Quick questions on Realism and instrumentalism explained: H2 Knowledge and Inquiry

Scientific realism holds that our best, mature scientific theories are at least approximately true, and that the unobservable entities they posit genuinely exist. On this view, when physics talks about electrons, it is describing real things, not merely a convenient fiction; science aims at, and to a large extent achieves, true description of a mind-independent world, including its unobservable parts. Theories are to be believed, not just used.

The leading argument for realism is the no-miracles argument, an inference to the best explanation. Science is strikingly successful: it makes novel, precise predictions and underpins reliable technology. The best explanation of this success is that our theories are at least approximately true and their posited entities real; otherwise the success would be a miracle, an inexplicable cosmic coincidence. So we should believe our best theories are approximately true.

The leading argument against realism is the pessimistic meta-induction. The history of science is full of theories that were predictively successful in their day yet are now regarded as false, positing entities (such as caloric or the luminiferous ether) we no longer believe exist. If past successful theories turned out false, then by induction our current successful theories may also be false. So success is not a reliable sign of truth, which undercuts the no-miracles argument.

Two influential positions try to keep the best of both sides. Constructive empiricism accepts theories only as empirically adequate, saving the observable phenomena, while remaining agnostic about the truth of claims about unobservables; it argues that empirical adequacy, not truth, is enough to explain success. Structural realism holds that what we can know, and what survives theory change, is the structure or pattern of relations the world has, even if our beliefs about the nature of the underlying entities change; this answers the meta-induction by pointing out that mathematical structure often carries over across revolutions even when ontology does not.

Distinguish scientific realism from instrumentalism. [6 marks]

Explain the no-miracles argument for realism. [6 marks]

Explain how the pessimistic meta-induction challenges realism and how structural realism responds. [8 marks]