A philosopher argues: 'Quantum electrodynamics predicts the magnetic moment of the electron to eleven decimal places. The best explanation for this stunning accuracy is that QED's theoretical entities — electrons, photons, quantum fields — actually exist and the theory approximately tracks truth about them.' Which philosophical position does this argument articulate, and what is it called?
AAnti-realism; this is the pessimistic meta-induction, arguing from past success to present skepticism
BScientific realism; this is the no-miracles argument, concluding that approximate truth is the best explanation of predictive success
CInstrumentalism; this argument treats theoretical accuracy as confirmation that the mathematical tools are useful calculational devices
DConstructive empiricism; this is an inference from empirical adequacy to truth
This is the no-miracles argument for scientific realism, associated with Hilary Putnam. The argument structure is inference to the best explanation: predictive success would be a cosmic miracle if our best theories were not approximately tracking truth about the world, including unobservable entities. Instrumentalism (option 2) would stop at 'the tools are useful' without committing to truth; constructive empiricism (option 3) would stop at 'the theory is empirically adequate' without inferring that unobservables exist. Scientific realism takes the further step of claiming the theory describes what is actually there.
Question 2 Multiple Choice
Which of the following best describes the central premise of Larry Laudan's 'pessimistic meta-induction' against scientific realism?
AScience does not make accurate enough predictions to warrant belief in its theoretical entities
BMultiple incompatible theories can always fit the same body of evidence, so no theory can be uniquely confirmed
CThe history of science is full of theories that were empirically successful but have since been abandoned as false — so current success is no guarantee of truth
DTheoretical entities like electrons cannot be directly observed and therefore should not be considered real
Laudan's pessimistic meta-induction is a historical argument: phlogiston theory explained combustion, caloric theory explained heat flow, the luminiferous ether was used to predict light properties — all were empirically successful and later abandoned. The inductive step is: if past successful theories were false, we have good inductive reason to expect current successful theories will also turn out to be false. This directly undercuts the no-miracles argument because it shows that empirical success is consistent with falsity. The realist's typical response is to distinguish which parts of past theories were doing the predictive work (often preserved in successor theories) versus which posits were abandoned.
Question 3 True / False
The no-miracles argument for scientific realism is a form of inference to the best explanation: it concludes that approximate truth is the most plausible explanation for why scientific theories make such accurate predictions.
TTrue
FFalse
Answer: True
Yes — the no-miracles argument explicitly uses the same inferential pattern that scientists use within their theories. Just as a scientist infers the existence of a virus from its effects, the realist infers that theories are approximately true from their predictive success. The argument is meta-level: it applies inference to the best explanation not to data about the world but to the fact of scientific success itself. Critics note that this circularity — using a scientific inferential method to justify trust in science — may beg the question, but the argument is widely regarded as the strongest positive case for realism.
Question 4 True / False
Scientific realists hold that mainly observable entities are real; theoretical entities like electrons, quarks, and quantum fields are useful fictions that help organize our observations.
TTrue
FFalse
Answer: False
This describes anti-realism — specifically, positions like instrumentalism or van Fraassen's constructive empiricism. Scientific realism is precisely the opposite view: it holds that unobservable theoretical entities posited by successful theories are real features of the world, not merely calculational conveniences. The central commitment of realism is that science aims at truth about unobservables as well as observables, and that successful theories approximately achieve it. The realist takes the electron to be as real as the chair you sit on.
Question 5 Short Answer
What is the pessimistic meta-induction, and why does it challenge scientific realism specifically — rather than simply undermining confidence in all scientific results?
Think about your answer, then reveal below.
Model answer: The pessimistic meta-induction (Laudan) is the argument that because past successful scientific theories — phlogiston, caloric, the luminiferous ether — were empirically successful yet ultimately abandoned as false, we should by induction expect our currently successful theories to also turn out to be false. It challenges realism specifically because realism tries to infer truth from success: if success is compatible with falsity (as history demonstrates), then success alone cannot license the conclusion that current theories are approximately true. It does not undermine all scientific results because empirical adequacy — the ability to make accurate predictions — is a weaker claim than truth, and even false theories can be empirically adequate within a domain.
The key is the asymmetry between empirical success and theoretical truth. Anti-realists (like constructive empiricists) aim only for empirical adequacy and are therefore not threatened by the pessimistic induction — they never claimed past theories were true. Realists, who go further and claim approximate truth, bear the full force of Laudan's historical challenge. The realist's best response is typically to argue that the parts of past theories that did the genuine predictive work were often retained (e.g., the mathematics of classical mechanics within relativistic mechanics), suggesting continuity in what is truth-tracking.