Minds and Computers Minds and Computers An Introduction to the Philosophy of Artificial Intelligence An Introduction to the Philosophy of Artificial Intelligence Matt Carter Could a computer have a mind? What kind of machine would this be? Exactly what do we mean by ‘mind’ anyway? A M n In The notion of the ‘intelligent’ machine, whilst continuing to feature in tro in numerous entertaining and frightening fictions, has also been the focus of d u d a serious and dedicated research tradition. Reflecting on these fictions, and ctio s on the research tradition that pursues ‘Artificial Intelligence’, raises a number n of vexing philosophical issues. Minds and Computers introduces readers to to these issues by offering an engaging, coherent and highly approachable th a e n interdisciplinary introduction to the Philosophy of Artificial Intelligence. P hilo d s Introductory material is presented from each of the disciplines which o p C constitute Cognitive Science: Philosophy, Neuroscience, Psychology, Computer h y Science and Linguistics. Throughout, readers are encouraged to consider the o o f implications of this disparate and wide-ranging material for the possibility of Ar m developing machines with minds. They can expect to develop a foundation for tific p philosophically responsible engagement with A.I., a sound understanding ia of Philosophy of Mind and of computational theory, and a good feel for l In u te t cross-disciplinary analysis. llig e e n r Features: ce s • A directed philosophical focus • A self-contained introduction to Computational Theory • Clear and accessible explanations of technical M material with abundant exercises a • A glossary of terms. t t Matt Carter is a Fellow of the Philosophy Department at Melbourne University. C This is his first book. a r t e r Cover illustration & design:RIVER DESIGN,Edinburgh Edinburgh University Press barcode E 22 George Square,Edinburgh EH8 9LF d Matt Carter i n www.eup.ed.ac.uk b u ISBN 978 0 7486 2099 9 rg h MINDS AND COMPUTERS for G who Helped and for Sue without whom ... MINDS AND COMPUTERS AN INTRODUCTION TO THE PHILOSOPHY OF ARTIFICIAL INTELLIGENCE Matt Carter EDINBURGH UNIVERSITY PRESS © Matt Carter,2007 Edinburgh University Press Ltd 22 George Square,Edinburgh Typeset in Times by Servis Filmsetting Ltd,Manchester,and printed and bound in Great Britain by Cromwell Press, Trowbridge,Wilts A CIP record for this book is available from the British Library ISBN 978 0 7486 2098 2 (hardback) ISBN 978 0 7486 2099 9 (paperback) The right of Matt Carter to be identified as author of this work has been asserted in accordance with the Copyright,Designs and Patents Act 1988. CONTENTS Acknowledgements ix 1 Introduction 1 2 Dualism 4 2.1 Substance Dualism 4 2.2 Cartesian Dualism 5 2.3 Positive Arguments for Cartesian Dualism 5 2.3.1 The Argument from Religion 6 2.3.2 The Argument from Introspective Appearance 7 2.3.3 The Argument from Essential Properties 8 2.4 Arguments against Cartesian Dualism 9 2.4.1 The Problem of Other Minds 9 2.4.2 Ockham’s Razor 10 2.4.3 The Problem of Interaction 11 2.5 Other Dualisms 12 2.5.1 Parallelism 12 2.5.2 Occasionalism 13 2.5.3 Epiphenomenalism 13 2.6 Anomalous Monism 14 3 Behaviourism 15 3.1 Early Empirical Psychology 15 3.2 Physiological Psychology 16 3.3 Introspectionist Psychology 17 3.4 Psychological Behaviourism 20 3.5 Philosophical Behaviourism 23 3.6 Objections to Philosophical Behaviourism 24 4 Neuroanatomy 27 4.1 Macro-Neuroanatomy 27 4.2 Micro-Neuroanatomy 32 vi    5 Australian Materialism 35 5.1 The Causal Theory of Mind 36 5.2 The Identity Theory 37 5.3 Arguments against Australian Materialism 38 5.4 What Mary Didn’t Know 42 6 Functionalism 44 6.1 Functional Definition 44 6.2 A Black Box Theory 45 6.3 Qualia Objections 48 7 Formal Systems 52 7.1 Effectivity 53 7.2 States and Rules 57 7.3 Specification 58 7.4 Generation and Derivation 61 7.5 Generation Trees 64 7.6 Formality and Isomorphism 67 8 Computability 70 8.1 Register Machines 70 8.2 Programs 71 8.3 Running a Program 73 8.4 Computation 75 8.5 Computable Functions 76 8.6 Building Programs 79 9 Universal Machines 85 9.1 Church/Turing Thesis 86 9.2 Gödel Coding 88 9.3 A Universal Machine 92 10 Computationalism 94 10.1 What Computationalism Isn’t 95 10.2 Software and Wetware 99 10.3 Variation 101 10.4 Learning 103 10.5 Creativity 106 10.6 Attributing Mentality 108 11 Search 113 11.1 Top Down,Bottom Up 113 11.2 Breadth Versus Depth 115 11.3 Heuristic Search 117  vii 12 Games 122 12.1 A Simple Game 122 12.2 Minimax 125 12.3 Pruning 127 12.4 Humans Versus Computers 128 13 Machine Reasoning 132 13.1 Logic and Deduction 132 13.2 Conditionality and Predication 134 13.3 Kinship 137 13.4 Expert Systems 141 14 Machines and Language 145 14.1 Interpreting Language 145 14.2 Generative Grammar 149 14.3 Phrase Structure Trees 150 14.4 Computing Language 152 15 Human Reasoning 154 15.1 Following Logically 156 15.2 Rational Performance 157 15.3 Mental Models 160 15.4 Explanatory Burden 161 16 Human Language 164 16.1 Obstruent Phonemes 165 16.2 Sonorant Phonemes 167 16.3 Allophones and Phonetic Realisation 170 16.4 First-Language Acquisition 172 16.5 Language and Rules 173 17 Meaning 175 17.1 The Chinese Room 175 17.2 Syntax and Semantics 177 18 Representation 181 18.1 Intentionality 181 18.2 Categories and Content 183 18.3 Symbols and Patterns 184 18.4 Cognitive Architecture 185 19 Artificial Neural Networks 187 19.1 Connectionist Architecture 187 19.2 Simple Artificial Neural Networks 189 viii    19.3 Synthesising Speech 191 19.4 Learning 196 19.5 Pattern Recognition 198 19.6 Two Paradigms? 199 19.7 It’s Only a Model 200 20 Minds and Computers 202 20.1 Consciousness 202 20.2 Personal Identity 203 20.3 Emotions 205 20.4 Computers with Minds 206 Appendix I:Suggestions for Further Reading 207 Appendix II:Glossary of Terms 211 Index 218 ACKNOWLEDGEMENTS I’d like to express my gratitude to all who participated, directly and indi- rectly,in the production of this book. Thank you to the teaching staffwho were based in the Cognitive Science programme at the University of Queensland in the final years of the twentieth century, for inspiring in me a commitment to the importance of cross-disciplinary analysis.My gratitude further extends to all of my teach- ers – both within and without Philosophy. Thank you also to the years of undergraduates who have suffered my instruction.In particular,I am grateful to my ‘Minds and Machines’class of 2002 for inspiring this textbook in the first instance, and to my classes of 2006 for reading and commenting on material contained herein. Thank you to the Philosophy Department at Melbourne University, where I was based while writing this book,and to its superb office staff. Thank you to all at EUP for publishing this volume and for being such a pleasure to deal with.Particular thanks to Jackie Jones for her initial enthu- siasm for the project. Thank you to all my friends for their support and understanding,partic- ularly to FB,Wayne and Eloise for tolerating innumerably many dinner-time drop-ins,and to Lester and Christie for assistance above and beyond the call of friendship. Thank you very much to Graham Priest,without whom this book would not have been written. Thank you to Mia and Linus for being adorable,and a million thank yous to Sue,for being wonderful. ix