Scientific Realism, Structural Realism, and the Pessimistic Meta-Induction Argument

By appealing to the no-miracle argument (NM), scientific realists claim that the approximate truth of scientific theories and the existence of their postulated entities are the cause of the predictive and explanatory success of science. Antirealists, however, by appealing to the pessimistic meta-induction argument (PMI), claim that a lot of past predictively successful and yet false theories show that there is not any relationship between success of a theory and its truth. One of the most influential responses of realists to PMI is Structural Realism, proposed by John Worral. The aim of this thesis is to show that during theory-shift there has been a continuity at the structural or formal level, and the central terms of successive theories refer to the same entities (structures). In the first part of this paper NM and PMI will be explained. Then, a critical evaluation of structural realism is given in both epistemological and ontological versions. It will be shown that this thesis is unable to rebut PMI conclusively. The conclusion of this paper, however, is that PMI cannot work against structural realists’ thesis if they limit the domain of their claim to existential sentences of scientific theories, to what I call “Existential Realism.”