DISJUNCTIVISM, CAUSALITY, AND THE OBJECTS OF PERCEPTUAL EXPERIENCE A Thesis Submitted to the College of Graduate Studies and Research In Partial Fulfillment of the Requirements For the Degree of Master of Arts In the Department of Philosophy University of Saskatchewan Saskatoon By Brandon Murray Copyright Brandon Murray, August, 2014. All rights reserved. Permission to Use In presenting this thesis in partial fulfilment of the requirements for a Postgraduate degree from the University of Saskatchewan, I agree that the Libraries of this University may make it freely available for inspection. I further agree that permission for copying of this thesis in any manner, in whole or in part, for scholarly purposes may be granted by the professor or professors who supervised my thesis work or, in their absence, by the Head of the Department or the Dean of the College in which my thesis work was done. It is understood that any copying or publication or use of this thesis or parts thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of Saskatchewan in any scholarly use which may be made of any material in my thesis. Requests for permission to copy or to make other use of material in this thesis in whole or part should be addressed to: Head of the Department of Philosophy 9 Campus Drive University of Saskatchewan Saskatoon, SK Canada S7N 5A5 i ABSTRACT One of the most immediately compelling arguments against the disjunctivist position within the philosophy of perception points to the well-accepted fact that hallucinations can have the same neural cause as veridical perceptions; this is known as the causal argument. Since the main motivation for disjunctivism is to preserve naive realism, critics claim that naive realism is then incompatible with certain, well-accepted claims of neuropsychology, and, thus, disjunctivism is false. After surveying the general arguments for disjunctivism offered by Hinton, Snowden, and Martin, the causal argument is split into a stronger version and a weaker version. The strong argument relies on a narrow conception of the ‘same cause, same effect’ principle and this narrow conception is extremely controversial, ultimately entailing that mental events supervene only on the total brain state of an individual. The weak argument, which embraces a wider conception of the ‘same cause, same effect’ principle finds the disjunctivist position explanatorily redundant. The two major camps within disjunctivism, positive disjunctivism and negative disjunctivism, offer different approaches to the weak argument, and what emerges from the discussion of these two theories is that negative disjunctivism has a major dialectical advantage against positive disjunctivism, and that negative disjunctivism offers a satisfying response to the weak causal argument. M. G. F. Martin offers an insightful analysis of ‘indistinguishability’ and in doing so clarifies the disjunctivist thesis, sets limits to our understanding of our own mental states, and places the burden with the common-kind theorist. ii ACKNOWLEDGMENTS First and foremost, I wish to thank the students and faculty of the University of Saskatchewan’s Philosophy Department for providing endless insights and challenging discussions over the past two years. The philosophical musings within this document began as a curiosity borne out of these classroom dialogues, and they never ceased to provide material on which to build. Thank you for providing an environment where discussions of this type are capable of flourishing. Furthermore, I am extremely grateful for the financial assistance received in part with my Graduate Teaching Fellowship within the University of Saskatchewan, the support of which made this project plausible. I would like to express my utmost appreciation to those members of my committee, Prof. Eric Dayton, Prof. Emer O’Hagan, and external Prof. Ulrich Teucher, in offering their time, support, and recommendations. To my supervisor Prof. Phil Dwyer, who provided inspiration, patience, and philosophical scholarship of the highest degree, I thank you for your dedication and hard work. Last, but not least, I wish to thank my family and friends for their tremendous support and sustained interest in this long, demanding process. I am especially thankful for the love and support provided by my partner Emily Dueck, whose strength and determination is more than partially responsible for the completion of this project. iii TABLE OF CONTENTS page PERMISSION TO USE ....................................................................................................... i ABSTRACT ........................................................................................................................ ii ACKNOWLEDGMENTS ................................................................................................. iii CHAPTER I .........................................................................................................................1 1.1 The Argument from Illusion and the Common-Kind ............................................... 6 1.2 Why Disjunctivism?................................................................................................ 10 1.3 Hinton and the Disjunctive Position ....................................................................... 16 1.4 Snowden's Translucence and Martin's Naïve Realism ........................................... 21 1.5 Disagreements in Disjunctivism ............................................................................. 27 CHAPTER II ......................................................................................................................30 2.1 The Cartesion Position, the Moderate, and the Disjunctivist................................. 30 2.2 The Strong Causal Argument and SCP ................................................................... 31 2.3 Replies and Supervenience ..................................................................................... 37 2.4 The 'Weak' Causal Argument and the Highest Common Factor ............................ 41 CHAPTER III ....................................................................................................................47 3.1 Snowden and the Positive Disjunctivist Response ................................................. 47 2.4 Martin, Negative Disjunctivism, and Indiscriminability ........................................ 54 3.2 Objections to Martin ............................................................................................... 67 CONCLUSION ..................................................................................................................73 LIST OF REFERENCES ...................................................................................................75 BIBLIOGRAPHY ..............................................................................................................78 iv CHAPTER I The fact that there are numerous theories offered within the philosophy of perception is, in its own way, truly remarkable. When I sit back and reflect on my awareness of the world, it seems obvious, at least initially, that what I am aware of is conspicuously simple: the world itself. The answer to such a question is unmistakeable even for a child. What they are aware of could be their family members, a particular building or specific cloud, or a particularly intriguing creepy-crawly. That is, what they are aware of in their experience is simply those everyday objects that we encounter; perhaps leaving space for something a little more exotic should we ever encounter unfamiliar objects. This view is referred to as naive realism. Naive realism is the philosophical theory that states that the properties that objects possess, as perceived by a subject, are actual properties of the objects;1 the finish is smooth, the water is cool, the penny is round, etc. Furthermore, the objects of perception appear to have the properties they do in virtue of possessing those properties. That is, one is directly aware of external objects, as such. It may then be surprising to someone stumbling upon philosophy for the first time that a great many philosophers find this account unconvincing. These philosophers state that what we are aware of in experience is, strictly speaking, not the world. Rather, ‘experience’ is an intermediary between us and the world; what we are acquainted with in perception consists of a type of ‘mental’ object. Imagine looking at a stick partially submerged in water. To the perceiver the stick will appear bent, despite the fact that our perceiver knows perfectly well that sticks generally maintain their spatial dimensions when submerged. How then does the stick appear bent without actually being so? The traditional answer to such a question is that one is not aware 1 Alex Byrne & Heather Logue, “Introduction” in Disjunctivism, ed. Alex Byrne & Heather Logue (London, The MIT Press, 2009), xix. This anthology served as the main source of research. 1 of ‘the stick’ in the first place, rather the direct objects of our experience are intra-mental objects; a common-kind that is ‘observed’ both when one is veridically perceiving and when one encounters an illusion or hallucination. The reason the stick appears bent is because we do not directly perceive the stick, but instead perceive a mental object; we are only ever indirectly aware of the external objects of the world. It is for these reasons