The Diversity of Truth A Case Study in Pluralistic Metasemantics William Gamester Submitted in accordance with the requirements for the degree of Doctor of Philosophy. The University of Leeds School of Philosophy, Religion and History of Science August 2017 i The candidate confirms that the work submitted is their own and that appropriate credit has been given where reference has been made to the work of others. This copy has been supplied on the understanding that it is copyright material and that no quotation from the thesis may be published without proper acknowledgement. © 2017 The University of Leeds and William Gamester. The right of William Gamester to be identified as Author of this work has been asserted by William Gamester in accordance with the Copyright, Designs and Patents Act 1988. ii Acknowledgements I have a huge amount to be grateful for – I’m afraid the straight-faced sincerity necessary to properly express it doesn’t come naturally. Below is my best effort. My heartfelt thanks go to everyone on this list. It’s been the best four years, you’re all the best. Thanks first and foremost to my supervisors. Robbie Williams has been an incredible source of wisdom and support throughout the last four years, helping to turn hunches and confusions into theories and arguments. I’m sure more or less every good idea in here has been plagiarised from an offhand comment of yours. Daniel Elstein has only come on board in the last year, but has dedicated an enormous amount of his time and energy to helping me improve the thesis. Practically every argument has been enhanced by your feedback. Paolo Santorio has seen my work as it has developed through all stages over the last four years, and has always been able to offer the most perspicuous advice for improving what I’m working on. Thanks so much to all of you for the support, patience, enthusiasm, and insight. I’m still quite overawed to have had such brilliant philosophers to go over my ideas and arguments, and to take them seriously. Granted, you were contractually obliged to do so, but it’s still been a wonderful experience for which I am grateful beyond words. I’d also like to thank the rest of the staff in the Leeds philosophy department for their contributions towards my philosophical development, be it in questions after talks or conversations in pubs. Pekka Väyrynen, in particular, has given up his time on more than one occasion, most notably when I was first finding my feet in the thick ethical concepts literature. I’d also like to thank my examiners, Matti Eklund and Jack Woods, for an invigorating viva voce. I’ve been lucky enough to have been a part of three fantastic philosophical groups over the course of my Ph.D. Perhaps most important is the Leeds postgraduate philosophy community. It’s been a blast. Thanks to Daniel Abrahams, Dani Adams, Sarah Adams, John Baldari, Mike Bench- Capon, Thomas Brouwer, Sam Careelmont, Fabio Ceravolo, Pei-Lung Cheng, Marc Cole, Adina Covaci, John Fernley, Jade Fletcher, David Heering, Lewis Hickley, Olof Leffler, Gary Mullen, Alice Murphy, Simon Newey, Christina Nick, Tadgh Ó Laoghaire, John Parry, Adam Patel-Summers, Emily Paul, Mat Rees (of the famed Rees-Gamester Hypothesis), James Rimmer, Bryan Ross, Sam Symons, Nahuel Sznajderhaus, Nick Tasker, Alison Toop, Andrea White, Marc Wilcox, and Nathan Wood – I don’t say this lightly, but you’re all basically tolerable as human beings. Thanks for making the last four years pretty much ok. In places. You’re alright. Special thanks are due to Jade Fletcher and Mike Bench-Capon for innumerable ultra-helpful chats about truth over the years, and to Nick Tasker for four years of weird philosophical brotherhood. You guys, in particular, are alright. Second is the international pluralisms community. I’ve had great trips to the University of Connecticut, U.S.A., Yonsei University, South Korea, and the University of Bologna, Italy, all to talk about this niche area of philosophy of language and logic (including a workshop on my thesis in Bologna). It’s really been fantastic. Thanks to Douglas Edwards, Filippo Ferrari, Nathan Kellen, iii Jiwon Kim, Junyeol Kim, Teresa Kouri Kissel, Sebastiano Moruzzi, Nikolaj Pedersen, Paul Simard Smith, Erik Stei, Elena Tassoni, Pilar Terrés Villalonga, Cory Wright, Jeremy Wyatt, Andy Yu, and Luca Zanetti for the good times. And the philosophy. I don’t know about this “pluralism” malarkey, but travelling around the world and hanging out with you all has been a lot of fun. You’re alright. Third is the Nature of Representation research group at the University of Leeds. Not many people get this kind of opportunity – I’ve learned so much, not just from the weekly seminar, but the near-constant conferences on awesome topics and visiting speakers. As well as Robbie, Daniel, and Nick, my thanks go to the postdocs, Jennifer Carr, Ed Elliott, Rachel Goodman, Simon Hewitt, and Gail Leckie. I’m yet to hear if we solved the nature of representation, I assume we did – if we didn’t manage it between us I doubt it’ll ever get done. It’s been great working with you all. You’re alright. And thanks to the ERC for funding the project and my research. You’re alright. Many of the chapters here have been presented in talks and seminars, and many people have provided useful feedback on these occasions or on drafts of papers. In addition to those mentioned above, I’d like to thank: Giulia Casini, Paul Horwich, Jess Isserow, David Liggins, Michael Lynch, and James Woodbridge. You’re alright. I have been extraordinarily lucky throughout the tumultuous highs and lows of postgraduate life to have had a veritable mob of friends and family around me. Frankly, the almost embarrassing levels of love and support has at times bordered on the irritating. Every once in a while, you want the whole world to abandon you. But, no. Thanks to all, and particularly to the following. Thanks to my housemates. Chronologically: Allie Rinck, Anna Heaton, Joey Whitfield, Ellis Jones, Bex Jarman, Daniel Ceballos Contreras, and (at the end now) Simon Lowe. Living with you all at the Grove has been the best – you’ve really made home feel like a home away from home. Thanks. You’re alright. Mum and Dad. You have rather selfishly put me in the awkward position of having to try and express gratitude for over 28 years of unconditional love and support in just a few sentences. If I don’t believe in me, your belief in me makes me believe in me, even though I know that I have better evidence about me than you do. Thanks for everything, for always being there. You’re alright. Thanks are also due to Peter Gibson and especially my brother, Ed, for inspiring me to take up philosophy. In fact, pretty much everything I’m interested in I’ve copied off Ed. Thanks for always putting up with that, and being the strongest (mentally and physically) and best person I know, a kaleidoscopic commotion of neon colour in a grey world. Thanks for the lifetime’s friendship and making me a better person. You’re alright. And thanks finally to my best friend and partner, Emma. You’ve been there with sympathy and patience as I’ve oscillated between despair and exhilaration over esoteric things you couldn’t care less about. Thanks for being there through it all. I’ll try not to forget you when the mainstream success of this thesis inevitably leads to an international movie franchise. I don’t know how I’ll cope without you. Badly, I expect. Thanks for being the best bit of life, every day. You’re alright. iv Abstract This thesis concerns pluralism about truth: roughly, the theory that there is more than one way to be true. Where ‘Grass is green’ might be true in one way, ‘Eating meat is wrong’ or ‘7 > 3’ might be true in another. I am interested in showing this theory in its best light. This requires casting a critical eye over extant incarnations of pluralism, formulating new, stronger motivations in its favour, and defending it from objections. Where most pluralists try to motivate the theory by assuming an underlying ontological diversity – in what different truthbearers are about, e.g., grass vs. wrongness vs. numbers – my arguments assume an underlying diversity, not in the world, but in our thought and talk. While ordinary discourse like ‘Grass is green’ expresses representational states (the belief that grass is green), I assume with metaethical expressivism that moral discourse like ‘Eating meat is wrong’ expresses desire-like states (e.g., disapproval of eating meat). Given this metasemantic pluralism, I provide a direct argument for thinking that truth within ordinary discourse consists in corresponding with reality, while moral truth is epistemically constrained; and I develop a novel theory of moral truth. I go on to argue that the most prominent objections to pluralism – which concern cases where truthbearers apt for different properties are “mixed” together – in fact pose no special problems for the pluralist. I provide a pluralist-friendly metaphysics of truth for complex truthbearers that dissolves the appearance of difficulty, arguing that the truth of a complex consists in a distinct property that is grounded in the truth properties relevant for its components. And in the final chapter, I show how this independently motivated metaphysics of truth can in turn be used to dissolve the liar paradox. v Table of Contents Title Page i Acknowledgements iii Abstract v Table of Contents vi Table of Figures x Introduction 1 Part I – Pluralism about Truth 4 Chapter 1: Truth and Pluralism 5 1.1 Language, Thought, Reality 5 1.1.1