PHILOSOPHICAL APPLICATIONS OF SEMANTIC ANTI-REALISM Timothy A. Kenyon Department of Philosophy Submitted in partial fuifilment of the requirernents for the degree of Doctor of Philosophy Faculty of Graduate S tudies University of Western Ontario London, Ontario July 1998 O Timothy A. Kenyon 1998 National Liirary Bibliothèque nationale I*I of Canada du Canada Acquisitions and Acquisitions et Bibliographie SeMces seMces bibliographiques 395 Wellington Street 395. tue Wellington OrtawaûiU KiAW OtEawaON KiA ON4 Caneda Canada The author has granted a non- L'auteur a accordé une licence non exclusive licence aüowing the exclusive permettant à la National Library of Canada to Bibliothèque nationale du Canada de reproduce, loan, distniute or sell reproduire, prêter, distiriuer ou copies of this thesis in microform, vendre des copies de cette thèse sous paper or electronic formats. la forme de microfiche/nlm, de reproduction sur papier ou sur format électronique. The author retains ownership of the L'auteur conserve la propriété du copyright in this thesis. Neither the droit d'auteur qui protège cette thèse. thesis nor substantial extracts fkom it Ni la thèse ni des extraits substantiels may be printed or otherwise de celle-ci ne doivent être imprimés reproduced without the author's ou autrement reproduits sans son permission. autorisation. Abstract This dissertation comprises four papers (plus an introduction). each of which focuses on some aspect or application of the philosophical view known as sernantic anti- realism. developed mainly by Michael Dummett. According to this view. reaiity is essentially knowable; as a corollary of this, the notion of truth is to be understood in terms of the availability of evidence. Chapter One considers a proposal for an anti-realist truth predicate advanced by Crispin Wright. 1 examine and reject various objections to Wright's proposai. before raising an objection of my own. Chapter Two reviews a potential objection to Dumrnett's philosophy of language. finding it not so much incorrect as hamiess. Chapter Three sets the stage for a discussion of contemporary realisrn towards the states and properties of intentionai psychology, by way of critically evaluating John Searle's clairn to offer an alternative to contemporary theories of rnind. And the finai cbapter synthesizes much of the preceding matenal, as 1examine instrumentaiism towards the mind: the thesis according to which mental states are merely what we propose in a rough-and-ready predictive heuristic, and are not actual states or objects. 1 reject this view. but not for the reasons often given. 1 then sketch the outlines of a realist theory of the rnind that respects cenain widespread intuitions about the normativity of mental state ascription: semantic anti-realism serves as a general theory against which this theory of mind may be developed. Keywords: semantic anti-realism, Dummett, Wright, realism, reductionism, physicalism, token identity theory, Dennett, Searle, Quine. Acknowledgements Many people had a hand in making the following essays much better than they would othenvise have been. ln general they know who they are. and have my sincere gratitude expressed in notes to various chapten. A few people have been more deeply implicated in these matters; without the efforts and input of sorne of hem, these essays might well have gone unwritten dtogether. For many useful conversations and encouragement at the early stages of wnting. my colleague Jason Holt has my thanks. Robert Stainton read much of this material. and was unfailingly generous with helpfùl comments, as was Crispin Wright, whose influence ought to be clear in much of this work. Paul Markwick read virtually every word, and gave a great deal of perceptive and constructive commentary; his ability to see to the heart of matters on which he is (supposedly!) not a specialist is humbling indeed. It has been my enormous good fortune to have William Dernopoulos and Ausonio Marras as my dissertation advison, and I take this opportunity to record my deepest thanks to them. They have taught me by example nothing Iess than what it means to do philosophy in a worthwhile manner: I wiil be very pleased if I cm someday work to the standard -4usonio and Biil continue to set in their own research and teaching. This work is dedicated to Colleen with love. Table of Contents Page .. Certificate of examination 11 . Abstract 111 Acknowledgements i v Table of contents v 1 Introduction: Themes in Realism, Tmth, and Reduction 2 Truth. Knowability, Neutrality Xppendix: What is Wright's Anti-Deflationism Argument? 3 Non-Sentences and the Dependence Thesis of Word Meaning 4 Searle Rediscovers What Was Not Lost 5 Instrumentalism, Indeterminacy. and Realism B ibliography Vita Chapter One Introduction: Themes in Realism, Truth, and Reduction What is the ultimate nature of reality, and how cm we know it? So frarned. the definitive questions of metaphysics and epistemology illustrate both the ambition of these disciplines. and the enormous scope of their undertaking. The increased diversification of Anglo-American philosophy over the past century into subdiscipiines (philosophies of science, mind. and language, inter alia) has been a reaction to the size of scope; the strategy has been to divide the unwieldy traditionai questions into more focussed research programmes where possible, taking advantage in particular of the opportunities to clarify issues by means of the formai concepts available since Frege (to say nothing here of formal rnethods). This strategy has been a success. ail things considered: a radical cynicism is required to support the view that mind and language are no better understood in Iight of the work of, say, Frege. Russell. and Turing -- cynicism, that is, about the utility of the concepts they introduced, and thus of an aitogether different nature from skepticism about the tenability of their particular theories. Optirnism about the fragmentation of philosophy is, however, consistent with the belief that the grander questions ought neither simply to vanish, nor to be portrayed as misconceived. It may sound like a platitude that a mutually beneficial traffic holds between general and specific lines of philosophical inquiry. But rnany who might assent to the platitude in theory have in practice no use, or simply no time, for the task of drawing out the connections between small-scale results and large-scale aims. That the diverse. technical, and often rnutually incomprehensible subdisciplines of analytic philosophy form an extended research programme into the great traditionai questions is therefore a thought that bears occasional emphasis. The following five papers convey such an emphasis. While 1should Say that this theme is explicit in no one of them. it is certainly implicit in their conjunction. Chapters Two and Three deal with aspects of the broad metaphysical position known as semantic anti-realism. most closely associated with Michael Dummett and, latterly, Crispin Wright. Chapter Four serves to introduce certain themes in contemporary philosophy of mind. by way of closing off what may appear to be a distinct theory of rnind proposed by John Searle. The final paper examines insmmentalism towards the rnind -- a metaphysical hdfway house between realism and anti-reaiism -- taking issue with one sort of objection to instrumentalism, but proposing another objection in tum. It then presents something of a synthesis of the issues broached in the preceding discussions, explicating an objection to Quine's indeterminacy argument, but aiming for a sympathetic diagnosis in semantic anti-realist terms. In the following remarks I will introduce some of the basic elements of the positions under consideration in these Papen, and attempt to motivate the project of drawing connections beiween the general debate over a particularly strong form of metaphysical realism and some of the more rarified investigations into the mind-body problem. Variefiesof anti-realism Meinong was a reaiist about non-existent entities; Dernocritus was a reaiist about atoms; Berkeley was a realist about ideas, but not physics; Quine is a reaiist about physics, but sometimes not about ideas. Depending on who we ask. Hume was either obviously an anti-reaiist about causal properties and moral properties, or clearly a realist about only one, or indubitably a realist about both. Mackie was a realist about physical properties, but not about moral properties. Russell was consistently a reaiist about sense- data and relations, a sometime realist about extemal structure, a cautious realist about external objects, and an anti-realist about cause. Demda is a realist about 'text', outside of whic h there exists nothing. So much for definition by example. What this list should make clear is not just the history and pervasiveness of disagreements about realism, but aiso the different senses in which the term may be used. There are a few distinct sorts of realism. and corresponding anti-'s, the occurrences of which in the following papen should be inferable from context once the distinctions are made clearer. There is, for example, a sort of realism informed by a particular view of physicalism. On this view, reality and physicality are mutually entding; anti-realisrn towards il discourse like mathematics or intentional psychology, in this sense, consists in denying the physical reference of characteristically mathematicai or psychologicai terms. Hence the norninalism towards numbers displayed by a physicalist like Hartry Field. Putative objects that are not obviously physical must, for this view, be candidates either for elimination or reduction. That is a theme to which 1 will retum shonly. However, we have qualified the debate insufficiently if we have only made note of the ambiguities of 'realism'. For, in most contexts, there is more than one way of being an anti-realist, on account of there being more than one notion of negation available (itself an important issue in this literature!). The idea should be clear to most philosophers regardless of familiarity with logical concepts: Consider the positions of libenarianism, determinisin, and compatibilism in the tnditional free will debate.