UC San Diego UC San Diego Electronic Theses and Dissertations Title Unmitigated Skepticism: The Nature and Scope of Pyrrhonism Permalink https://escholarship.org/uc/item/6fk1n2b1 Author Wong, Andrew David Publication Date 2017 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA, SAN DIEGO Unmitigated Skepticism: The Nature and Scope of Pyrrhonism A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Philosophy by Andrew David Wong Committee in charge: Professor Monte Johnson, Chair Professor Casey Perin, Co-Chair Professor Samuel Rickless Professor Donald Rutherford Professor Edward Watts 2017 © Andrew David Wong, 2017 All rights reserved. The Dissertation of Andrew David Wong is approved, and it is acceptable in quality and form for publication on microfilm and electronically: Co-Chair Chair University of California, San Diego 2017 iii DEDICATION To my mother and father iv EPIGRAPH By way of preface let us say that on none of the matters to be discussed do we affirm that things certainly are just as we say they are: rather, wereport descriptively on each item according to how it appears to us at the time. Sextus Empiricus v TABLE OF CONTENTS Signature Page ................................... iii Dedication ..................................... iv Epigraph ...................................... v Table of Contents ................................. viii List of Abbreviations ................................ ix List of Symbols ................................... x List of Figures ................................... xi Acknowledgments ................................. xii Vita ......................................... xiii Abstract of the Dissertation ............................ xiv Introduction .................................... 1 1 Sextus Empiricus and Pyrrhonian Skepticism ................ 4 1.1 A Brief History ............................... 4 1.2 The Works of Sextus Empiricus ..................... 8 1.3 The Skeptical Approach to Philosophy ................. 10 1.4 How Skepticism Operates ......................... 12 1.4.1 Skepticism is an ability. ...................... 13 1.4.2 The Skeptic’s ability is the ability to set out oppositions among things. ................................ 14 vi 1.4.3 The opposed things are those which appear and are thought of in any way at all. .......................... 21 1.4.4 The exercise of the Skeptic’s ability, in conjunction with equipol- lence, results in suspension of judgment. ............. 25 1.4.5 Suspension of judgment is followed by tranquility. ........ 29 1.4.6 Summary and Conclusion ..................... 34 1.5 The Search for Truth ........................... 37 1.6 The Role of Belief ............................. 42 2 The Force of Pyrrhonism ............................ 48 2.1 The Skeptical Modes ........................... 48 2.2 The Five Modes of Agrippa ........................ 50 2.3 The Pyrrhonian Problematic ....................... 55 2.4 The Problematic as a Declarative Argument .............. 65 2.5 Reconceiving the Problematic Procedurally ............... 73 3 A Procedure for Unmitigated Skepticism ................... 84 3.1 The Interpretive Groundwork ...................... 84 3.2 The Procedural Account ......................... 93 3.3 The Effects of the Procedure ....................... 111 3.4 The Significance of the Procedure .................... 115 4 Pyrrhonian Moral Skepticism ......................... 121 4.1 A Skeptical Commitment? ........................ 121 4.2 The Legacy of Aenesidemus ....................... 125 4.3 Sextus’ Historical Development ..................... 129 4.4 The Argument for Consistency ...................... 140 vii A The Ten Modes of Aenesidemus ....................... 148 B The Two Modes ................................ 151 C The Eight Aetiological Modes ......................... 155 Bibliography .................................... 157 viii LIST OF ABBREVIATIONS Acad. Cicero, Academica Diff. Puls. Galen, De Differentiis Pulsuum DL Diogenes Laertius, Lives of Eminent Philosophers LS Long and Sedley, The Hellenistic Philosophers LSJ Liddell, Scott, and Jones, A Greek-English Lexicon M Sextus Empiricus, Against the Mathematicians PH Sextus Empiricus, Outlines of Pyrrhonism Praen. Galen, De Praegnotione ad Epigenem ix LIST OF SYMBOLS ¬ Negation ∧ Conjunction ∨ Disjunction → Material Conditional ↔ Material Biconditional ∀ Universal Quantifier ∃ Existential Quantifier ∈ Set Membership ⇒ Logical Implication ⇔ Logical Equivalence ℕ The Set of Natural Numbers ℤ The Set of Integers x LIST OF FIGURES Figure 1.1: An overview of the operation of skepticism. ........ 35 Figure 3.1: A reproduction of Barnes’ (1990d) diagram of his “System of Three Modes” (120). ................... 88 Figure 3.2: A single claim can have more than one index value if it appears multiple times in the sequence of support. .... 99 Figure 3.3: A network of multiple, branching support relations. ... 101 Figure 3.4: If the sequence of support terminates in an unsupported claim, the Skeptic makes an incompatible unsupported claim. ............................. 104 Figure 3.5: Basic circularity. Every claim in the circle supports and is supported by another claim in the circle. ......... 105 Figure 3.6: Pure circularity. No claim in the circle receives support from any claim outside the circle. ............. 106 Figure 3.7: Mixed circularity. At least one claim in the circle receives support from some claim outside the circle. ........ 107 Figure 3.8: Infinite regress. ........................ 110 Figure 3.9: The Procedure represented as a flowchart. ......... 112 Figure 4.1: A map of the logical space. Asterisks indicate hitherto unendorsed positions. .................... 125 Figure A.1: The structure of the Ten Modes of Aenesidemus. .... 150 Figure B.1: A reproduction of Barnes’ (1990d) diagram of the “System of Two Modes” (118). .................... 154 xi ACKNOWLEDGMENTS I owe a special debt of gratitude to Monte Johnson and Casey Perin for serving as the co-chairs of my doctoral committee. This dissertation would not have been possible without their steadfast support. I am also especially grateful to Samuel Rickless, Donald Rutherford, and Edward Watts for serving as members of my doctoral committee. The many detailed and constructive sets of comments they have provided on past versions of this work have been invaluable. For many fruitful discussions about Pyrrhonism in general and my work in particular, I wish to thank Clinton Tolley, Blythe Greene, Greg Gandenberger, the participants of Monte Johnson’s seminar on Pyrrhonian Skepticism, the partici- pants of Daniel Schwartz’s Science and Certainty conference, and the participants of the UC San Diego History of Philosophy Roundtable. I am truly fortunate to have been surrounded by such philosophical excellence. Last, but certainly not least, I will be eternally grateful to Mariska Leunissen, Dennis DesChene, John Heil, and Eric Brown for guiding the early development of my thought and work on Pyrrhonism. Material from Chapters 2 and 3 has been included in the following paper, which has been submitted for publication: Wong, Andrew David. “Procedural Pyrrhonism”. The dissertation author was the sole author of this material. xii VITA 2017 Ph.D. in Philosophy, University of California, San Diego 2013 C.Phil. in Philosophy, University of California, San Diego 2009 A.B. magna cum laude in Philosophy, Washington University in St. Louis xiii ABSTRACT OF THE DISSERTATION Unmitigated Skepticism: The Nature and Scope of Pyrrhonism by Andrew David Wong Doctor of Philosophy in Philosophy University of California, San Diego, 2017 Professor Monte Johnson, Chair Professor Casey Perin, Co-Chair The “scope” of Pyrrhonian Skepticism refers to the extent to which Skeptics bear epistemic commitments. There are two respects in which the debate between unmitigated and mitigated interpretations of Skepticism is significant. First, there is the philosophical question of which version of Pyrrhonism is more coherent and compelling when considered on its own merits. Second, there is the historical question of which sort of interpretation accurately characterizes Pyrrhonism itself, xiv as it is presented in the works of Sextus Empiricus. My own arguments proceed accordingly. On the philosophical front, I argue (primarily in Chapters 2 and 3) that when the force of the Skeptical modes is fully understood, they are unmitigated in scope. On the historical side, I argue (primarily in Chapters 1 and 4) that an unmitigated interpretation of Pyrrhonism is consistent with the Sextan corpus. Throughout, my ultimate aim is to present a vision of unmitigated skepticism that is, if not an expression of the historical reality of Pyrrhonism, at least a direct descendant of it. The central argument concerns the Five Modes of Agrippa, which are widely regarded as comprising the most powerful argument of Pyrrhonian Skepticism: the “Pyrrhonian Problematic.” The intuitive force of the Problematic lies in its generality. It threatens to cast into doubt every claim that can be advanced on every subject. According to the standard interpretation, the Problematic achieves this by constituting a declarative argument that consists of appealing premises and the conclusion that epistemic justification is impossible. I argue that this interpretation fails to capture the intuitive force of the Prob- lematic in two ways: First, it is