Some Optimism for the Pessimist

Abstract

Robert Nola (this volume) presents a detailed case study of the history of the scientific investigation of the electron, and develops a strong argument for the referential continuity of the term “electron”, in the face of a history of significant change in our favoured theories about electrons. Nola argues that we can reliably induce that future scientific theories will continue to refer to many of the same entities in the world, such as the electrons that we have discovered, even if these theories differ significantly from our current theories. This is his optimistic meta-induction (hereafter OMI). Nola’s OMI is directed against proponents of the pessimistic meta-induction (hereafter PMI), such as Laudan (1981) and (particularly) Putnam (1978, pp. 24–25) who stress the number of theoretical entities, such as phlogiston, that have failed to survive the test of time and who dispute the referential continuity of apparently referentially stable theoretical terms such as “electron”, in the face of significant change in our favoured scientific theories. The PMI is one of the most potent weapons in the intellectual arsenal of opponents of scientific realism (Stanford, 2003). Scientific realists hold that the theories that mainstream contemporary scientists advocate are true or approximately true, and that the theoretical entities that are postulated in contemporary scientific theories – quarks, electrons, genes and so on – exist. Because the scientific realist is committed to the view that contemporary scientific theories are true or approximately true, the scientific realist is also committed to the view that past scientific theories that are distinct from contemporary scientific theories are false, and that the entities postulated in such theories do not exist. Because the scientific realist asks us to believe that contemporary chemical theory is true or approximately true and that oxygen exists, she is committed to the view that distinctly different past chemical theories, which once were dominant, such as Lavoisier’s phlogiston theory, are false and that there is no such entity as phlogiston. A scientific realist of Lavoisier’s day would have been committed to the view that phlogiston theory is true, or approximately true, and that phlogiston exists. Thinking about the standpoint of a scientific realist of the past prompts the question posed to the contemporary scientific realist by Putnam: “ how do you know you aren’t in error