THE UNIVERSITY OF CHICAGO ARISTOTLE ON THE NECESSITY OF WHAT WE KNOW A DISSERTATION SUBMITTED TO THE FACULTY OF THE DIVISION OF THE HUMANITIES IN CANDIDACY FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF PHILOSOPHY BY JOSHUA MENDELSOHN CHICAGO, ILLINOIS JUNE 2019 TABLE OF CONTENTS ACKNOWLEDGMENTS . iv ABSTRACT . v 1 INTRODUCTION . 1 1.1 Aristotle on what we know ........................... 1 1.2 Previous approaches ............................... 7 1.3 Some first steps toward an answer ....................... 25 1.4 Chapter breakdown ................................ 34 2 ARISTOTLE’S DURABILITY ARGUMENTS . 36 2.1 Knowledge in the Categories ........................... 36 2.1.1 Knowledge as a relative: Categories 7 . 36 2.1.2 Knowledge as a state: Categories 8 ................... 51 2.1.3 The tension between the two principles . 59 2.2 When what is changeable goes out of view: Nicomachean Ethics VI.3 . 66 2.2.1 The sense of “necessity” ......................... 74 2.2.2 A Platonic precursor: Theaetetus 163c–164b . 75 2.3 Durability and demonstration: Posterior Analytics I.6 . 79 2.4 Knowledge of sensible particulars: Metaphysics Ζ.15 . 86 2.5 Taking stock ................................... 88 3 THE OBJECT OF KNOWLEDGE . 90 3.1 The introduction of the Forms ......................... 93 3.2 The irrelevance of the Forms .......................... 96 3.3 Essentiality and necessity: Posterior Analytics I.4 . 102 3.3.1 “Of all” and “per se” . 103 3.3.2 Per se predications and necessity . 108 3.3.3 “Universal” ................................112 3.3.4 Demonstrative necessities concerning individuals . 115 3.4 Per se necessity in natural science . 120 3.4.1 Per se necessity in biology: Parts of Animals II.3 . 120 3.4.2 Necessities like the eclipse of the moon: Posterior Analytics I.8 . 126 3.5 Conclusion: Per se necessity as an alternative to the Forms . 131 4 THE SOURCE OF DEMONSTRATIVE NECESSITY . 134 4.1 The structure of Aristotle’s answer: Metaphysics Δ.5 . 135 4.2 Truth concerning incomposites: Metaphysics Θ.10 . 146 4.2.1 The term reading and the existential reading . 151 4.3 Incomposites as “things with no other cause” . 160 4.4 Truths about incomposites and demonstrative principles . 172 4.4.1 Proper principles and per se predications . 173 ii 4.4.2 Per se truths and truths about incomposites . 177 4.4.3 Axioms ..................................180 4.5 Incomposites in the natural sciences? . 184 4.6 Appendix: The role of the Principle of Non-Contradiction in demonstration 190 5 NECESSITY AND OUR KNOWLEDGE OF NATURE . 193 5.1 Leunissen on necessity and teleology . 196 5.2 Aristotle on necessity in nature: Parts of Animals I.1 . 200 5.3 Truth for the most part as interrupted necessity: Prior Analytics I.13 . 208 5.4 Necessity and exceptions in natural and mathematical sciences . 219 5.5 Necessity and complexity: Physics II.9 . 225 CONCLUSION AND OUTLOOK . 229 APPENDIX: EPISTĒMĒ AS UNDERSTANDING . 232 A.1 Burnyeat’s proposal ................................232 A.2 Knowledge and explanation ............................238 A.3 Further doubts about epistēmē as understanding . 240 BIBLIOGRAPHY . 244 INDEX LOCORUM . 260 iii ACKNOWLEDGMENTS I am enormously indebted to each of the members of my committee (Martha Nussbaum, Marko Malink, Michael Kremer and Agnes Callard) for their patience, flexibility, probing feedback and tireless support. Over the course of writing this dissertation, the Ancient Greek and Roman Philosophy Workshop at the University of Chicago has provided not only exceptionally thoughtful feedback but a supportive community. I also received im- portant feedback on chapter two from an audience at the 2017 Annual Conference of the Australasian Association of Philosophy and on chapter four from the audience of the 2018 Marquette Summer Seminar on Aristotle and the Aristotelian Tradition. I am grateful for conversations with Serena Lai, Arnold Brooks, Dhananjay Jagannathan, Elana Co- may del Junco, Rik Peters, Josh Trubowitz, Matt Teichman, Ryan Simonelli, Martijn Wallage, Stephen Cunniff, Nic Koziolek, Justin Vlastis, Chris Hauser, Christoph Roser, Whitney Schwab, Toomas Lott, Dominic Dold, James Lee, Molly Brown, Hannah McK- eown, Tama Coutts, David Bronstein, Anubav Vasudevan, Gabriel Lear, Robert Bolton, Anselm Mueller, Emily Katz and other faculty and graduate students at the University of Chicago and New York University. I owe a special thanks to Bronwyn Lommel, who read the entire manuscript and pointed out numerous typographical errors and mistakes. iv ABSTRACT Aristotle holds that we only have scientific knowledge of what cannot be otherwise. This may seem to imply that we only have scientific knowledge of changeless mathematical truths and other products of a priori reflection. Yet Aristotle is a pioneer of natural science, and exhorts us to study the natural world, which he himself characterizes as a realm of contingency, exception and chance. This dissertation asks why Aristotle holds the view that we only know what cannot be otherwise and whether he is able to reconcile this view with his engagement in and esteem for natural science, especially the study of animals. Aristotle holds that we only have scientific knowledge of necessities, I argue, as a way to reconcile his view that knowledge requires persisting agreement with the world and his view that scientific knowledge remains stable over time. Properly understood, Aristotle’s claim does not pose a threat to the possibility of natural science but rather is at the heart of an attempt to explain how the study of nature is possible. We can have scientific knowledge about changeable and capricious things because the content of our knowledge strictly extends only to those facts about them that remain perpetually true on account of their essences. v CHAPTER 1 INTRODUCTION 1.1 Aristotle on what we know Aristotle claims that anything that is known “cannot be otherwise,”1 or is “necessary.”2 He frequently adds that the objects of knowledge are universal,3 eternal,4 and subject neither to generation nor corruption.5 The person who has knowledge in an unqualified sense must grasp what she knows as necessary.6 She must grasp the facts that constitute her knowledge as necessary truths that follow necessarily from the most fundamental truths, or “principles,” of the domain to which her knowledge belongs.7 This requires that she has analyzed the structure of what her knowledge is about “right down to its elements,”8 and implies that the items of our knowledge can be represented as the premises and conclusions of deductive proofs9 that articulate the structure of some genus or domain of study.10 Aristotle infers that there is strictly no knowledge of contingencies,11 of what occurs by 1. Post. An. I.2, 71b.12, 15–16, I.4, 73a.21, I.6, 74b.6. Translations of Aristotle are my own except where noted. Translations listed in the bibliography have however been con- sulted and occasionally phrases are borrowed without further explicit attribution. Epistēmē and epistasthai are translated with “knowledge” and “know”. On the translation of these terms, see section 1.2 below and the Appendix. 2. Post. An. I.33, 89a.10, I.4, 73a.22. 3. Post. An. I.31, 87b.38–39. 4. Nic. Eth. VI.3, 1139b.23. Cf. Post. An. I.8, 75b.22–24, I.31, 87b.28–39. 5. Nic. Eth. VI.3, 1139b.24. 6. Post. An. I.33, 89a.33–37. 7. Post. An. I.9, 75b.4–7. 8. Phys. I.1, 184a.14. 9. Post. An. I.2, 71b.16–23. 10. Post. An. I.10, 76b.13, I.28, 87a.38–87b.4. 11. Post. An. I.33, 88b.32–34. 1 chance,12 of the corruptible and the perishable,13 or of particulars at all.14 Of particulars there is merely “perception,”15 and of what can be otherwise there is no knowledge but only “belief.”16 Anyone who lacks a demonstrative proof of what they know from first principles or a grasp of its essence has knowledge only in a “sophistical”17 or “accidental”18 way. Aristotle’s reasons for these claims, which have been a sticking point for both his- torical19 and contemporary readers,20 are not easy to discern. The Posterior Analytics, especially the first book, develops these ideas by elaborating what is required of a proof so 12. Post. An. I.30, 87b.19. 13. Post. An. I.8, 75b.24–25, Nic. Eth. VI.3, 1139b.22–24. 14. Post. An. I.18, 81b.6–7, Rhet. Ι.2, 1356b.32–33. Cf. Post. An. I.31, 87b.28–39 and Met. Ζ.15, 1029b.27–1040a.5 (where, however, the point is limited to sensible particulars). 15. Post. An. I.18, 81b.6, I.33, 87b.29–30; cf. Top. II.8, 114a.23. 16. Post. An. I.33, 89a.30–35, Met. Ζ.15, 1039b.32–1040a.1. 17. Post. An. I.2, 71b.9–10. 18. Post. An. I.2, 71b.10, Nic. Eth. VI.3, 1139b.35. 19. Philosophers in the Jewish, Christian and Islamic traditions struggled with the conse- quences of these claims. Avicenna received censure for his claim that God knows particulars only “in a universal way,” which al-Ghazālī deemed irreligious in The Incoherence of the Philosophers (Marmura 2000, 134; Marmura 1962, 299). Peter Adamson has argued that Avicenna’s position was not a special theological doctrine but rather simply the application of a general Aristotelian theory of knowledge in the divine case: “the reason God does not ‘know particulars’ is very simple: there is no such thing as knowledge of particulars. This holds true for humans no less than for God” (Adamson 2005, 294). William of Auvergne struggled with the apparent consequence that God could not know the acts and prayers of individual people (Marenbon 1987, 113), while Henry of Ghent sought to explain the possibility of knowledge of a world that God could alter at will (Marenbon 1987, 148–49).