Theoretical Relicts: Progress, Reduction, and Autonomy

Citation

Robertson K & Wilson A (2023) Theoretical Relicts: Progress, Reduction, and Autonomy. The British Journal for the Philosophy of Science. https://doi.org/10.1086/724445

Abstract
When once-successful physical theories are abandoned, common wisdom has it that their char-acteristic theoretical entities are abandoned with them: examples include phlogiston, light rays, Newtonian forces, Euclidean space. But sometimes a theory sees ongoing use, despite being su-perseded. What should scientific realists say about the characteristic entities of the theories in such cases? The standard answer is that these ‘theoretical relicts’ are merely useful fictions. In this paper we offer a different answer. We start by distinguishing horizontal reduction (in which a superseded theory approximates the successor theory) from vertical reduction (in which a higher-level theory abstracts away from the lower-level theory, but nonetheless can be con-structed from it); these are usually regarded as having different ontological consequences. We describe a ‘verticalization’ procedure that transforms horizontal reductions into vertical reduc-tions. The resulting verticalized theories are abstractions rather than approximations, with re-stricted domains. We identify a sense in which the higher-level theory describes distinct subjectmatters from the lower-level theory, enabling in certain cases the higher-level theory to retain distinctive explanatory power even in the presence of reduction. We suggest that theoretical en-tities from superseded theories should be retained in a scientific realist worldview just when, reinterpreted as higher-level abstractions, those theories and their characteristic entities continue to perform distinctive explanatory work in providing the best explanation for less fundamental phenomena of interest. In slogan form: a good relict is an emergent relict

Keywords
History and Philosophy of Science; Philosophy; History

Journal
The British Journal for the Philosophy of Science