NAMING WITHOUT NECESSITY By NIGEL SABBARTON-LEARY A thesis submitted to The University of Birmingham for the degree of DOCTOR OF PHILOSOPHY Department of Philosophy School of Philosophy, Theology and Religious Studies College of Arts and Law The University of Birmingham March 2010 1 ABSTRACT In this thesis I argue that we should break with the dominant Kripkean tradition concerning natural kind terms and theoretical identity. I claim that there is just no interesting connection between the metaphysics and semantics of natural kind terms, and demonstrate this by constructing a version of descriptivism that is combined with the same metaphysics – that is, a nontrivial version of essentialism – found in Kripke, but which effectively avoids all of the standard criticisms. With my version of descriptivism in place, I present what I take to be the most reasonable version of metaphysical essentialism, positing only what I call ‗thin‘ essences. I claim that thin essences are perfectly adequate to underpin scientific realism, and moreover that they are sufficient to support the version of descriptivism developed here. In effect, what I offer here is an error theory of the Kripkean tradition: Kripke is right to think that there are interesting things to say about meaning and essence, but just wrong about what those things are. Thus whilst Kripke thinks that it is possible to make discoveries about the meanings of natural kind terms, I think, rather, that we make empirical discoveries that lead to revisions in meaning. Furthermore, whilst Kripke thinks there is a dichotomy between de re and de dicto necessity, and that theoretical identities are necessary de re, I think this distinction is both misleading and inaccurate, and that the necessity of theoretical identities is neither entirely de re nor entirely de dicto. By separating and insulating questions concerning meaning from questions concerning essence I show that whilst scientific discoveries are contingent and a posteriori, the definition of scientific terms are both necessary and a priori. 2 TABLE OF CONTENTS INTRODUCTION ..................................................................................................................... 7 CHAPTER 1 ............................................................................................................................ 13 1.1 Frege‘s Puzzle ................................................................................................................... 14 1.2 Description theory of meaning and reference.................................................................... 16 1.3 Kripke‘s objections ............................................................................................................ 18 1.3.1 The Modal Argument ................................................................................................ 18 1.3.2 The Epistemological Argument ................................................................................ 21 1.3.3 The Semantical Argument ........................................................................................ 22 1.4 The Causal Theory of Direct Reference ............................................................................ 23 1.5 A Solution to Frege‘s Puzzle? ........................................................................................... 29 1.6 Natural Kinds ..................................................................................................................... 32 1.7 Puzzles ............................................................................................................................... 37 CHAPTER 2 ............................................................................................................................ 44 2.1 Putnam‘s semantics of natural kind terms ......................................................................... 44 2.2 Cross-world reference........................................................................................................ 50 2.3 A posteriori necessity ........................................................................................................ 54 2.4 The Kripke-Putnam programme ........................................................................................ 57 2.5 Reference and Kuhnian incommensurability .................................................................... 60 2.6 LaPorte on Twin Earth ...................................................................................................... 66 2.7 Later Putnam ..................................................................................................................... 68 CHAPTER 3 ............................................................................................................................ 75 3 3.1 Natural kind terms, predicates and identities..................................................................... 76 3.2 Revisiting Kripke ............................................................................................................... 80 3.3 Soames‘ positive account I ................................................................................................ 88 3.3.1 Essentialist Predicates ............................................................................................... 90 3.3.2 Correspondence rigidity ........................................................................................... 96 3.4 Soames‘ positive account II ............................................................................................... 98 3.5 Simple theoretical identification sentences ..................................................................... 107 3.6 Kinds of a type T? ............................................................................................................ 112 3.7 The Special Auxiliary Assumption.................................................................................. 115 3.8 False theoretical identities ............................................................................................... 121 3.9 Complex natural kind terms and essentialism ................................................................. 126 CHAPTER 4 .......................................................................................................................... 135 4.1 Salmon vs. Soames .......................................................................................................... 136 4.2 Salmon‘s (CDR) .............................................................................................................. 137 4.3 Objections to descriptivism about natural kind terms ..................................................... 143 4.4 Theoretical identity and a posteriori necessity................................................................ 148 4.5 Kripke‘s essentialist premise ........................................................................................... 153 4.6 Essentialism, a priori or a posteriori? ............................................................................. 156 4.7 Salmon‘s account of theoretical terms............................................................................. 159 4.8 The trivialisation problem ............................................................................................... 162 4.9 The semantics of science ................................................................................................. 166 TAKING STOCK: THE STORY SO FAR ........................................................................... 169 4 CHAPTER 5 .......................................................................................................................... 173 5.1 Kripke vs. Description Theory ........................................................................................ 174 5.2 Rigidity and Descriptionality .......................................................................................... 177 5.3 De Facto Rigidity, Essentialism and Descriptivism. ....................................................... 181 5.4 Descriptivist Essentialism................................................................................................ 186 5.5 Locating Meaning ............................................................................................................ 189 5.5 A priori knowability ........................................................................................................ 194 5.6 The metasemantics of natural kind terms ........................................................................ 196 5.7 Intuitive Kinds vs. Theoretical Kinds .............................................................................. 200 5.8 Conclusion ....................................................................................................................... 208 CHAPTER 6 .......................................................................................................................... 211 6.1 Real Essence, Nominal Essence and Real Constitution .................................................. 213 6.2 The Knowledge Objection ............................................................................................... 220 6.3 The Ontological Objection .............................................................................................. 226 6.4 The Better Candidate Objection ...................................................................................... 231 6.5 Locke‘s Contemporary Relevance..................................................................................