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LEIBNIZ

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LEIBNIZ Deterministy Theist, Idealist ROBERT MERRIHEW ADAMS OXFORD UNIVERSITY PRESS New York Oxford

Oxford University Press Oxford New York Athens Auckland Bangkok Bogota Buenos Aires Calcutta Cape Town Chennai Dar es Salaam Delhi Florence Hong Kong Istanbul Karachi Kuala Lumpur Madrid Melbourne Mexico City Mumbai Nairobi Paris Sao Paulo Singapore Taipei Tokyo Toronto Warsaw and associated companies in Berlin Ibadan Copyright 1994 by Robert Merrihew Adams First published in 1994 by Oxford University Press, Inc. 198 Madison Avenue, New York, New York 10016 First issued as an Oxford University Press paperback, 1998 Oxford is a registered trademark of Oxford University Press, Inc. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of Oxford University Press. Library of Congress Cataloging-in-Publication Data Adams, Robert Merrihew. Leibniz : determinist, theist, idealist / Robert Merrihew Adams. p. cm. Includes bibliographical references and indexes. ISBN 0-19-508460-8 ISBN 0-19-512649-1 (pbk.) 1. Leibniz, Gottfried Wilhelm, 1646-1716. I. Title. 135798642 Printed in the United States of America on acid-free paper

For my mother, Margaret Baker Adams, the historian of our family

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Preface I did not set out to write a book on Leibniz. Through more than twenty years I have taught graduate and undergraduate courses on the philosophy of Leibniz once at the University of Michigan, and more times than I can now enumerate at UCLA, usually at intervals of two or three years. My debt to the students, and sometimes colleagues, who attended those classes is enormous, and no longer specifiable in detail. About fifteen years ago I began to publish articles on Leibniz. Eventually, at the suggestion of colleagues, I began to think about publishing a collection of papers on Leibniz, and set out to write a couple of new ones to complete the collection. These grew, and the older pieces were thoroughly revised, and in large part reorganized and rewritten, and all the pieces acquired multiple cross-references to each other. The result is a book, and no longer a collection of papers. The majority of the material is new. Chapter 1 is a reworking of "Leibniz's Theories of Contingency," Rice University Studies, 63, No. 4 (Fall 1977), pp. 1 41. Chapter 2 and much of Chapter 3 are a reworking of "Predication, Truth, and Trans-World Identity in Leibniz," which was published in How Things Are: Studies in Predication and the History and Philosophy of Science, edited by James Bogen and James E. McGuire (Dordrecht: Reidel, 1985), pp. 235-83. Some material in Chapter 8 comes from "Presumption and the Necessary Existence of God," Nous 22 (1988): 19-32. Chapters 9 and 10 contain much material from "Phenomenalism and Corporeal Substance in Leibniz," Midwest Studies in Philosophy 8 (1983): 217-57. A German version (not in all parts exactly a translation) of much of the material of Chapter 11 is forthcoming in Studia Leibnitiana, vol. 25 (1993), under the title, "Form und Materie bei Leibniz: die mittleren Jahre." I am grateful to the publishers of these pieces for their permission to reprint the material here. I am grateful also to the many scholars with whom I have discussed Leibniz and related topics, orally and in writing, over the years, particularly to Marilyn McCord Adams, Wallace Anderson, David Blumenfeld, Herbert Breger, Tyler Burge, John Carriero, Keith DeRose, John Earman, Ursula Franke, Amos Funkenstein, Daniel Garber, Glenn Hartz, Paul Hoffman, Jeremy Hyman, William Irvine, Nicholas Jolley, Marianne Kooij, Mark Kulstad, Marc Lange, Marianne Laori, Louis Loeb, J. E. McGuire, Fabrizio Mondadori, Massimo Mugnai, Alan Nelson, Derk Pereboom, Ayval Ramati, Nicholas Rescher, Marleen Rozemond, Donald Rutherford, Heinrich Schepers, Robert C. Sleigh, Jr.,

viii Preface Houston Smit, Margaret Wilson, Norton Wise, and Robert Yost. John Carriero, Daniel Garber, and Paul Hoffman provided extremely valuable written comments on part of the work. Marleen Ro/emond and later Ayval Ramati gave important help as my research assistants. I have benefited from the extraordinary scholarly generosity of Heinrich Schepers and associates at the Leibniz-Forschungsstelle of the University of Miinster and the late Albert Heinekamp and associates at the Leibniz Archive of the Niedersachsische Landesbibliothek in Hannover, who made the documents on which they are working available to me and other scholars. Professor Schepers was particularly helpful with advice about the dating of texts. Robert Sleigh and Massimo Mugnai were also generous in sharing texts. I am grateful to UCLA for sabbatical support during the first writing of Chapters 9 and 10 and for funding research assistance in the later stages, but mainly for providing the environment for research and especially for teaching in which this book developed. I was inspired by generous encouragement of the project from my colleagues Alan Nelson, David Kaplan, Robert Yost, and the late Montgomery Forth. The book would be much poorer, if it would exist at all, without the stimulus of the splendid graduate students we have had in our department. It is a pleasure to record these debts of gratitude. Los Angeles, California June 1993 R.M.A.

Contents Introduction, 3 I. Determinism: Contingency and Identity 1. Leibniz's Theories of Contingency, 9 1. Leibniz's First Main Solution, 10 2. Leibniz's Second Main Solution, 22 3. Leibniz and Possible Worlds Semantics, 46 4. On Leibniz's Sincerity, 50 2. The Logic of Counterfactual Non-identity, 53 1. Problems of Transworld Identity, 53 2. The Conceptual Containment Theory of Truth, 57 3. Actuality in the Conceptual Containment Theory, 63 4. An Anti-Semantical Theory of Truth, 65 5. Why Did Leibniz Hold the Conceptual Containment Theory?, 67 6. Conceptual Containment and Transworld Identity, 71 3. The Metaphysics of Counterfactual Nonidentity, 75 1. Substance and Law, 77 2. Substance and Miracle, 81 3. Perception and Relations, 102 4. Conclusions, 106 Appendix: A Priori and A Posteriori, 109 II. Theism: God and Being 4. The Ens Perfectissimum, 113 1. Absolute Qualities as "Requirements" of Things, 115 2. Sensible Qualities, Knowledge, and Perfection, 119 3. Is Leibniz's Conception of God Spinozistic?, 123

X Contents 5. The Ontological Argument, 135 1. The Incomplete Proof, 136 2. Proof of Possibility, 141 6. Existence and Essence, 157 1. Is Existence an Essential Quality of God?, 158 2. Defining Existence, 164 3. Existence Irreducible, 170 7. The Root of Possibility, 177 1. The Proof of the Existence of God from the Reality of Eternal Truths, 177 2. Leibniz's Theory Examined, 184 8. Presumption of Possibility, 192 1. Jurisprudence and Pragmatism in Theology, 194 2. Jurisprudence and the Logic of Probability, 198 3. A Proof for the Presumption of Possibility, 202 4. Presuming the Possibility of Beings as Such, 206 5. Objections Considered, 209 III. Idealism: Monads and Bodies 9. Leibniz's Phenomenalism, 217 1. Phenomena, 219 2. Esse Is Per dpi, 235 3. Aggregates, 241 4. The Reality of Phenomena, 255 10. Corporeal Substance, 262 1. Bodies and Corporeal Substances, 262 2. The Structure of a Corporeal Substance: Alternative Interpretations, 265 3. The Structure of a Corporeal Substance: Some Texts, 274 4. Monadic Domination, 285 5. Principles of Unity, 291 11. Form and Matter in Leibniz's Middle Years, 308 1. Form, 309 2. Matter, 324 3. Realism, 338

Contents 12. Primary Matter, 341 1. Three Senses of "Matter" in a Letter to Arnauld, 341 2. Matter and the Eucharist, 349 3. Bernoulli's Questions, 361 4. The Debate about Thinking Matter, 364 5. Conclusions, 375 13. Primitive and Derivative Forces, 378 1. The "Mixed" Character of Derivative Forces, 378 2. Primary Matter and Quantity, 393 Bibliography, 401 Index of Leibniz Texts Cited, 411 General Index, 423 xi

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LEIBNIZ

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Introduction The last twenty years or so have seen a flowering of Leibniz studies. The organizers of a recent international workshop called it "the Leibniz renaissance." 1 In the United States interest in the philosophy of Gottfried Wilhelm Leibniz (1646-1716) was enhanced in the 1970s by the excitement over modal logic and "modal metaphysics." The idea of a possible world was central to these developments, and that gave them an obvious connection with Leibniz. I think there was also a subtler and deeper, though perhaps more debatable, connection between Leibniz and the new work in modal metaphysics. From its beginning, partly through the influence of the Vienna Circle, analytical philosophy had been Kantian rather than Leibnizian in its methodology. By that I mean that its treatment of philosophical topics, especially in metaphysics, tended to be governed by epistemological views and subject to strict, prior epistemological constraints. It was characteristic of much early modern philosophy, and especially the critical philosophy of Kant, to assign a dominant role to epistemology. Of the great early modern philosophers, however, Leibniz was probably the least preoccupied with epistemology. He was typically willing to begin an argument with whatever seemed true to him and might seem true to his audience, without worrying too much about whether epistemology would present it as something we can really know. Much of the development of modal metaphysics in the 1970s and since has proceeded in this Leibnizian way perhaps because of the strength of the grip that certain "intuitions" have had on many of the philosophers involved in the movement. The Leibnizian approach to metaphysics might seem embarrassingly uncritical, and perhaps it would be if strong constraints on metaphysics could be derived from an epistemology that deserved our full confidence. If we view available epistemologies more skeptically, however, we may think that they are not generally more reliable than our "intuitions," and that we cannot usually do better than to begin our thinking with what seems right to us. Our interpretation of Leibniz need not depend on our own stance on this issue. Excellent work on his thought has been done by philosophers whose views on methodology in meta- 1 Centre Florentine, Leibniz Renaissance. I give all references by abbreviations or by short names and titles; full details are found in the bibliography. 3

4 Introduction physics are quite opposed to his. 2 For better or worse, however, this is a point on which my own views are supportive of Leibniz. Leibniz: Determinist, Theist, Idealist is not an introduction to Leibniz's philosophy, nor even a fully comprehensive account of his metaphysics. It is a piece of research into three areas related to the three attributes mentioned in the title. 3 The three topics are connected, as is everything in Leibniz's thought. My development of the first is presupposed in my treatment of the other two. That Leibniz was a theist is hardly debatable. How much a determinist and how much an idealist he was are more controversial; I believe he was more of both than some interpreters have thought. I am not sympathetic with his determinism, but am very much in sympathy (though not in detailed agreement) with his theism and his idealism. The question of Leibniz's determinism has drawn much recent attention, in large part because of its connection with two theses related to modal metaphysics. One is Leibniz's doctrine that every predicate true of any substance is contained in the individual concept of that substance. The other is his closely related denial of counterfactual individual identities his denial that Antoine Arnauld, for example, would have existed, and been the same individual, if he had married. These theses have held fascination for students interested in the relation of logic to metaphysics. The second has been seen as a rejection of what has been known in recent modal metaphysics as "transworld identity." The first has been one of the grounds for suspicion that no truths at all can be contingent for Leibniz. These issues, and others connected with them, form the subject of Part I of the book. One theme that emerges from my argument there (a theme in tune with much of the most recent Leibniz scholarship) is that Leibniz's views on these topics are less dominated by his logical doctrines than was thought by Bertrand Russell and Louis Couturat, the most influential Leibniz scholars of the early part of our century. Leibniz's view of the problems was largely shaped by his theology, and his use of logical doctrines in dealing with them cannot be understood apart from such metaphysical conceptions as that of substantial form. The metaphysical core of Leibniz's philosophical theology has attracted less attention than its intrinsic interest deserves. In some ways it is also the core of his metaphysics. It is intricately connected with his logical doctrines and is the context for his fullest reflections about the nature of existence and of essence, and also about the most general structural relationships of the properties of things. These topics are discussed in Part II of the book, in the framework of a comprehensive study of Leibniz's treatment of the ontological argument for the existence of God, which I regard as exceptionally interesting. I do not think Leibniz's or any other version of the ontological argument is likely to convince many people of the existence of God, but a related argument, which seems to me to have more persuasive force, and perhaps to be the most promising of all a priori arguments for the existence of God, is discussed in Chapter 7. One reason for the neglect of this part of Leibniz's thought 2 For such disagreement by fine scholars, see, e.g., Mates. Philosophy of Leibniz, p. 51, and C. Wilson, "Critical and Constructive Aspects of Leibniz's Monadology," p. 293. 'What I have to say about another major topic of Leibniz's metaphysics, the identity of indiscernibles, has been said in a much less historical context in R. Adams, "Primitive Thisness and Primitive Identity."

Introduction 5 is that its fullest development, in most respects, came in his early years, and many of the most important texts were quite inaccessible until the relevant volume of the Academy edition of Leibniz's works (A VI,iii) was published in 1980.1 have tried to give a full account of the most important texts. Leibniz's doctrine of monads and his theory of the physical world may have been overshadowed at times by the interest in his philosophy of logic, but they can hardly be said to have been neglected. How could they be neglected? In teaching about Leibniz I have always found that students are instantly fascinated by the monads, and full of questions about them. At the same time, Russell's wellknown report that he initially "felt... the Monadology was a kind of fantastic fairy tale, coherent perhaps, but wholly arbitrary," 4 resonates with the first impressions of many students. In fact, I believe that Leibniz's theory of monads, in its essentials, though not in all its details, represents an important, permanent metaphysical alternative, one of the handful of fundamental views in this area that has a real chance of being true. I would not claim to prove that much here, but I will try to give in Part III a full account of Leibniz's view, including those of his arguments that seem to me of most permanent importance, and those aspects of his view that may commend it as preferable to other forms of idealism or phenomenalism. I argue that throughout the mature period of his thought (1686-1716), his view is as idealistic as is implied in his statement of 1704 that "there is nothing in things except simple substances, and in them perception and appetite" (G II,270/L 537). Some interpreters have tried to find more realistic commitments in some period or strand of his mature philosophy, and some of these attempts are addressed in Part III. Particular attention is paid to interpretations that find more realistic implications in Leibniz's efforts to rehabilitate certain Aristotelian Scholastic conceptions; I argue that the Aristotelian conceptions that Leibniz undoubtedly does use are employed in the service of his idealism. I have tried throughout to maintain a rigorously historical approach, attempting to establish as accurately as possible, and with the best evidence possible, what Leibniz actually said and meant. This is not to say that my approach is unphilosophical. I believe that historical accuracy and careful attention to the historical context are important to the philosophical as well as the historical value of work in the history of philosophy and, conversely, that philosophical argument and critique are important for historical understanding in philosophy. One reason for the philosophical importance of patient and careful attention to the actual meaning of Leibniz's writings in their historical context is that he was indeed a great philosopher, great enough that an arbitrary interpretation of his work, more relevant to our historical context than to his, is unlikely to be as interesting philosophically in the long run as what he actually thought. Indeed, the very strangeness of his context, and of some of his thoughts, is a boon for philosophy. Progress in philosophy is more likely to consist in understanding possible alternatives than arriving at settled conclusions. And we are familiar enough with the familiar; part of what the great dead philosophers offer us is alternatives to our usual way of thinking alternatives thought out in great 4 Russell, Philosophy of Leibniz, p. xiii.

6 Introduction depth and with uncommon rational sensitivity. Part of what we are doing in studying the history of philosophy, moreover, is placing our own philosophizing in its largest context in a conversation that has been going on for many hundreds of years. Just as we are likely to understand better what we are doing in any discussion if we accurately remember and understand how it has gone, so we are likely to understand our own philosophizing better if our conception of its longer historical context is accurate. As for the value that philosophical argument and critique have for historical understanding, I believe that R. G. Collingwood's view, that the proper method of history is that of rethinking past thoughts in one's own mind, 5 is largely true of the history of philosophy. The aim of the rethinking is to discover the inner rationale of the thoughts one studies. As Collingwood recognized, this method can be fruitfully applied only to thoughts (and actions) that lend themselves to understanding in terms of a rationale. It therefore may not be applicable to as much of history as Collingwood may have hoped. But if applicable anywhere, it is surely applicable in the history of philosophy, where the objects selected for study, for philosophical reasons, are always people whose thoughts are believed to have had a notable rationale. The rationale is a structure that there is a permanent possibility of recreating in thought a point that fits nicely with Collingwood's idealism. The historical question in the history of philosophy is what the actual rationale was. It is a question we cannot very well answer without attaining a good philosophical understanding of the rationale. To do that, we must try to develop the arguments involved in the rationale, and we must subject the rationale, as we understand it, to searching criticism. For it is a piece of philosophy we are trying to understand, and argument and criticism are essential to philosophy. This approach may sound, and my practice of it may seem, too ethereal for some historians. Other approaches may be more appropriate for other historical subjects, but I think this one is appropriate for the history of philosophy. I have tried to pay attention to the relation of Leibniz's metaphysics to its intellectual context, including the scientific and especially the religious thought of his time, and the social pressures at work in the discussions he was involved in. Yet my principal concern is with the intrinsic rationale of his thought. I have made no general application of a hermeneutics of suspicion. Not that I think (nor would Leibniz himself have thought) that he was free of hidden and unconscious motives. On some points, the project of understanding his rationale itself requires some attention to suspicions of insincerity in his statements. In the end, however, Leibniz's reasons are more interesting than his motives. He had one of the most brilliant intellects of all time, but he was not particularly impressive in the more practical aspects of his life. His writings contain a reasoned structure of thought (at least one) that has a permanent claim on the attention of philosophers, whether or not it accurately reflects all the motives that may have underlain his writing as well as his other conduct. What is most interesting about such a person is likely to be best understood by a historian whose training and interests are primarily philosophical. 'Collingwood, Idea of History, pp. 205-31.

I Determinism: Contingency and Identity