The following notes are based on the “Philosophy Bites” podcast in which Nigel Warburton interviews David Papineau of Kings College, London, on the meaning of scientific realism and scientific scepticism.
Scientific realism is the belief that unseen causes of seen (empirically testable) effects are just as real as those effects. It is similar to philosophical realism, which maintains that the world and reality is independent of our minds and mental constructs: in other words, truth corresponds to something in reality independent of the mind. Scientific and philosophical realism stand in opposition to scepticism and empiricism.
With the dawn of the Enlightenment period, speculation about causes at work in the universe were considered unverifiable, and hence to be consigned to the epistemological bin. Newton had taught that the universe followed a set of demonstrable laws. While there were consequences of his science—or at least questions raised by it—that could not be verified as such (as with the ontology of light or gravity), these were considered to be too speculative to be of concern to science.
However, the inability of science to answer all questions about the nature of the physical world lead to an increase in scepticism (one can see the influence of scepticism in Hume, Russell, Ayer and other philosophers we have examined).
Two sceptical positions that arose to challenge scientific realism were (1) underdetermination of evidence and (2) Pessimistic meta-induction.
The first position—that of underdetermination—holds that for every position, there at least two and sometimes many plausible theories to support the evidence (consider for example, the different theories about the nature of light or gravity). Consider scientific data that can be explained by more than one theory. Consider that these theories cannot be empirically verified. There seems to be no reason to accept one of these theories over another.
The pessimistic meta-induction claim holds that since our empirical knowledge is constantly subject to improvement, and that many scientific theories are proven wrong our outdated, we never have sufficient reason to believe that any one scientific theory is totally reliable.
Papineau regards both these challenges as answerable.
In the case of the underdetermination argument, theories do conflict and abound it is true, but they also get established and, as knowledge improves, solve objections. Just because there are many competing theories does not mean that they are all equal: the truth will out.
As for the pessimistic meta-induction argument: some scientific disciplines seem more prone to confusion than others, such as psychology which frequently is challenged and contradicted. However, there are also many scientific disciplines in which discoveries are well-established, as in chemistry and physics for example, which have excellent track records.