Varieties of Unconventional Scientific Realisms

Abstract

Of the many notable scientific realist positions on offer today few provide penetrating insights which promise to transform the very debate. This thesis provides a critical exposition of three positions that I argue do work to transform the debate. I label these ‘unconventional’ scientific realisms as they go against the more conventional understanding of scientific realism. These are:
- Hilary Putnam’s Common Sense Realism
- Nancy Cartwright’s Modelling-based Realism
- Hasok Chang’s Pragmatic Realism
Common sense realism is the last of Putnam’s positions on realism but it is also the least studied and most underappreciated compared to his former positions. It includes a component on direct realism in perception, convergent scientific realism and a form of metaphysical realism. It presents the later Putnam as a metaphysical realist who is keen to reject deflationist accounts of scientific realism and to bring realism back to the common man.
Modelling-based Realism rejects common readings of Cartwright as instrumentalist or as entity realist, by showing that underlying her diverse views on realism is a robust unified position which does not fit within the usual theory-based framework. Modelling-based Realism is a form of model-based particularism that denies that theories and laws express claims and treats them instead as principles that are short-hand labels for powers and our practices for using them. It accepts as representative, when successful, local system-specific models and is committed to theoretical entities which powers are properties of.
Pragmatic Realism, for Chang, aims to reorient the realism debate away from truth and towards practice. It does that by replacing the common proposition-based framework by an action-based alternative. It does away with truth as correspondence for what Chang calls ‘operational coherence’. It ultimately accepts a pragmatic theory of truth and reality, whereby a claim is considered true and an entity real if taking them as such is pragmatically necessary to carry out a coherent and successful epistemic activity.
All three positions highlight different places where the scientific realism debate in its current form is defective, such as failing to appreciate the proper place of scientific realism within metaphysical realism thus positing an illusory conflict between science and common sense, committing to theories despite them not being the proper loci of scientific success, and overlooking the crucial role of practice in arguing from success to truth. Each of these three philosophers suggests ways to overcome these different defects. I argue that their three proposals are all compatible. I conclude by providing some groundwork for a scientific realist position that integrates their diverse insights into a synthetic whole.