Two-Dimensionalism: Semantics and Metasemantics YEUNG, \y,ang -C-hun ...:' . '",~ ... ~ .. A Thesis Submitted in Partial Fulfilment of the Requirements for the Degree of Master of Philosophy In Philosophy The Chinese University of Hong Kong January 2010 Abstract of thesis entitled: Two-Dimensionalism: Semantics and Metasemantics Submitted by YEUNG, Wang Chun for the degree of Master of Philosophy at the Chinese University of Hong Kong in July 2009 This ,thesis investigates problems surrounding the lively debate about how Kripke's examples of necessary a posteriori truths and contingent a priori truths should be explained. Two-dimensionalism is a recent development that offers a non-reductive analysis of such truths. The semantic interpretation of two-dimensionalism, proposed by Jackson and Chalmers, has certain 'descriptive' elements, which can be articulated in terms of the following three claims: (a) names and natural kind terms are reference-fixed by some associated properties, (b) these properties are known a priori by every competent speaker, and (c) these properties reflect the cognitive significance of sentences containing such terms. In this thesis, I argue against two arguments directed at such 'descriptive' elements, namely, The Argument from Ignorance and Error ('AlE'), and The Argument from Variability ('AV'). I thereby suggest that reference-fixing properties belong to the semantics of names and natural kind terms, and not to their metasemantics. Chapter 1 is a survey of some central notions related to the debate between descriptivism and direct reference theory, e.g. sense, reference, and rigidity. Chapter 2 outlines the two-dimensional approach and introduces the va~ieties of interpretations 11 of the two-dimensional framework. Chapter 3 critically 'evaluates AlV: names and natural kind terms are reference-fixed by properties that may not be known by speakers. I argue that, contrary to what AlE claims, these expressions are reference-fixed by metalinguistic properties that are implicitly known by speakers. I go further to show that a special kind of arguments known as the methods of cases-including AlE-can be blocked by the a priori argument. Chapter 4 examines the force of AV: reference-fixing properties do not play significant roles in understanding and communication, as different speakers may associate different reference-fixing properties with the same expression. I show that AV fails because it is insensitive to the influence of context on the content competent speakers must know when they learn a language and the content communicated among them. HI 摘要 怎樣解釋克里普克 (s . Kripke) 所提出的後驗必然真理 (nece ssary a posteriOli truth s) 以 及先驗偶然真理 (contingent a priori truths) 一直眾說紛耘。其中，二維語意論提出的 r 不可化約的解釋 J (non-reductlve analysis) 被某些人認為最有希望解決這個難 題 。 傑克遜(F. Jackson) 及查路瑪斯 (D. Chalmers) 對此理論提出的語意論的理解 (semantic interpretation) ， 有相當描述理論 (descripti vism) 的元素 (a) 所有名稱及自 然類項 (natural kind terms) 的指謂 (referents) 是由 一些屬性決定、 (b) 講者能先驗地知 道這些屬性 、 (c) 這些屬性代表句子的認知意義 (cognitive significancε) 。本論文駁 斥兩個對有關這些描述理論元素的批評，分別是「無知及錯誤的批評 J (Argument from Ignorance and Error, ‘AIV' ) 及「可變性的批評 J (Argument from Variability, ‘AV' )。 筆者嘗試從中論証指謂屬性的ference - fixing properties) 是名稱及自然類 項的意義 ( semantic s) ，而不是它們的「 後設意義 J (metasemantics) 。 第一章 旨在解釋一些有關描述理論及直接指涉理論 (direct reference theory) 之間的 爭議的重要概念 ，例如 意義 (sense ) 、指稱 (reference) 及嚴僅指涉 (rigidity) 等。第 二 章介紹二維語意論及各種對二維語意論的理解 。 第三章主要探討 AIV 0 AIV 指出 名稱及自然類項的指謂是被一些講者所不知的屬性決定。我不同意這個立場 ， 因 為我們有理由相信名稱及自然類項的指謂是由一些講者約略 (implicitly) 知道的 「後設語言的屬性 J (metalinguistic properties) 決定。 此外，此章証明一類句括 AIV 在內的「情況方法 J (methods of cases) 的論証均被「先驗論証 J (a priori argument) 駁倒 。第 四章考察 AV o AV 稱由於不同的講者有可能給予 同一個名稱或自然類 項不同的指謂屬性，故這些屬性既不是每個講者均要知道，也不會是人們溝通時 傳達的內容 ( communicated content ) 。 我在此章，駁斥 AV' 因為 AV 忽略了情境 (context) 對講者所要知道的指涉屬性以及他們溝通時傳遞的內容的影響 。 lV Acknowledgements! 1 The following is the totality of my thanks to people who have contributed either directly or indirectly to this study. 2 I owe more thanks than I can say to my primary supervisor, Professor Kai-Yee Wong. 2.1 In the course of my writing this thesis, Professor Wong was never hesitant about reminding me, from time to time, how inadequate of my thesis-in-progress was, both in terms of its content and writing. During several occasions when I had long dry spells, he always took the trouble to help me bound back. 2.2 It goes without saying how much I owe intellectual debts to him. 2.3 Most importantly: contrary to countless people I have encountered, he sets an example of how one should live, instead of how one should NOT live. 3 I would also like to thank my secondary supervisor, Professor Chris Fraser, for his valuable comments on my early ideas of this thesis. 4 I am also grateful to Professor Chong-Fok Lau, Professor Hon-Lam Li, Professor Xiaogan Liu, and Professor Kwong-Loi Shun. 5 Thanks are also due to fellow students Thomas Cham, Pengbo Liu, Issac Lowe, Brian Wong, and in particular, Hong-Ting Li and Calista Lam, for all the 1 It should be transparent to readers that this acknowledgement mimics the.structure of the book Tractatus Logico-Philosophicus written by Wittgenstein. v enjoyable discussions over the last two years. 5.1 It is a pleasure to discuss ideas with Hong-Ting Li, who is always ready for a lengthy discussion about direct reference, possible-world semantics, and the like, regardless of his Continental Philosophy background. 5.2 Calista Lam has given many constructive comments on the early drafts that led to improvements. 6 This thesis is dedicated, if it is worth being dedicated, to my parents, sister, and brother, without whom I might not have learnt the meaning of unconditional devotion. 7 When one is not truly talented, his thesis can, at best, offer nothing but some modest contribution. VI Table of Contents Declarations Acknowledgements Table of Contents Introduction 1 PART I FROM MIXED TRUTHS TO TWO-DIMENSIONALISM Chapter One: Rigidity, Descriptivism, and Direct Reference 1. 1. Meaning and Reference 7 1. 2. Rigidity and the Dusk of Descriptivism 13 1. 3. Different Theories of Reference 22 1. 4. Apriority and Necessity 32 Chapter Two: Two-Dimensionalism 2. 1. Possible-World Semantics 38 2.2. Two-Dimensional Semantics 43 2.3. Variety of Two-Dimensionalism 48 PART 11 TWO-DIMENSIONALISM AND ITS CRITICS Chapter Three: The Argument from Ignorance and Error 3. 1. A-Intension and Associated Properties 59 3. 2. The Argument from Ignorance and Error 65 3. 3. The a Priori Argument 73 Chapter Four: The Argument from Variabil ity 4.1. Associated Properties and Meanings 88 4.2. A-Intension and Understanding 90 4.3. A-Intension and Communication 97 CONCLUDING REMARKS 109 BIBLOGRAPHY 112 vu Introduction: Names and Reference-fixing Properties 'Hesperus' and 'Phosphorus' are the names for the same celestial body, namely Venus. The description 'being the evening star' is known as the reference-fixing description for 'Hesperus'. This thesis can be considered as part of the project studying the relation between names (also natural kind terms) and reference-fixing properties described by the associated descriptions. What is the meaning of names? Descriptivism, a theory of naming ins'pired by Russell and Frege, holds that the meaning of names is their associated descriptions that specify the individuating properties of the bearers. Accordingly, names and associated reference-fixing properties cannot be more strongly linked. Descriptivism is widely believed to be demolished nearly single-handedly by Kripke, who has famously argued that since names are rigid designators while descriptions are not, they are not synonyms. As Kripke has also argued, in general names are not reference-fixed by the descriptions known by speakers. Direct referent theory, Kripke and Putnam being its most well-known advocates, holds that the meaning of names is exhausted by their referents. Some may think that this theory entails that names and reference-fixing properties are totally unrelated. This is a rash conclusion. Even though Kripke rejects the idea that descriptions give the semantic values of names, he would agree that reference-fixing properties, be it the descriptions about the relevant causal chain or the descriptions said by the Baptists, belong to the metasemantics of names. The distinction between semantics and metasemantics is suggested by David Kaplan. Semantics says what semantic values of expressions are in a given language; metasemantics is an account of what the facts are in virtue of which expressions have the semantic values they have. 1 As I understood, Kripke's discussion about 'epistemic might' hints that, contrary to the general perception of him, he thinks names and associated properties are more interconnected tha~ the picture presented by direct reference theorists. Talking about the possibility that Hesperus might not have been Phosphorus, Kripke stresses that the 'might' is purely 'epistemic'. Although it is necessary that Hesperus is Phosphorus, we can still ask sensibly whether Hesperus is Phosphorus. It is because in that case, we are only considering the 'epistemic duplicates' of Hesperus and Phosphorus, which concern about the way we conceive the objects in some qualitative epistemic situation, where things only appear qualitatively to us. As it is possible that the evening star is not identical to the morning star, it is possible, in the epistemic sense, that Hesperus is not Phosphorus. This is a supportive argument for the claim that it is a posteriori that Hesperus is Phosphorus. Some philosophers, notably lackson and Chalmers, have proposed a two-dimensional