GOTTFRIED WILHELM LEIBNIZ: THE ART OF CONTROVERSIES The New Synthese Historical Library Texts and Studies in the History of Philosophy
VOLUME 60
Managing Editor: Simo Knuuttila, University of Helsinki
Associate Editors: Daniel Elliot Garber, Princeton University Richard Sorabji, University of London
Editorial Consultants: Jan A. Aertsen, Thomas-Institut, Universität zu Köln Roger Ariew, University of South Florida E. Jennifer Ashworth, University of Waterloo Michael Ayers, Wadham College, Oxford Gail Fine, Cornell University R. J. Hankinson, University of Texas Jaakko Hintikka, Boston University Paul Hoffman, University of California, Riverside David Konstan, Brown University Richard H. Kraut, Northwestern University, Evanston Alain de Libera, Université de Genève John E. Murdoch, Harvard University David Fate Norton, McGill University Luca Obertello, Università degli Studi di Genova Eleonore Stump, St. Louis University Allen Wood, Stanford University
The titles published in this series are listed at the end of this volume. GOTTFRIED WILHELM LEIBNIZ
The Art of Controversies
Translated and Edited, with an Introductory Essay and Notes
by
MARCELO DASCAL Tel Aviv University, Israel
with
QUINTIN RACIONERO AND ADELINO CARDOSO ´ Library of Congress Control Number: 2008920394
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En un mot, l’art de conferer et disputer auroit besoin d’estre tout refondu. [In a word, the art of negotiating and disputing should be entirely redone.] Leibniz, Nouveaux essais sur l’entendement humain (4.7.11)
[…] you have to find a way to put the extremes together, not necessarily by diminishing the extremity of each one, but to form the art of transition. […] You have to keep the extremes but find the link, always find the link, so that there is an organic whole. Daniel Barenboim (In Barenboim and Said 2004: 68-69)
Et qui publice loquitur, pati debet publice contradicentem. [And the person who speaks in public must bear to be contradicted in public.] Leibniz, Letter to Honoré Fabri (GP IV 246) Contents
Abbreviations xi About the Apparatus xiii Acknowledgements xv Introductory Essay xix 1. Vices of Mingled Disputes 1 2. The Controversy of Controversies 7 3. The Religion of a Peasant 25 4. The Elements of Thinking 29 5. The Balance of Law 35 6. Can there be an Obligation to Believe? 41 A. First draft 42 B. New version 44 C. Final version 44 7. Controversies on Sacred Matters 49 8. The Judge of Controversies 55 A. First draft 57 B. Definitive version 58 C. Richelieu and De Groot on controversies 60 D. The utility of controversies 61 E. The most useful kind of controversies 61 F. Controversies 62 9. Towards a Heuristics for Litigation 65 A. Preserving form in litigation 65 B. All possible litigations 66 C. A handbook of practical litigations 67 D. Juridical commonplaces 68 E. Brocardic principles 70 F. The art of writing dialogues 72 10. The Method of Jurists and the Method of Doctors 75 11. Interpretation and Argumentation in Law 77 A. Prolegomena 78 B. On the interpretation, foundations, application 79 and system of laws 12. Towards a Heuristics for Discovery 93 A. The art of invention 94 B. Tables, divisions, and the plurality of methods 98 vii viii Contents
C. A principle of discovery 101 D. A rule of discovery 101 13. Estimating the Uncertain 105 14. Towards a Numerical Universal Language 119 15. The Encyclopedia and the Method of Discovery 129 16. Towards a Heuristics for Persuading 143 A. The power of persuading 144 B. Concurrence of arguments 145 C. Quickly defeating an adversary 145 D. Words 146 E. Paradoxes 147 F. Wrongdoing 148 G. How grave a sin is not saying the truth? 148 H. The occasion for persuading 152 I. Disputing until completion 155 17. The Other’s Place 163 18. Persuading a Skeptic 167 19. On Controversies 201 20. On Principles 209 21. Two Prefaces to the General Science 213 A. The instauration of the sciences: A preface 214 B. Foundations and examples of a new general science 216 22. Introduction to a Secret Encyclopedia 219 23. On the Creation of a New Logic 225 24. New Openings 231 25. Theology and the Principle of Contradiction 237 26. Changing Religion 241 27. Methods of Reunion 247 28. An Ars Characteristica for the Rational Sciences 263 29. ‘Characterizing’ Definitions and Demonstrating Propositions 271 30. Advancing the Art of Discovery 275 31. Correspondence with the Hamburg Jungians 285 A. Leibniz to Placcius (March 1679) 286 B. Leibniz to Placcius (January 1687) 290 C. Leibniz-Vagetius-Leibniz (1686-1687) 291 D. Leibniz to Placcius (1687) 295 E. Leibniz to Placcius (April 1695) 296 F. Leibniz to Placcius (May 1696) 297 32. The Philosophical Sin Controversy 305 Contents ix
33. Confronting the Catholic Hardliners: Two 309 Memoirs for Pellisson A. First memoir 309 B. Second memoir 315 34. Defining what Pertains to Faith 325 35. Judgment of a Catholic Doctor 329 36. Presumptions and Fictions in Legal Argumentation: 341 Correspondence with Johannes Werlhof A. Leibniz to Werlhof (July 1696) 342 B. Leibniz to Werlhof (1687-1696) 343 C. Werlhof to Leibniz (July 1696) 347 D. Leibniz to Werlhof (July 1696) 349 E. Werlhof to Leibniz (August 1696) 350 F. Leibniz to Werlhof (August 1696) 352 37. The ‘Method of Establishments’: 359 To Thomas Burnett of Kemeny 38. The Achievements of Logic and Beyond 373 To Gabriel Wagner 39. Pacts, Contracts, and Natural Law 391 40. Approaching the Church of England 399 A. Annotator’s preface (A) 400 B. Annotations to the translator’s preface 405 C. Synopsis 406 41. Dialectic Principles and their Application 419 A. The strength and the weakness of reason 420 B. Between Bayle and Le Clerc 420 C. Letter to Jaquelot (October 1706) 422 42. The History and Tasks of Logic: 429 To Cornelius Dietrich Koch 43. Bold Conjectures: 435 To Louis Bourguet 44. The Dynamics of Formulating and Expounding the System: 445 To Nicolas-François Remond 45. The Use of Logic against Skepticism: 451 To Karl G. Ehler Biographical Notes 455 References 473 Subject Index 483 Name Index 509 Abbreviations
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In addition to the Introductory Essay, each Chapter comprises an Introduction that sketches its background, gives an overview of its contents, offers some interpretative suggestions, and indicates the Chapter’s significance in the context of the book. For multi-text Chapters, in most of the cases an Introduction is given for each of the individual texts too. The footnotes contain marginal additions or corrections by Leibniz as well as additional information on textual matters. The endnotes provide information about persons, events, concepts, and controversies mentioned in the text, which a 21st century reader is unlikely to be familiar with; they also include cross-references to other Leibniz texts (in this volume or elsewhere), references to relevant studies, and interpretative suggestions. The two kinds of notes have been distinguished in order to allow for a continuous reading of the text and its modifications, prior to considering the additional material given in the endnotes.
The References contain only the titles referred to or made use o f and i s n ot intended as a bibliography on Leibniz’s Art of Controversies. Most of the references to writings Leibniz himself refers to are included in the endnotes of the Chapters, with the e xception o f a few classical works, which are listed in the References. Further information on authors Leibniz often mentions can be found in the Biographical Notes. These authors are marked with an asterisk in their first occurrence in each of the Chapters.
A list of Abbreviations serves to refer to the most used editions of Leibniz’s works. A few Leibniz titles are included in the References. Spelling in the 17th century varied. In general, Leibniz’s spelling was respected. Proper names are rendered either in Latin or in the person’s national language. Words added to the translation in order to make it clearer are in square brackets. When necessary, words in the original language are given in italics, within parentheses. The nominative singular is used for Latin words.
xiii Acknowledgements
The idea of a collection of Leibniz’s texts on the art of controversies arose in 1995, in the Institute of Advanced Studies of the Hebrew University of Jerusalem. I had organized an international research group on “Leibniz the Polemicist” for a whole academic year, and the Institute accepted and financed the idea. As fellows of the Institute we maintained a weekly seminar on Leibniz and his controversies and held daily conversations and sometimes fierce discussion about the texts we studied together. In the course of that memorable year in Jerusalem, two of us – Quintín Racionero and myself – became convinced that this overlooked aspect of Leibniz’s work deserved to be brought to the attention of the learned public in the form of a book. This idea developed into the project, which after ten years of intermittent work throughout the world, new partners, countless modifications, and many other vicissitudes, comes now to fruition in the form of this volume. It has been a challenge that only persevering cooperative work, gracious support by many colleagues, friends and institutions, and a firm belief in the value of the effort could face. Let all those who made it be faced be thanked and explicitly mentioned, as far as my memory can be trusted. My first thanks go to the Institute’s head at the time, David Shulman, for recognizing the significance of the original research proposal and for supporting it, not only with a generous grant, but also with his active interest in the progress we were making. Thanks are also due to the Institute’s staff for providing all we needed and more – efficiency, sympathy, and care. Even the doorkeepers, who had no idea who is this Leibniz, contributed their share to the positive atmosphere, be it late at night or on Shabbat and holidays. The year-long fellows of the group, Gideon Freudenthal, Massimo Mugnai, Carl Posy, Quintín Racionero, Elhanan Yakira, as well as our short term visitors – Fernando Gil, Kuno Lorenz, Olga Pombo, Alan Gross, Maria Rosa Antognazza, Hans Burkhardt, Sergio Cremaschi, Nuno Nabais, Martha Spranzi, Alfredo Tomasquin, were wonderful companions, colleagues, and critics. So too the regular participants in our weekly seminar – Daniel Cook, Noa Zauderer xv xvi Acknowledgements
Na’aman, Yaron Senderowicz, Galia Yanoshevsky, Daniel Mishori, David Heyd, Yaron Ezrahi, Ashraf Nur, Ora Gruengard, Rodica Amel. Their willingness to engage in an attentive and often controversial dialogue centered on controversies and on Leibniz was the stimulating background without which this book could not be born. Ever since that primordial research group dispersed, the enthusiasm it generated regarding the role of controversies in the history of ideas led to the creation of the International Association for the Study of Controversies. Many colleagues have since joined this Association, which has convened so far meetings in Tel Aviv, Madrid, Paris, Vercelli, Lugano, Pisa, Istanbul, Jerusalem, Taipei, Amsterdam, and is preparing further ones. IASC, inspired by the spirit of Leibniz’s art of controversies, stimulates fruitful debates that contribute to the advancement of knowledge, and thanks are due to its members for not despairing to see this book in print. The Spanish Ministry of Education granted me a research fellowship, thanks to which I could spend several months at the Universidad Nacional de Educación a Distancia in Madrid, devoting most of my time to this project. The Centre d’Histoire de la Philosophie Moderne (Conseil National de la Recherche Scientifique, Paris) offered me a fellowship that allowed me to make use of the rich material in the libraries of Paris. Thanks to the Alexander von Humboldt Foundation, which granted me its prestigious prize, I could spend one fruitful year in Germany, pursuing my research on controversies and on Leibniz. Half of this year I was the Leibniz Professor at Leipzig University’s Institute for Advanced Studies thanks to Georg Meggle’s invitation, and the other half, a visiting professor at Giessen University, thanks to Gerd Fritz’s invitation. The Gulbenkian Foundation granted me, thanks to Olga Pombo, a Professorship at the Centro de Filosofia da Ciência, Faculty of Sciences, University of Lisbon, where I intensively worked with Adelino Cardoso in furthering the book. The Centro de Filosofia of the University of Lisbon contributed generously to the formatting and final preparation of the book for printing, which was expertly performed by Filipa Afonso. Tel Aviv University granted me the sabbaticals and leaves of absence for all the travel involved in the research. To all these institutions, I can only say that I have done the best in order to justify their support of this project. In the translation of some texts the cooperation of Leibniz scholars such as Gideon Freudenthal and Daniel Cook was extremely helpful. Daniel also read parts of the manuscript and suggested corrections. Bernardino Orio de Miguel read the whole manuscript and his remarks were always valuable. Pol Boucher thoroughly revised some of the juridical translations and provided useful historical and technical information. João Lopes Alves and José de Sousa e Brito also provided assistance regarding juridical terminology. Serhii Wakulenko helped to decipher and translate a Acknowledgements xvii difficult manuscript. Andreas Blank, during his stay at Tel Aviv University, co-conducted with me a seminar using the texts here collected, read and helped to improve most of the manuscript, and was a constant source of support and insight. So were my colleagues at Tel Aviv University, especially Noa Zauderer Naaman and Yaron Senderowicz, whose unfailing interest and challenging questions were always stimulating. Olga Pombo, an old friend in Leibniz, listened attentively to my lengthy speculations about this or that text at her home in Lisbon (where part of the work on this book was performed), making enlightening remarks and demonstrating unrestricted enthusiasm for the project. Cristina Marras was very helpful in collecting bio- and bibliographical information, locating original manuscripts, suggesting additional relevant texts, and discussing the material. Miguel Smid contributed to the first English version of several of the Latin texts. Iñigo Medina García contributed to the notes and made useful remarks on the translations. Mogens Laerke read carefully parts of the manuscript and detected some mistakes. And, last but not least, the graduate students in my annual Leibniz seminar in Tel Aviv, as well as in seminars and research workshops in several other universities, provided perceptive remarks that left their mark on this book, although they cannot be individually traced. The German-Israeli research group on “Controversies in the République des Lettres” (financed for three years by the German Israeli Research Foundation) was an attentive forum for discussing Leibniz’s art of controversies. Members of the group in Tel Aviv and Giessen provided valuable criticism of the Introductory Essay and made suggestions concerning some of the translations and notes. In particular I would like to thank Thomas Gloning and Gerd Fritz for their careful reading of several texts and for their helpful suggestions. The cooperation of the colleagues in the three hubs of the Academy Edition of Leibniz’s writings was essential for carrying out this project. I wish to extend, particularly, my warmest thanks for their generous help to Heinrich Schepers (Münster), Herbert Breger (Hanover), and Hartmut Rudolph (Potsdam). They have been extremely supportive and helpful in advice, criticism, finding the manuscripts, and helping in deciphering and interpreting them. Stephan Waldhoff (Potsdam) deserves my special thanks for his detailed and patient help in this respect. Philip Beeley (Münster) generously provided valuable missing information. Three women, whether they know it or not, are deeply involved in the completion of this project and deserve our gratitude: our wives – Varda, Lola, Isabel. Their wonderful hospitality and their tolerance for our eccentricities and oblivion of the rest of the world whenever we met (in Tel Aviv, in Madrid, in Jerusalem, in Lisbon, or elsewhere) to advance the xviii Acknowledgements project, was not of the passive, but of the very active, supportive, and stimulating kind. It is not easy, finally, to give appropriate expression to my gratitude to Quintín Racionero and Adelino Cardoso, without whom this book would not be now in your hands (or computer screen), dear reader. Quintín and I were partners of this project since its inception and shared its conception and most of its evolution. His unbelievable erudition and his vast knowledge of Leibniz have left their mark throughout this volume. He managed to fit his busy schedule to mine in order to take a week off, in Tel Aviv, Madrid, Lisbon, Giessen, Paris, for working together on a few chapters and notes at a time. He generously offered his home and the facilities of the UNED for our work when I was in Madrid. Unfortunately, due to personal reasons, Quintín had to interrupt his work on this project. But I hope the final result does justice to his spirit and to his belief in its importance, and will please him. When I first talked with Adelino about the project, he was immediately enthusiastic about it, and jumped on board without hesitating. He not only dedicated much of his time to it, but also obtained the financial support of the Centro de Filosofia, of which he is a leading member. His expertise in Leibniz contributed to valuable cross- references and his special focus on the idea of mediation, which he considers central to leibnizianism, fits as a glove the key elements of Leibniz’s art of controversies; both enriched significantly the book. To both of you, dear friends, my profound gratitude for this wonderful cooperative- controversial partnership of many years, which (how could it be otherwise?) both illustrates and confirms the essence of Leibniz’s art of controversies.
Marcelo Dascal Tel Aviv, April 2006 Introductory Essay
In one of several intellectual self-portraits Leibniz wrote in the course of his life, he describes a “man of religion” he met one day in Paris (K IV 452-454). This man had “meditated at length about controversies”. He enjoyed reading the Church Fathers, but his veneration for them was not excessive. By the age of 17 he had “penetrated so deeply the subtleness of the Schoolmen that he embarrassed his teachers”. Contrary to the current opinion that this kind of study was useless, he believed it had made him realize “up to what point the refinement of the human mind can go”. Their writings, he was sure, contained so many solid and beautiful things that they would be admired by all learned persons if they were formulated clearly and neatly – which he was capable to do, since he excelled in his singular ability of “explaining a passage and making its true sense apparent”. He was versed in history and the writings of the ancients, and he possessed a natural and simple style, yet strong and touching when necessary. One could say that he “mastered perfectly the humanities”. His studies of jurisprudence between the ages of 18 and 21 soon brought him fame and a position at a princely court, where up to 25 years of age he had “the occasion of studying controversies”. The rumors about the new discoveries in mathematics and physics motivated him to contribute to the advancement of science, leaving aside his earlier studies. In two years he became a famous mathematician, invented machines that were considered extraordinary and, in spite of being a foreigner, he was acclaimed for his achievements. It was at this time, Leibniz writes, that he met this man. He was surprised to see him “reading books of controversies”. His modest appearance and his ordinary way of speaking did not bear out his fame as a professional mathematician. Upon Leibniz’s manifestation of his surprise, the man told him that people were mistaken about him. His main concern, he said, was theological. He had applied himself to mathematics, as he had done to scholasticism, with the sole purpose of perfecting his mind and learning the art of inventing and of demonstrating – which he now thought to have achieved as far as anyone else. xix xx Introductory Essay
The man Leibniz —met“ in Paris was now well equipped œ we might add œ to return to his original and main interest, the art of controversies and theology. He was now prepared to apply the skills acquired in a long and fruitful detour to what really mattered for him. And indeed, three decades after Paris he composed a masterpiece of controversy in theology, with the help of all he had learned and created in science, epistemology and metaphysics œ no doubt comparable if not surpassing the refinement of the human mind achieved in scholastics, which he admired so much. Yet, while throughout his life he dealt with controversies, both theoretically and practically, this man never assembled in a single work his insights on this topic; nor did he elaborate a blueprint for such a work – as he did for many other ideas of his, even though he rarely carried out such projects; in short – he never actually wrote a systematic account that would deserve the name of ‘Theory of Controversy’. But this is not unusual in Leibniz’s modus operandi and we must pick up the glove. It is the task of his readers and interpreters, as so many similar tasks he left for posterity, to identify the relevant pieces and to recover from them the design of the mosaic he probably had in mind. This is what the painstaking collecting, translating, and commenting represented by the present volume purports to begin to do. Though the result perhaps does not reveal a full-fledged general theory, it certainly unearths enough shared goals, elements, principles, strategies, and argumentative practices, to be appropriately called ‘art of controversies’ – an enriched ars disputandi deserving a place next to the other pillars or Leibniz’s method, the ars inveniendi and the ars judicandi.
1. Introduction
In all likelihood, Leibniz is the early modern thinker who maintained the largest and most varied network of correspondents, with whom he discussed an impressive array of topics, in a wide range of disciplines. He wrote several substantive letters a day and, although he condemned the ‘spirit of contradiction’ that animates some polemicists, he did not shy away from engaging in sustained debate in philosophy, law, theology, politics, or science – whenever he deemed them necessary and useful. In his major works he employed the dialogical form as a sharp critical tool, and he used the journals of his time as a forum where he criticized the theories of his contemporaries and defended his own views against his opponents. He also sought the criticism of others, which he deemed invaluable as a source of learning, and – somewhat naively – assumed Introductory Essay xxi others would rejoice in receiving his own serious and well-intentioned criticism. No wonder that he reflected and wrote quite a lot about the principles that should govern such a time-consuming praxis, in order to make sure that it would be not a waste of time but rather a tool in the construction of knowledge. The growth of knowledge, he believed, required the cooperation of many minds – and he worked for the creation of appropriate institutional frameworks (academies, societies, journals) for this purpose. Such cooperation would be best served by infusing it with a critical spirit that values the confrontation of opposed positions, not for the doubtful pleasure of winning, but for its potential contribution to advancing our knowledge. Rather than presuming harmony, knowledge should be built out of the variety of diverging views. In this spirit, objections should be praised and taken seriously as key contributions to conceptual clarification, and major efforts should be made to learn about opposed points of view, acknowledge their respective contributions to truth, detect their points of divergence, and seek to reconcile between them. Leibniz was a firm believer in the persuasive power of such an intellectual strategy not only in theoretical, but also in practical matters. In spite of its importance in Leibniz and for Leibniz, this aspect of his work has been systematically neglected. One of the reasons for this may be the fact that the philosophical climate at the beginning of the 20th century œ when Couturat undertook the publication of Leibniz‘s by then still unpublished logical and methodological manuscripts œ favored a selection centered on the more formal writings, along with those describing and advertising the projects in which logic in the formal or ”analytic‘ sense was the flagship. This left aside those writings where Leibniz developed the more dialectical and less formal aspects of his method.1 As a result, the full
1 In spite of Leibniz’s persistent inclusion in his projects of a “General Science” of a chapter devoted to the methods for solving controversies, Couturat – who dealt with this subject in his book La Logique de Leibniz (1901) – did not include in his 1903 edition of Leibniz’s unpublished texts those manuscripts that develop the theme. Mollat too, in both his editions of juridical texts (1885 and 1893), did not notice the relevance of the art of controversies, even though some of the texts he selected for publication clearly emphasize the value of the modes of argumentation employed by the early jurists in dealing efficiently with polemics. As for Grua’s 1948 edition, guided by his interest in Leibniz’s philosophy of law (cf. Grua 1953, 1956), it was no doubt instrumental in calling attention to Leibniz’s ideas on many other subjects as well, and included texts directly related to controversies. Grua, however, did not recognize the methodological significance of the texts he published on this topic – which is perhaps the reason why he didn’t single them out in a separate section of his edition. Baruzi (1909), interested mainly in Leibniz’s religious thought and politics (cf. Baruzi 1907), was perhaps the only xxii Introductory Essay range of Leibniz’s writings on the “art of controversies” – the art that is supposed to theorize about the praxis briefly described above – remains to this day largely unheeded to. Another reason for that is that these writings were, in general, not included in the “philosophical” series of the Academy edition, which led researchers to presume they had no philosophical interest. Furthermore, only a very small portion of it was available in translation. The unquestionable significance of this work is the motivation for this volume, which will provide the reader with a further piece of the “Leibniz puzzle” – a piece that offers a quite unusual perspective for appreciating his thought and action. In this introductory essay, we will first present the historical background explaining the rise of interest in negotiations, dialogue, tolerance, and the peaceful solution of controversies in the second half of the seventeenth century. We will then survey the intellectual sources that provided Leibniz with the materials for the development of an “art of controversies”. An overview of the contents of this art will then follow, in which the role of each of its components will be highlighted. Next, we will show how the principles and techniques of this art are part and parcel of Leibniz’s major fields of research and action – theology, law, politics, metaphysics, epistemology, and science. We will then highlight the significance of the art of controversies for Leibniz’s entire philosophical stance – a significance that ultimately lies in its essential role in Leibniz’s “rationalism”. Finally, we describe the criteria that guided us in the compilation of this volume.
2. Motivation
The peace of Westphalia, which puts an end to the 30 years war in Europe is signed in 1648, two years after Leibniz’s birth. The peace of Utrecht, which puts an end to the 14-years long Spanish succession war, is signed in 1714, two years before Leibniz’s death. Both were “world wars” in the sense of generalized European wars.2
20th century editor of Leibniz’s unpublished writings who devoted special attention to Leibniz’s practice of and reflection about the art of controversies (he must be also credited with re-printing the self-portrait of Leibniz with which this Introductory Essay opens). 2 The Thirty Years War (1619-1648) was the first global war in Europe, as well as the most devastating one, especially in central Europe. Its last phase, the so-called Franco- Swedish period (1635-1648), was characterized by an absence of stable fronts, a situation where the only regular tactics was the systematic destruction of the territories through which the armies passed. The more reliable calculations mention the astronomic Introductory Essay xxiii
Between these two dates, European intellectuals and politicians were concerned with the ways of promoting peace and avoiding the devastating effects of these wars. This political and intellectual concern gave birth not only to intensive political negotiations, but also to an intensive reflection on the conditions for the achievement of peace in Europe, coupled with attempts by their proponents to persuade their intellectual colleagues in other countries and to muster their influence upon the political leaders for the implementation of such projects. In this, and other ways, the community of European intellectuals known as the “République des Lettres” played a key role. Pierre Bayle, an exile in the wake of Louis XIV’s anti-Huguenot policies, and a fighter for tolerance, was certainly aware of this role when he founded his journal Nouvelles de la République des Lettres.3 The Nouvelles are perhaps the best example of a new type of intellectual communication, namely a supra-national forum for the
proportion of 30% to 50% of population reduction within the Empire, with local variations related to the proximity to the battle zones (see Lutz 1982: I 24). Even though England didn’t take part in this war, its own revolutionary process, from 1621 (with the first conflicts between Charles I and the Parliament) to 1649 (with Cromwell’s victory and the king’s execution), evolved chronologically and involved an amount of devastation parallel to that of the continental war (Hill 1965). No doubt the period inaugurated with the Peace of Westphalia was not, strictly speaking, peaceful. But the wars undertaken by Louis XIV did not significantly modify the international status quo, which respected the stipulations of the peace treaty. The balance of power was altered by two events: on the one hand, the succession to the Spanish throne (which Carlos II’s will assigned to a grandson of Louis XIV) and, on the other, the ascension of Russia which challenged Sweden’s supremacy in the north. Under these conditions war became once more inevitable, this time reaching beyond Europe, due to the participation of the American colonies. The diversification of the fronts in the double war – the Spanish Succession War (1700-1716) and the Great Northern War (1700-1721) caused less devastation in any particular territory; but, as a whole, the result was as bloody as that of the Thirty Years War. Nevertheless, the period between the two wars yielded the basis for European stability, which, after the Treaties of Utrecht (1716) and Nystadt (1721), would not undergo significant changes until the French Revolution and the Napoleonic wars. 3 The journal was founded in 1684 and published in Rotterdam, where Bayle lived in exile. Each monthly issue included reviews of recently published books on theology, politics, philosophy, science, history and other subjects. The quality as well as the critical character of the reviews made the journal an obligatory reference for the intellectual life of the time, as well as a vehicle for debate. The earliest examples of this kind of journals were the Philosophical Transactions, published by the Royal Society of London since 1661 and the Journal des Sçavans, a private publication that begins to appear in Paris in 1665. But soon they were emulated, among many others, by the Acta Eruditorum of Leipzig (1682), the Miscellanea curiosa and the Ephemerides of Nürenberg, several Giornalli dei litterati, published in various Italian cities since 1685, and the Journal de Trévaux, a Jesuit publication that began to appear in 1701. xxiv Introductory Essay exchange of ideas. Along with other journals and an intense private and semi-private correspondence, it contributed to create a vast network of contacts among intellectuals of all Europe, an achievement made possible by the favorable climate following the Peace of Westphalia. This network, that included also the newly created academies (which, though supported by each state, were in fact international in their membership), allowed for cooperation in the construction of knowledge and provided a framework wherein ideological conflicts could become the object of rational discussion. Without over-estimating the role played by this “République des Lettres” in political affairs, one should not under-estimate it either. Even though the actual influence of intellectuals upon political praxis was scant, their new forms of communication and debate permitted to remove several important topics from the exclusive area of confessional dispute. In this way, the République des Lettres contributed to the development of an autonomous realm of reason, independent of issues of faith. Its importance, from our point of view, lies in its decisive role in the emergence of an arena for debate, as well as in providing a living model of coexistence, and even cooperation, in spite of and through disagreement. Leibniz became a key node in this forum of debate and communication. He symbolized, perhaps more than any other savant of his time, the connection between knowledge and politics. As we shall see, his “Art of Controversies” is nourished by this double source, stemming from the intrinsic connection, in Leibniz’s thought, between science – whose ultimate aim is the happiness of humankind – and morality. The efforts to bring about peace through meetings, in which reasonable solutions to the theological and ecclesiastical i ssues in dispute w ere s ought, preceded the Thirty Years War .In the first phase of the Reformation and Counter-Reformation, a methodology of “colloquia” was put in place for this purpose.4 But the success of the Reformation in the north of Europe and the refusal by the pope to convene an Ecumenical Council and by the Protestants to subscribe to any obedience formula, brought an end to the
4 This methodology relied upon the so-called politiques – most of them followers of Erasmus, who “not having sworn neither to the Pope nor to Luther, were only motivated
by the glory of God and by the go od o f C hristendom”. It employed the attempts to develop a syncretistic theology as a propaedeutic tool. The Diet of Augsburg (1530) convened by Charles V was the first major attempt of this sort. But Philip of Hesse had already made a similar experiment, when he organized a colloquium in Marburg, where Luther and Zwingli were invited to resolve doctrinal divergences. Also Maria of Medicis, France’s regent, employed the same procedure in the Poissy colloquium (1561), with the aim of reducing the divergences between Huguenots and Catholics. Introductory Essay xxv politics of reconciliation through colloquia.5 Instead, the recourse to arms became ever more frequent, leading to the general conflagration of the Thirty Years W ar. The war demonstrated, anyhow, that the confessional differences not always coincided with the politics of the powerful, whose principles were often abandoned in favor of their interests. Only when, as a result of the restrictive clauses of the Peace of W estphalia, it became clear that none of the parties could eliminate its adversaries, the politics that inspired the colloquia could be renewed and gain a new meaning. It is important to notice that the 16th and early 17th century negotiations were inspired by two quite different approaches, both of which would blossom in the second half of the 17th century. On the one hand, the tolerance-based proposals, originated in late renaissance skepticism, assumed that the differences were irreducible and irresolvable, and concluded that the most that can be done in order to avoid violent conflict is to —tolerate“ the —wrong“ position, rather than to try to suppress it by force. The conciliation-based proposals, on the other hand, assumed that the differences were not so radical and could be overcome through a process of rational negotiation aimed at defining a common core shared by both parties.6 W hile the former implicitly accepted the schism, the latter aspired to reunify Christendom. The model of tolerance, as developed for example by Locke, became the most influential model at the time.7 But Locke goes well beyond the
5 The colloquium of Thom, organized by the Jesuits in 1648, a few months before the Peace of Westphalia, when the situation in Poland was still uncertain, demonstrates the limits of the colloquia methodology prior to the Peace of Westphalia. Once the re-catholicization of Poland was assured, the Jesuits lost all interest in continuing the discussions. Their interest shifted to the application of the ius reformandi, whose principal victims would be the Calvinists and the Socinians. 6 The literature on the development and application of the principle of tolerance is considerable. See, among others, Chaunu (1984), Decobert (1988), Garrison (1991), Leclerc (1994), Kamen (1967), and Nederman and Laursen (1996). As far as we know, the many and laborious efforts of conciliation made in the 16th and 17th centuries have not been so far the object of a comprehensive study. See, however, Christin (1997), Turchetti (1984), and Hazard (1966), especially part II, chap. II, devoted to the Leibniz- Bossuet reunion attempt. 7 The final form of the lockean doctrine of tolerance is that of the four Letters Concerning Toleration. The first letter was published anonymously in Latin in 1689, the second and third, by the author, in 1690 and 1693, and the fourth, incomplete, postumously in 1706. All of them can be found in volume 6 of The Works of John Locke (London 1823; reprinted by Aalen Verlag, Hildesheim, 1963). It is well known that Locke didn’t always hold the views expressed in the Letters. As a young man he defended the right of the magistrates to prosecute religious dissidents – a position he argued for in his Two Tracts on Government. His change of opinion is usually attributed to the influence of Lord xxvi Introductory Essay extremely limited notion of tolerance advocated and partially implemented earlier. For example, the Edit de Nantes (1598) œ the first of the ordinances ensuring religious tolerance œ only allowed the Calvinists to preach in the areas where they were already established, but did not grant them the right to extend their areas of influence nor build new churches, even within their own areas.8 For Locke, tolerance was predicated on the basis of a distinction between the public and the private sphere. According to him, a person is entitled to hold any religious opinion privately. The state has no right to interfere in this private domain. In this sense, religious opinions are fully tolerated. W hat is not tolerated are those opinions whose public manifestation is liable to alter the public order œ whether because they are opinions that are themselves intolerant (e.g., those of the Catholics) or because they call into question the established social order (e.g., those of the Socinians or of the atheists). None of this means, of course, that Locke did not believe that those opinions which do not conform to the true religion are wrong. He was persuaded that there are decisive criteria to establish religious truth: —We may as well doubt of our own being as we can whether any revelation from God be true. So that faith is a settled and sure principle of assent and assurance, and leaves no manner or room for doubt or hesitation“.9 In other
Ashley, first Earl of Shaftesbury, whose Whig government policy included “tolerance, commercial interest, individual freedom, Protestantism, and parliamentary supremacy”. This influence is now well documented with the publication of An Essay Concerning Tolerance, written by Locke in 1667 – the year he entered the service of Shaftesbury as his physician and confident. The best version of this unpublished and for the most part lost work is available in J. Locke: Scritti Editi e Inediti sulla Tolleranza, edited by C. Viano (Torino, 1961, pp. 81-107). There is no point here in referring the reader to the vast literature on Locke’s doctrine of tolerance. As for the influence of his model of argumentation on this issue, which has overshadowed the earlier – as well as many of the latter – models, it suffices to quote Nederman and Laursen (1996: 2): “A virtual consensus seems to exist in the English-speaking world that the first true theoretical defense of tolerance was proposed by John Locke”. 8 See Parker (1980: chap. 4). Nevertheless, the Edit de Nantes was a truly tolerant ordinance. For, within the limits established in its 94 overt and 57 covert articles, it permitted the realization of periodic national synods of the Reformed Church, as well as the teaching of Calvinism in three universities (Montauban, La Rochelle, and Nîmes). As demonstrated by ulterior events, the French authorities found ways to restrict quite drastically the conditions stipulated in the Edit, so as to make life for the Huguenots in France impossible. From the conquest of La Rochelle by Richelieu in 1628 until their final expulsion with the revocation of the Edit by Louis XIV in 1685, the number of Huguenot believers was reduced from 1250000 to a mere 80000. 9 Essay (4.16.14). In order to understand Locke’s argument in this paragraph, it is worthwhile noticing that, for him, it is precisely in virtue of their reliance upon divine revelation that religious beliefs should not be included among those propositions that are probable. Introductory Essay xxvii words, one has not to be an epistemological skeptic in order to be tolerant. So, Locke’s notion of tolerance is in fact a condescending attitude of “toleration” towards opinions about whose falseness there is no doubt whatsoever. They are tolerated on exclusively political grounds, i.e., in so far as they are not perceived as socially dangerous. Thus, although Locke’s model undoubtedly marks a progress in grounding the notion of tolerance in a reflection that goes beyond considerations of realpolitik, it remains however a minimalist model. For it seeks to ensure nothing more than the preservation of a peaceful coexistence within a given social fabric. There is nothing in this model suggesting the possibility of a reconciliation of the divergent opinions, and therefore the need to stimulate a rational debate between them. Error and truth are a priori assigned to one or to the other – which makes such a debate irrelevant and eventually also dangerous. The possibility – and need – of such a debate is precisely what other models developed after the Peace of Westphalia acknowledged. Leibniz is certainly the thinker that envisaged this possibility most seriously and undertook to shape such an alternative model. He was clearly not satisfied with Locke’s notion of tolerance. According to him, the conception of tolerance as a resting point ensuring political stability is insufficient. Rather, tolerance must be viewed as a starting point, capable of promoting the rational debate aimed at overcoming the differences, instead of taking them for granted. In Chapter 40A, Leibniz declares t hat he has a method by means of which “it is possible to go beyond mere tolerance”. He goes on to claim that tolerance should be viewed as moderation – something that is especially necessary in those issues in which controversy arises. In a letter to Molanus (22 February 1698; GR 412-415), he defines moderation as the attitude of “talking without condemning” (loquendum tantum de non condemnando – GR 415). Once this attitude is adopte d, it paves the way for applying the “method” Leibniz has in min d, namely “placing in front of one ’s eyes the weight of both sides’ arguments as if in a balance” (Chapter 40A). Tole rance, thus, is not a result of the endeavor to prevent confrontation. It is the necessary preamble for allowing for a true, passionless confrontation of reasons to take place: “… the powers should first agree as to mutual tolerance in order to sweeten the minds” (To the Landgrave of Hessen-Rheinfels, February 1685; GR 190). Without this step it would be foolish to expect to achieve any results – not to mention a stable peace.
Consequently, any doubt concerning these beliefs can only come from a lack of understanding of what is revealed or from a defect in the believer’s faith. xxviii Introductory Essay
Whereas for Locke tolerance is an ethical-political requirement with which stability would be ensured without the need for any further dialogue or negotiation, for Leibniz it is a basic principle of the ethics of communication and debate, without which the negotiation, necessary for rationally weighing the positions and eventually overcoming the differences, would be impossible. Consequently, in his Synopsis (Chapter 40C ), Leibniz distinguishes between two strategies for handling the solution of controversies: controversiae conciliatio per tolerantiam and per consensum. We should not mistakenly believe that the first of these strategies corresponds to the application of Locke’s “toleration”. For, such an application does not in fact solve a controversy – it just leaves it unsolved, while preventing its eventual harmful social consequences. The first strategy, in Leibniz’s view, simply leads to a solution in case the mere removal of mutual condemnation and passionate discourse reveals that there is no real opposition and thereby brings the debate to rest. The second strategy is required when moderation alone does not entirely remove the opposition. Nevertheless, moderation is required for it clears the ground for a dispassionate consideration of the arguments involved and allows the parties to seek (and eventually reach) an agreed upon solution. Leibniz’s “art of controversies” consists precisely in the ensemble of efforts by him to elaborate the conceptual framework and tools required for the use of this second strategy.
3. Sources
Leibniz’s concern with controversies runs through his whole life. Among his earlier remembrances, he mentions the lively interest aroused in him by reading medieval disputationes – which he did read in spite of his teacher’s prohibition.10 Two months before his death, he is still concerned with the topic. He talks once more about the “judge of controversies” and keeps looking for the appropriate conceptual framework for analyzing and
10 “Leibniz’s life” (K I xxxv). This autobiographical fragment – written by Leibniz in 1676, presumably as a resumé intended to accompany his requests for employment in Germany after his sojourn in Paris – shows the role of controversies in his early education. Leibniz writes: “when as little more than a child I wandered casually through my father’s library, I stumbled upon some books of controversies […]; I then first began to realize that, in general, not all that is said is correct and that often people hold excessively passionate opinions about problems that do not always have much value. So that, before reaching the age of 17, I was working on an exact discussion of a certain controversy” (p. xl). Introductory Essay xxix solving controversies. His advice to the young Ehler is to persevere in this task, declaring that he has no doubt that it can be achieved (Chapter 45). As in most of the projects he considered of fundamental importance, Leibniz’s work on the art of controversies was intermittent and – as far as we know from his published manuscripts – did not reach the stage of a full mature formulation. The letter to Ehler shows that he is fully aware of the incompleteness of his work in this domain, but this does not prevent him to continue to have faith in its importance and feasibility, and to entrust its achievement to the next generations. The attention he devoted to the project, at different times in his life, was determined both by his commitment to other major intellectual endeavors and by the surrounding circumstances. Among the latter, the ups and downs of the reunification negotiations, as well as his mood regarding their prospects of success.11 In order to elaborate his art of controversies, Leibniz – following St. Paul’s advice to always work opportune et importune, i.e., taking advantage of each and every available clue (GR 190) – makes use of a variety of sources. The first of these sources was the practice and theory of disputations. Originally, the disputatio was an amplification of the expositio, i.e., the explication of a text through interlinear or marginal remarks. As such remarks grew in size, the expositio became a systematic and more or less independent commentary of the text. Given the diversity of possible interpretations, the commentaries had to argue against each other. The disputatio results from the codification of the rules for such disputes, including their proper order, the roles of the participants (defendens, arguens; proponens, opponens), the kinds of permitted moves (e.g., concedo, nego, distingo), and the questions that can be debated and those that cannot. From the 13th century onwards, the disputatio frees itself from the role of textual commentary, leaving room for debates about any chosen theme – quodlibet – which at first were permitted only once a week. Along with this thematic ‘freedom’, however, logical strictures developed concerning the moves the contenders were allowed to make. This was particularly emphasized in the variety of disputatio called obligatio, in
11 For the various stages and results of the negotiations for the reunification of the Christian churches, as well as for Leibniz’s involvement therein, see Racionero (2001). As a rule, Leibniz was aware of the difficulties in reaching a consensus in matters that depended to a large extent upon the varying interests of politicians. For this reason, he usually remained at the backstage, letting the official initiatives (e.g., the requests of the imperial representative, Rojas y Spínola, or the exploratory suggestions of the Elector of Brandenburg, Friedrich Wilhelm) play the leading role. In particular, he took care of the methodological, historical, and doctrinal aspects of the debates. He was, however, an important figure in such negotiations and spent an enormous amount of work in them. xxx Introductory Essay which each of the disputants was ‘obliged’ to reply in logically specified ways (see Yrjönsuuri 2001). In this respect, the art of disputing played the role of a procedure for teaching and exercising logic. The model of disputation, in its several varieties, became also a tool for conducting intra-religious as well as inter-religious debates (see Dascal 2004b). In the first decades after the Reformation, the disputatio was the prototype for the inter-confessional colloquia which, instead of solving the divergences between Catholics and Protestants, exacerbated them, as Leibniz pointed out (NE 4.7.11; A VI 6 417-418).12 Disputatio, which was still in use in Leibniz’s time, was well-known to him, and was to contribute significantly to the logical, dialectical, and rhetorical aspects of his art of controversies. His teacher, Jakob Thomasius had published in 1670 a manual of logic for beginners, which included, for adults, a large section on disputation (Erotemata Logica pro incipientibus, accessit pro adultis Processus disputandi; Leipzig: G. H. Frommann). In his letter to Thomasius of 2 September 1663 (GP I 7-18), he displays already at a young age his skill in this genre. As a man of his century, however, he soon became aware of the predominant mood of Early Modern thought – a pitiless criticism of ‘scholasticism’, which included the uncompromising dismissal not only of Aristotelian logic, but also of disputatio. The latter was viewed by thinkers such as Bacon, Descartes, Locke, and Malebranche as consisting essentially in futile verbal skirmishes, which deviated the mind from real inquiry and was useless for the advance of knowledge. To be sure, Leibniz too criticized the disputatio model. But, in conformity with his tolerant outlook, he acknowledged also its potential usefulness. What is to blame – he argued against Locke, for example – is not the tool itself, but the bad use it is made of by some. Locke had argued that, in order to prevent “the running out of disputes into an endless train of syllogisms” (Essay 4.7.11), the Schoolmen had introduced “general propositions, most of them indeed self-evident, […] beyond which men in
12 The genre ”disputatio‘ outlived by far the Middle Ages. Formal disputations were held and treatises about them were written up to the end of the 18th century, in theology as well as in other areas of knowledge, e.g., in medicine. For example, a well-known and often referred to medical disputatio of the 17th century is Pedro Garcia‘s Disputationes medicae super primam libri primi Avicennae, etiam philosophis valde utiles (1611); and as late as the mid-18th century the important physician Albrecht Haller (1708-1777) published several volumes of medical disputations, e.g., Disputationum anatomicarum selectarum, 6 vols., Göttingen, 1746-1751; Disputationes chirurgicae selectae, 5 vols., Venice, 1755-1756; Disputationes ad morborum historiam et curationem facientes, Lausanne, 1757. One can discern traces of this genre in the défis (challenges) and prize- competitions that became popular in the 18th century (cf. Dascal 1998b). Introductory Essay xxxi dispute could not retreat”; he thus made disputatio directly responsible for stopping inquiry at vacuous generalities, rather than stimulating the search for the true “foundations whereon the sciences [are] built” (ibid.). For Leibniz, however, the bad use of the ‘maxims’ or ‘principles’ “should not lead to blaming their use in general; all truths are subject to the inconvenience that, when they are joined to falsities, one can draw false conclusions and even contradictory ones” (NE 4.7.12; A VI 6 422). The same is true of disputation. He willingly admits the misuses to which it is subject, and attributes these in part not only to the incompetence of the disputants and to their tendentious motives, but to the fact that it is “ill- governed” (malreglé), which is why “often one does not conclude anything or concludes wrongly” (NE 4.7.11; A VI 6 418). None of this means, however, that “the art of disputing or of combating by reasons” cannot be improved; in fact it must be corrected, developed, and, ultimately, “redone” (tout refondu), for it is “very big and very important” (ibid.). In fact, the chapters of this book illustrate the variety of ways in which Leibniz – ever more aware of the importance of this art – endeavored, from his youth, to fulfill the task of re-creating it on sounder grounds. From early on, he pointed out that the formal dialectical structure of disputatio was insufficient to capture what is at stake in most significant controversies and per se did not provide a method ensuring a well- grounded, non-arbitrary decision of the debated issue (Chapter 1). He noticed the insufficiency of deductive logic alone to deal with issues of interpretation (Chapter 11) and for drawing probabilistic and presumptive inferences that involve uncertainty (e.g., Chapters 5, 36, 38). He sought to improve the medieval model by introducing the idea of a ‘balance of reason’ (e.g., Chapter 2). And he also kept some of the features of this model, such as the rules which distribute asymmetrically the onus probandi of opponent and proponent – dialectical rules that play in fact a crucial role in his argumentation against Bayle, for example (Chapter 41; see also Théodicée, Discours Préliminaire; Dascal 1987: Chapter 6). Naturally, logic was to play a key role in Leibniz’s art of controversies – to wit his often mentioned ideal of devising a method for solving any controversy as it were ‘arithmetically’ (e.g., Chapters 14, 28). But, as mentioned above, the logic of disputatio was not enough for fulfilling such a dream. On the one hand, it was necessary to transform it in a real calculus. And Leibniz indeed contributed significantly to the systematization of syllogistic logic and created new extensional and intensional calculi – thereby in fact articulating for the first time the modern concept of formalization (cf. Dascal 1978). On the other, he soon realized the insufficiency of traditional logic for his purposes, and looked xxxii Introductory Essay for other sources, in modern thought, to remedy this deficit. This is why, presumably, he was attracted by the work of Joachim Jungius in logic and epistemology, which he held in high esteem, though not always agreeing with him.13 Jungius had dealt with the difficult problem of so-called oblique syllogisms œ a kind of inference which is essential for the logic of relations, and it was by opposing his solution to the problem that Leibniz developed his own (Chapter 31C).14 For Jungius, logic was, like for the Port Royal Logic, the Ars mentis nostrae, i.e., the analysis of the mental operations œ concept or notion, enunciation or judgment, and dianoea or discourse œ through which we are able to discern truth from falsity. Leibniz was interested, first, in Jungius‘s analysis of concepts or notions, in so far as it is based on a viewpoint different from that of Descartes‘s analysis of ideas. He was also interested in Jungius‘s doctrine of inferences, whose extension from the field of apodictic statements and arguments to heuristic and dialectic (or probable) ones provided him with a vast repertoire of inferential strategies œ all of them extremely relevant for his project of developing and grounding a logic of argumentation, broader in scope œ although deductively weaker œ than strict demonstrative logic. A significant addition to his endeavor to expand the role of logic and mathematics was provided by his encounter, in Paris, with Pascal‘s work on
13 Leibniz’s appreciation for Joachim Jungius, as well as the latter’s influence upon the genesis and development of Leibniz’s logical thought, are generally acknowledged, but scarcely studied in detail (see, however, Kangro 1969). It can be conjectured that Jungius’s empiricist ideas regarding natural science also influenced Leibniz. In a 1679 letter to Christian Philip, recalling the conversation they had in Hamburg, Leibniz linked his criticism of Cartesian mechanics with Jungius’s views, whom he credits with a better understanding of “the general analysis of concepts” than Descartes (A II 1 495). The same link is established in Chapter 14, where Leibniz argues that, if Jungius’s work had been better known, the reform of the sciences would have gone well beyond Descartes. Although it is difficucult to assess the hypothesis of a direct influence of Jungius’s physics upon Leibniz, the influence of his logic and epistemology is beyond doubt. Leibniz was familiar with the first edition (1638) of the Logica Hamburgensis, which he quotes in the above mentioned letter to J. Thomasius, as well as with the second one (1681), a copy of which he owned and kept in his private library. His abundant annotations on this and other works of Jungius are now available (A VI 4 1048-1090). On Jungius’s logic, see Scholz (1931) and Ashwort (1967). On the place of logic in Jungius’s and Leibniz’s systems, see Schupp (1980). For further references to Jungius, see Chapter 31. 14 Many recent studies address the logical difficulties posed by relations for Leibniz. Most of them seek to contest or at least to amend the standard account, due to Russell, according to which Leibniz had reduced all relational predicates to monadic ones. Among the most influential of these studies, mentioned in chronological order: Parkinson (1965), Rescher (1967), Hintikka (1972), Ishiguro (1972), Mates (1984), Mugnai (1992). For an assessment of the problem and its interpretations, see Racionero (1999). Introductory Essay xxxiii probabilities.15 This encounter was extremely influential in the development of Leibniz’s own studies in the field of probabilities (Chapter 13). With a rigorous treatment of probabilities, Leibniz expected to overcome the limitations of the purely deductive method of solving controversies. The latter could only be applied to matters subjected to strict necessity – the realm of “eternal truths”. With the addition of a calculus of probabilities, the way would be paved for treating disputes about contingent or factual matters with comparable rigor.16 This would permit the application of the art of controversies to a much wider variety of domains. The thus extended Characteristica, Leibniz boasts, “will give us the means to calculate in all matters as in arithmetic, in order to determine either certitude, when there are enough data for it, or at least the degrees of probability” (To Jean- Frédéric, April 1679; A II 1 557). In this spirit, Leibniz undertook to formalize probabilities through the study of various types of games. Most of the studies about Leibniz’s work on probabilities focus on its formal-mathematical aspect, overlooking the fact that it involved other aspects as well – those for which the name ‘dialectical’ is appropriate. Couturat himself observed that the restriction of Leibniz’s views on probability to their mathematical aspects was inaccurate. “For the mathematicians – he says – the theory of probabilities was nothing but an occasion to formulate and solve purely mathematical problems, whereas for Leibniz, it was really a part of logic” (Couturat 1901: 248-249). He further identified this “part of logic” with “the true Topics or Dialectics” (ibid.). And indeed, this is the constant point of view held by Leibniz, from his earliest writings such as the Nova Methodus (1667) and Chapter 15 (1679), to the more mature texts such as Chapter 37 (1697) and Chapter 9E (1711). As far
15 Leibniz became acquainted with Pascal’s thought through Arnauld, who put him in contact with the Jansenist circles. He had shown interest in Pascal since the early 70’s, with the publication of Pascal’s Pensées (To Jean-Frédéric, 21 May, 1671; A II 1 112). Thanks to des Billettes and to the Perrier family, Leibniz consulted Pascal’s manuscripts on geometry, where – as he admitted many years later (GM V 399) – he found the “light beam” that led him to the discovery of the infinitesimal calculus. As late as December 1696, Leibniz asks des Billettes about the fate of these manuscripts, but the latter is unable to inform him (GP VII 464). He also studied Pascal’s manuscripts on probabilities, this time through Nicole and Pascal’s sisters, Mmes de Saint-Amour and de Roannez. Pascal had proposed solutions to the problems the Chevalier de Meré had submitted to Huygens, Fermat and himself (GP IV 570). Apparently, it is from these solutions that Leibniz obtained all the information he needed for establishing the foundations of his own calculus of probabilities, as developed in Chapter 13, which in fact consists in a generalization of Pascal’s theorems. 16 “Thus, the form of disputation has been shown to be necessary in necessary matters, where eternal truths occur, but not in contingent matters where the most probable must be chosen” (Chapter 38). xxxiv Introductory Essay as the art of controversies is concerned, in Leibniz‘s eyes none of the purely formal ways of handling probabilities was sufficient for determining the values of probabilistic propositions that had to be taken into account in evaluating their relative —weights“ in a confrontation of arguments, for —it is not the case that probable reasonings can become demonstrative ones“ (To Berthet, 1677; A III 2 236-237). In fact, in the texts so far available on the use of probabilities in the context of resolving controversies, the ”computational‘ conception of probability exists side by side with a different, ”dialectic‘ or ”rhetorical‘ conception. Both are conceived as complementary parts of the ”new logic‘ Leibniz intends to develop, which should provide a comprehensive —balance of proofs, presumptions, conjectures, and indications“ (GP VII 201).17 Leibniz’s juridical background – as can be seen from the terminology he consistently employs, as illustrated in the preceding paragraph – was another essential source of his thought on controversies. Several of the Chapters in this volume emphasize that it is the jurists that provide the best examples of work in the direction of the ‘new logic’ and that they deserve to be imitated in this. In Chapter 5 he goes as far as to suggest that, instead of taking science (including mathematics) as a model of knowledge to be followed in other domains, it is rather the juridical model that should serve as a paradigm for science. In so far as the natural sciences consist in the ‘interrogation of nature’, they have a lot to learn from the detailed interrogation procedures developed by the legal disciplines, and this includes the set of rules for determining the value or weight of each type of evidence. Having been in London, where he had the occasion to observe first hand the discussions in the Royal Society regarding the proper conduction of experiments and observations and the interpretation of their results, his juridical mind presumably realized how far the new experimental science was from having developed a systematic, precise, and detailed epistemology, if compared to what two millennia of jurisprudence had achieved in Law. In Chapter 38, where he gives a survey of the components of logic and assesses their value, Leibniz points out two specific problems that remain unsolved after one adds the tools of mathematical probability to logic’s arsenal, namely the crucial roles of presumption and of the ways for
17 The nature and use of probabilities was also a controversial issue in theology, where “probabilists” and “canonists” maintained a long controversy on this subject. See Chapter 5, note i. Leibniz studied and annotated this literature, as shown by his highlighting passages such as the passage of Baronius’s Manuductio, where four degrees of probability are distinguished (A VI 4 C 2006). Introductory Essay xxxv estimating the degrees of probability. Both have to do with the rhetorical- dialectical dimension, to which we turn now. The notion of presumption was borrowed by Leibniz from the domain of juridical logic, a domain to which he consistently attributed a central position in his art of controversies.18 Juridical practice is based on a set of procedural rules that assign different values or weights to the elements of each case brought before the court. Presumptions, defined in this context by Leibniz as —proofs taken to be full proofs (preuves entieres) provisionally, i.e., as long as the contrary is not proven“ (NE 4.16.9), constitute a subset of these rules. They in fact function as a method for assigning a priori probabilities to each component of a case. The probability thus assigned, however, differs from mathematical probability because the presumptive rules are not conclusive, but defeasible. That is to say, the probability or likelihood of a claim based on a presumption may be contested by an opponent and eventually modified through a process of argumentation. In fact, for a court to proceed properly, the activity of such an opponent is a necessary requirement (e.g., in many legal systems, a trial without a defense counsel is considered invalid). That is, presumptions regulate as well as require a dialectical-rhetorical process of persuasion/dissuasion. According to Leibniz, a similar procedure is required whenever the estimation of probabilities (or, as he says, of the degree of —credibility“) is involved in matters other than simple and finite mathematical games.19 Jurists have come a long way to call attention to this fundamental fact and to address it through a set of rules, says Leibniz. But much more needs still to be done in order to generalize their insights and thus to be able to apply them to other fields, for the jurists —have not
18 The logic employed by jurists to estimate the value of different kinds of presumptions is a recurrent theme in Leibniz’s correspondence with the Bernouilli brothers about the calculus of probabilities. As against the purely mathematical treatment the latter proposed for the Ars conjectandi, Leibniz insists on the relevance of the juridical and political approach: “I have also reflected on these matters in the past, especially as they are used in jurisprudence and politics; I call it the doctrine of the degrees of probability” (To Jacques Bernouilli, 5 March 1697; GM III 377). In another letter, he lists different kinds of proof that can be extracted from juridical logic in order to estimate probabilities: “Since my youth I dealt with this kind of argument when I first wrote about law, discussing conjectures, indications, presumptions and incomplete, semi-complete, complete, and similar degrees of proof. In fact, no one has elaborated this kind of argument better than the jurists” (To Jean Bernouilli, 6 June 1710; GM III 850). A similar list of kinds of proof can be found in Chapter 5 and in NE (4.16.5). On the sources of this hierarchy of proofs in the tradition of penal law, see Chapter 36, note z. 19 Jurists are not the only ones who rely on presumptions. For example – as Leibniz points out (Chapter 10) – a physician engaged in diagnosis employs the same kind of logic in his reasoning (see also NE 4.16.9). xxxvi Introductory Essay sufficiently reduced [their treatment of probabilities] to secure principles and to method“ (To Jean Bernouilli, 6 June 1710; GM III 850). Just as standard logic has to be expanded, so too juridical logic must be expanded in order to occupy its proper place in the art of controversies. Forever hopeful, Leibniz writes: —I have therefore thought a good bit about this matter and hope sometime to fill this need“ (Chapter 38).20 The need for a dialectical evaluation of the weights of evidence, claims, and arguments, requires, in its turn, special attention to the problems involved in their interpretation. The elements of a juridical hermeneutics had already been sketched in the Nova Methodus (1667; second, unpublished version 1697) and their theoretical underpinnings are elaborated in detail in Chapter 11, making clear that they transcend the juridical field. This chapter in fact proposes a general —situational logic“ or pragmatics, which takes into account the various kinds of contextual factors relevant for the interpretation of laws, as well as of other texts and events. The entire first part of Chapter 2 consists in a mini-treatise on the interpretation of the sacred texts, which is part and parcel of the attempt to define a method that might act as a —judge of controversies“ œ which, as Leibniz makes clear in the second part of this chapter, is useful not only for theological purposes. In later writings (e.g., Chapters 19 and 40) one of the essential steps of the art of controversies is presented as consisting in the proper exposition of the contending positions. This methode d‘eclaircissement, as Leibniz calls it, does not limit itself to reproducing the statements of the contending parties as such. It functions rather as an active generalized hermeneutic procedure, whereby unclear or obscure meanings can be clarified, developed or constructed in such a way as to permit the resolution of a controversy. Hermeneutics is thus, for Leibniz, an art belonging to the family of the arts of discovery, and its contribution to the solution of controversies is indispensable.21 Thus, the whole range of traditional, as well as modern tools of rhetoric is mustered for the construction of the new leibnizian Topics, towards the fulfillment of the plan of expanding logic well beyond its traditional scope. The components of this new Topics he lists in his project of a new encyclopedia of 1679 indicate the central role he assigns in the project to those rhetorical components directly associated with the art of controversies, namely loci dialectici, inventio Rhetorica, ars argutiarum,
20 As far as we know, the first Leibniz scholar to call attention to the centrality of the concept of presumption in Leibniz’s ars disputandi was the late Ezequiel de Olaso (1975, 1990). 21 The importance of hermeneutics in those domains (e.g., theology, jurisprudence) where historical knowledge is required is emphasized by Leibniz in Chapter 37. Introductory Essay xxxvii ars deciphratoria sive divinatoria (Chapter 15). The fact that this list concludes with algebra, which not only —provides beautiful examples of the ars Topica“, but also suggests —how general rules can be formed“ (ibid.), highlights the integration of elements of various sources Leibniz seeks.22 These sources, both logical and rhetorical, will be, each of them, enriched and modified in a web of inter-relations that alone can take full advantage of the epistemic value of the complex phenomenon of controversy, without emasculating it. 4. Content
Alluding to a well-known topos, Leibniz contrasts controversies with war. He defines controversy as —a question debated in a trial (judicium)“, where ”trial‘ means —the state of those who contest by means of reasons in the hope of success“. This state is opposed to war, which is —the state of those who contest by means of force“ (Chapter 7). This contrast is elaborated in detail by Leibniz, functioning as an Ariadne‘s thread for his analysis of the different levels, types, and components of controversies. At the most general, strategical level, the opposition between —reasons“ and —force“ allows him to point out that not all forms of polemical exchanges are properly called —controversies“. For example, in a memorandum prepared for the Landgrave of Hessen-Rheinfels in 1687, that Foucher de Careil titled —On the methods of reunion“ (Chapter 27), he excludes from this category the —way of rigor“ (la voie de la rigueur): force or repression œ as exemplified by the forced conversion of the Jews in
22 Leibniz never gives a complete list of the dialectical and rhetorical means that can be used in the ars inveniendi. His lists of such means vary in his different formulations of this art. They include, among others, the “art of interrogating”, i.e., of eliciting testimony and checking one testimony against another (Chapter 38); the “art of experimenting”, which is nothing but the art of interrogating nature (GP VII 126); the “art of conjecturing” or of forming hypotheses (C 174); the “art of deciphering” cryptograms as well as any proposition comprising fragmentary data; and the “art of guessing” the meaning of enigmas, which consists in the ability to ask intelligent questions, combining the useful data and excluding the wrong and superfluous ones (ibid; see also C 162). All these “arts” are accompanied by an arsenal of formal or quasi-formal heuristics, appropriate for different purposes (cf. Chapters 9, 12, 16), which Leibniz on one occasion subsumes under what he calls ars formularia (Chapter 15). The plurality and openness of the means that constitute the network-like structure of the ars inveniendi suggests that Leibniz believes that only a plurality of methods and a rich and multiply accessible data-base can serve as a satisfactory tool for discovery. For, not only truth can be found in a variety of ways, but it can also be approximated, estimated, partially found, etc. – for all of which purposes “the best method is to make as many comparisons as one can” (A V I 4 961). xxxviii Introductory Essay
Spain œ does not ensure the desired change in convictions. Similarly, a dispute strategically governed by total submission to the —way of authority“ œ another form of appealing to —force“ in a dispute œ cannot be considered a controversy, especially when what is at stake is precisely the legitimacy of the authority appealed to by one of the parties. Neither in the way of rigor nor in the way of authority do reasons play a significant role. Leibniz‘s exclusion of the way of authority is historically related to the situation created by the Protestants‘ refusal to admit both the infallibility of the Pope in matters of doctrine and the ecumenical nature of the Council of Trent‘s decisions. In Rojas y Spínola‘s plan for the unification of the churches, which was discussed in Hanover in 1683, the way of authority had a primary role, due to the use of a skeptical mode of argumentation. According to Rojas y Spínola, since it is impossible to demonstrate the correctness of the interpretations of certain theological doctrines about which the Christians diverge, one must accept as a criterion of truth the authority of tradition, as it has been exercised without interruption within the church. Leibniz reacts to this argument in Chapter 20 in a way that assigns to dialectics a fundamental status for the understanding of the very notion of demonstration. He argues that a demonstration does not require the absolute proof of its premises, for —demonstrations do not proceed from assertions but from concessions or hypotheses, and they do nothing else but showing that some hypotheses are in conflict with each other“. For this purpose it is sufficient, he says, to assume the validity of the syllogistic form and the principle of contradiction; no use needs to be made of —material principles, or the matter of demonstration, other than those hypotheses of the adversary of which I show that they contain a falsity“. And he concludes: —It follows that all demonstration is ad hominem“. This way of avoiding the need of an appeal to authority, which governs Leibniz‘s methodological attitude vis-à-vis reunion, will lead to a frontal clash with Bossuet‘s viewpoint, in the new round of negotiations held in the 1690‘s.23
23 In the first significant letter addressed by Leibniz to Bossuet (8 January 1692), he formulates the —essential point“ of controversy, asking whether —the churches united with Rome would be allowed en conscience to establish an ecclesiastical union with churches submitted to the opinions of the Catholic church and even ready to accept the Roman hierarchy, while remaining in disagreement about certain decisions, because they are led, by very strong and almost unbearable appearances, to not believing that the Catholic church has authorized them œ a fact that requires an effective reformation of the abuses that Rome itself cannot approve of“ (FC I 1306). In the following letters, Leibniz reiterates this formulation. It implies either the provisional suspension of Rome‘s authority, thus granting the parties the right to express themselves as equals, or else at the very least to admit the coexistence of different points of view within the shared church, Introductory Essay xxxix
Leibniz’s typology further excludes from the domain of “controversies” the “way of dispute or discussion”, where the contenders proceed in a completely disorderly way, employing at will arguments, invectives, evasion, and all sorts of stratagems. In this kind of clashes, the objections and proposals of the adversary are not subjected to serious scrutiny, and there is no concern for, nor possibility of advancing towards a solution based on reasons. The dispute resembles the Hobbesian pre-contractual war of all against all, where nobody can win – certainly not rationally. Here, the parallel with war lies at the procedural level: “there are no rules that disputants are obliged to follow rigorously” (Chapter 27). The need of methods for avoiding the “vices” that transform controversies into disputes was one of the first theoretical concerns of the young Leibniz in this matter (Chapter 1). Reasons, as well as orderly procedure, are no doubt present in another of the “ways” Leibniz considers as not deserving the title “controversy”. This is the “way of accommodation” (la voie de l’accommodement), which “leads to a blind alley” (Chapter 27). It leads to a blind alley because its purpose is merely devising an ad hoc means of neutralizing the opposition between the contenders. Therefore, instead of addressing the deep reasons underlying the conflict, the solutions this way proposes are short-lived because they remain at a rather superficial level. The reasons used in such an approach are typical of the instrumental use of reason, where the ultimate ends (Max Weber’s Zweckrationalität) are not under discussion. In warfare, the “way of accommodation” is comparable to the establishment of occasional pacts, not based on the real, long-term strategical interests of the partners. Sometimes, the desire for compromise may lead to what Leibniz calls “the way of condescending” (la voie de la condescendence), where a contender makes concessions to the demands of the opponent, forgetting that there are points “in which concessions are impossible” (ibid.). Condescending in fact amounts to yielding to the opponent without seriously considering the implications of this act. In this respect, it differs
pending the progress of the negotiations. Bossuet (June/October 1693) rejects altogether Leibniz’s definition of the issue, arguing that infallibility is not a matter of fact, so that the only admissible starting point for the Catholics is that “the church cannot be mistaken”. Consequently, “there is no hope for a reunification if one wishes to suppose that the decisions on matters of faith of the Council of Trent may remain suspended” (FC I 501). One can see that, while Leibniz was correct theoretically by rejecting the “way of authority” as blocking a true discussion of the issues (i.e., a true “controversy”), he failed in practice, for he should have known that the Catholics would not give up the prerogatives granted them by the principle of authority as a basis for the negotiations. For an analysis of the Leibniz-Bossuet controversy, see Frémont (Forthcoming). xl Introductory Essay from controversy, which is characterized by the most serious examination of the positions in conflict as well as of their implications. Leibniz also excludes from the category —controversy“ another way of conducting a debate, which he calls —Huet‘s historical method“. This method seeks to end the theological-philosophical controversies by establishing the most remote antiquity of truth and the consensus of all ancient peoples. Its core consists in the demonstration of the historical priority of Moses over the founders of other ancient religions, which are in some way different branches of a common mosaic trunk.24 This strategy amounts to employing the criterion of —universal consensus“ adopted by the libertines and deists of the time in order to combat them on their own ground œ a move that is vigorously condemned by Arnauld.25 Leibniz, who is sympathetic towards Huet (see Chapter 37 and A VI 4 435), agrees with him that history is very useful for the demonstration of the truth of religion, and suggests the need of a universal history, both sacred and profane (To Huet, February 1679; A II 1 459), which should comprise all sorts of facts: —nature and art, the migrations of peoples, the changes in languages and empires“ (To Huet, March 1679; A II 1 465). He thus accepts Huet‘s proof of antiquity as contributing to the determination of truth, but claims that it is not an absolute proof and must be controlled by the ars critica (ibid.) œ the —art of criticism“, which is needed in order —to distinguish the imagined from the true and fable from history“ (A VI 4 953).26
24 Making use of his vast historical and philological erudition, Huet establishes a parallel between Moses and the Egyptian Thoth, the Phoenician Taautus, the Persian Zoroaster, the Greek Hermes, and the Roman Mercury. 25 The libertines and deists argued against the unique and exclusive claims of truth of the Christian religion on the grounds of its convergence with the natural religion of the pagans. Huet makes use of the same premise to reach the opposite conclusion. Referring to Huet‘s Demonstratio evangelica, which he sees as very close to La Mothe le Vayer‘s De la vertu des payens, Arnauld condemns Huet‘s argument as containing —horrible things capable to convince young libertines that one must have a religion, but that all of them are good and even paganism is comparable to the Christian faith“ (Õ uvres III, p. 400). 26 Leibniz comments on Huet‘s method in a letter to Hermann Conring (A II 1 457), the Helmstedt Calixtine. Naturally the Calixtines were favorable to the method proposed by Huet, who shared their ideals. Indeed, the reunion proposals of George Calixte (1586- 1656) were based on the determination of the convergences between the confessions, as a means to find, in the preliminary stage, formulations that could be accepted by all. In his Consensus quinquesaecularis, Calixte had established the fundamental doctrines that could be acknowledged by the totality of Christians by virtue of their common history. But in fact he only provoked a strong rejection by the orthodox Lutherans who, like Abraham Calov (1612-1686), refused to see in this —common history“ anything other than the obstinacy of Introductory Essay xli
The historical method could be generalized in terms of the principle that a dispute could be solved if we could reconstruct the shared past of the present contenders, so as to find out exactly the historical point where divergence arose. We could then eliminate the divergence by going back to the point where agreement prevailed. Leibniz’s critique has in view not so much the fallibility of historical knowledge as the lack of available methods capable of grounding it. If such methods were available, they would certainly permit to establish the truth of revealed religion, for “it is grounded upon facts of ancient history” (To Nicaise, 30 April 1697; GP II 57). But this would require much more time than what one could dispose of in the pressing problem of the reunification of the Christian churches. Another difficulty Leibniz discerned in the application of the historical method to controversies was that, even if it were secure, the formulations yielded by it would always be poorer in content than those required for the suppression of divergences, because they would be unable to capture the additional contents highlighted by these divergences.27 Furthermore, the use of the historical method in a situation of controversy could not ensure that the reconstruction of the past by the present contenders would be agreed upon. The present dispute is rather likely to project itself onto the past. That is to say, the “historical” reasons adduced run the risk of being not “real” reasons, but rather merely apparent or “ideological” ones.28 In order to avoid this, the “historical method” would have to become a “critical” one, as we have seen. In particular, it would have to be coupled with a rigorous hermeneutic methodology that would provide the “controls” necessary to avoid fanciful interpretations of the past.29
the church in standing by error and its desire to repress the dissidents fiercely (see Calov’s Systema locorum theologicorum, 1655-1677). 27 To Seckendorff (1683; A II 1 533-534), where he again mentions Huet. 28 Leibniz was familiar with – and also somewhat guilty of – such obstinate “misunderstandings” where historical interpretations often became ideological confrontations. The correspondence with Bossuet, for instance, displays numerous examples of this kind of abuse of history. In his letter of 1691, Leibniz had made use of the case of the Bohemian Utraquists, whom the church had admitted as true Catholics, in spite of the fact that they did not follow the resolutions of the Council of Konstanz about the administration of the sacraments of the Eucharist (FC I 344). But Bossuet rejected this example as a precedent that fits the situation of the Protestants vis-à-vis the Council of Trent, making use of many other historical references (FC I 495). What is instructive in this case is the fact that both Leibniz and Bossuet display a remarkable historical erudition, which does not lead them, however, to doctrinal agreement. 29 As the historian of the house of Brunswick-Lüneburg, Leibniz was naturally interested in the problem of transforming this discipline into a science. He may be rightly considered one of the founders of modern historical methodology. He viewed “history”, conceived in a broad sense, as one of the central tools for the Encyclopedia, which xlii Introductory Essay
On the basis of what controversy is not, we may now try to delineate its leibnizian identi-kit. A controversy is an orderly (rather than random) debate where reasons (rather than power) are the decisive tools. These reasons should address the deep and general (rather than superficial and ad hoc) issues; they should consider seriously (rather than condescendingly) the opponent’s views; and they should be based on strict methodological control (rather than on ideologically-prone free interpretation). In spite of this emphasis on the role of reasons, one should not forget the initial parallel with war. Contenders engage in a controversy because they have a reasonable hope to win. Therefore, the “serious aim” of a contest of this sort – just as in other warlike games – is to put an end to the contest (Chapter 7; see also Chapter 1). Controversy’s prize, unlike in other warlike games, is the persuasion “either of the adversary himself or else of some other listener” and “a full victory is the one that subjugates declared enemies also in their minds”, by the force of reasons alone (ibid.). Such reasons, however, are always contextually given, plural, and motivated. “Thus, in order to understand in depth how controversies can arise … we must take into account the person of the contestants, the contest’s prize, the hope of success according to the laws of competing, and finally the reasons used in the contest” (ibid.); we should not overlook either the situation in which the controversy takes place (Chapter 16H). It is the need to take into
should contain “the general inventory of our public treasure”. As such it would include a historia rerum (containing all the observations already performed about physical, psychological and social facts) as well as a historia locorum et temporum, comprising geography and history in the usual sense (De ratione perficiendi Encyclopaediam Alstedii; D V 183; cf. Couturat 1901: 158, 570-571). The methods of these two “histories”, natural and civil (Historia universalis, id est tam naturalis quam civilis, K I 51), are essentially analogous, for in both cases one has to establish the reliable data from which one can go on to discover general truths (C 524). Their difference lies in the different types of observation involved in each. In history, the crucial point is how to determine the reliability of the various kinds of “testimony”. Hence his insistence on the combination between history and criticism and on the need of a comparative method, as mentioned above. The “art of criticism”, he says, consists in “the examination and use of the ancient monuments” (To Nicaise, 1697; GP II 567). This must be done through a comparative approach applied to at least three levels or domains of historical research: to the ‘archaeological’ domain, where the task is to copy and examine all kinds of documents (letters, diplomas, seals, etc.) or monuments (ruins, clothes, habits, etc.); to the “philological” domain, where the main topic of research is the etymological and comparative study of languages; and to the “hermeneutic” domain, where the objective is to clarify the meaning of the texts or obscure expressions through its comparison with other similar texts or expressions (cf. his correspondence with Koch on some Greek philosophers; GP VII 469-481). Leibniz’s contributions to all three domains were considerable. See Davillé (1909), Conze (1951), Spitz (1952), Racionero (1991), and De Mauro and Formigari (1990). Introductory Essay xliii account so many variables that explains why the art of controversies cannot be reduced to a narrow conception of logic. As far as we know, no single leibnizian text expounds the various components of this art. We can find, however, scattered in the many writings here collected, written in virtually all the periods of his life, elements of this art that correspond to the components of the above definition. At what might be called the tactical level, we find a series of methods designed both to avoid the negative properties and to promote the positive ones. In the earliest systematic text in our collection – significantly called “Vices of a mingled dispute” (Chapter 1) – Leibniz classifies the causes and types of disorder and confusion that affect controversies. The avoidance of such causes not only prevents controversies to lapse into non- controversies; it is coupled with positive suggestions as to the forms of organization and conduct of a controversy. The capital importance of the order of the arguments in a controversy leads Leibniz to propose various ways of conceiving of and preserving ‘form’ in a controversy. ‘Form’, referring to controversies, is sometimes conceived by Leibniz as a reduction to a symbolic language, the Characteristica Universalis, which w ill allow then the s olution of t he controversy by m ere calculation (Chapters 14, 21). It may also merely mean the observation of an “art of disputing” (Kunst aus zu disputieren, Chapter 16I), i.e., the ‘syntactic’ structure of a dispute – a procedure that should at least assure its ‘completion’ in the sense that all arguments and counter-arguments presented by the contenders are put in their proper place and thus taken into account. It may rather refer to the nature of the arguments presented, with a view to ensuring their relevance to the step in the debate in which they are presented, and avoiding undue interference not only in the procedure but also in the content of other, independent arguments (Chapter 9A). And this is only a sample of the forms in which ‘form’ – whose absence is, as stated in the opening sentence of Chapter 1, the major vice of a controversy – is interpreted by Leibniz, and illustrated in many other chapters. Another tactical operation to be performed is the —control“ of interpretations. For this purpose, refining the hermeneutical method is the most important step. As we have already seen (Chapter 11), Leibniz devotes much effort to this task. By considering different hypotheses about the circumstances of the debate, the intentions of the opponents, the available knowledge about the text and the meanings of its components, etc., he presents a systematical table of interpretive options. Each of these options provides a tentative definition of a problematic term or claim. But not all of them are equally acceptable. A series of considerations œ philological, xliv Introductory Essay historical, logical, semantic, pragmatic, etc. œ are used in order to reduce the set of possible interpretations to that of the plausible ones. Once these clearly defined interpretations are at hand, the truth of a claim, under each of them, can be estimated and its weight as a reason can be properly taken into account (Chapter 2, paragraphs 33, 34, 65). The hermeneutic method thus is both a method for restraining interpretive freedom and for providing the ”masses‘ that put into motion the —scales of reason“ upon which the resolution of controversies depends.30 This careful interpretive and selective labor œ says Leibniz œ should be preserved by compiling its results in a comprehensive volume including definitions, theorems, historical and experimental data, and indexes (Chapter 2, paragraphs 66-70). This is the first time Leibniz formulates the idea of a new encyclopaedia, which was to become one of his major projects. W e see here how this project is connected with the art of controversies. Interpretations the parties in a controversy agree upon cannot always be reached even with the use of an adequate hermeneutic method. This need not, however, paralyze the debate. It can move on by provisionally setting aside the difficulty, and pursuing other topics. In C hapter 2 7 Leibniz calls this tactic the —way of abstraction or suspension“. It is applicable only when questions of interpretation are not the core issue and are not to be subjected to the —way of authority“. This is not the case, for example, in Leibniz‘s debate with Bossuet, where œ as we have seen (see note 28) œ the latter makes clear that the Catholic Church is not prepared to make any concessions about whose interpretation is to prevail.31 The most important and innovative tactics discussed by Leibniz is perhaps the one he develops in Chapter 19. He emphasizes the importance and novelty of his proposal, which he announces as —a very peculiar method, which ha[s] two great advantages: First, it could not be
30 The image of a “balance of reason” is central in Leibniz’s art of controversies, and appears, explicitly or implicitly, in many of the chapters of this book. It is associated with the idea of a rationality that, in the absence of deductive certainty, contents itself with ‘inclining’ reasons. See Dascal (2001, 2003b, 2004a, 2005). 31 In fact, the “suspension” tactic had been designed by Rojas y Spínola. The bishop’s idea was to obtain a provisional reunification, setting aside difficult – but not essential – issues of a theological nature, until the return of a climate of confidence would permit their calm discussion within a reunited church. Leibniz had been favorable to this tactic, both in the negotiations between Protestants and Catholics and between the Lutherans and the Reformed. But he was aware of the difficulty in establishing an agreed upon list of issues that could be set aside. While Rojas y Spínola had in mind problems such as the Virgin’s conception, the Protestants wanted to include in the list the problem of papal infallibility – which the Catholics obviously were not prepared to “suspend” even provisionally (cf. the echoes of these debates, not at all hypothetical in Chapter 27). Introductory Essay xlv disapproved by anyone; second, it would lead to the end, furnishing a sure means to arrive at a conclusion”. Leibniz’s proposal in fact grants the notion of moderation a new tactical role. Whereas, as a component of tolerance, it was a precondition for a rational debate to take place, here it acquires the further role of endowing the controversy with a – so to speak – “rational dynamics”. Leibniz clearly discerns this dual role of moderation: “… there is nothing that makes a dispute more commendable than the moderation of the disputants; well, I claim that this moderation will be manifest here in a quite special and indisputable way”. Such a way consists in providing a structure for the debate such that it will force the contenders to be moderate. The central piece of this structure is the active participation of a rapporteur (expounder), whose function – unlike that of the judex controversiarum of Leibniz’s earlier writings – is not that of a judge nor of a conciliator. His function is to maintain the order of the debate and, especially, to reformulate and summarize the contenders’ positions and arguments so that the whole “economy of the issue” emerges unmistakably. The rapporteur thus functions as “a palpable sign of moderation and equity”. The figure of the rapporteur represents in fact a procedure intended to permit the comparison of the opposed positions in a controversy regarding the points they share and those where they actually diverge. This is achieved through a process of reformulation, analysis, and synthesis, which gradually modifies the contenders’ perspectives on the issues under dispute. The general principle of this change of perspectives is the rule “Put yourself in the place of the other!”, whose epistemic import is pointed out by Leibniz: “one has to think calmly, after having placed oneself in the place of the other, because this provides considerations that are appropriate to know better the consequences of what oneself does” (Chapter 17). In this way one would be less prone to commit the mistakes that all too often occur in controversies: “One sticks to personal matters, to the readings and considerations that are favorable to a certain party; one does not pay attention to what the opposed party puts forth; and through these and a thousand other maneuvers one employs unintentionally and unawares, one manages to mislead oneself or at least to change, converting or perverting oneself according to what one has met” (NE 2.21.22; A VI 6 182).32 The importance Leibniz attributed to this rule for the proper conduct of controversies is manifest in the fact that, in the heat of the irenic
32 In addition to its tactical and strategic role in the conduct of controversies, the principle “Put yourself in the place of the other!” has not only an epistemological use, but is a fundamental principle of interpretation, as well as an ethico-political use in Leibniz (cf. Dascal 1993, 1995; Naert 1964; Racionero 1995). xlvi Introductory Essay negotiations, he took the time to reformulate the Lutheran theses in Catholic terms, in the hope that this would bring about the rational persuasion required for a breakthrough in the negotiations. It is interesting to observe, however, how in this scheme, which required œ for its practical success œ hiding the identity of the writer behind a fictitious —Catholic Doctor“ (Chapter 35), the dissimulation and lying characteristic of the ”strategic‘ use of the Place of the Other Principle go hand in hand with the ethical-political aim of thereby avoiding future conflict and war.33 The actual presence of the rapporteur is not necessary, in so far as the contenders themselves can perform his task according to the principle that
33 Leibniz employed a similar device œ this time, however, posing as a neutral observer œ in a book length manuscript written in 1686, whose editor, P. Lacroix, called Systema theologicum and whose actual title is Examen religionis christianae (A VI 4 2355-2455; FC I 531-652). Here too, he writes from the point of view of a Catholic, trying to express in the latter‘s language the reformators‘ theses, in order to show that there are no invincible obstacles against a shared doctrinal interpretation. Since the text was addressed to a double audience œ Catholics and Protestants, however, he had to keep both satisfied, by avoiding misrepresentation of any of the parties‘ positions (for an analysis of this extremely subtle dialectical exercise, see Dascal 2003b). The success of this strategy (or stratagem?), at least on the Catholic side, is shown by the debate initiated by Lacroix when he discovered and published the Systema theologicum. Lacroix argued that, on the basis of this text, it was possible to claim that Leibniz was a crypto-Catholic. In fact, this opinion was pre-figured by the fears and hopes of some of Leibniz‘s contemporaries. It was feared to be true by his relatives (cf. the letter of Johan Friedrich Leibniz to his brother; A I 1 420-421); it was hoped for, albeit covertly, by Arnauld (letter to a Franciscan in the court of Mainz; GU II 66-67); and it was manifestly expressed by Landgrave Ernst von Hessen-Rheinfels (A I 3 324-327) as well as by the Roman curia through cardinal Casanata (A I 7 495- 499). Leibniz always refuted these claims, which were sometimes œ as in the case of the Landgrave œ mere invitations for him to convert. He consistently affirmed his resolve to remain in the bossom of the —moderate Confession of Augsburg“ (To Landgrave Ernst, 11 January 1684; A I 4 319-322). But his resolve, though doubtlessly firm, was in a sense contingent upon the success of the reunification thrust. For, as we have seen, ecclesiastical reunification ultimately consisted, for Leibniz, in the possibility of reformulating the theses of the contenders, so as to make them all bound by a doctrinal formula capable of satisfying their private convictions. In a letter to the duke Jean- Fréd ér ic of 1679, Leibniz presents his Demonstrationes catholicae in terms that announce the Systema theologicum: —One should forge a text as if it were written by a Catholic in order to convert a Protestant“ (K IV 455). But the most incontrovertible evidence is to be found in a letter to Madame de Brinon, of September 1693. In this letter, responding to a fear expressed once by the late Pellisson, Leibniz writes: —You are right when you say that,
making progress in the way we are proceeding (de la maniè re dont nous nous y prenons), it seems that all the Catholics will become Protestants and all the Protestants, Catholics. This is what we purport too. God willing, a mixed one will appear, who will have all the good you recognize in us and all the good we recognize in you. (…) I have said a long time ago that when all Protestants will be made Catholics, it will be found that all Catholics have become Protestants“ (FC II 506). Introductory Essay xlvii animates it.34 In fact, the mutual reformulation of each other’s positions and arguments has the further advantage of enriching the exchange of perspectives with a parallel exchange of conceptual frameworks or “languages” – an achievement of whose difficulty Leibniz is well aware of: “it seems to me as difficult to make these people change their language as to teach a raven to sing like a nightingale” (Chapter 19). In order to make viable the reformulation of the opponents’ positions and thereby to reconstruct the “true place of the other” in a debate, Leibniz makes use of an arsenal of tools for the implementation of his art of controversies. This arsenal comprises, first, both the ars iudicandi and the ars inveniendi. The former elaborates demonstrative proof (which, when applicable, is supposed to decide conclusively a dispute), as well as the doctrine of mathematical probabilities (which, when applicable, permits the formalization of non-conclusive proof). The latter includes the traditional tools of rhetoric and dialectics, as well as other ones, either adapted from other domains (e.g., the already mentioned ars deciphratoria and ars argutiarum) or created by Leibniz himself, such as a variety of semiotic means (cf. Dascal 1978). In several chapters, the dialectic value of some of these semiotic means is apparent. For example, Chapter 40 contains a synoptic table that is invaluable for sorting out possible controversial points. Or the reconsideration of the Platonic method of division by means of diagrams or tables that reveal its shortcomings, if taken as a sine qua non that does not permit the use of a plurality of ‘intermediate’ genera and species (Chapter 12B). Others are useful ‘formal’ devices for ordering the arguments in a controversy (Chapter 16I). And, on the linguistic end of the semiotic spectrum, one should not forget the fundamental dialectic value of loci communes (Chapter 9D), rhetorical paradoxes (Chapter 16E), the ambiguity of terms (Chapter 16D), real or apparent clashes or concurrence of arguments (Chapter 16B), stratagems (Chapters 16C and 16F), and so on. What is important to keep in mind is that all these texts, which certainly
34 Sometimes Leibniz calls this method of conducting a controversy simply the “exposition method” (methodus expositoria) or the “method of diminished refutations” (methodus imminuti elenchi), thereby showing the internal, rather than necessarily external role of the rapporteur (Chapter 40). The essential contribution of this method to the reconciliation between the adversaries consists, according to him, in showing to each other “the plausibility of the opponent’s arguments” (ibid.). Only when the contenders are incapable of performing by themselves this reformulation task, the presence of the rapporteur – or, as he is called in this text, the annotator (whose mission is “to show that the divergencess are not so many as thought”) – becomes necessary. One should notice that this later position of Leibniz differs from his earlier position (Chapter 1), that grants the actual presence of a ‘director’ of a dispute a fundamental role in avoiding its deterioration. xlviii Introductory Essay are part and parcel of Leibniz‘s dialectics, are not alien to his project of a rigorous development of the ars disputandi, but rather œ as Leibniz emphasizes œ are part of it. W e should not forget also that Leibniz‘s arsenal of tools for the art of controversies includes also, as already pointed out, his project of an encyclopedia œ a major piece of his art of discovery (Chapter 15). This ensemble of strategies, tactics, and tools is what provides Leibniz with the means to transcend the narrow Lockean notion of tolerance as the upper limit of what can be expected regarding controversies. For example, in Chapter 40 he points out that the —exposition method“ (see note 34) allows the negotiations between the churches —to go beyond tolerance“. That is to say, the availability of means for systematically ordering, interpreting and reformulating the contenders‘ positions paves the way for being much more ambitious than merely acknowledging the existence of views opposed to one‘s own. Leibniz believes that these means lead to the eventual resolution of controversies through what he calls conciliatio per consensum.35 It proceeds by a very serious application of the rule —Put yourself in the place of the other!“. For this, one has to overcome the tendency to refute the opponent, even though this is easier than to defend one‘s own position. Leibniz often claims to be averse to a critical attitude, and claims he prefers to attend to what he can learn from an author rather than to the author‘s mistakes (e.g., Chapter 31E). This attitude (which fits his call for moderation) ends up œ he contends œ by yielding —more congruent propositions“, whose implications can then be drawn and accepted by the contenders (Chapter 40). This process, therefore, implies amplifying and deepening the conceptual basis upon which conciliation will be built, rather than remaining at the level of the opposed views. Such a process clearly goes beyond reconciliation through compromise or by way of syncretism œ both of which are —static“ in so far as they do not undertake to modify the starting positions of the contenders but merely to combine them somehow. By contrast, conciliatio per consensum, in Leibniz‘s sense, is a dynamic process that re- conceptualizes the issue, thus overcoming the deadlock. The consensual method is not viewed by Leibniz as opposed to the method of tolerance, but as presupposing it. He refers to “conciliation through consensus” in several juridical texts, where he elaborates upon its underlying idea, namely that it involves the finding or construction of
35 He employs this expression in the synopsis through which he sums up the themes treated by G. Burnet in An Exposition of the thirty nine Articles of the Church of England (Chapter 40). Leibniz’s formula distinguishes between two ways of resolving controversies or of conciliation: per consensum and per tolerantiam. Introductory Essay xlix
—more congruent propositions“. Consensus, thus, admits of degrees, ranging from the minimal agreement involved in mutual tolerance to total agreement, in which maximal congruence is achieved. Leibniz‘s notion of consensus has a juridical origin. It has to do with the notion of convention and its cognates (contract, pact, etc.). A convention, while respecting the will of the parties, creates for them an obligation for which they are accountable as soon as the convention has been agreed upon (cf. Systema juris, paragraphs 45-48; GR 828).36 In an undated series of definitions collected under the title Definitionum juris specimen, Leibniz defines a convention as the conjunction of a promise and its acceptance (GR 733), and goes on to spell out the various conditions under which different kinds of obligations are generated by a convention. It turns out that, although some consensus is necessary for any convention, it need not be a full consensus, but can be based on a less-than-full consensus (Chapter 39). Consequently, there is a whole family of ”conventions‘, each characterized by a different degree of consensus. For example, in Meier‘s terminology (which Leibniz does not question in Chapter 39), a ”treatise‘ obtains if —the contracting parties did not yet reach a full agreement, but have at least discussed the affair in view of declaring to each other, without committing themselves, their intention to reach an agreement“; if all that has been agreed upon is to reach a treatise, then what obtains is merely a ”pact to negotiate‘ (pactum de tractando); pacts, in turn, may be ”bare‘ or ”dressed‘; and there are ”contracts‘ as well as ”semi-contracts‘; etc. In fact, Leibniz‘s conception of consensus transcends the juridical framework and has ontological and epistemological underpinnings. In order to climb the stairs that lead towards full consensus, it is not so much the number of congruent propositions that must be increased, but also so to speak their quality. This corresponds to his general principle that —inferior things are found in superior things in a nobler form than in themselves“ (To Boineburg, 2 September 1695; K VI 111). ”Nobler‘ must mean clearer, higher in the hierarchy of beings, and ontologically better grounded. In the case of controversies, this implies that —the most useful“ ones are those in which the contenders undertake to perform the ascension to a higher plane, where the basic issues at stake are clear and it is obvious to the contenders that they cannot but agree to the basic principles involved, over and above their disagreements regarding details.37 Consensus, when based on agreement at a higher level, overcomes the disagreements at a lower level
36 On Leibniz’s notion of juridical obligation and its implications, see Racionero (1993). For another sense of ‘obligation’ and its implications, see Chapter 6. 37 In Chapter 8E Leibniz exemplifies this procedure. l Introductory Essay because it expresses (in the metaphysical as well as semiotic senses Leibniz endows this term with) better the real structure of the situation. The clearer this expression is, i.e., the fuller the consensus it corresponds to, the less arbitrary it is and therefore the more it manifests universal harmony. Herein one may perhaps discern the sense of Leibniz’s “eclecticism”. It does not consist in the juxtaposition of apparently reconcilable theses belonging to opposed systems, without modifying such theses – as the Calixtines and others thought to be possible. Nor does it consist in the integration of diverse materials into a synoptic-syncretistic vision – in the Ciceronian way. It consists rather in developing a ‘higher’ viewpoint, wherein the theses in confrontation are inscribed in a more comprehensive order which grants them a new meaning within an harmonious framework. In this respect, Leibniz’s eclecticism corresponds to Leibniz’s ontological notion of harmony: “the commerce of substances or monads does not result from influx but from the consensus whose origin is divine pre-formation” (De ipsa natura; GP IV 510). At the epistemological level, the search for consensus thus functions as a dynamic process whereby reason can overcome what, at lower levels, seem to be irreconcilable contradictions. With the “consensual method” we thus reach the rock bottom foundation for not only resolving but also benefiting from controversies: “When [reason] destroys a thesis, it builds the opposing thesis. And when it seems that it simultaneously destroys the two opposed theses, it is then that it promises something deeper, provided we follow it as far as it can go, not in a spirit of dispute, but with an ardent desire to search for and disentangle the truth, [a desire] that will always be recompensed by some considerable success” (Théodicée, Discours Preliminaire, 80; GP VI 97). The leibnizian goal, therefore, is neither to amalgamate in a ‘system’ divergent positions nor to merely destroy such divergences; it is rather to integrate them within a broader perspective that explains the reason and meaning of the detected opposition. Contradiction, which is both logically and metaphysically impossible, serves as a trigger of great heuristic fecundity in this relentless movement to overcome it. Controversial reason is always situated and progressive. It is a laborious work towards higher perfection, which operates – analytically and synthetically – upon what is known to us at any given point or situation,38 the aim always being to advance in the establishment of truths that are self-grounded and attested, but not validated, by consensus, in conformity with the ‘method of establishments’ (Chapter 37), with the help of all the means a broader conception of logic and rationality has developed so far and will certainly continue to develop.
38 Recall Leibniz’s ubiquitous use of the expressions ex datis and quoad nos. Introductory Essay li
5. Scope
It is well known that Leibniz’s major works do not have the form of theoretical treatises. He prefers to present his ideas in the form of dialogical exchanges with his contemporaries. This choice reflects a burgeoning underlying polemical activity, which is no doubt the prevalent modus operandi of Leibniz the thinker and the man of action, whose devise was Theoria cum Praxi. Naturally, his writings on the art of controversies are intimately connected with this polemical activity, and shed light on it. Since Leibniz was engaged in controversies in virtually every topic he dealt with, the scope of application of his art of controversies is practically the totality of his oeuvre.39 As a devoted activist of the irenic cause, church political controversies and their theological counterparts figure prominently in his controversy- related writings.40 Leibniz addressed the most important doctrinal and theological questions in debate: predestination, justification, the original sin and its effects upon Adam’s progeny, the relationship between faith and reason and between natural and revealed religion. Beyond countless doctrinal points, what is at stake – on the theoretical and political level – is the very conception of the Church: is it merely an institution with its interests, hierarchical structure, and rules or, above all, a moral entity, whose most distinctive norm is charity? Whatever the answer, it had wide ranging anthropological, cultural, and political implications, e.g., for the conception of human and for the encounter of Christian Europe with other peoples and cultures, in the West, the East, and the South. Although the main objective of Leibniz’s irenic activity was to solve the practical problem of creating a shared doctrinal basis for reuniting Christendom, its theoretical import is immense in his thought. The importance of what was at stake in these controversies and the difficulty in finding solutions were, no doubt, a determinant factor in shaping Leibniz’s art of controversies. The ideas of moderation, of reformulation of the adversary’s position, of “congruent propositions” as an expanded and deeper basis for consensus, etc. take shape in his participation in these
39 For analyses of a sample of his controversies, see Dascal (ed.) (Forthcoming b). 40 On the importance of theological and church political concerns in Leibniz’s philosophy, the classical work is Baruzi’s (1907). See also Genin (1980) and Dascal (1975). Leibniz’s participation in the religious negotiations for the reconciliation between the Christian churches is documented in Eisenkopf (1975). See also Racionero (2001). The corpus of religious debates in which Leibniz intervened remains to be compiled, but an approximate idea of its scope can be gathered from the texts in the five first sections of Grua’s edition. lii Introductory Essay controversies and in his reflections about them. Although these ideas did not yield the practical results Leibniz hoped for, they had a lasting effect in Leibniz’s firm belief that controversies can lead to productive results, at least in other areas. As a philosopher of law, Leibniz debated with leading thinkers – among whom some of the most important jurists of his time – about the foundations of justice and of natural law.41 As a jurist, he was considered an authority, and maintained a detailed correspondence on key technical and theoretical issues (see Chapters 31, 36, and 39). He undertook the systematic reform of civil and international European law – an undertaking guided by the concerns for order, clarification, and redefinition of the juridical positive corpus.42 As a lawyer, he experienced the problem of the so-called “hard cases”, where the need of a rigorous method of interpretation arises with particular acuteness.43 In all these capacities, the peculiar nature of juridical confrontations, as well as the potential
41 The two classical books on Leibniz’s juridical philosophy are those of Grua (1953, 1956). In addition to his analysis of the materials he published in his 1948 edition, Grua studies the historical antecedents of each leibnizian theme he presents, as well as the main debates concerning them. Schneiders (1966) and Sève ( 1989) update Grua’s treatment. See also König (1998), Boucher (Forthcoming a), and Döring (Forthcoming) .There is no available compilation or even catalogue of the juridical polemics in which Leibniz intervened, but their presence in th e ensembl e o f his work i s considerable . A followe r (although with major modifications) of Grotius’s natural law approach, Leibniz debated mainly with the followers of Hobbes’s voluntarism (Pufendorf, Barbeyrac, Sharrock), as well as with those who, extending this line of thought, began to open the way for juridical individualism (particularly Locke). 42 Leibniz’s most important contribution to the history of the ordering, cataloguing, and codification of laws is the Codex juris gentium diplomaticus (1693), which includes a preface that sums up the principles of his juridical philosophy. The circumstances in which he compiled and selected this corpus of ancient diplomatic laws, as well as the objectives that guided him in this task are described in a letter to Basnage de Beauval of 16 October 1692 (GP III 90). In 1700 he published a second part of this work, the Mantissa Codicis juris gentium diplomatici. 43 See especially his early writings: Disputatio juridica de Conditionibus, a dissertation submitted by Leibniz in 1665 for obtaining the degree of bachelor in law (and published in 1669 without his authorization), and De casibus perplexis in iure, a dissertation that earned him the doctor’s degree from the University of Altdorf in 1667, at the age of 21. In these two dissertations, Leibniz develops a method of evaluation of the juridical norms applicable to hard cases. Although he didn’t elaborate it further, this method comprises a non-mathematical model of the logic of probabilities, to which he often refers to later. This model has been studied by Kalinowski (1977). Miguel Sánchez Mazas, in several of his studies (e.g., 1978), systematized and developed this model, applying to it ideas of the Characteristica Universalis. See also the recent study of the “method of cases” by Boucher (Forthcoming b). Introductory Essay liii applicability to other areas of “juridical logic” became apparent to him (see, e.g., Chapters 5, 10, 31, 38). As a senior counselor at the Mainz and Hanover courts, Leibniz was prevented from engaging in public political disputes.44 Nevertheless, in his correspondence, as well as in his memoranda and notes not intended for publication, the debate form is evident. His contenders are often philosophers who – like Hobbes and Spinoza – had already died.45 But there are also cases of actual political controversies, like the one he conducted in his last years with Saint Pierre about the latter’s plan for a perpetual peace in Europe.46
44 Such a restriction did not apply to earlier political writings, such as the Specimen demonstrationum politicarum pro eligendo rege polonorum (1669), where he proposed a method to solve the problem of electing the King of Poland, and the Caesarinus Fürstenerius - De Suprematu Principium Germaniae (1677), where he redefined the notion of sovereignty in view of the ‘double sovereignty’ situation in Germany; nor did it apply to writings such as the Mars Christianissimus (1683), which served the anti- Louis XIV policies of the German princes. In the period when he was most influential (1690-1710), Leibniz acted not only as a minister of the court of Hanover (where he accumulated the functions of counsel, librarian, and official historian), but also as advisor of the courts of Vienna and Saint Petersburg. By virtue of his specialr elation with Sophie Charlotte, his voice was also influentia l in the cour t of Brandenburg, where he had founded and presided (though only nominally) the Berlin Academy of Sciences. Since 1700 he was also a member of the Paris Academy, by a special decision of Louis XIV. Even after he no longer was in favour in Hanover (which was only relative to his aspirations, for he was not dismissed of any of his jobs), Leibniz’s area of influence grew, both in England – through Princess Caroline of Wales – and in France – through his friendship with duchess Elisabeth-Charlotte and Nicolas Remond, respectively mother and chief counsellor of the regent, Philippe d’Orleans. 45 As far as Hobbes is concerned, see among others the Meditations about the common notion of justice (M 56-81), as well as the Remarks on the French translation of Shaftesbury’s Letter on Enthusiasm (GP III 407-417), which contains a critique of contractualist theories. As for Spinoza, even though there is no text specifically devoted to a refutation of his political theory by Leibniz, part of the analysis devoted to Spinoza in the Preliminary Discourse of the Théodicée may be interpreted in this way. 46 The Abbé de Saint Pierre was couselor of Duke Philippe d’Orléans and wrote, among other political and economic tracts, a project for achieving perpetual peace in Europe. Leibniz’s debate with him is quite peculiar. First, because – contrary to his habit of avoiding political confrontations – Leibniz engaged in it directly and second, because Saint Pierre’s opinions in part became representative of the new French international policy, once the duke became Regent upon Louis XIV’s death. Leibniz may have abandoned his customary caution in these matters because, after the Elector of Hanover moved to England in 1714, he felt free to express his political views; furthermore, he was desperate to establish new contacts in order to avoid isolation. In addition to that, the content of this debate touched upon Leibniz’s long-term defense of a conception of Europe according to which the status quo imposed by the national states (upon which the subsequent policy of a balance of power between France and England was based) should liv Introductory Essay
It is, however, in his work as a publicist defending particular political proposals that Leibniz displays his tactical mastery, by employing the full range of rhetorical weapons and other topoi of his art of controversies, in the service of not only winning a particular battle, but always with a view to a more comprehensive solution of political conflicts. One may discern three types of models employed by him in these writings, depending on the nature of the audience and circumstances. In the “secret memorandums”, written upon the request of some prince, he follows the traditional pattern of situational analysis. But he strengthens its logical aspects, so as to make the policy recommendations emerge, at the end, as the logical consequence of weighing the preceding considerations, sometimes as the only possible way, sometimes as the preferred alternative among the few remaining ones.47 The “manifests” were designed as pieces addressed to public opinion in order to justify the necessity or importance of certain decisions already taken or that should be taken by the ruler. Their style is both solemn and passionate, although the use of affective tropes never obscures the thread of reasoning.48 The third and most original of the leibnizian models is the one where he employs the form of a “dialogue”.49 As it were,
be overcome. He took thus the opportunity to promote his conception of a peace based on a true “unity in diversity”. The texts of this debate are compiled in Robinet (1995). See also Racionero (2001). 47 For the former, see for example Securitas publica (1670; A IV 1 131-214) or Denkschrift zur Begründung einer neuen protestantischen Kur (1684; A I 4 221-237). For the second, see Consilium Aegyptiacum (1671-1672; A IV 1 217-410), especially the text titled De eo quod Franciae interest (A IV 1 246-252). Although not secret, Leibniz’s plan for the election of the king of Poland (Specimen demonstrationum politicarum pro rege Polonorum eligendo, 1669; A IV 1 3-98) for Baron Boineburg, belongs to this type of model. This text – which is almost a political treatise – begins by praising mathematical demonstration and one of its original formal proposals is the assigning of different weights to the votes of different classes of voters. Nevertheless, its procedures are more dialectical than mathematical. In this sense it is parallel to juridical texts of the same period, such as the Nova Methodus (1667) and the De casibus perplexis in jure (1666). The Specimen was published too late for the election, but Boineburg made use of it in his speech in support of the Count Palatine of Neuburg. 48 The series of tracts written by Leibniz against Louis XIV’s policy are magnificent examples of this category, including several pieces, from Mars christianissimus (1683; A IV 2 446-502) to La justice encouragée (1701; FC III 313-344) and Paix d'Utrecht inexcusable (1713; FC IV 1-147). 49 Leibniz in fact employs this model not only in politics or in polemics, but in all sorts of domains, throughout his life. One of his first writings, the Confessio Philosophi (1674), which establishes the grounds for his project of a rational theology, is in dialogical form, as is also Chapter 3, of the same year. In physics, the long dialogue Pacidius Philalethi (1676) synthesizes his studies on movement. A set of dialogues written in 1679, which Baruzi called “mystical”, are in fact part of his metaphysical and epistemological Introductory Essay lv a real dialogue is reported, and each party presents its best arguments. There is, however, a slight imbalance in favor of the party representing Leibniz‘s opinion, so that the intended audience is supposed to be persuaded in the —right“ way. Nevertheless, Leibniz takes pains to use the procedure of reformulating each party‘s position from the point of view of the other in as fair and plausible a way as possible.50 In spite of the variety of styles and logico-rhetorical means used in these three models, they embody implicitly or explicitly the structure of a debate and are ruled by the underlying presupposition that a conciliation of the opposed positions, when stripped of their more aggressive elements, is both possible and desirable. Leibniz‘s political thought is infused with the belief that politics must incorporate rational debate at its core. An ideal prince, for him, should have œ of course œ the most important virtues, especially justice, which is essential for maintaining the social bond between the citizens of a state. But justice goes beyond respect for the law (which is all-important for Leibniz), and the prince should have also clemency; which, in turn, he should use only with moderation (otherwise the fear of punishment would disappear). Moderation or prudence is the rule for the exercise of all other princely virtues. This rule presupposes the ability to evaluate the pros and cons of every course of action as well as the readiness to take into account all positions and arguments œ be they those of one‘s opponents or of one‘s
onslaught on skepticism: Dialogue entre Poliandre et Théophile, Dialogue entre Théophile et Polidore, Dialogus inter theologum et misosophum, and Chapter 18. Sometimes the characters in the dialogue are not given names, as in the De connexione inter res et verba (1678; translated in Dascal 1987) or the Dialogus (1677). In these cases, the dialogical form seems to help Leibniz to formulate his own position against traditional views or proposals by other philosophers (in the Dialogus, for instance, he is arguing for an intimate relation between signs and words which avoids the ‘super- nominalism’ of Hobbes). Sometimes his “dialogues” reproduce actual conversations, as the Dialogue effectif sur la liberté de l’homme (1695), which transcribes the dialogue he held in the same year with Dobrzensky. Leibniz justifies the use of the dialogical form by the fact that “it insinuates the truth with familiar language, by making apparent the order of meditation that goes from what is known to what is unknown” (Pacidius Philalethi; C 594). Apart from the didactic effectiveness of this rhetorical genre, however, the leibnizian dialogues implement and illustrate the way Leibniz thought controversies following the order of reasons should be conducted. See Chapter 9F for his reflections on the art of writing dialogues. 50 This is remarkably achieved in Chapter 18 and in the Dialogue entre un cardinal et l'amirante [sic] de Castille (1702; FC III 345-359), and less successfully in the Nouveaux essays and the Essais de Théodicée. lvi Introductory Essay advisors.51 His principal advice to a court politician consists in a set of rules for seeking and conducting fruitful discussions with fellow politicians, with open-minded scholars, and eventually also with a spiritual guide. These rules, which go beyond politics for they amount in fact to principles for organizing Leibniz’s own cooperative intellectual work, a work he conducts in so many simultaneous fronts, include recommendations such as: finding an appropriate “companion of studies”; writing down a detailed project of action for oneself, similar to the “instruction one gives to public ministers”; maintaining a list of “all that can be of help, including useful thoughts”; and, above all, taking into account “the point of view of the other”.52 It is well known how eager Leibniz was to submit his metaphysical proposals to discussion by the most important philosophers of his time. He discussed them with his seniors (Hobbes, Spinoza, Arnauld, Malebranche, Locke, J. Thomasius, Huet, Conring, etc.), as well as with members of his age group (Bayle, C. Thomasius, Foucher, Jaquelot, Placcius, de Volder, etc.), and of the younger generation (Hartsoeker, Eccard, Wolff, des Bosses, Wagner, Koch, etc.). In all these intellectual encounters, his aim is threefold: (a) to understand as fully as possible the most important metaphysical alternatives to his own; (b) to identify the shared elements and the remaining divergences; and (c) to sharpen his own system in the light of his competitors’ objections. For example, his confrontation with Spinoza’s system is, for him, the lever for providing a better explanation of the non-deterministic character of his notions of contingency and freedom in a world ruled by pre-established harmony.53 Another example is
51 The best known of Leibniz’s “prince portraits” is the one bearing the title Portrait du prince tiré des qualités et de vertus héroïques du Duc Jean-Frédéric de Brunswick- Lüneburg (1679; K IV 459-487). The same ideas are elaborated and presented without the panegyric elements in the Projet de l’éducation d’un prince (1690; MA 265-278), which was written for the ambassador La Bondinière. In texts such as these, Leibniz’s views are presented as contrasting with those of Machiavelli. 52 Cf. Chapter 18 (ad finem). For the significance of such rules for Leibniz’s epistemology, see Dascal (2000). 53 Leibniz’s relationship with Spinoza’s philosophy was intense and prolonged. Spinoza and Jungius were the only thinkers whose virtually entire available work was carefully annotated by Leibniz; and in Spinoza’s case, more than once. It is important, however, to point out that the core of Leibniz’s views on contingency and necessity (or on freedom and determinism) had already taken shape before he learned about Spinoza’s philosophy. His first contact with it was through the Tractatus theologico-politicus, which was sent to him by Graevius (April 1671). In spite of the latter’s comment that the Tractatus was a “liber pestilentissimus” (A I 1 142), Leibniz was sufficiently impressed to write immediately to Spinoza (October 1671), under the pretext of requesting information about his optical work. By that time he had already written the Confessio Natura (1668), Introductory Essay lvii
Leibniz’s submitting to Arnauld, prior to publication, the first mature version of his metaphysics, the Discours de Métaphysique. When “the great Arnauld” responds by dismissing Leibniz’s thesis summarily, Leibniz is upset and forcefully demands Arnauld’s attention and serious criticism. Leibniz’s insistence leads to a dense and polemical correspondence with Arnauld, whose upshot is a clarification and deepening of the conceptual basis of Leibniz’s metaphysics.54 Through such discussions, controversy becomes an integral part of the system itself and of its constitution, rather than merely a way of defending a ready-made theory. Obviously, since controversy always involves a partner, its course cannot be entirely determined by one’s aims and tactical moves. The story of the relationship between Leibniz and Locke illustrates this fact. Leibniz realized quite early the philosophical importance of Locke’s An Essay Concerning Human Understanding (1690), whose French summary, published by Le Clerc in his Bibliotheque Universelle already in 1688, he read and annotated. In 1696, he “found the draft” of these early comments and sent them to Thomas Burnett, suggesting that he should give them to Locke (GP III 176, 180). But Locke declined to reply to Leibniz’s
the Von der Allmacht (1670-1671) and a letter to Wedderkopf (May 1671) – all texts where, no doubt still somewhat immaturely, he had formulated the basis of his enduring solution to the problem above mentioned. In fact, only in 1675 did Leibniz get to know (partially) Spinoza’s Ethica, through a manuscript borrowed from Tschirnhaus. Presumably his fragmentary reading induced Leibniz to try to meet Spinoza. For this purpose he went from London to The Hague in November 1676. He reports that they talked “at length several times” (A II 1 378-381); Spinoza’s references to these conversations describe a rather cold atmosphere (GP I 123-130). Given the lack of trust in which Spinoza lived, it is natural that the reaction of both thinkers was different. At any rate, Leibniz’s reaction was of profound admiration, since between the first and second meetings he writes the Quod Ens perfectissimum existit in order to present it to Spinoza; and immediately after (in December), he writes several notes on topics presumably suggested by the conversations (later included in his De summa rerum book project; GR 263-268; SR). A later plan to go to Holland was abandoned due to Spinoza’s death. But Leibniz continued to be interested in Spinoza’s philosophy. In 1678 he receives from Schuller the Opera postuma, which he reads attentively and annotates profusely (A VI 4 17 05-1777; GP I 139-152). 54 It is a well-known fact that Arnauld’s motivation in relation to Leibniz was not purely theoretical. He saw in Leibniz, the Lutheran who had been appointed by the Duke of Mainz to conduct negotiations for the reunification of the Christian churches, a very important potential convert to Catholicism. Leibniz was, of course, well aware of this motivation. Nevertheless he placed the philosophical interest of elaborating a coherent and defensible metaphysics above such a circumstantial interest. On Leibniz’s use of the strategy described in Chapter 16F in the beginning of the correspondence with Arnauld, see Dascal (1995). lviii Introductory Essay comments.55 Nevertheless, with the publication of Coste’s complete French translation of the Essay in 1700, Leibniz developed his earlier comments into a full-fledged commentary, which he intended to publish at some point, still hoping to be able to first discuss the issues with Locke. A new opportunity arose when Lady Masham, Cudworth’s daughter and a close friend of Locke since 1681, wrote to Leibniz in early 1704, inquiring about his reaction to Bayle’s criticism of his system in the article “Rorarius” of the Dictionnaire Historique et Critique. She concluded her letter by saying: “Mr. Locke whose company I am so happy as to injoy in my familie, desires me to present you his humble service” (To Leibniz, 29 March 1704; GP III 338).56 Leibniz undertook to expound to her the principles of his
55 As reported by Burnett, upon receiving Leibniz’s “paper”, Locke declared that this was “the greatest favor done to him by you, whom he much appreciates” (To Leibniz, 30 November 1696; GP III 186). Later on, Burnett suggests that Locke’s unwillingness to reply lies in his satisfaction with a situation where the “German scholars do not know our books, and we do not read theirs”, a situation that prevents “scholarly wars” between the two countries (To Leibniz, 23 July 1697; GP III 208). In fact, however, we know (and Leibniz came to know later, with the posthumous publication of Locke’s correspondence) what Locke’s opinion of Leibniz’s views was. He had read not only Leibniz’s comments on the Essay but also his important epistemological paper, “On cognition, truth and ideas” (1684), published in the Acta Eruditorum. His conclusion was far from flattering: “I must confess to you that Mr. L.-‘s great name had raised in me an expectation which the sight of his paper did not answer, nor that discourse of his in the Acta Eruditorum, which he quotes, and I have since read, and had just the same thoughts of it, when I read it, as I find you have. From whence I only draw this inference, That even great parts will not master any subject without great thinking, and even the largest minds have but narrow swallows” (Locke to Molyneux, 10 April 1697; GP V 6n). Upon learning about these comments, Leibniz also expressed a non-flattering view about Locke’s philosophy, saying that “it contains some good things, but rather thin, and some of them have no solidity whatsoever” (To Caroline, 10 May 1715; K 11 39). 56 In fact, it was Leibniz who first approached Lady Masham, in a letter dated 14 December 1703, with the pretext that he “had learned” that she was about to send him a copy of her father’s Intellectual System. He praises the book as containing “much erudition and as much light combined together”, and declares that he has “contributed a little to this great system that your father has legated to us” (GP III 336). Presumably, Leibniz knew that Locke was living at the Mashams’ residence, and initiated the correspondence with Lady Masham as a way of re-establishing contact with him. No doubt the renewal of his interest in communicating with Locke was also related to the fact that, as established by the Act of settlement of 1703, the House of Hanover was to inherit, sooner or later, the crown of England. Besides the political appeal of becoming the advisor of the king of a major power, Leibniz did not hide his intellectual interest in moving to “a large city like London” (GP III 182), where “sçavants hommes abound, from whom one can benefit and who can help you, for there are many things that a single person cannot do alone” (GP III 175). In this respect he contrasted London and Paris with the grim situation in Hanover, where “one hardly finds with whom to talk” (ibid.). Introductory Essay lix philosophy, interpreting her replies as coming directly from Locke’s mouth.57 Furthermore, given this new opportunity for discussing with Locke – albeit indirectly – Leibniz virtually completed his commentary on the Essay by April 1704 (To Sophie Charlotte, 25 April 1704), a commentary he described as aiming not to refute Locke, but to close the gap between their philosophies as well as “to clarify many things which he (Locke) treats only superficially” (To Sophie Charlotte, 25 April 1704; K 10 230). However, Locke alleged his poor health as a reason for not really entering in the debate Leibniz so hoped for, for it had “put an end to his inquiries into philosophical speculations” (Lady Masham to Leibniz, 3 June 1704; GP III 351). Locke’s death in November 1704, in any case, put an end to Leibniz’s hopes of a fruitful controversy with Locke. Leibniz could have been summarizing this story by saying that “death does not take into account our desires, nor the growth of knowledge” (To Burnett, 7 March 1696; GP III 175). Given the circumstances, Leibniz had no alternative but to engage in a debate with Locke’s text, whose result, the Nouveaux essais sur l’entendement humain, was only posthumously published. What is remarkable is that, although he is the sovereign author of this dialogue, Leibniz undertakes (most of the time) to formulate Locke’s positions in the most faithful and favorable possible way. His aim is clearly not refutation, but rather the integration of Locke’s insights with his own, in order to yield a broader comprehensive system. In this he no doubt follows his own rules for the conduct of a rational controversy, namely moderation, reformulation, expansion of the basic notions and principles, and conciliation at a deeper level. The fact that he decided not to publish the Nouveaux essais after Locke’s death and his justification of this decision testify to his deep belief in the fruitfulness of a direct exchange of views. Referring to his intensive work on the Essay in the months prior to Locke’s death, he wrote several years later: “I have devoted several weeks on remarks on this important work, in the hope of discussing about it with Mr. Lock himself. But his death has stopped me, and brought about that my reflections were left behind, although they were completed. My aim was to clarify things, rather than to refute another’s views” (To Coste, 16 June 1707; GP III 392; our italics).
57 “I consider the correspondence I have with Lady Masham as if it were partly with Mr. Lock himself, for, since he was at her home in Oates when this lady wrote and replied to me about my philosophical hypothesis, making it plain that Mr. Lock saw our letters, it seems that he had some role therein, at least regarding his judgment about it, which he did not hide from that lady” (To Burnett, 2 August 1704; GP III 297-298). lx Introductory Essay
The art of controversies was also significant in Leibniz’s scientific work. Let us consider here a single example, which prima facie seems to have no significance other than personal – the famous controversy with Newton about the priority of the invention of the calculus.58 On the face of it, the issue is factual: who was the first to invent a certain mathematical tool? Thus conceived, the dispute might be solved by gathering all the relevant evidence. But things turn out to be not so simple. First of all, what exactly is the mathematical invention claimed by both Leibniz and Newton? Is it indeed “the same”? If we take into account, for example, the different notations used by them, their calculi are not observationally “the same”. (Recall that Leibniz was a semiotician who attributed extreme importance to appropriate notations.) No doubt at a certain level – say, of the mathematical operations permitted by the calculus – “sameness” can be justifiably claimed, and accepted by both contenders. But this does not make the controversy subside. The further question of the new calculus’ significance and function immediately arises. Newton saw in the calculus a tool for handling certain physical problems – which is why he didn’t care to publish his invention in the first place. Leibniz, on the other hand, saw in it the herald of a major revolution that would mark the end of the Cartesian conception of mathematics.59 Furthermore, the further development of the calculus – the “results” it yielded – also become significant in the controversy. Leibniz had a broader view of its significance that led to the rapid expansion of the mathematics of the infinite by himself and his colleagues and disciples, whereas Newton had a limited view of the calculus’ function that kept it within the narrow role of ancilla physicae.60
58 Rupert Hall (1980) is still the most complete account of the dispute between Newton and Leibniz concerning the invention of the calculus, although he doesn’t analyze systematically its argumentative aspects and its broader mathematical significance. Gross (1998) argues that controversies over priority in science are not just psychological or sociological marginal curiosities. 59 This can be gathered from Leibniz’s correspondence with Bodenhausen (collected in GM V and VII) and from the Nouvelles remarques touchant l’analyse des transcendantes différentes de celles de la Géométrie de M. Descartes (GM V 278-279) that Leibniz published in 1692 in the Journal des Sçavans. 60 This is not to say that Leibniz had provided better mathematical foundations for the calculus than Newton. In fact, as pointed out by Bourbaki (1960: 168), none of them provided `foundations' for the calculus ± a task that was only accomplished in the 19th century: ªone must observe that the way to modern analysis is paved only when Newton and Leibniz, turning their back to the past, accept to look for the justification of the new methods provisionally, i.e., not in rigorous demonstrations but in the fecundity and coherence of the resultsº. Serfati (Forthcoming) attributes this `operational' or `pragmatic' approach to the issue of `providing foundations' to Leibniz, who reacted in this way to Newton's disciples insistence ± in their controversy with Leibniz's Introductory Essay lxi
Viewed under this light, the former, rather than the latter, may be considered its real ªinventorº. This controversy thus illustrates how the various components of Leibniz's art of controversies must be taken into account in order to assess an apparently simple `matter of fact'. The only thing blatantly missing in it was moderation.
6. Significance
The Newton-Leibniz controversy illustrates, in addition, another aspect of the close link between a dialectical approach to the construction of knowledge and the peculiar nature of Leibniz's method ± as we shall see. Leibniz's attitude vis-à -vis the events that prevented his actual dialogue with Locke in fact reveals and puts into practice an original epistemological conception. Instead of assuming the need to begin from the first principles or from scratch ± as in a tabula rasa ±, he conceives of the construction of knowledge as a historically situated process. One always begins, so to speak, in medias res and, rather than having to clear the ground completely before proceeding, one has to take advantage of the existing conceptual structures in order to make further progress.61 It may well be that Locke's alleged lack of interest in debates was one of the reasons for his lack of interest in discussing with Leibniz.62 But it is also possible that it reflects an epistemological outlook ± profoundly different from Leibniz's ± according
followers ± on a demand for foundations. In any case, the difference between Leibniz and Newton lies rather in the kind of results they envisaged. Unlike Newton, Leibniz stressed not only the broader mathematical implications of the calculus, but also ± as we have just seen ± the epistemological importance of the ªprovisional methodº. 61 “ I thu s understood tha t th e opinion s o f th e ancients should not be demolished, but rather they should be explicated and corroborated, for they are presently condemned and held in contempt for no other reason than [the fact] that their meaning is ignored” (Specimen demonstrationum catholicarum seu apologia fidei ex ratione; GR 30). Leibniz elaborates this theme in his correspondence with Remond, where – against the wholesale rejection of the past prevalent in his time – h e defend s th e existenc e o f a “ perenn ial philosop hy” wh ich rests upon the sediments of truth present in past (and other) traditions: “ By calling attention to these traces of truth in the Ancients, or (more generally) in those that preceded us, one would extract gold from mud, a diamond from its ore, and light from darkness; and it would in fact be a sort of perennial philosophy” (To Remond, 26 August 1714; GP 3 624-625). 62 Locke’ s modus operandi in general, and in particular his rhetoric in the Essay, has been described as “ conversationa l” rather than “ disputational” (Walmsley 1993). This might have been one reason for his avoidance of an open debate with Leibniz, although in other occasions Locke did not refrain from engaging in private and public controversy – e.g., with Bishop Stillingfleet. lxii Introductory Essay to which communication and debate are essentially external, rather than intrinsic to the formation and evolution of knowledge.63 Leibniz’s epistemological strategy, just as it is opposed to Locke’s, is opposed to the Cartesian requirement of eliminating all dubious beliefs as a precondition for establishing the sure foundations of knowledge. By the same token, it is a more efficient strategy – Leibniz believes – to combat skepticism. In fact, both Locke and Descartes are vulnerable to skeptical objections, in so far as they rely upon the foundational role of either the senses or intellectual intuition – which are the sources of “knowledge” most heavily questioned by the skeptics. Leibniz, on the contrary, by admitting the provisional value of the traditions where knowledge is always embedded, is not equally dependent upon a foundational moment as they are. For him, the search of solid foundations should not deter us from proceeding on the basis of “provisional foundations” in order to advance knowledge. Against Descartes, who “has recommended so much the art of doubting” while at the same time “contenting himself with the alleged evidence of ideas”, Leibniz emphasizes that even axioms must be demonstrated; nevertheless – he continues – “one often can and must be satisfied with relying upon some assumptions, at least until some day one can transform them into theorems, for otherwise one would eventually be stopped too much”.64 Leibniz’s method of analysis and synthesis consists in fact in a double movement, whereby one proceeds to derive results from a provisionally given set of axioms while at the same time trying to ground them upon deeper principles.65
63 On the correlation between epistemological positions and attitudes towards controversy, see the case of Arnauld vs. Malebranche (Dascal 1990b). On Locke’s ‘externalist’ view of the role of language in thought, as opposed to Leibniz’s, see Dascal (1987, 1994, 1998a). 64 Recommandation pour instituer la science generale (A VI 4 7 04; GP VII 165). This text, first published by Erdmann, was probably prepared for publication in a French or Dutch journal, according to Gerhardt. Couturat (1901: 148) conjectures that it was intended for the French Academy; upon the Academy’s unfavorable reaction, Leibniz would have addressed Louis XIV himself to sponsor his project. Couturat dates this text at around 1680. 65 Even the most obvious “primary propositions” such as The whole is greater than its part should be demonstrated – and Leibniz undertakes to do so in On the demonstration of primary propositions (1671-1672; A VI 2 479-486; translated in Dascal 1987). But this should not hamper the progress of inquiry: “I am of the opinion that no proposition should be accepted without proof, and no word without explanation; but only in so far as the delay in the investigation of the subject matter can be tolerated” (id.; in Dascal 1987: 147). According to Leibniz, synthesis (whose model for him is the ars combinatoria) begins with the simplest elements in order to generate the complex ones, whereas analysis starts from the complex and seeks to establish the simple elements. However, Introductory Essay lxiii
The ultimate reason for proceeding in this way is to avoid delaying indefinitely the useful results of scientific inquiry: it is well known that, as for Bacon, for Leibniz the value of science lies in its contribution to humankind’s happiness (C 169). But the “provisional method” is also relevant for dealing with controversies: “… one must always try to advance our knowledge, and even the establishment of many things upon a few assumptions will not lack utility. For at least we would know that these few assumptions remain to be proven in order to reach a full demonstration, and in the meantime we would have at least hypothetical [demonstrations] and we would get rid of the confusion of disputes”.66 Notice that he speaks of getting rid of the confusion of disputes or of confused disputes (as in Chapter 1) but not of disputes as such. Actually, the “provisional method” functions as a means of introducing order in controversies, and thereby of increasing the hope of solving them rationally. And in so doing, the requirements of rigor, characteristic of the demonstrative method, are not loosened, but rather fastened. To be sure, the assumptions provisionally taken to be true are not certain, but they are far from being arbitrary; they should be explicitly made rather than tacitly taken for granted; the conclusions deduced from them should be rigorously demonstrated and they should be clearly marked as conditional upon the assumptions, so that no reader would be misled.67 Under these strictures, says Leibniz, “one should hope to have many books written in this way, where there would be no danger of error” (A VI 6 450). Without abandoning the ideal of a demonstrative science, Leibniz thus takes a realistic – perhaps one could even say a pragmatist – methodological stance, which fully acknowledges the role of uncertainty in the pursuit of useful knowledge. This realism, in
the former should not “wait” for the latter to achieve its task, otherwise inquiry would be paralyzed. Instead, both should proceed simultaneously (C 159). A feedback loop between them would ensure the appropriate adjustments of the results obtained and thus permit progress. Therefore, they are both complementary parts of the ars inveniendi (C 167). See Chapter 12 and Dascal (1987: 130-132). 66 Recommandation pour instaurer la science generale (A VI 4 7 04; GP VII 165). See also Chapter 43, where Leibniz defends the need for ‘bold conjectures’. 67 “… it is very important to make explicitly all the assumptions one needs, without taking the liberty to take them tacitly for granted, under the pretext that the thing is evident by itself through the inspection of the figure or through the contemplation of the idea” (Recommandation, ibid.). “Thus, one is very far from accepting gratuitous principles. To which one should add that even principles whose certainty is not full may be useful, provided one builds upon them only through demonstration. For even though all the conclusions in this case are only conditional and valid only under the assumption that these principles are true, this very connection, as well as the conditional propositions are at least demonstrated” (NE 4.12.6; A VI 6 450). lxiv Introductory Essay turn, is not only practically useful, but also methodologically justified, in so far as, given our cognitive limitations, we cannot know in advance the perfect demonstrative order, which we can approach only in the course of the growth of our knowledge.68 Leibniz’s ‘pragmatist’ attitude towards a calculus that ‘worked’ without (both) its inventor(s) being able to provide its foundations is not – unlike perhaps Newton’s – casual: it is consonant with the methodological stance we have just described. Under this light, he and Newton seemingly diverge at a deeper level – namely, their attitude vis-à-vis a controversy’s epistemic value. For Newton, as shown in his performance in other debates he was involved in (cf. Dascal 1998b), experimental results are supposed to decide unequivocally any truly scientific contest; if a contender refuses to accept the verdict of such results, he can only do so because of hidden motives that have nothing to do with the scientific enterprise, and there is no point in pursuing a debate of this kind. On this view, there is no room for a controversy where the contenders, by the very act of disagreeing, contribute to the clarification of the issue and the eventual emergence of alternative conjectures for explaining their divergences as well as the experimental results about whose interpretation they diverge. Needless to say, at this point, that this attitude is quite different from Leibniz’s, for whom controversy is not only useful, but presumably also constitutive of a construction of knowledge that cannot but be collective. This suggests that controversies are essential for Leibniz’s modus operandi, i.e., for his “method”. Unlike Malebranche, he does not consider them as a disturbance one has to engage in only to protect one’s reputation.69 Nor are they – as for Descartes – something accessory, a mere
68 “The perfect scientific order is the one where propositions are ranged according to their simplest demonstrations, and in such a way that they flow from each other, but this order is not known in advance, and it is increasingly discovered with the perfectioning of science. One can even say that the sciences abbreviate themselves by augmenting themselves – which is a quite true paradox, for the more one discovers truths, the more one is in a position to notice in them an ordered sequence and to formulate ever more universal propositions, from which the others are nothing but instances and corollaries” (Discours touchant la methode de la certitude et l’art d’inventer pour finir les disputes et pour faire en peu de temps des grands progrés; A VI 4 95 9; our italics). 69 In his 20-years long controversy with Arnauld, Malebranche often complains that the former makes use of railing rather than argument, with the aim of exciting the imagination and the passions and thereby winning the audience’s favor (e.g., Oeuvres Complètes VI 141, 267). He takes this situation to be the rule in controversies, which he considers to be useless for the acquisition and growth of knowledge. His only reason for engaging in this controversy, he declares, is to protect his credibility against Arnauld’s attempts to undermine it (ibid. VI 189). Dascal (1990b) argues that Malebranche’s attitude vis-à-vis controversies is not only tactical, but derives from his epistemology: it Introductory Essay lxv device used by an essentially monologic reason to confirm one’s convictions. To be sure, Descartes employs what Beyssade and Marion (1994) call a “responsorial schema”. These authors point out that at the end of the Discours de la Methode he asks for comments and criticisms; the Meditations provide a reply to the metaphysical criticisms leveled against the Discours; Descartes sends the manuscript to a selected group of scholars, whose objections, along with his replies he publishes together with the original text in a single volume. He thus makes use of a dialogical process that seems to play a significant role in the development of his thought. Nevertheless this role is far from constitutive, as it is for Leibniz. For what Descartes wants to obtain by this process is to dispel possible misunderstandings of his position and to present it so as to eliminate any possible future mistakes.70 There is no question of modifying – at least explicitly – his previously formulated views. In so far as there is ‘controversy’ with his objectors, it is not intended to absorb whatever is valuable in their insights. The objectors function only as a test-group for the clarity and distinctness of the author’s views. In this sense, for Descartes, the responsorial schema plays no significant role in the formation of knowledge. As we have seen, this is not the case in Leibniz’s conception of controversies and their use in knowledge formation. In the light of this constitutive role, one can understand why the art of controversies functions as an overarching principle of organization for Leibniz’s various logical, rhetorical/dialectical and methodological concerns. This, in turn, contributes to elucidating the nature of Leibniz’s appeal to “formalism”. No doubt the importance he attributed to the choice of appropriate notations (cf. Cajori 1925) and his endless attempts to
is the attitude of a Platonist philosopher who firmly believes that knowledge is achieved through meditation, not through dialogue. 70 For instance, he takes the first series of objections, by Caterus, as a courteous attempt to “help” him, rather than as those of an adversary. Consequently, he takes them as an occasion to explain the meaning of key terms he had used in the Meditations, e.g., the term ‘idea’: Caterus, says Descartes, “feigns to understand my words quite differently from what I intended, in order to give me the opportunity to explain them more clearly” (First Replies, AT IX 81). And he concludes his Sixth Replies (to the objections of a group of theologians and philosophers) by claiming that the very fact that these learned and authoritative scholars, in spite of their “extremely exact and extensive examination” of his text, have not found “any error or paralogism in my demonstrations”, proves their solidity (AT IX 244). The same attitude can be found in Descartes’s mathematical correspondence. For example, in his quarrel with Fermat he accuses the latter’s objections of involving either paralogisms or misunderstanding: “in each point he objects to again, he either commits a new paralogism, or he corrupts the sense of my reasons, thus showing that he has not understood them” (AT II 12-13). lxvi Introductory Essay
“algebricize” logic suggest a narrow interpretation of this notion, as a brilliant but unsuccessful anticipation of modern logic.71 But Belaval (1960) has shown that it has a much broader epistemological scope, if contrasted with the “intuitionism” that underlies Descartes’s method. In our view, this insightful characterization must be further extended by acknowledging the fact that, for Leibniz, ‘formal’ includes all sorts of systematic procedures, in addition to the use of formalized calculi. His “method” consists in taking advantage, on each occasion and for each kind of subject matter, of the most adequate component of a rich arsenal of different kinds of “formalisms”, not necessarily reducible to a narrow conception of logical form. From the viewpoint of the role of the art of controversies in Leibniz’s methodology, a better understanding of his conception of rationality can be achieved. Rationality, for him, is not monological, but dialogical;72 it is not confined to algorithmic methods, but comprises a variety of heuristic procedures as well; it goes beyond the domain of the necessary that pertains to all possible worlds, for it is embodied and situated in the actual world. In short it is a rationality that – to use an expression of Leibniz himself (Chapter 15) – can be said to be “softer” (blandior), a rationality that comprises more than calculative-demonstrative rationality alone. If there is a controversy Leibniz the rationalist and the believer cannot afford not to win, it is the battle with the skeptics of his time. The art of controversies would be useless if it could not provide the means for facing this challenge. And it does, providing – as it should be expected in the light of the principle of the other’s place – an appropriate strategy for each kind of skeptic opponent. We find indeed, in the chapters of this volume, at least four different types of skeptic, whom Leibniz combats with different strategies. Let us examine each of them. In Chapter 2, Hobbes is picked up as the representative of skeptical relativism. Appeals to right Reason in order to decide, for instance,
71 Couturat (1901: 386-387) argues that Leibniz “possessed almost all the principles of Boole’s and Schröder’s logic, and on some points he was even more advanced than Boole himself”; nevertheless, his system of logic ultimately failed because “algorithmic logic (i.e., rigorous and exact logic) cannot be based on the confused and vague notion of comprehension”. In the same vein, Couturat claims that Leibniz disregarded the mathematical work on probabilities of his contemporaries because they did not realize that probability theory should be “a part of logic”, i.e., it should have “its own special symbolism and algorithm” (p. 249). For another, ‘semiotic’ interpretation of Leibniz’s notion of formalism, see Dascal (1978: passim). 72 In Chapter 4 Leibniz introduces a justification of the referential power of language in its communicative use that might be considered as a foundation for what today one might call a dialogical theory of meaning. Introductory Essay lxvii controversial legal issues, whose solution is not explicitly dictated by positive law – he argues – are useless, because one can always ask “whose reason?”, thus either incurring in infinite regress in the search of a criterion or in arbitrariness. To which Leibniz responds: “But those who object in this way have not, so far, understood what I have in mind. In the first place, it is not clear that it is impossible to choose right reason as a judge, at least in some questions, examples of which follow” (Chapter 2, paragraph 56). His examples are “questions that are immediately obvious to the senses”, where “there is no need for another judge of controversies besides the senses themselves” (paragraph 57) and questions “amenable to calculation”, where “the necessary conclusion emerges with maximum evidence” (paragraph 58). The certainty of sensory evidence or mathematical proof is thus the reply to the skeptic. Although this chapter introduces the image of the Balance of Reason pointing out all the care necessary for properly using Reason and provides a set of subtle procedures for the difficult hermeneutic problem of interpreting the Scriptures and the mysteries of faith, Leibniz is here still, as far as the battle against skepticism is concerned, a Cartesian, in spite of professing not to be one.73 In Chapter 18, the ‘adversary’ is not a doctrinaire skeptic, but simply a learned and intelligent gentleman who is disappointed with the variety of methods that purport to provide secure means to attain knowledge – especially with those methods supposedly capable of overcoming doubt. This is not a reason for Leibniz not to address seriously the objections this man, who comes to him in the hope of overcoming his doubts, raises. Quite on the contrary, for this is the kind of man that a philosopher like Leibniz, who is himself weary of Cartesianism, should be able to rescue from the grip of skepticism. To achieve this, he employs a dialectic strategy which, rather than attempting to refute head-on, in a dogmatic way, the objections, argues from the point of view of the opponent, acknowledging the weight of some of his reasons and even justifying them. In a Socratic way, he seeks thereby to lead the opponent to admit the possibility that he might be wrong, thus paving the way for him to persuade himself – with the help of some guidance and a set of practical rules – of the unjustified nature of his generalized doubt and of the possibility of overcoming it.
73 “I confess that I am nothing less than a Cartesian” (To J. Thomasius, 20 April 1669; A II 1 15). Responding to Galloys’s ‘phenomenalism’ and ‘probabilism’ (cf. Chapter 22), Leibniz also appeals to the certainty of evidence, arguing that not everything is appearance nor merely probable – which he exemplifies in a Cartesian vein: that I feel myself feeling (me a me sentiri sentientem) is something that is absolutely certain, although it is a truth of fact (To Galloys, 1672; A II 1 222-229). lxviii Introductory Essay
In Chapter 41, Leibniz confronts Bayle, a skeptic who skillfully uses reason and the art of disputation in order to argue for the irrationality of faith. Here, again arguing from the point of view of the opponent, Leibniz employs ‘hard’ reason and the rules of disputatio – especially the asymmetry between proponent and opponent concerning the burden of proof. This strategy allows him to distinguish (a classical move in disputatio) between objections that prove the falsity of a thesis and those to which so far no satisfactory response has been found. The latter only show that the thesis is difficult to defend (and perhaps also that its current defenders are incompetent), but not that it is indefensible. Since the rules do not require the proponent to prove the truth of the thesis, he takes this distinction in order to refute Bayle’s objection, as it is formulated in the response to Le Clerc. In Chapter 45, Leibniz mercilessly attacks arguments that he dubs “merely Pyrrhonic” for their absurd consequence, namely, that they would imply that all opinions are indistinguishable as to their factual value. That this is not the case can be shown, in some cases, by traditional logic. When this is not sufficient, a ‘new logic’, capable of dealing with non- demonstrative arguments, will do the job. This short paragraph, written half a year before Leibniz’s death, summarizes the punch of his mature strategy against a skeptic: Whenever possible, a deductive knockout; when not, a series of knock downs using the broader repertoire of non-demonstrative logic. The amplification of the notion of rationality is essential for facing skepticism’s onslaught on rationalism, which the skeptics equate with the attainment of certainty. Leibniz’s rationalism refuses to accept the combat in these terms, for it refuses to reduce the scope of rationality to the limits imposed by such an equation. By including within the scope of rationality procedures that do not necessarily yield certainty, Leibniz extends the range of rational beliefs and actions to those areas which skeptics and narrow, ‘harder’ rationalists alike would be forced to exclude from rationality’s domain. Against Descartes’s demand to accept as true only what is absolutely certain (which excludes beliefs tainted even by minimal reasons for doubt), the skeptic argues that in all alleged absolute certainties it is possible to disclose minimal reasons for doubt. Consequently, if rationality requires absolute certainty it is to be found practically nowhere. Facing the narrow rationalist’s position that demands a total inclination of the “Balance of Reason” in order to accept something as true, the skeptic contends that this Balance in fact never inclines towards one of the scales, i.e., that it remains forever in equilibrium (isostheneia), since there are always reasons of equal weight for and against any position. While the Introductory Essay lxix skeptic seeks to suppress altogether the role of reason as a guide for rational decisions and beliefs, the narrow rationalist insists that reason is able to perform this role, but actually reduces it to the very limited domain of certain or necessary truths. What Leibniz’s broader conception of rationality – which, pace Couturat (1901: 259) goes well beyond the calculus of probabilities – offers is a way out of this dilemma (cf. Dascal 2005). By admitting that reasons have different weights, that debates take place in an asymmetrical space structured by presumptions, that to attain knowledge one does not have to begin with absolute foundations or with a tabula rasa, Leibniz’s “art of controversies” shows that the absence of certainty does not necessarily lead to the paralysis of isostheneia. He thereby substantiates his claim that reason can “incline without necessitating”.74 Nothing could be a clearer proof of the central role of the art of controversies for Leibniz.
7. Policies
The selection of texts was guided by the bias that motivates this volume. Unlike what Leibniz requires from his rapporteur (Chapter 19), we want to state from the outset the parti pris underlying the conception of this volume. It is grounded on the view that the usual, logically based picture of leibnizian rationality severely limits the scope and nature of his rationalism. We believe that, in addition to and along with strict, deductive logic, Leibniz has elaborated also a variety of tools intended to capture other aspects of rationality, both practical and theoretical, which complete the picture by letting us be reasonable also in situations where our choices cannot derive from logical considerations alone. Controversies are one such situation – certainly not the only one. They require whoever wishes to be reasonable in participating in them or judging the positions in confrontation to weigh carefully the reasons adduced in favor of each. Ideally – as Leibniz himself thought it possible – this might be done by a sort of logic- inspired calculus. Some of the best texts in which Leibniz expresses this belief are translated in this volume. For example, Chapter 21B contains the often quoted passage where Leibniz claims that, with his proposed method, controversies could be solved by an unquestionable computation. What those who quote this passage systematically forget to mention are the hedges in quantum and ex datis through which he severely limits the scope of the calculative procedure. They also overlook the fact that this text
74 This phrase is included by Leibniz in the summary of paragraph 13 of the Discours de Metaphysique (Lestienne edition, p. 42). lxx Introductory Essay begins by mentioning the value of dialectics and provides a list of themes to be dealt with by the General Science, which include many disciplines that cannot be handled in purely mathematical ways. W ithin such a context, it becomes apparent that, even when he states most emphatically the ”calculative‘ view, he does not overlook the fact that it is but one of the gamut of rational means needed to deal with controversies and, more generally, with contingent matters. In fact, Leibniz himself recognized both the difficulty of performing the full analysis of concepts required for creating the calculus capable to achieve the calculative ideal and the fact that, even if achieved, it would serve only for a quite small segment of human knowledge and human concerns. This led him, from the beginning to the end of his life œ as the chapters of this book illustrate œ to speak about and dream of the development of other tools of thinking and acting, appropriate to those domains not covered by the calculus he never ceased to dream of. Although our selection seeks to bring to light the less familiar side of this picture, by putting side by side the two parallel dreams, we intend to lead to a better understanding of both as contrastive and complementary components of the encompassing rationalism of Leibniz. The main criterion for inclusion of a text in this volume is its direct contribution to the elaboration of the theoretical framework of Leibniz‘s —art of controversies“. This criterion led us to exclude those texts where this art is practiced by Leibniz, without explicit mention of its theoretical underpinnings. It also led us to exclude a large amount of texts where there are a few scattered (though sometimes quite significant) observations that refer to the principles of the art of controversies or explicitly appeal to them in the course of the argumentation. W e gave precedence to those texts that clearly indicate œ through their self-defining titles or choice of terminology œ their belonging to the topic of controversies, their principles, and their conduct. Our second main criterion of selection takes into account the public‘s familiarity with the texts. Part of the Leibniz corpus that œ as we have argued in this Introductory Essay œ belongs to the broad project of an —art of controversies“ has been traditionally included (especially since Couturat) in compilations of Leibniz‘s —logical“ work. W e have decided to provide here only a sample of these well known texts, in order to allow the reader to grasp the whole picture and to see how these —logical“ texts fit it. In this sample, we have sought to include texts that Couturat published only partially, and we have used œ as in all the other texts here included œ the latest versions available from the Academy‘s edition. Introductory Essay lxxi
The ordering of the chapters is mainly chronological, with the intention of giving an idea of the evolution of Leibniz’s ideas about controversies. Yet, as in other domains, it is surprising how many of Leibniz’s ideas are so to speak pre-formed and indestructible, recurring in and on from the beginning to the end of his career, so that talk of a linear evolution is always problematic regarding his career. In some cases the chronological criterion was superseded by the criterion of thematic grouping. In this way, closely related texts – usually very short – could be put together in a single chapter in order to provide some ‘critical mass’ to a particular aspect of the art of controversies. This criterion, in its turn, was violated in the case of certain texts – notably Chapter 17 – which, being relevant to various thematic groupings and sufficiently important on their own, were kept apart as a separate chapter. Our goal was to provide a representative collection of those texts that form the “non-logical” bulk of Leibniz’s “art of controversies”. As far as the present state of the edition of Leibniz’s works goes, and as far as we could find out concerning the unpublished manuscripts, our compilation has probably achieved this goal – with an important proviso. We have not included in this volume excerpts of easily available and translated works (such as the Nouveaux essais or the Théodicée) which are directly pertinent to the “art of controversies”. We have included chunks of Leibniz’s correspondence which are relevant to the book, either because they discuss controversies or because in them Leibniz actually engages in debates in different domains. No doubt in his huge correspondence other letters relevant for this volume might be found. Our main criterion here was to look for those letters that explicitly refer to the principles, aims, strategies, tactics and moves, either of controversies in general or of the specific controversial issues the correspondence in question deals with. In this respect, obviously we could not aim at completion. Nor could we, however, ignore the correspondence altogether, since – after all – most of Leibniz’s polemical activity (and a significant part of his reflection about controversies) was conducted in his correspondence. In some cases we found it useful to group in a single chapter a number of related texts that, together, reveal some particular aspect of Leibniz’s art of controversies. Whenever available, we used the version of the texts as published in A. In other cases, we checked the published versions with the manuscripts and, eventually, translated also parts of the manuscript omitted by the editors. Our translation policy was to produce a fluent and readable English text, while keeping the flavor as well as the terminological and stylistic peculiarities of Leibniz’s Latin, French or German. Admittedly, this is not an easy task. Our note-policy was designed with a view to making this lxxii Introductory Essay volume useful for Leibniz scholars, historians of ideas, logicians, rhetoricians, argumentation theorists, pragmatists, philosophers, as well as for a larger audience. We also had in mind to let the reader experience the incredibly rich, multi-faceted network of disciplines, themes, issues, texts, and authors that constituted the dialogical background within which Leibniz’s thought took shape and evolved dialectically. Our cross-reference policy, across the chapters of this book as well as to other writings in the Leibniz corpus, is intended to bring to mind the plurality of methods and applications of Leibniz’s art of controversies, out of which a coherent picture emerges. With these policies, we purport to share with the reader our exciting hands-on experience of the plural forms, sources and domains of Leibniz’s pluralism. The art of controversies is a crucial component of this pluralism. For it is concerned with no less than the ability to be critical and yet to be able to discern what can be learned from each doctrine, ancient or modern, close or distant; with the ability to go beyond apparent oppositions, to uncover their possible convergences and to create the basis for their reconciliation in a ‘system’ whose unity is not achieved through the elimination of the particularity and opposition of its components, and nevertheless is ‘organic’.