Howard Sankey

This paper considers the relevance of the Duhem-Quine thesis in economics. In the introductory discussion which follows, the meaning of the thesis and a brief history of its development are detailed. The purpose of the paper is to discuss the effects of the thesis in four specific and diverse theories in economics, and to illustrate the dependence of testing the theories on a set of auxiliary hypotheses. A general taxonomy of auxiliary hypotheses is provided to demonstrate the confounding of auxiliary hypotheses with the testing of economic theory.

The paper takes off from the suggestion of Jouni-Matti Kuukkanen that Kuhn’s account of science may be understood in coherentist terms. There are coherentist themes in Kuhn’s philosophy of science. But one crucial element is lacking. Kuhn does not deny the existence of basic beliefs which have a non-doxastic source of justification. Nor does he assert that epistemic justification only derives from inferential relationships between non-basic beliefs. Despite this, the coherentist interpretation is promising and I develop it further in this paper. I raise the question of whether Kuhn’s account of science can deal with the input objection to coherentism. I argue that the role played by problems in Kuhn’s theory of science ensures that there is input from the external world into scientists’ belief-systems. I follow Hoyningen-Huene in pointing to the causal role played by the external world in determining perceptual states. I next turn to the question of whether Kuhn’s rejection of foundationalism implies coherentism. I argue that Kuhn’s rejection of the one-to-one relation between object and experience is compatible with a foundationalist account of justification. Nor does Kuhn’s rejection of the given entail the same coherentist implications as Sellars’ critique of the myth of the given.

Relativism in the philosophy of science is widely associated with the work of Thomas Kuhn and Paul Feyerabend. Kuhn and Feyerabend espoused views about conceptual change and variation of scientific method that have apparent relativistic implications. Both held that scientific theories or paradigms may be incommensurable due to semantic variation. Two ways that truth may be relative because of semantic incommensurability will be distinguished. Davidson’s criticism of the idea of an untranslatable language will be discussed, as well as a response to incommensurability based on the causal theory of reference of Kripke and Putnam. A form of relativism with respect to epistemic rationality may also be derived from the claims of Kuhn and Feyerabend about methodological variation. Kuhn’s initial suggestions about paradigm-dependent standards and absence of extra-paradigmatic standards give rise to a view on which rationality is relative to paradigm. Kuhn’s later view that there is a stable set of shared scientific values is less prone to relativistic interpretation. Feyerabend’s claim that “anything goes” suggests an extreme form of relativism, but should be understood instead as the view that all rules of method may be violated in some circumstances. The latter brings Feyerabend’s view into line with Kuhn’s later view.

It is argued that to believe is to believe true. That is, when one believes a proposition one thereby believes the proposition to be true. This is a point about what it is to believe rather than about the aim of belief or the standard of correctness for belief. The point that to believe is to believe true appears to be an analytic truth about the concept of belief. It also appears to be essential to the state of belief that to believe is to believe true. This is not just a contingent fact about our ordinary psychology, since even a non-ordinary believer must believe a proposition that they believe to be true. Nor is the idea that one may accept a theory as empirically adequate rather than as true a counter-example, since such acceptance combines belief in the truth of the observational claims of a theory with suspension of belief with respect to the non-observational claims of a theory. Nor is the fact that to believe is to believe true to be explained in terms of an inference governed by the T-scheme from the belief that P to the belief that P is true, since there is no inference from the former to the latter. To believe that P just is to believe that P is true.

This is a sequel to my paper, ‘What is Scientific Realism?’, which appeared in an earlier issue of this journal (Sankey, 2000a). A number of papers by other authors on topics relating to scientific realism have followed in subsequent issues. In this paper I revisit some of the themes developed in my earlier paper in the light of these later papers. I begin by restating the key ideas of the earlier paper. Next, I mention a number of afterthoughts which I have had since the appearance of the paper. I then offer some comments on three of these subsequent papers. I hope these comments advance the discussion by clarifying and developing a number of key points.

The paper explores the relativistic implications of the thesis of incommensurability. A semantic form of incommensurability due to semantic variation between theories is distinguished from a methodological form due to variation in methodological standards between theories. Two responses to the thesis of semantic incommensurability are dealt with: the first challenges the idea of untranslatability to which semantic incommensurability gives rise; the second holds that relations of referential continuity eliminate semantic incommensurability. It is then argued that methodological incommensurability poses little risk to the rationality or objectivity of science. For rational theory choice need neither be dictated by an algorithm nor governed by a binding set of rules. The upshot of the discussion is deflationary. There is little prospect for a relativistic conception of science based on inflated claims about the incommensurability of scientific theories.

Does science provide knowledge of reality? In this paper, I offer a positive response to this question. I reject the anti-realist claim that we are unable to acquire knowledge of reality in favour of the realist view that science yields knowledge of the external world. But what world is that? Some argue that science leads to the overthrow of our commonsense view of the world. Common sense is “stone-age metaphysics” to be rejected as the false theory of our primitive ancestors. Against such eliminativists about common sense, I argue that science both preserves and explains commonsense experience of the world. Though science may lead to the overthrow of deeply held beliefs, common sense reflects a more basic and durable level of experience. Commonsense beliefs are well-confirmed beliefs which are vindicated by their role in successful practical action each and every day. Common sense provides a firm basis on which to establish the realist approach to science.

As is well known, Putnam changed his philosophical position on a number of occasions throughout his career. In this paper, I reconsider the position of internal realism which Putnam defended from the mid-1970’s until around 1990. The paper opens with a discussion of the position that Putnam called “metaphysical realism”, since his internal realism emerged out of a critique of that position. The paper then briefly presents the internal realist view as one which involves an epistemic conception of truth, as well as an anti-realist metaphysical outlook on which objects depend on conceptual scheme. The paper then provides a survey of the key objections to internal realism which emerged in the ensuing debate with defenders of realism. The paper concludes with a brief consideration of the relevance of Putnam’s later adoption of a direct realist theory of perception with respect to the issue of realism.

In ‘Induction and Natural Kinds’, I proposed a solution to the problem of induction according to which our use of inductive inference is reliable because it is grounded in the natural kind structure of the world. When we infer that unobserved members of a kind will have the same properties as observed members of the kind, we are right because all members of the kind possess the same essential properties. The claim that the existence of natural kinds is what grounds reliable use of induction is based on an inference to the best explanation of the success of our inductive practices. As such, the argument for the existence of natural kinds employs a form of ampliative inference. But induction is likewise a form of ampliative inference. Given both of these facts, my account of the reliability of induction is subject to the objection that it provides a circular justification of induction, since it employs an ampliative inference to justify an ampliative inference. In this paper, I respond to the objection of circularity by arguing that what justifies induction is not the inference to the best explanation of its reliability. The ground of induction is the natural kinds themselves.