PRAGMATICS AND SEMANTICS OF FREE CHOICE DISJUNCTION PRAGMATICS AND SEMANTICS OF FREE CHOICE DISJUNCTION By BRADLEY SHUBERT, B.A. hon., M.A., M.A. A Thesis Submitted to the School of Graduate Studies in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy McMaster University Copyright by Bradley Shubert, September 2019 McMaster University DOCTOR OF PHILOSOPHY (2019) Hamilton, Ontario (Philosophy) TITLE: Pragmatics and Semantics of Free Choice Disjunction AUTHOR: Bradley Shubert, B.A. Honours (University of Victoria) M.A. (University of Waterloo) M.A. (University of Toronto) SUPERVISOR: Professor David Hitchcock EXTERNAL EXAMINER: Professor Johan van Benthem COMMITTEE MEMBERS: Professor Nicholas Griffin Professor Sandra Lapointe NUMBER OF PAGES: xii, 200 ii Lay Abstract A disjunction is a statement using ‘or’, like ‘Anne has a Ford or a Tesla’. From such a statement, we cannot infer either disjunct—e.g. ‘Anne has a Ford’. In choice situations like ‘You may have coffee or tea’ we can infer either option. Why this choice inference is legitimate is the problem of free choice disjunction. I explore the history of solutions to the problem, including semantic solutions that propose a special meaning to choice disjunctions and pragmatic solutions that appeal to the circumstances in which they are uttered. I draw connections between semantics and pragmatics and present a formal account of one major pragmatic approach to the problem. Where others have sought to explain how 'May(P or Q)' entails 'May P and May Q', I argue instead that the meaning of ‘May (P or Q)’ in choice scenarios translates directly into logical formalism as ‘May P & May Q’. iii Abstract A disjunction is an expression using ‘or’, such as ‘Anne has a Ford or a Tesla’. From such a statement, we cannot usually infer either disjunct, for example, that ‘Anne has a Ford’. However, in choice situations like ‘You may have coffee or tea’ we can infer either option. The problem of free choice disjunction is to determine why these choice inferences are legitimate (von Wright 1968, Kamp 1973, Meyer 2016). Central to this discussion is the observation that a modal possibility operator ranging over a disjunction sometimes implies a conjunction of possibilities. In the case of permission, we express this as the choice principle ‘May (P or Q)’ entails ‘May P and May Q’ (Zimmerman 2000). Unfortunately, this inference cannot hold in a logical language without significant modification of the systems involved. I explore the history of proposed solutions to this problem, including semantic solutions that assign a distinctive meaning to free choice disjunctions and pragmatic solutions that use features of their utterance to solve the problem. I draw connections between semantics and pragmatics and, using the tools of dynamic logic (Baltag et al. 1998, van Benthem 2010), I present a formal account of one major (Gricean) approach to the problem (Kratzer & Shimoyama 2002). Ultimately, I explore the role of logic in this debate and argue that we should formally represent the meaning of these expressions directly as conjunctions of possibilities. Thus, rather than trying to account for the choice principle within a logical system, we must instead account for the fact that, in choice situations, the meaning of ‘May (P or Q)’ translates into logical formalism as (May P & May Q). iv Acknowledgements First and foremost, thanks go to my supervisor Dr. David Hitchcock, who has provided extensive and useful comments, feedback, and advice about every aspect of this thesis. I have not always been an ideal student, but I have been lucky in finding a supervisor so diligent, helpful, knowledgeable and kind. Next, thanks go to my committee members Dr. Nick Griffin and Dr. Sandra Lapointe. The comments and feedback received from my committee have been helpful, extremely motivating and have improved this thesis. My committee had the sometimes difficult job of keeping me on track and it is not lost on me that without them I may not have completed this project. Special thanks go to my external examiner, Professor Johan van Benthem, not only for his participation and feedback, but also for his larger work which has shaped so much of my thinking as well as many of the ideas in this thesis. The department of Philosophy at McMaster University helped this project along in a number of crucial ways. The administrative assistance of Kim Squissato, Rabia Awan, and Jessica Bouchard was invaluable, as was the overall leadership provided by Dr. Elisabeth Gedge and Dr. Stefan Sciaraffa. I received much appreciated advice and encouragement about my progress and work from the excellent Ph.D. advisors Dr. Violetta Igneski, Dr. Elisabeth Gedge and Dr. Mark Johnstone. All of the faculty members mentioned above have improved my thinking but in addition to these instructors I’d also like to thank Dr. Richard Arthur, Dr. Nancy Doubleday, Dr. Barry Allen, Dr. Brigitte Sassen, and Dr. Megan Stotts for their instruction, encouragement and as well as the example they set for my own professional life. Additional thanks go to my Ph.D. cohort for an extremely productive proseminar year in which many of these ideas began to bloom. In particular among my student colleagues I thank Rich Neels for many office conversations in which I was able to express and explore these and other ideas. I’d also like to thank the many excellent graduate students at McMaster who were v regularly distracted by my conversations. Thanks especially to Rand, Antonio, John, Chandra, Sean and Paul. Without the warm, fun, and collegial atmosphere that I found among my office mates this process would have been far less enjoyable. The school of graduate studies at McMaster University deserves considerable credit for the organization and facilitation of their many excellent Thesis Writing Bootcamps. These proved to be especially productive working environments and I am grateful to have participated. I am very grateful to Dr. Audrey Yap who, in addition to introducing me to modal logic, has provided many valuable comments and insights regarding the technical details of the Gricean formalization I sketch in chapter six. I have been very lucky in finding the very best mentors and teachers and I’d be remiss if I did not mention more of them here; many thanks to Dr. John Woods, Dr. Bryson Brown, Dr. Patrick Rysiew, Dr. Jeff Foss, and Dr. Doreen Fraser. Warm thanks to Joshua and Daniel Wood – good friends who deserve a great deal of credit for having introduced me to the problem of free choice disjunction and whose conversations so many years ago inspired me to think about this topic. This project comes at the end of a very long road. I’m sure I would not have been able to make the journey without the love and support of my family who have been with me every step of the way. Thanks Mom, Dad, Dez, Trent and Andrea. This thesis is dedicated to you and, more than you know, has been improved by your presence in my life. Finally, I thank Josi, whose love and patience has made all the difference. vi Table of Contents PRAGMATICS AND SEMANTICS OF FREE CHOICE DISJUNCTION ........................................................... i Lay Abstract ............................................................................................................................................................. iii Abstract....................................................................................................................................................................... iv Acknowledgements ................................................................................................................................................ v Table of Contents .................................................................................................................................................. vii List of Figures and Tables ................................................................................................................................... ix List of Abbreviations and Symbols .................................................................................................................. x Declaration of Academic Achievement ............................................................................................................ xii Chapter One Introduction .................................................................................................................................... 1 1.1 Free Choice ‘or’ ......................................................................................................................................... 1 1.2 Organization .............................................................................................................................................. 5 Chapter Two Paradoxes of Permission and Obligation ............................................................................. 13 2.1 Preliminaries .......................................................................................................................................... 13 2.2 Ross’ Paradox ......................................................................................................................................... 16 2.3 Deontic Logic .......................................................................................................................................... 21 2.4 The Paradox of Free Choice Permission ....................................................................................