Assessment Sensitivity Relative Truth and its Applications JOHN MACFARLANE CLARENDON PRESS . OXFORD 2014 PREFACE This book is about how we might make sense of the idea that truth is relative, and how we might use this idea to give satisfying accounts of parts of our thought and talk that have resisted traditional methods of analysis. Although there is a substantial philosophical literature on relativism about truth, going back to Plato’s Theaetetus, this literature (both pro and con) has tended to focus on refutations of the doctrine, or refutations of these refutations, at the expense of saying clearly what the doctrine is. The approach here will be to start by giving a clear account of the view, and then to use the view to solve some problems that have concerned philosophers and semanticists. The main aim is to put relativist solutions to these problems on the table, so that they may be compared with non-relativist solutions and accepted or rejected on their merits. Comparatively little space will be devoted to blanket objections to the coherence of relativism, because these will largely be dispelled by a clear statement of the view. When I finished graduate school, I would never have guessed that my first book would be a defense of relative truth. To proclaim oneself a relativist about truth, I assumed, was to ally oneself with the kind of postmodernist scepticism about the objectivity of science that the physicist Alan Sokal lampooned in his famous hoax article for Social Text (Sokal 1996b; Sokal 1996a). I regarded relativism about truth as hopelessly confused, easily refuted, and a sure sign of deficient intellectual character. And I was not alone in this: I did not know of a single prominent analytic philosopher who espoused relativism about truth, or even took it seriously enough to spend more than a few pages on it. What happened? I have not changed my view that there is an objective world, or we can come to know about it using the methods of science. And I still think that most talk of relative truth has been hopelessly muddled. But I have become convinced that relativism about truth can be made philosophi- cally intelligible, even to hard-headed scientific realists, and that it is a good tool for understanding parts of our thought and talk that fall short of being fully objective. My own path to relativism began not with the usual worries about taste and morality, but with reflections on the semantics of contingent statements vi Preface about the future, inspired mainly by Belnap and Green (1994). By June of 2002, I had concluded that the natural setting for a Belnap/Green-style approach to future contingents was a framework in which truth was relativized to both a context of use and a context of assessment. I presented this idea at ECAP IV in Lund, Sweden, where I found a fellow traveler: Max Kölbel, who had just finished Truth Without Objectivity (2002). By the end of August, 2002, I had written a manuscript “Three Grades of Truth Relativity,” which was the germ of the present book. (Though this paper was never published, a self-standing treatment of future contingents was published as MacFarlane 2003.) At this time, the philosophical literature was full of discussions of various forms of contextualism, and I could see that the relative-truth framework I had applied in “Three Grades” to future contingents, accommodation, and evaluative relativism had applications in these areas as well. I worked out two of these—to knowledge-attributing sentences and to epistemic modals—in summer 2003, and presented them as talks at Stanford, Utah, and Yale. (These became MacFarlane 2005a and MacFarlane 2011a.) Conversations with Jeff King and Jason Stanley spurred me to think more about how one might do relativist semantics in a propositional (rather than a sentential) framework, and the result was my Aristotelian Society paper “Making Sense of Relative Truth” (MacFarlane 2005c). Others had been working independently along parallel lines. Andy Egan, John Hawthorne, and Brian Weatherson came out with their own relativist treatment of epistemic modals (Egan, Hawthorne, and Weatherson 2005). Mark Richard noticed the applications to knowledge attributions and ac- commodation (Richard 2004). And the linguist Peter Lasersohn, working at first in isolation from the emerging literature in philosophy, wrote an in- fluential paper arguing for a relativist treatment of predicates of personal taste, employing a modification of Kaplan’s semantics for indexicals that was very similar to my own approach in “Three Grades” (Lasersohn 2005). In September, 2005, LOGOS sponsored a well-attended conference on relativist semantics in Barcelona. What continued to distinguish my work from others’ was the notion of a context of assessment. Others had made the move of relativizing propositional truth to parameters other than worlds, such as judges, perspectives, or stan- dards of taste. But I had argued in MacFarlane (2005c) that this alone was not enough to make one a relativist about truth in the most philosophically interesting sense. The interesting divide, I argued, is between views that allow Preface vii truth to vary with the context of assessment and those that do not. My next batch of papers (2007a, 2009, 2008) was devoted to making this point in more detail, and to fleshing out the distinction between “nonindexical contextualist” views, which relativize propositional truth to nonstandard parameters but do not posit assessment sensitivity, and genuinely “relativist” views. In Spring 2007 I sat in on my colleague Niko Kolodny’s seminar on reasons and rationality, and this led to a fruitful and ongoing collaboration. Niko helped me bring my semantic ideas into contact with important debates in the literature on practical reasoning. Our joint paper (Kolodny and MacFarlane 2010) applied relativist ideas to the semantics of deontic modals and indicative conditionals. This is a large project, with many interconnecting parts, and journal papers have not been the ideal medium for presenting it. Without the applications, the foundational ideas appear abstract and sterile; but the applications cannot be adequately explained without the foundational ideas. Moreover, because it would not be rational to make significant changes in one’s semantic frame- work just to handle one recalcitrant construction, it is important to see that there are many systematically related applications of the proposed framework. Hence I have always envisioned a book-length treatment covering founda- tions and applications in a unified way. Though the present book draws on earlier articles, with a few exceptions I have written everything afresh, remov- ing inconsistencies, improving explanations, and responding to criticism that has appeared in the literature. Analytic philosophers are now considerably more open to relativism about truth than they were when I began this project. My initial aim was merely to place relativist views on the table as real options. Many of those who initially accused these views of incoherence have come around to regarding them as merely empirically false. I am grateful for the company, and I hope that the book is still timely. J. M. Berkeley ACKNOWLEDGEMENTS I began this book while on leave in 2003–4, thanks to a Berkeley Humanities Research Fellowship and an ACLS/Andrew W. Mellon Fellowship for Junior Faculty. An additional semester of leave in fall 2008, supplemented again by a Berkeley Humanities Research Fellowship, allowed me to make considerable progress on the manuscript. Many of the ideas herein were first worked out in journal articles. Chap- ters 3–5 draw on MacFarlane (2003), MacFarlane (2005c), MacFarlane (2009), MacFarlane (2008), and MacFarlane (2011b). Chapter 6 draws on MacFar- lane (2007a). Chapter 9 draws on MacFarlane (2003) and MacFarlane (2008). Chapter 8 draws on MacFarlane (2005a), MacFarlane (2005b), MacFarlane (2009), and MacFarlane (2007a). Chapters 10 and 11 draw on MacFarlane (2011a) and Kolodny and MacFarlane (2010). Some passages in Chapter 5 are reprinted verbatim from MacFarlane (2005c), by courtesty of the Editor of the Aristotelian Society. Thanks also to Oxford University Press for allowing me to use some material from MacFarlane (2011b), MacFarlane (2008), and MacFarlane (2011a) in Chapters 5, 9, and 10, respectively. In developing my ideas, I have been greatly helped by students in two graduate seminars at Berkeley (Spring 2005 and Spring 2008), especially Michael Caie, Stanley Chen, Fabrizio Cariani, Kenny Easwaran, Michael Riep- pel, and Skip Schmall. Joe Karbowski did excellent work as my research assistant in 2004, as did Michael Rieppel in 2009 and 2011, and Ian Boon and Sophie Dandelet in 2012. I benefited immensely from intensive seminars on the first six chapters of the book given for the LOGOS group in Barcelona in March 2009, the Cogito group in Bologna in June 2010, and the Institut Jean Nicod in Paris in October 2010, and I thank Manuel García-Carpintero, Paolo Leonardi, and François Recanati, for making these possible. In March 2012, I had the opportunity to present some material from the book in three lectures at Princeton as Whitney J. Oates Fellow in the Humanities Council. I am grateful to Princeton’s Humanities Council for the opportunity, and to the philosophers there for lively discussion. I have also benefited from questions from audiences at talks in Berkeley, Bristol, Buenos Aires, Chicago, Connecti- cut, Davis, Dublin, Guangzhou, Harvard, Irvine, Las Vegas, London, Los Acknowledgements ix Angeles, MIT,