swans, but it can be proven false by one black swan. Science should exploit this asymmetry by designing tests that could actually show the theory wrong, rather than searching for confirming instances — which can always be found for any sufficiently vague claim.