Theories as Families of Models

The alternative to the ‘Syntactic Approach’ is the Semantic Approach, according to which theories should be characterized in terms of families of models. The issue of the linguistic independence of this framework is discussed and it is suggested that this approach offers a ‘toolbox’ of resources that can be deployed to capture various features of scientific practice. One such tool is the notion of a ‘partial structure’ by which such models can be formally presented, together with the associated device of partial isomorphisms, as deployed elsewhere. A recent critique of this approach is also discussed in some detail and it is argued that this critique assumes that theories are things with well-defined identity conditions, which is precisely the claim that is denied here. The chapter concludes by noting van Fraassen’s point that the critique also ignores the representational function of these models, which leads into Chapter 3.

Theories as Sets of Propositions

In this chapter, the so-called ‘Syntactic Approach’ is outlined that takes theories to be sets of propositions. This account has come under fire for its perceived inadequacy in capturing various aspects of scientific practice. However, recent developments in this approach have indicated how it may have the resources to accommodate these features. These developments are presented and the nature of propositions themselves explored, as abstract entities and fictions. The former raises obvious concerns about ontological inflation, whereas the latter requires changes in how we talk about the practices of scientists. A more economical view is offered by eliminativism and thus this chapter lays the groundwork for discussion of these issues in the rest of the book.

Theories in the Realism Debate

If there are no theories, how can they be said to represent anything? And how can one be a realist or antirealist about them? In this final chapter the notion of ‘practice’ is extended to cover philosophical practices in order to answer these questions. Furthermore, returning to the topics of Chapters 1 and 2, we should understand the Syntactic and Semantic Approaches and the accounts of representation based on them, as meta-representational devices that allow us to capture those features of practices that we are interested in. This offers the possibility of a suitably reflective philosophy of science that is better adapted to accommodate the hetereogeneous and multi-faceted nature of science itself.

Theories in History and Practice

This eliminativist view must immediately face the concern that scientists themselves appear to be committed to the existence of theories. They talk about them, apparently refer to them, argue that they are equivalent or not and so forth. However, here it is shown that when it comes to classical and quantum mechanics, as well as quantum field theory—to give just three examples—what is meant by the theory is hugely contested. Indeed, this meaning is typically constructed retrospectively and promulgated by various means, such as through the use of certain textbooks, for example. Likewise it is contentious whether two putative formulations of the ‘same’ theory should be regarded as equivalent or not and again the role of interpretive practices comes to the fore.

Theories as Fictions

An alternative and well-known option when it comes to the ontological status of theories is to understand them as fictions. Here again there is ‘trading’ between the philosophy of art and the philosophy of science as Walton’s account of fiction in terms of ‘make-believe’ is typically deployed in this regard. As before, the role of the imagination is crucial and in this case the issue of accommodating the heuristic processes involved can be more straightforwardly dealt with than in the case of theories conceived of as ‘abstract artefacts’. Nevertheless, it is not clear that this view of theories as fictions can embrace all the different kinds of models and theories deployed in science and it too incurs certain costs. Despite its attractive features, then, and given that an even less costly account is available, this view should also be rejected.

Theories as Abstract Artefacts

An alternative way of resolving the dilemma is to regard both artworks and theories as ‘abstract artefacts’ in some sense. The work of both Popper and Thomasson is drawn upon to help articulate this view and again comparisons are made between theories and artworks, particularly literary works. One obstacle to the extension of this view into science is that theories appear to be multiply discoverable and modally flexible in ways that artworks are not. However, on closer examination it appears that this barrier is not as significant as might be thought. Nevertheless, the ‘abstract artefacts’ view runs into serious problems in accommodating the heuristic moves underlying scientific ‘discovery’.

Theories as Abstract Entities

In this chapter a well-known dilemma is presented for musical works, involving their purported abstract nature and creativity. A similar dilemma is presented for scientific theories and various ways of resolving both dilemmas are canvassed. One is to take artworks and theories to be abstract and understand the creative act in terms of the author’s situation in some abstract space. Another is to insist that both are imaginary things and that appreciation of either involves intelligent reconstruction. Such views not only involve ontological proliferation but also fail to accommodate the heuristic processes involved.

Theories Eliminated!

Finally, a way forward through all these debates and dilemmas is suggested which involves adopting a form of eliminativism previously applied to musical works and deploying it in the philosophy of science. This eliminates theories as things but allows us to continue to talk about them and about their scientific and aesthetic qualities by adopting a form of ‘truth-maker’ theory, according to which that talk is made true by the relevant scientific practices. This shifts the philosophical focus to where it should be, namely on those practices but it is important to recognise that this does not amount to the claim that theories are constituted by such practices. According to the view motivated and defended here, there are no theories!

Theories as Representations

The nature of scientific representation has been the subject of considerable discussion recently with frequent comparisons made between theories and depictive artworks. Here it is argued that the Semantic Approach can be understood as a useful means of capturing this representational relationship, in both the scientific and artistic domains. In particular, by deploying the device of partial structures it can capture the manner in which apparently inconsistent theories and pictures can represent, as well as that of certain abstract artworks. Nevertheless, care must be taken in drawing on examples from one domain to support or undermine arguments made about the nature of representation in the other. The comparisons involved highlight crucial differences between theories and artworks that will be drawn upon in subsequent chapters.