This paper is obsolete. It is superseded by the book, Conditionals in Context, MIT Press, 2005.

I will discuss those epistemic accounts of truth that say, roughly and at least, that the truth is what all ideally rational people, with maximum evidence, would in the long run come to believe. They have been defended on the grounds that they can solve sceptical problems that traditional accounts cannot surmount, and that they explain the value of truth in ways that traditional (and particularly, minimal) accounts cannot; they have been attacked on the grounds that they collapse into idealism. (...) I show that all these claims are mistaken. The system of statements accepted by an adherent of an epistemic account who also accepts the equivalence scheme is the same as that accepted by an adherent of a traditional account who also accepts a remarkably strong thesis of epistemic optimism. The singling out of one rather than another claim within this system as defining 'true' cannot make as much difference as to imply idealism or refute scepticism. However, it can make all the difference when it is a matter of explaining the value of truth. For a crucial point in such explanation depends on what can be soundly substituted for what in intensional contexts; above all those governed by such verbs as 'know', 'hope', 'believe', 'value'. That is, it depends on what expressions are intensionally equivalent. And one point of singling out one formulation as definitional can be to settle just this. But though some epistemic theorists have deemed ability to explain the value of truth a merit of their account (and lack of this ability a fatal defect of traditional accounts, of minimal accounts in particular), it turns out that minimal accounts of 'true' fit a sound account of our valuing of truth in a way that epistemic accounts do not. In the course of this argument I rebut related positions: e.g. Dummett's, that minimal definitions fail because they cannot account for the point of having a notion of truth, and that an account of the practice of assertion is what would fill this lacuna. I argue to the contrary that if the point of the notion could not be explained on the basis of a traditional definition, it could not be explained at all. (shrink)

The realist programme has degenerated by now to the point where it is quite beyond salvage. A token of this degeneration is that there are altogether too many realisms. It is as though by splitting into a confusing array of types and kinds, realism has hoped that some one variety might yet escape extinct. I shall survey the debate, and some of these realisms, below. Here I would just point out the obvious; that in so far as the successes of (...) science mount while realism continues to decline we must conclude that scientific success lends no support to realism. Since it is unlikely to support anti-realism, we have some reason to suspect that the philosophical debate over realism does not concern issues that can be settled by developments in the sciences, no matter how successful science may be. Further, since that success grounds a culture of acceptance for science and its entities, we have reason to believe that the existence of those entities is also not actually the issue that concerns realism. Afortiori, it is not the issue that concerns anti-realism either; nor, I might add, is anti-realism the winner in the philosophical debate that realism has lost. (shrink)

I argue in this paper that anyone who accepts the ontology of scientific realism can only accept a pragmatic theory of truth, i.e., a theory on which truth is what it is epistemically right to believe. But the combination of realism with such a theory of truth is a form of internal realism; therefore, a scientific realist should be an internal realist. The strategy of the paper is to argue that there is no adequate semantic or correspondence theory of truth (...) compatible with a realist ontology, that a redundancy theory cannot account for the value of truth, and that the only kind of truth theory which can account for the value of truth, and is compatible with a realist ontology, is a pragmatic theory. The kind of truth theory I wish to defend is objective and naturalistic, and the ontology is realistic. My position is, therefore, one of objective, naturalistic realism. (shrink)

ABSTRACTIan Hacking puts forward a distinction between two kinds of scientific realism. According to scientific realism about theories, scientific theories are accepted as approximately true; according to scientific realism about unobservable entities, the theoretical terms occurring in scientific theories refer to existing, real entities. This article seeks to show that Claude Bernard's philosophy of science is a realist one about scientific theories, but anti-realist about unobservable entities. The term “fictionalism” is used here to stand for this sort of anti-realism about (...) unobservable entities. (shrink)

This paper explores early Australasian philosophy in some detail. Two approaches have dominated Western philosophy in Australia: idealism and materialism. Idealism was prevalent between the 1880s and the 1930s, but dissipated thereafter. Idealism in Australia often reflected Kantian themes, but it also reflected the revival of interest in Hegel through the work of ‘absolute idealists’ such as T. H. Green, F. H. Bradley, and Henry Jones. A number of the early New Zealand philosophers were also educated in the idealist tradition (...) and were influential in their communities, but produced relatively little. In Australia, materialism gained prominence through the work of John Anderson, who arrived in Australia in 1927, and continues to be influential. John Anderson had been a student of Henry Jones, who might therefore be said to have influenced both main strands of Australian philosophical thought. (shrink)

In this comprehensive work on theories of rationality, Leslie Allan builds on the seminal insights of Imre Lakatos. Allan begins by critically reviewing Lakatos' theory of rationality (MSRP) and his meta-theory of rationality (MHRP) and suggesting improvements to his scheme. Allan's main task is developing a theory of rationality that avoids Lakatos' Achilles' heel; the presupposition that science is a rational enterprise. To achieve this, he attempts to draw out from the general demands of an objectivist epistemology the various criteria (...) of dependence and independence applying to evidence-statements. He concludes by considering two serious objections to his framework. (shrink)

This is a position paper concerning the role of empirical studies of human default reasoning in the formalization of AI theories of default reasoning. We note that AI motivates its theoretical enterprise by reference to human skill at default reasoning, but that the actual research does not make any use of this sort of information and instead relies on intuitions of individual investigators. We discuss two reasons theorists might not consider human performance relevant to formalizing default reasoning: (a) that intuitions (...) are sufficient to describe a model, and (b) that human performance in this arena is irrelevant to a competence model of the phenomenon. We provide arguments against both these reasons. We then bring forward three further considerations against the use of intuitions in this arena: (a) it leads to an unawareness of predicate ambiguity, (b) it presumes an understanding of ordinary language statements of typicality, and (c) it is similar to discredited views in other fields. We advocate empirical investigation of the range of human phenomena that intuitively embody default reasoning. Gathering such information would provide data with which to generate formal default theories and against which to test the claims of proposed theories. Our position is that such data are the very phenomena that default theories are supposed to explain. (shrink)

This is a defense of the doctrine of scientific realism. SR is defined through the following two claims: Most essential unobservables posited by the well-established current scientific theories exist independently of our minds. We know our well-established scientific theories to be approximately true. I first offer positive argumentation for SR. I begin with the so-called 'success arguments' for SR: 1) scientific theories most of the times entail successful predictions; 2) science is methodologically successful in generating empirically successful theories. SR explains (...) these facts via inference to the best explanation. I combine Hacking's experimental argument for entity realism with Salmon's common-cause principle. I take entity realism to be foundational to SR: one may believe in the existence of some theoretical entities without believing in any particular theory in which these are embedded. Its motivation comes from experimental practice, where the manipulation of these entities often relies on incompatible theoretical accounts. The underdetermination topic is thereafter discussed. Several attempts to distinguish between an observable and an unobservable realm are critically discussed, as well as the possibility that for any given theory, there are empirically equivalents generated by means of algorithms. I present extensive argumentation to the effect that such algorithmic rivals are not to be taken seriously. Social constructivism is being critically treated. I proceed by distinguishing between a metaphysical, a semantic, and an epistemic variant of SC. I conclude that only a moderate metaphysical constructivism can stand on its own feet. Its claim is merely that some facts about the world are socially constructed. I finish with a plea for a selective SR, able to do justice to the presence of both instrumentalism and modest constructivism in scientific practice. (shrink)

First, ranking functions are argued to be superior to AGM belief revision theory in two crucial respects. Second, it is shown how ranking functions are uniquely reflected in iterated belief change. More precisely, conditions on threefold contractions are specified which suffice for representing contractions by a ranking function uniquely up to multiplication by a positive integer. Thus, an important advantage AGM theory seemed to have over ranking functions proves to be spurious.

Imre Lakatos holds a well-deserved primary place in current philosophy of science. In this essay, Leslie Allan critically examines Lakatos' theory of knowledge in two key areas. The first area of consideration is Lakatos' notion that knowledge is gained through a process of competition between rival scientific research programmes. Allan identifies and discusses four problems with Lakatos' characterization of a research programme. Next, Allan considers Lakatos' proposed test of adequacy for theories of rationality using his methodology of historiographical research programmes. (...) Allan discovers tensions within Lakatos' criteria and suggests ways of strengthening his test. (shrink)

The author challenges both the eliminative idealist's contention that physical objects do not exist and the phenomenalist idealist's view that statements about physical objects are translatable into statements about private mental experiences. Firstly, he details how phenomenalist translations are parasitic on the realist assumption that physical objects exist independently of experience. Secondly, the author confronts eliminative idealism head on by exposing its heuristic sterility in contrast with realism's predictive success.

Drawing on insights from Imre Lakatos' seminal work on theories of rationality, Leslie Allan develops seven criteria for rational theory choice that avoid presuming the rationality of the scientific enterprise. He shows how his axioms of rationality follow from the general demands of an objectivist epistemology. Allan concludes by considering two weighty objections to his framework.