It’s All in the Brain A Theory of the Qualities of Perception Jesper Östman Department of Historical, Philosophical and Religious Studies Umeå 2013 Umeå Studies in Philosophy 11 Department of Historical, Philosophical and ISSN 1650-1748 Religious Studies ISBN 978-51-7459-679-3 Umeå University, 901 87 Umeå www.idesam.umu.se Umeå Studies in Philosophy 11 It’s All in the Brain A Theory of the Qualities of Perception Jesper Östman Akademisk avhandling som med vederbörligt tillstånd av Rektor vid Umeå universitet för avläggande av filosofie doktorsexamen framläggs till offentligt försvar i Hörsal F, Humanisthuset måndagen den 10 juni, kl. 13:15. Avhandlingen kommer att försvaras på engelska. Fakultetsopponent: Professor, Howard Robinson, Department of Philosophy, Central European University, Budapest, Hungary. Institutionen för idé- och samhällsstudier Umeå universitet Umeå 2013 Organization Document type Date of publication Umeå University Doctoral thesis 20 May 2013 Department of Historical, Philosophical and Religious Studies Author Jesper Östman Title It’s All in the Brain: A theory of the Qualities of Perception Abstract This dissertation concerns the location and nature of phenomenal qualities. Arguably, these qualities naively seem to belong to perceived external objects. However, we also seem to experience phenomenal qualities in hallucinations, and in hallucinations we do not perceive any external objects. I present and argue for a theory of the phenomenal qualities, "brain theory", which claims that all phenomenal qualities we experience are physical properties instantiated in the brain, regardless of whether they are experienced in veridical perceptions or in hallucinations. I begin by more carefully identifying the phenomenal qualities, discussing how they are related to "qualia" and "phenomenal character". Then I present brain theory, and investigate its implications for the perceptual relations we stand in to external objects, noting that it is mostly neutral. I also compare brain theory to a similar theory of perception advocated by Bertrand Russell. Next, I provide an overview over the competing theories of phenomenal qualities, and relate them to theories of perception, such as representationalism, qualia theory, sense data theory and disjunctivism. The majority of my argumentation for brain theory focuses on arguing that the phenomenal qualities are instantiated in the brain, rather than on arguing that they are physical properties. Instead, I largely assume physicalism. However, even independently of the physicalism assumption, I show that we have reason to believe that phenomenal qualities are experienced in hallucinations, and that qualities experienced in hallucinations are instantiated in internal objects, such as our brains or sense data. In the first step towards this conclusion I argue that theories which deny that phenomenal qualities are experienced in hallucinations face serious problems. In the next step I argue that theories which deny that phenomenal qualities experienced in hallucinations are instantiated in internal objects face serious problems. Finally, an important part of the argumentation is my replies to objections against brain theory, including common sense objections and the "observation objection". From these conclusions, together with the physicalism assumption, I infer that we have reason to believe that brain theory is true about hallucinations. On this basis, I then argue, through a generalizing argument, that the same is the case for veridical perceptions. Keywords Philosophy of perception, philosophy of consciousness, hallucination, phenomenal qualities, qualia, sense data, physicalism, Russell, disjunctivism, representationalism, brain theory, color, the brain. Language ISBN ISSN Number of pages English 978-91-7459-679-3 1650-1741 iv, 168 It‘s All in the Brain A Theory of the Qualities of Perception Jesper Östman Department of Historical, Philosophical and Religious Studies Umeå 2013 Umeå Studies in Philosophy 11 © Jesper Östman 2013 Series editors: Sten Lindström and Pär Sundström Department of Historical, Philosophical and Religious Studies Umeå University SE-901 87 Umeå, Sweden This work is protected by the Swedish Copyright Legislation (Act 1960:729) ISBN: 978-91-7459-679-3 ISSN: 1650-1748 Cover image is based on a drawing by Chippolito. Elektronisk version tillgänglig på http://umu.diva-portal.org/ Printed in Sweden by Print & Media, Umeå University, Umeå Distributor: Department of Historical, Philosophical and Religious Studies, Umeå University, SE-901 87 Umeå, Sweden. Umeå, Sweden 2013 To mother, father and grandmother Table of Contents Table of Contents i Abstract iii 1. Introduction 1 2. The phenomenal qualities 7 2.0 Introduction 7 2.1 Phenomenal qualities 7 2.2 Other ways of speaking about the phenomenal qualities 10 3. Brain theory 15 3.0 Introduction 15 3.1 Stating brain theory 15 3.2 Brain theory and spatial qualities 17 3.3 Brain theory and perceptual relations 24 3.4 Similarities to Russell 30 4. Theories of the phenomenal qualities 35 4.0 Introduction 35 4.1 Three questions about phenomenal qualities 35 4.2 II theories 38 4.3 EI theories 43 4.4 EX theories 46 4.5 EN theories 49 4.6 NN and XX theories 57 5. Preliminaries to the argumentation 61 5.0 Introduction 61 5.1 How I argue against the alternatives to brain theory 61 5.2 Definitions and theses 62 6. The experience thesis 67 6.0 Introduction 67 6.1 The knowledge-acquisition argument 67 6.2 The value argument 69 6.3 The first premise 71 6.4 The second premise 74 6.5 The no value objection 76 6.6 The disassociation objection 77 6.7 The final inference 79 7. The instantiation thesis 83 7.0 Introduction 83 7.1 Property-ism 83 7.2 Platonism 84 7.3 Aristotelianism 92 7.4 Nominalism 97 7.5 Trope theory 99 i 7.6 Nothingism and Meinongianism 101 8. Physicalism 107 8.0 Introduction 107 8.1 Type physicalism 107 8.2 The arguments for physicalism 107 8.3 The anti-physicalist arguments 111 9. Generalizing to the veridical case 115 9.0 Introduction 115 9.1 The first step 116 9.2 The identity argument 117 9.3 The third step 118 9.4 The causal generalizing argument 120 10. Objections and replies 125 10.0 Introduction 125 10.1 The observation objection 125 10.2 The common sense objection 130 10.3 The extension objection 133 10.4 The epistemic objection 137 10.5 The phenomenal intransitivity argument 140 11. Brief summary of the results 147 Acknowledgements 149 References 151 ii Abstract This dissertation concerns the location and nature of phenomenal qualities. Arguably, these qualities naively seem to belong to perceived external objects. However, we also seem to experience phenomenal qualities in hallucinations, and in hallucinations we do not perceive any external objects. I present and argue for a theory of the phenomenal qualities, "brain theory", which claims that all phenomenal qualities we experience are physical properties instantiated in the brain, regardless of whether they are experienced in veridical perceptions or in hallucinations. I begin by more carefully identifying the phenomenal qualities, discussing how they are related to "qualia" and "phenomenal character". Then I present brain theory, and investigate its implications for the perceptual relations we stand in to external objects, noting that it is mostly neutral. I also compare brain theory to a similar theory of perception advocated by Bertrand Russell. Next, I provide an overview over the competing theories of phenomenal qualities, and relate them to theories of perception, such as representationalism, qualia theory, sense data theory and disjunctivism. The majority of my argumentation for brain theory focuses on arguing that the phenomenal qualities are instantiated in the brain, rather than on arguing that they are physical properties. Instead, I largely assume physicalism. However, even independently of the physicalism assumption, I show that we have reason to believe that phenomenal qualities are experienced in hallucinations, and that qualities experienced in hallucinations are instantiated in internal objects, such as our brains or sense data. In the first step towards this conclusion I argue that theories which deny that phenomenal qualities are experienced in hallucinations face serious problems. In the next step I argue that theories which deny that phenomenal qualities experienced in hallucinations are instantiated in internal objects face serious problems. Finally, an important part of the argumentation is my replies to objections against brain theory, including common sense objections and the "observation objection". From these conclusions, together with the physicalism assumption, I infer that we have reason to believe that brain theory is true about hallucinations. On this basis, I then argue, through a generalizing argument, that the same is the case for veridical perceptions. iii Keywords: Philosophy of perception, philosophy of consciousness, hallucination, phenomenal qualities, qualia, sense data, physicalism, Russell, disjunctivism, representationalism, brain theory, color, brain iv 1. Introduction "The mind ... perceives nothing but its own ideas." - John Locke1 We experience certain salient qualities.2 These qualities seem to me to exhaust my sensory fields: to completely fill up my visual field, my auditory field, my olfactory field and so forth.3 Naively, I take them to be colors, shapes, tastes, sounds and other such properties which we experience in perception. When thinking about these qualities, I can easily focus on the