Pagina principale The Rise of Modern Philosophy: A New History of Western Philosophy Volume 3
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The Rise of Modern Philosophy This page intentionally left blank A NEW HISTORY OF WESTERN PHILOSOPHY volume iii The Rise of Modern Philosophy anthony kenny CLARENDON PRESS OXFORD 3 Great Clarendon Street, Oxford ox2 6dp Oxford University Press is a department of the University of Oxford. It furthers the University’s objective of excellence in research, scholarship, and education by publishing worldwide in Oxford New York Auckland Cape Town Dar es Salaam Hong Kong Karachi Kuala Lumpur Madrid Melbourne Mexico City Nairobi New Delhi Shanghai Taipei Toronto With oYces in Argentina Austria Brazil Chile Czech Republic France Greece Guatemala Hungary Italy Japan Poland Portugal Singapore South Korea Switzerland Thailand Turkey Ukraine Vietnam Oxford is a registered trade mark of Oxford University Press in the UK and in certain other countries Published in the United States by Oxford University Press Inc., New York ß Sir Anthony Kenny 2006 The moral rights of the author have been asserted Database right Oxford University Press (maker) First published 2006 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior permission in writing of Oxford University Press, or as expressly permitted by law, or under terms agreed with the appropriate reprographics rights organization. Enquiries concerning reproduction outside the scope of the above should be sent to the Rights Department, Oxford University Press, at the address above You must not circulate this book in any other binding or cover and you must impose the same condition on any acquirer British Library Cataloguing in Publication Data Data available Library of Congress Cataloguing in Publication Data Data available Typeset by SPI Publisher Services, Pondicherry, India Printed in Great Britain on acid-free paper by Biddles Ltd, King’s Lynn, Norfolk ISBN 0–19–875277–6 978–0–19–875277–6 1 3 5 7 9 10 8 6 4 2 SUMMARY OF CONTENTS List of Contents vii Map x ; Introduction xi 1. Sixteenth-Century Philosophy 2. Descartes to Berkeley 3. Hume to Hegel 4. Knowledge 5. Physics 80 117 165 6. Metaphysics 181 7. Mind and Soul 8. Ethics 212 246 9. Political Philosophy 10. God 33 273 303 Chronology 332 List of Abbreviations and Conventions Bibliography 337 List of Illustrations 344 Index 347 333 1 This page intentionally left blank CONTENTS Map x Introduction xi 1. Sixteenth-Century Philosophy Humanism and Reform 1 Sin, Grace, and Freedom 5 Authority and Conscience 7 The Decline of Logic 11 Scepticism, Sacred and Profane 13 Counter-Reformation Philosophy 16 Giordano Bruno 20 Galileo 22 Bacon 26 2. Descartes to Berkeley Descartes 33 Hobbes 41 The Cambridge Platonists Locke 49 Pascal 53 Malebranche 58 Spinoza 61 Leibniz 70 Berkeley 76 3. Hume to Hegel 80 Hume 80 Smith and Reid 86 The Enlightenment 90 Rousseau 93 WolV and Lessing 97 Kant 100 Fichte and Schelling 108 Hegel 111 33 47 1 CONTENTS 4. Knowledge 117 Montaigne’s Scepticism 117 Descartes’ Response 119 Cartesian Consciousness 121 The Empiricism of Hobbes 127 Locke’s Ideas 131 Spinoza on Degrees of Knowledge 137 The Epistemology of Leibniz 142 Berkeley on Qualities and Ideas 146 Hume on Ideas and Impressions 151 Kant’s Synthetic a priori 156 Realism vs Idealism 160 Idealist Epistemology 163 5. Physics 165 Natural Philosophy 165 Cartesian Physics 169 The Atomism of Gassendi 172 Newton 173 The Labyrinth of the Continuum Kant’s Antinomies 177 174 6. Metaphysics 181 The Metaphysics of Suarez 181 Descartes on Eternal Truths 184 Three Notions of Substance 187 Single Necessary Substance 190 Making Room for Contingency 193 Berkeley’s Idealism 199 Hume on Causation 204 The Response of Kant 207 7. Mind and Soul 212 Descartes on Mind 212 Dualism and its Discontents 216 Determinism, Freedom, and Compatibilism 219 Locke on Personal Identity 223 The Soul as the Idea of the Body in Spinoza 227 viii CONTENTS Leibniz’s Monadology 231 Berkeley and Hume on Spirits and Selves Kant’s Anatomy of the Mind 240 235 8. Ethics 246 Casuistry 247 Mysticism and Stoicism 251 Pascal against the Jesuits 253 Spinoza’s Ethical System 258 Hume on Reason, Passion, and Virtue 261 Kant on Morality, Duty, and Law 264 Hegel’s Ethical Synthesis 267 9. Political Philosophy 273 Machiavelli’s Prince 273 More’s Utopia 275 Just and Unjust Wars 281 Hobbes on Chaos and Sovereignty 283 Spinoza’s Political Determinism 289 Locke on Civil Government 290 Montesquieu on Law 293 Rousseau and the General Will 295 Hegel on the Nation-State 300 10. God 303 Molina on Omniscience and Freedom Descartes’ Rational Theology 305 Pascal and Spinoza on God 308 The Optimism of Leibniz 312 The God of Berkeley 315 Hume on Religion 317 Kant’s Theological Dialectic 323 The Absolute of Hegel 329 303 Chronology 332 List of Abbreviations and Conventions 333 Bibliography 337 List of Illustrations 344 Index 347 ix 0 Stockholm Derry 0 Glasgow Edinburgh Dublin Cloyne Chatsworth Königsberg Oxford Cambridge Amsterdam London Utrecht Leiden Paris la Fleche ` Wittenburg Berlin Halle Leipzig Jena Prague Tübingen Augsburg Zurich Geneva Venice Padua Valladolid Pisa Florence Madrid Rome Granada Naples Vienna Warsaw 100 200 200 300 400 400 600 500 miles 800 km INTRODUCTION his is the third volume of a projected four-volume history of philosophy from the beginnings to the present day. The Wrst volume, Ancient Philosophy (2004), described the early centuries of philosophy in classical Greece and Rome. The second volume, Medieval Philosophy (2005), took the story from the conversion of St Augustine to the humanist Renaissance. This volume takes up the narrative from the beginning of the sixteenth century to the beginning of the nineteenth century. A Wnal volume is planned to cover the history of philosophy from the age of Karl Marx and John Stuart Mill up to the present day. The present volume has the same structure as the two previous volumes. In the Wrst three chapters I oVer a chronological survey of the philosophical thinkers of the period. In the remaining chapters I oVer a thematic treatment of their contribution to the discussion of particular philosophical topics of abiding importance. Some readers are interested in the history of philosophy principally because of the light it sheds on the people and societies of the past. Other readers study the great dead philosophers in order to seek illumination on themes of current philosophical inquiry. By structuring the book in this way I hope to cater for the needs of both sets of readers. Those whose primary interest is historical may focus on the chronological survey, referring where necessary to the thematic sections for ampliWcation. Those whose primary interest is philosophical will concentrate rather on the thematic sections of my volumes, referring back to the chronological surveys to place particular issues in context. The audience at which these volumes are primarily aimed is at the level of second- or third-year undergraduate study. However, many of those interested in the history of philosophy are enrolled in courses that are not necessarily philosophical. Accordingly, I try not to assume a familiarity with contemporary philosophical techniques or terminology. Again, with the exception of the original texts of the thinkers of the period I have not included in the bibliography works in languages other than English. T INTRODUCTION I endeavour also to avoid jargon and to write suYciently clearly for my history to attract those who read philosophy not for curricular purposes but for their own enlightenment and entertainment. This has been the easier to do since in the case of many of my historical subjects I write of necessity as an amateur rather than as a professional. In an age when the academic study of past philosophers has expanded exponentially, no one person can read more than a fraction of the vast secondary literature that has proliferated in recent years around every one of the thinkers discussed in this volume. I have myself contributed to the scholarly discussion of some of the great philosophers of the early modern age, in particular Descartes; and I have published monographs on some of the subjects covered by my thematic chapters, such as the philosophy of mind and the philosophy of religion. But in compiling the bibliography for the volume I was made aware how vast was the extent of material I have not read in comparison with the amount that I am familiar with. Any single author who attempts to cover the entire history of philosophy is quickly made aware that in matters of detail he is at an enormous disadvantage in comparison with the scholars who have made individual philosophers their Weld of expertise. By compensation, a history written by a single hand may be able to emphasize features of the history of philosophy that are less obvious in the works of committees of specialists, just as an aerial photograph may bring out features of a landscape that are almost invisible to those close to the ground. To someone approaching the early modern period of philosophy from an ancient and medieval background the most striking feature of the age is the absence of Aristotle from the philosophic scene. To be sure, in the period covered by this volume the study of Aristotle continued in the academic establishment, and at Oxford University there has never been a time since its foundation when Aristotle was not taught. But the other striking characteristic of our period, which marks it oV from both the Middle Ages and the twentieth century, is that it was a time when philosophy was most energetically pursued not within universities but outside them. Of all the great thinkers of the seventeenth and eighteenth centuries, none before WolV and Kant held professorships of philosophy. Both good and evil consequences resulted when philosophy turned its back on Aristotle. For philosophy in the broad sense—philosophy as it was understood during most of our period, to include the physical sciences as xii INTRODUCTION ‘natural philosophy’—the removal of Aristotle’s dead hand was a great boon. Aristotle’s physics was hopelessly erroneous, and had been shown to be so as early as the sixth century of our era; the deference that was paid to it during the Middle Ages was a great brake on scientiWc progress. But for philosophy in the narrow sense—philosophy as it is now practised as a distinct discipline in universities—there were losses as well as gains resulting from the abandonment of Aristotle. Our period is dominated by two philosophical giants, one at its beginning and one at its end, Descartes and Kant. Descartes was a standardbearer for the rebellion against Aristotle. In metaphysics he rejected the notions of potentiality and actuality, and in philosophical psychology he substituted consciousness for rationality as the mark of the mental. Hobbes and Locke founded a school of British empiricism in reaction to Cartesian rationalism, but the assumptions they shared with Descartes were more important than the issues that separated them. It took the genius of Kant to bring together, in the philosophy of human understanding, the diVerent contributions of the senses and the intellect that had been divided and distorted by both empiricists and rationalists. The hallmark of Cartesian dualism was the separation between mind and matter, conceived as the separation of consciousness from clockwork. This opened an abyss that hampered the metaphysical enterprise during the period of this volume. On the one hand, speculative thinkers erected systems that placed ever greater strains on the credulity of the common reader. Whatever may be the defects of Aristotle’s hylomorphism, his substances—things like cats and cabbages—did at least have the advantage of undoubted existence in the everyday world, unlike unknowable substrata, monads, noumena, and the Absolute. On the other hand, thinkers of a more sceptical turn deconstructed not only Aristotelian substantial forms, but primary and secondary qualities, material substances, and eventually the human mind itself. In the introduction to his lectures on the history of philosophy Hegel warns against dull histories in which the succession of systems are represented simply as a number of opinons, errors, and freaks of thought. In such works, he says, ‘the whole of the history of Philosophy becomes a battleWeld covered with the bones of the dead; it is a kingdom not merely formed of dead and lifeless individuals, but of refuted and spiritually dead systems, since each has killed and buried the other’ (LHP, 17). xiii INTRODUCTION Though I try to record faithfully the opinions of the successive philosophers of my period, I hope that this volume will not fall under Hegel’s censure. I believe that despite handicapping themselves by throwing away some of the most valuable tools that philosophy had forged for itself in Antiquity and in the Middle Ages, the philosophers of this period made many contributions of permanent value, which are identiWed and described in the thematic chapters. In the course of the book I hope to trace the graph of both the gains and the losses. There is much to be learnt, I believe, from studying even the vagaries of those whom Hegel calls ‘heroes of thought’. Great philosophers in every age have engendered great errors: it is no disrespect to them to try to expose some of the confusions to which they appear to have succumbed. The division into themes in this volume diVers from that in the previous volumes in two ways. First, there is no special chapter devoted to logic and language, since philosophers in our period made no contribution in these areas at all comparable to that of the Middle Ages or that of the nineteenth and twentieth centuries. (It is true that the period contains one logician of genius, Leibniz; but his logical work had little impact until the nineteenth century.) Second, there is for the Wrst time a chapter devoted to political philosophy. It is only from the time of Machiavelli and More that the political institutions of the age begin to bear suYcient similarity to those under which we live now for the insights of political philosophers to be relevant to contemporary discussions. The chapter on physics is briefer than in previous volumes, because with Newton the history of physics becomes part of the history of science rather than the history of philosophy, leaving to philosophers, for a while at least, the abstract treatment of the notions of space and time. I am indebted to Peter MomtchiloV and his colleagues at Oxford University Press, and to three anonymous readers for improving an earlier draft of this volume. xiv 1 Sixteenth-Century Philosophy Humanism and Reform he decade beginning in 1511 can well be regarded as the high point of the Renaissance. In the Vatican Raphael was frescoing the walls of the papal apartments, while Michelangelo covered the ceiling of the Sistine Chapel with his paintings. In Florence the Medici family, exiled since the time of the reformer Savonarola, returned to power and patronage. One of the oYcers of the former republic, Niccolò Machiavelli, now under house arrest, used his enforced leisure to produce a classic text of political philosophy, The Prince, which oVered rulers frank advice on the acquisition and retention of power. Renaissance art and Renaissance ideas travelled northward as far as Germany and England. A colleague of Michelangelo’s designed Henry VII’s tomb in Westminster Abbey and the foremost scholar of the age, the Dutchman Desiderius Erasmus, lectured at Cambridge early in the reign of his son Henry VIII. Erasmus was a frequent guest at the house of Thomas More, a lawyer about to begin a political career that would make him, brieXy, the most powerful man in England after the king. Erasmus and More and their friends propounded in Northern Europe the humanist ideas that had taken root in Italy in the previous century. ‘Humanism’ at that time did not mean a desire to replace religious values with secular human ones: Erasmus was a priest who wrote best-selling works of piety, and More was later martyred for his religious beliefs. Humanists, rather, were people who believed in the educational value of the ‘humane letters’ (literae humaniores) of the Greek and Latin classics. They studied and imitated the style of classical authors, many of whose texts had been recently rediscovered and were being published thanks to the newly T SIXTEENTH-CENTURY PHILOSOPHY developed art of printing. They believed that their scholarship, applied to ancient pagan texts, would restore to Europe long-neglected arts and sciences, and, applied to the Bible and to ancient Church writers, would help Christendom to a purer and more authentic understanding of Christian truth. Humanists valued grammar, philology, and rhetoric more highly than the technical philosophical studies that had preoccupied scholars during the Middle Ages. They despised the Latin that had been the lingua franca of medieval universities, far removed in style from the works of Cicero and Livy. Erasmus had been unhappy studying at the Sorbonne, and More mocked the logic he had been taught at Oxford. In philosophy, both of them looked back to Plato rather than to Aristotle and his many medieval admirers. More paid a compliment to Plato by publishing, in 1516, a Wctional blueprint for an ideal commonwealth. In More’s Utopia, as in Plato’s Republic, property is held in common and women serve alongside men in the army. More, writing in an age of exploration and discovery, pretended that his state actually existed on an island across the ocean. Like Plato, however, he was using the description of a Wctional nation as a vehicle for theoretical political philosophy and for criticism of contemporary society.1 Erasmus was more sceptical about Plato as a guide to politics. In the teasing Praise of Folly that he dedicated to More in 1511 he mocks Plato’s claim that the happiest state will be ruled by philosopher kings. History tells us, he says, ‘that no state has been so plagued by its rulers as when power has fallen into the hands of some dabbler in philosophy’ (M, 100). But when, in the same year as Utopia, he published his Instruction to a Christian Prince, he did little but repeat ideas to be found in Plato and Aristotle. For this reason his treatise of political philosophy has never achieved the renown of Machiavelli’s or of More’s. Erasmus was more interested in divinity than in philosophy, and he cared more for biblical studies than for speculative theology. Scholastics like Scotus and Ockham, he complained, merely choked with brambles paths that had been made plain by earlier thinkers. Among the great Christian teachers of the past his favourite was St Jerome, who had translated the Bible from Hebrew and Greek into Latin. Erasmus worked 1 The political philosophy of Machiavelli and More is discussed at length in Ch. 9 below. 2 SIXTEENTH-CENTURY PHILOSOPHY Desiderius Erasmus in Holbein’s portrait in the Louvre 3 SIXTEENTH-CENTURY PHILOSOPHY for some years annotating the Latin New Testament, and then decided to produce a Latin version of his own to amend corruptions which had crept into the accepted text (‘the Vulgate’) and, where necessary, to improve on Jerome himself. In 1516 he published his new Latin version along with his annotations, and almost as an appendix, he added a Greek text of the New Testament—the Wrst one ever to be printed. In his Latin version, in striving for Wdelity to the Greek original, he did not hesitate to alter even the most beloved and solemn texts. The Wrst words of the fourth Gospel, In principio erat verbum, became In principio erat sermo: what was in the beginning was not ‘the Word’ but ‘the Saying’. Erasmus’ Latin version was not generally adopted, though passages of it can still be read in the chapel windows of King’s College Cambridge. However, the Greek text he published was the foundation for the great vernacular testaments of the sixteenth century, beginning with the monumental German version published in 1522 by Martin Luther. Luther was an Augustinian monk, as Erasmus had been until released by papal dispensation from his monastic commitments. Like Erasmus, Luther had made a close study of St Paul’s Epistle to the Romans. This had made him question fundamentally the ethos of Renaissance Catholicism. The year after the publication of Erasmus’ New Testament Luther issued, in the University of Wittenberg, a public denunciation of abuses of papal authority, in particular of a scandalously promoted oVer of an indulgence (remission of punishment due to sin) in return for contributions to the building of the great new church of St Peter’s in Rome. Erasmus and More shared Luther’s concern about the corruption of many of the higher clergy: they had both denounced it in print, Erasmus pungently in a satire on Pope Julius II, More with ironic circumspection in Utopia. But both were alienated when Luther went on to denounce large parts of the Catholic sacramental system and to teach that the one thing needful for salvation is faith, or trust in the merits of Christ. In 1520 Pope Leo X condemned forty-one articles taken from Luther’s teaching, and followed this up with an excommunication after Luther had burnt the Bull of Condemnation. King Henry VIII, with some help from More, published an Assertion of the Seven Sacraments, which earned him the papal title ‘Defender of the Faith’. Erasmus strove in vain to dampen down the controversy. He tried to persuade Luther to moderate his language, and to submit his opinions for 4 SIXTEENTH-CENTURY PHILOSOPHY judgement to an impartial jury of scholars. On the other hand, he questioned the authenticity of the papal bull of condemnation and he persuaded the emperor Charles V to give Luther a hearing at the Diet of Worms in 1521. But Luther refused to recant and was placed under the ban of the empire. Pope Leo died and was succeeded by a Dutch schoolfriend of Erasmus, who took the name Adrian VI. The new pope urged Erasmus to take up his pen against the reformers. Very reluctantly, Erasmus agreed, but his book against Luther did not appear until 1524, by which time Pope Adrian was dead. Sin, Grace, and Freedom The ground Erasmus chose for battle was Luther’s position on the freedom of the will. This had been the subject of one of the theses which had been nailed to the door at Wittenberg in 1517. Among the propositions condemned by Leo X was ‘freewill after sin is merely an empty title’. In response, Luther reinforced his assertion. ‘Free will is really a Wction and a label without reality, because it is in no man’s power to plan any evil or good’ (WA VII.91). In his Diatribe de Libero Arbitrio Erasmus piles up texts from the Old and New Testament and from Church doctors and decrees to show that human beings have free will. His constant theme is that all the exhortations, promises, commands, threats, reproaches, and curses to be found in the Scriptures would lose all point if it was necessity, and not free will, that determined good or evil acts. Questions of Bible interpretation dominate both Erasmus’ book and Luther’s much longer reply, De Servo Arbitrio. Philosophically, Erasmus is unsubtle. He refers to, but does not improve upon, Valla’s dialogue on free will. He repeats commonplaces of centuries of scholastic debate which are inadequate responses to the problem of reconciling divine foreknowledge with human freedom—he insists, for instance, that even humans know many things that will happen in the future, such as eclipses of the sun. A theory of free will that leaves us no freer than the stars in their courses is not a very robust answer to Luther. But Erasmus is anxious to avoid philosophical complications. It is a piece of irreligious curiosity to inquire, as the scholastics did, whether God’s foreknowledge is contingent or necessary. 5 SIXTEENTH-CENTURY PHILOSOPHY Luther, though no friend to the scholastics, Wnds this outrageous. ‘If this is irreligious, curious, and superXuous,’ he asks, ‘what, then, is religious, serious and useful knowledge?’ God, Luther maintains, foresees nothing contingently. ‘He foresees, purposes, and does all things according to His immutable, eternal, and infallible will. This thunderbolt throws free will Xat and utterly dashes it to pieces’ (WA VII.615). Luther endorses the opinion that the Council of Constance ascribed to Wyclif: that everything happens of necessity. He distinguishes, however, between two senses of ‘necessity’. The human will is subject to ‘necessity of immutability’: it has no power to change itself from its innate desire for evil. But it is not subject to another form of necessity, namely compulsion: a human being lacking grace does evil spontaneously and willingly. The human will is like a beast of burden: if God rides it, it wills and goes where God wills; if Satan rides it, it goes where Satan wills. It has no freedom to choose its rider. Luther prefers to abandon altogether the term ‘free will’; other writers, before and after, have regarded the spontaneity that he accepts as being the only thing that can genuinely be meant by the term.2 Luther’s principal concern was to deny free will in matters that make the diVerence between salvation and damnation. In other cases he seems to allow the possibility of genuine choice between alternative courses of action. Humans have free will in respect not of what is above them, but in respect of what is below them. The sinner, for instance, can make his choice between a variety of sins (WA VII.638). The Bible, as Erasmus had copiously shown, contains many passages that imply that human choices are free, and also many passages that proclaim that the fate of humans is determined by God. Over the centuries, scholastic theologians had sought to reconcile these contradictory messages by making careful distinctions. ‘Much toil and labour has been devoted to excusing the goodness of God,’ Luther says, ‘and to accusing the will of man. Here those distinctions have been invented between the ordinary will of God and the absolute will of God, between the necessity of consequence and the necessity of the consequent, and many others. But nothing has been achieved by these means beyond imposing upon the unlearned.’ We should not waste time, Luther believes, in trying to resolve the contradiction 2 See vol. I, p. 197, on the distinction between liberty of spontaneity and liberty of indiVerence. 6 SIXTEENTH-CENTURY PHILOSOPHY between diVerent Bible texts: we should go to extremes, deny free will altogether, and ascribe everything to God. Distaste for scholastic subtlety was not peculiar to Luther: it was shared by Erasmus, and also by More. More himself entered the debate on free will in his controversy with Luther’s English admirer, the Bible translator William Tyndale. To counter Lutheran determinism More uses a strategy which goes back to discussions of fate in Stoic philosophy: One of their sect was served in a good turn in Almayne, which when he had robbed a man and was brought before the judges, he would not deny the deed, but said it was his destiny to do it, and therefore they might not blame him; they answered him, after his own doctrines, that if it were his destiny to steal and that therefore they must hold him excused, then it was also their destiny to hang him, and therefore he must as well hold them excused again. (More 1931: 196) The claim that if determinism is true everything is excusable, would no doubt be rejected by Luther, since he believed that God justly punished sinners who could not do otherwise than sin. From a philosophical point of view these early Reformation debates on freedom and determinism do no more than rehearse arguments which were commonplaces of ancient and medieval philosophy. They illustrate, however, the negative side of humanist education. Scholastic debates, if sometimes arid, had commonly been sober and courteous. Thomas Aquinas, for instance, was always anxious to put the best possible interpretation on the theses of those he disagreed with. Erasmus shared something of Aquinas’ eirenic spirit; but More and Luther attack each other with bitter vituperation made only the more vulgar by the elegant Latin in which it is phrased. The pugnacious conventions of humanist debate were a factor which led to the hardening of positions on either side of the Reformation divide. Authority and Conscience The debate on free will continued and ramiWed through and beyond the sixteenth century, and, as we shall see in later chapters, more sophisticated controversialists were to bring new subtlety into the philosophical treatment of the topic. For the present the most important new element introduced into the debate by Luther was a general hostility not just to 7 SIXTEENTH-CENTURY PHILOSOPHY scholasticism but to philosophy itself. He denounced Aristotle, and in particular his Ethics, as ‘the vilest enemy of grace’. His contempt for the powers of unaided reason was the outcome of his belief that in Adam’s Fall human nature had become totally corrupt and impotent. In one way, Luther’s scepticism about philosophical speculation was a continuation of a tendency already strong in late medieval scholasticism. Since the time of Scotus philosophers had become ever more reluctant to claim that reason alone could establish the nature of the divine attributes, the content of divine commands, or the immortality of the human soul.3 The counterweight to their increasing philosophical scepticism had been their acceptance of the authority of the Church, expressed in Christian tradition and the pronouncements of popes and councils. This attitude found expression at the beginning of Erasmus’ treatise: ‘So great is my dislike of assertions that I prefer the views of the sceptics wherever the inviolable authority of the Scriptures and the decision of the Church permit’ (E, 6). The Lutheran Reformation, by taking away this counterweight, gave new impetus to the sceptical trend. To be sure, the Bible was retained and indeed emphasized as a decisive authority: with respect to the teaching of the Scriptures, Luther insisted, the Christian had no liberty to be a sceptic (WA VII.604). But the content of the Bible was no longer to be subjected to professional scrutiny by philosophically trained theologians. Every Christian, Luther said, had the power of discerning and judging what was right or wrong in matters of faith. Tyndale boasted that his translation would make a boy driving the plough understand the Bible better than the most learned divine. Pessimism about the moral capacity of the trained intellect unaided by grace went hand in hand with optimism about the intellectual ability of the untrained mind illumined by faith. Squeezed between the two, philosophy found its role greatly diminished among devout Protestants. The problem for Luther was that individual consciences, unconstrained by universal authority, and unwilling to submit faith to rational arbitrament, began to produce a great diversity of beliefs. French and Swiss reformers, such as Jean Calvin and Ulrich Zwingli, agreed with Luther in rejecting papal authority but diVered from him in their understanding of 3 See vol II, pp. 247, 274. 8 SIXTEENTH-CENTURY PHILOSOPHY the presence of Christ in the Eucharist and of the decrees through which God chose the elect. Calvin, like Luther, placed the ultimate criterion of religious truth within the individual soul: every faithful Christian experienced within himself a marvellous conviction of heavenly revelation which was more reassuring than any reasoning could ever be. But how could one tell who were faithful Christians? If one counted only the reformed, then Calvin’s criterion was question-begging; on the other hand, if one counted all those who had been baptized, it led to an anarchy of belief. Protestants argued that the Church could not be the ultimate authority because its claims rested on biblical texts. Catholics, quoting Augustine, claimed that the only reason for accepting the Bible was that it had been given us by the Church. The questions at issue in Europe at the Reformation were in the end settled neither by rational argument nor by interior enlightenment. In country after country conXicting answers were imposed by force of arms or by penal legislation. In England Henry VIII, irked by Vatican refusal to free him from a tedious marriage, broke with Rome and executed More for his loyalty to the pope. The country then lurched from his schismatic version of Catholicism to Calvinism under his son Edward VI, to Counter-Reformation Catholicism under his daughter Mary, and Wnally to an Anglican compromise under her sister Elizabeth. This chequered history produced hundreds of martyrs, both Protestant and Catholic; but England was spared the sanguinary wars of religion which raged for many decades in continental Europe. By the mid-sixteenth century doctrinal positions had hardened into a form that they were to retain for some 400 years. Luther’s lieutenant Melancthon formulated at Augsburg in 1530 a confession of faith to provide the test of orthodoxy. A concordat agreed in the same city in 1555 provided that the ruler of each state within the Holy Roman Empire could decide whether his subjects were to be Lutheran or Catholic: the principle later known as cuius regio, eius religio. Calvin’s Institutes of the Christian Religion (1536) provided the standard for Protestants in Switzerland, France, and later Scotland. In Rome Pope Paul III (1534–9) promoted a CounterReformation, instituting a new religious order of Jesuits, and convening a Council at Trent to reform Church discipline. The council condemned the Lutheran doctrine of justiWcation by faith alone, and the Calvinist doctrine that God predestined the wicked to hell prior to any sin. Free will, it insisted, had not been extinguished by Adam’s Fall. It reaYrmed the 9 SIXTEENTH-CENTURY PHILOSOPHY The Council of Trent in its final session, as represented in a contemporary Spanish engraving doctrine of transubstantiation and the traditional seven sacraments. By the time the council had Wnished its work, in 1563, Luther was dead and Calvin was dying. The division of Christendom was an unnecessary tragedy. The theological issues which separated Luther and Calvin from their Catholic opponents had been debated many times in the Middle Ages without leading to sectarian warfare; and few twenty-first-century Catholics and Protestants, if not professionally trained in theology, are aware of the real nature of the diVerences between the contrasting theories of the Eucharist, of grace, and of predestination which in the sixteenth century led to 10 SIXTEENTH-CENTURY PHILOSOPHY anathema and bloodshed. Questions of authority, of course, are easier to understand and more diYcult to arbitrate than questions of doctrine. But the unity of Christendom could have been maintained under a constitutional papacy subject to general councils, such as Ockham had suggested, such as had been the practice in the Wfteenth century, and such as even Thomas More, for the greater part of his life, believed to be the divine design for the Church. The Decline of Logic The combined eVects of the Renaissance and the Reformation made the sixteenth century a barren one in most areas of philosophy. Logic was perhaps the branch of philosophy that suVered most severely. Logic did continue to be taught in the universities, but humanist scholars were impatient of it, regarding its terminology as barbarous and its complexities as pettifogging. Rabelais spoke for them when in Pantagruel (1532) he mocked logicians for inquiring whether a chimera bombinating in a vacuum could devour second intentions. Most of the advances in the subject that had been made by Stoic and medieval logicians were lost for four centuries. Instead, a bowdlerized version of Aristotle was taught at an elementary level in popular textbooks. In the mid-century these began to be published in vernacular languages. The Wrst in English was Thomas Wilson’s The Rule of Reason, dedicated to Edward VI in 1551: he was the Wrst to use the English words that are now the common terms of logic, such as ‘proposition’. Others rejected such Latinisms and did their best to invent a solid Anglo-Saxon terminology. Ralphe Lever thought that logic should be called ‘Witcraft’; and when he wanted to explain in his textbook that a contradictory proposition consisted of two propositions, one aYrmative and one negative, with similar subject, predicate and verb, he produced the following: ‘Gaynsaying shewsayes are two shewsayes, the one a yeasaye and the other a naysaye, changing neither foreset, backset nor verbe.’4 These English logic texts left little mark. Matters were diVerent in France: Peter Ramus (Pierre de la Ramée, 1515–72) achieved lasting fame 4 W. and M. Kneale, The Development of Logic (1979), p. 299. 11 SIXTEENTH-CENTURY PHILOSOPHY quite out of proportion to his actual merits as a logician. Legend has it that for his master’s degree he defended the thesis that everything Aristotle had ever taught was false. Certainly he went on to publish a short antiAristotelian treatise, and after his appointment as professor at the Collège Royale he followed this up with twenty books of Animadversions on Aristotle. His Dialectic, which was published in French in 1555, in Latin in 1556, and in English in 1574, was meant to supersede all previous logic texts. For the Wrst time, he maintained, it set out the laws which governed people’s natural thinking. Logic, he tells us, is the art which teaches how to dispute well. It is divided into two parts: invention and judgement, to each of which a book of his text is devoted. Treating of ‘invention’, he lists nine places or topics to which one may look to Wnd arguments to support a conclusion one wishes to defend. They are cause, eVect, subject, adjunct, opposite, comparative, name, division, and deWnition. He illustrates each of these topics with copious quotations from classical authors, which take up nearly half of his short Wrst book. For instance, Ramus deWnes ‘adjunct’ as ‘that which has a subject to which it is adjoined, as virtue and vice are called the adjuncts of the body or soul; and to be short all things that do chance to the subject, beside the essence, is called the adjunct’. He then illustrates this with a long quotation from a speech of Cicero’s, beginning: Doth not his very head and over brow altogether shaven and scraped so clean signify that he is malicious and savoureth of knavery? Do they not utter and cry that he is a crafty fox? (L, 33) Despite his oYcial contempt for Aristotle, most of the topics for argument that he lists are taken from various places in the Aristotelian corpus and deWned in similar ways. The only novelty is the discussion, at the end of the book, of what he calls ‘inartiWcial’ arguments, examples of which are the pronouncements of divine oracles and human testimony in a court of law. The second book comes closer to the traditional subject matter of logic. Once again Ramus draws heavily on Aristotle in his classiWcation of diVerent kinds of statement and his analysis of syllogisms of diVerent forms. His main innovation is that he devotes much more attention than Aristotle did to arguments containing proper names, such as ‘Caesar oppresseth his native country; Tullius oppresseth not his native country; Tullius therefore is not Caesar’ (L, 37). 12 SIXTEENTH-CENTURY PHILOSOPHY Modern historians of logic can Wnd little merit or originality in Ramus’ work, but for long after his death debates raged between Aristotelians and Ramists, and there were even groups of semi-Ramists campaigning for compromise. Ramus became a Calvinist in 1561 and was killed in the massacre of Protestants on St Bartholomew’s Day in 1572. His status as a martyr gave his writings a prestige they could never have earned in their own right, and his inXuence lasted through the centuries. John Milton, for instance, published a volume of Ramist Logic Wve years after the completion of Paradise Lost. The popularity of Ramist works impoverished logic for a long period. No further progress was made in formalizing the logic of modality and counterfactuality that had fascinated medieval logicians, and much of their own work passed into oblivion. Scepticism, Sacred and Profane It was not only Catholics who killed heretics. In 1553 Michael Servetus, a Spanish physician who had discovered the pulmonary circulation of the blood, was burnt in Calvin’s Geneva for denying the Trinity and the divinity of Jesus. A French classicist teaching at Basel, named Sebastian Castellio, was shocked at the execution of Servetus and wrote a treatise Whether Heretics are to be Persecuted (Magdeburg, 1554) in which he pleaded in favour of toleration. His arguments are mainly quotations of authoritative texts or appeals to the example of Christ. ‘O Christ, when thou didst live upon earth, none was more gentle, more merciful, more patient of wrong . . . Art thou now so changed? . . . If thou, O Christ, hast commanded these executions and tortures, what hast thou left for the devil to do?’5 But in a later work, The Art of Doubting, Castellio developed more epistemological arguments. The diYculty of interpreting Scripture, and the variety of opinions among Christian sects, should make us very cautious in laying down the law on religious matters. To be sure, there are some truths that are beyond doubt, such as the existence and goodness of God; but on other religious topics no one can be suYciently certain so as to be justiWed in killing another man as a heretic. Castellio, in his time, was a lone voice; but later supporters of toleration looked back to him as a forerunner. 5 Quoted by O. Chadwick, The Reformation (Harmondsworth: Penguin, 1964), p. 402. 13 SIXTEENTH-CENTURY PHILOSOPHY Some contemporaries who regarded Castellio as excessively sceptical about religion began to feel the attractions of scepticism in non-religious areas. This was greatly reinforced when, in mid-century, the works of the ancient Greek sceptic, Sextus Empiricus, were rediscovered after total oblivion in the medieval period. Sextus’ sceptical arguments were made popular by the French nobleman Michel Eyquem de Montaigne (1533 –92) in an essay which is nominally a commentary on a century-old work of natural theology translated by him at the request of his father. The Apology for Raimond Sebond (1569), written in clear and witty French prose, became the classic modern statement of scepticism.6 The Apology contains much more than a rehearsal of ancient sceptical arguments. Prior to presenting them, Montaigne works hard to induce in his reader a proper degree of intellectual humility. Human beings are inclined to regard themselves as being at the summit of creation; but are men really superior to the other animals who share the earth with them? ‘When I play with my cat,’ Montaigne asks, ‘who knows whether she is passing her time with me no less than I am passing my time with her?’ (ME, 2, 119). Animals of diVerent kinds have individual senses sharper than ours; they can acquire by swift intuition information that humans have to work out laboriously. They have the same needs and emotions as we have, and they display, often to a more remarkable extent, the same traits and virtues that humans take pride in. Montaigne piles up stories of faithful and magnanimous dogs and grateful and gentle lions, to contrast with the cruelty and treachery of human beings. Most of his examples of beasts’ ingenuity are drawn from Greek and Latin texts, such as the legendary logical dog, who while following a scent reaches a crossroads, and sniVs out two of the routes, and on drawing a blank charges immediately down the third route without further sniYng. But Montaigne also draws on his own experience, for instance of guide-dogs leading the blind, and some of his examples of animal tool-usage would not look out of place in papers discussed at present-day associations for the advancement of science. Montaigne was particularly impressed by the skills of migratory birds and Wshes: 6 Montaigne’s sceptical arguments will be considered in Ch. 4 below. See vol. I, p. 175. 14 SIXTEENTH-CENTURY PHILOSOPHY The swallows which we see exploring all the nooks of our houses when spring returns: do they search without judgement, and choose without discretion, that one of a thousand places which is the most commodious for their residence? In the course of building their wonderful and beautiful nests they choose square shapes rather than round, obtuse angles rather than right angles: can they do that without knowing the appropriate conditions and eVects? (ME, 2, 121) Tuna Wsh, Montaigne assures us, not only compete with humans in geometry and arithmetic, but are actually superior to them in astronomy. They swim in battalions formed into a perfect cube, and at the winter solstice they stop dead where they are and do not move again until the spring equinox (ME, 146). Montaigne believes that the skilful performances of animals prove that the same thoughts go through their heads as through ours. A fox will cock his ear to listen in order to Wnd the safest way over a frozen river. ‘Surely we have therefore reason to judge that there passes through his head the same discourse as would run through ours, reasoning from sensation to conclusion: what makes a noise, moves; what moves, is not frozen; what is not frozen is liquid; what is liquid gives way’ (ME, 127). The two spheres in which above all humans plume themselves on their unique gifts are religion and philosophy. Montaigne makes a gallant attempt to prove that we are not alone in our capacity for worship by describing the funeral rites of ants and the sun-worship liturgy of elephants. He is more persuasive when he shows that humans can take little pride in their theological beliefs and activities, given the variety of contradictory doctrines on oVer, and given the often debasing nature of religious practices. As for philosophy, he has no diYculty at all in showing that there has never been a philosopher whose system has been able to withstand the criticism of other philosophers. Like many another after him, he presses into service a dictum of Cicero: ‘It is impossible to say anything so absurd that it has not been said already by some philosopher or other’ (ME, 211). Montaigne’s deXation of human nature in Raimond Sebond is the antithesis of the gloriWcation of mankind in Pico della Mirandola’s 1486 On the Dignity of Man.7 The optimism generated by the rediscovery of classical texts and the exuberance of the visual arts in Renaissance Florence gave way to the 7 See vol. II, p. 109. 15 SIXTEENTH-CENTURY PHILOSOPHY pessimism natural in a Counter-Reformation France torn by sectarian warfare. Montaigne contrasted the educated and civilized citizens of European states, to their disadvantage, with the simplicity and nobility of the inhabitants of the recently discovered New World. However, Montaigne’s emphasis on the limits of the human intellect does not prevent him from claiming to be quite certain of the truth of Catholic Christianity. On the contrary, he can claim that in his scepticism about philosophy he is following in the footsteps of St Paul in First Corinthians: ‘Hath not God made foolish the wisdom of this world? For after that in the wisdom of God the world by wisdom knew not God, it pleased God by the foolishness of preaching to save them that believe.’ Pauline texts such as these were painted on the beams of Montaigne’s study along with quotations from Sextus such as ‘all that is certain is that nothing is certain’. To reconcile his scepticism with his orthodoxy, Montaigne emphasizes that what he has been attacking are the pretensions of the human intellect to achieve truth by its own eVorts. But faith is not an achievement, it is a free gift of God: It is not by reasoning or understanding that we have received our religion, it is by authority and command from above. The weakness of our judgement is more help than its strength, and our blindness is more help than our clear sight. It is through ignorance, not through knowledge that we become wise with divine wisdom. (ME, 166) Counter-Reformation Philosophy Montaigne’s exaltation of revelation to the exclusion of reason—‘Wdeism’ as it came to be called—was not typical of the Counter-Reformation. In reaction against Luther’s insistence that the human intellect and will had been totally corrupted by the sin of Adam, Catholic controversialists tended to emphasize that basic religious truths were within the scope of unaided human intellect, and that faith itself needed the support and defence of reason. In the forefront of this optimistic thrust of the Counter-Reformation were the Jesuits, the members of the new Society of Jesus. This order was founded by the Spanish ex-soldier Ignatius Loyola and was approved by 16 The ceiling of the church of S. Ignazio in Rome, painted by Andrea Pozzo, depicts the glorification of the founder of the Society of Jesus 17 SIXTEENTH-CENTURY PHILOSOPHY Pope Paul III in 1540. In addition to the vows of poverty, chastity, and obedience taken by all members of religious orders, the Jesuits took a further vow of unquestioning loyalty to the papacy. Its members soon distinguished themselves in educational and missionary work in many parts of the world. In Europe they were happy to risk martyrdom in the Counter-Reformation cause; in America, India, and China they showed more sympathy with indigenous religions than many other Christian proselytizers, Catholic or Protestant. In philosophy and theology in the universities they were soon able to compete with the long-established religious orders such as the Franciscans and Dominicans. They promoted a new and, as they saw it, improved version of scholasticism. Whereas medieval scholastics had based their university lectures upon canonical texts such as the works of Aristotle and the Sentences of Peter Lombard,8 Jesuits in universities began to replace commentaries with selfstanding courses in philosophy and theology. By the early seventeenth century this pattern was adopted by Dominicans and Franciscans, and this led to a sharper distinction between philosophy and theology than had been common earlier. The pioneer of this movement to reform philosophy into independent textbook form was the Spanish Jesuit Francisco Suarez, whose Disputationes Metaphysicae (1597) were the Wrst such systematic treatment of scholastic metaphysics. Born in Granada in 1548, Suarez joined the Society of Jesus in 1564 and spent the whole of his professional life as a university professor, lecturing at six diVerent universities in Spain and in the Jesuit college in Rome. He was a devout and erudite man, and in terms of sheer intellectual power he has a strong claim to be the most formidable philosopher of the sixteenth century. In the history of philosophy, however, he does not have a place commensurate to his gifts, for two reasons. First, most of his work is a restatement and reWnement of medieval themes, rather than an exploration of new territory. Second, as a writer he was not only proliWc, leaving behind a corpus that Wlls twenty-eight volumes, but also prolix and tedious. In so far as he had an inXuence on subsequent philosophy, it was through the writings of lesser but more readable imitators. The two areas in which he was, indeed, inXuential were metaphysics and political philosophy. He had a great reverence for St Thomas Aquinas, but 8 See vol. II, p. 56. 18 SIXTEENTH-CENTURY PHILOSOPHY as a metaphysician he followed in the footsteps of Avicenna and Duns Scotus rather than those of Aquinas himself. Paradoxically, much that was to pass for Thomism during the seventeenth, eighteenth, and nineteenth centuries was closer to Suarezian metaphysics than to the Summa Contra Gentiles. In political philosophy Suarez’s contribution was the De Legibus of 1621, which was the unacknowledged source of many of the ideas of betterknown thinkers. In his own day he was most famous for his controversy with King James I about the divine right of kings, in which he attacked the theory that temporal monarchs derived their sovereignty directly from God. King James had his book publicly burnt.9 Of the philosophical issues dividing the Catholic and Protestant camps in the sixteenth century none was more thorny than human free will, which had been proclaimed at the Council of Trent in opposition to Lutheran determinism and Calvinist predestinarianism. The Jesuits made themselves champions of the libertarian account of human freedom. Suarez and his Jesuit colleague Luis de Molina oVered a deWnition of free agency in terms of the availability of alternative courses of action—‘liberty of indiVerence’ as it came to be known. ‘That agent is called free which in the presence of all necessary conditions for action can act and refrain from action or can do one thing while being able to do its opposite.’ Such a deWnition did ample justice to humans’ consciousness of their own choices and their attribution of responsibility to others. But by comparison with more restrictive accounts of freedom, it made it very diYcult to account for God’s foreknowledge of free human actions, to which both Catholics and Protestants were committed. Molina, in his famous Concordia (1589), presented an elaborate solution to the problem, in terms of God’s comprehensive knowledge of the actions of every possible human being in every possible world.10 Ingenious though it was, Molina’s solution was unpopular not only among Protestants but also among his Catholic co-religionists. Dominican theologians, of whom the most vociferous was the Thomist Domingo Banez (1528–1604), thought that the Jesuit theologians were excessively exalting human freedom and derogating from divine power. The dispute between the two religious orders became so bitter that in 1605 9 Suarez’s metaphysics is discussed at greater length in Ch. 6 and his political theory in Ch. 9. 10 Molina’s theory of ‘middle knowledge’ is reported in detail in Ch. 10. 19 SIXTEENTH-CENTURY PHILOSOPHY Pope Clement VIII, without resolving the question at issue, imposed silence on both sides. Ironically, within the reformed camp, a Leiden divine named Arminius propounded views which were similar to, if less sophisticated than, those of Molina. The Synod of Dort in 1619 declared them incompatible with Calvinist orthodoxy. Giordano Bruno The most colourful philosopher of the latter part of the sixteenth century operated far outside the bounds of orthodoxy, whether Catholic or Protestant. Giordano Bruno (1548–1600) was born near Naples and became a Dominican there in 1565. By 1576 he was already suspected of heresy and expelled from the order. He Xed northwards to Geneva, but there became equally unpopular with the Calvinists. He had better success in France, studying and lecturing in Toulouse and Paris and enjoying, for a time, the favour of King Henri III. Bruno’s Wrst major work, On the Shadows of Ideas, combined an elaborate Neoplatonic metaphysical system with practical advice on the art of memory. There is a hierarchy of ideas with human ideas at the lowest level and at the topmost level the divine Ideas forming a unity in God’s mind. These are, in themselves, impenetrable to us; but they are expressed in Nature, which is the universal eVect of God. Images of the celestial world are closer to God than images of our sublunar world; hence, if we wish to organize our knowledge in such a way that we can recall it systematically we should mentally dispose our thoughts within the pattern of the signs of the zodiac. In 1583 Bruno moved to England and visited Oxford, where he gave some lectures. His stay there was not a success. He was not to be the last continental philosopher to visit the university and Wnd himself treated as a charlatan, and in his turn to regard his philosophical hosts as more interested in words than in ideas. He expressed his disdain for Oxford pedantry, along with ideas of more universal philosophical concern, in a series of dialogues in 1584 beginning with Supper on Ash Wednesday (La cena de le ceneri). He seems to have written these while acting as a double agent in London for both the French and the English secret services. Bruno’s dialogues are not easy reading. They are peopled by beings of grand but mysterious status, like Wagner’s gods and Tolkien’s creatures, 20 SIXTEENTH-CENTURY PHILOSOPHY with powers of uncertain limits and motives of slender intelligibility. Although bearing the names of classical deities, they operate at some distance from Homer and Vergil. The Latin Mercury, for instance, corresponds not only to the Greek Hermes, but to the Egyptian god Thoth: he represents often the teachings of the fashionable Hermetic cult. This was based on recently discovered documents believed to go back to the Egypt of Moses’ time. Hermetism, in Bruno’s view, was superior to Christianity and was destined to supersede it. In the system propounded in the dialogues, the phenomena we observe are the eVects of a world-soul which animates nature and makes it into a single organism. The world of nature is inWnite, with no edge, surface, or limit. But the world’s inWnity is not the same as God’s inWnity because the world has parts that are not inWnite, whereas God is wholly in the whole world and wholly in each of its parts. This diVerence perhaps suYces to distinguish Bruno’s position from pantheism, but the relation between God and the world remains obscure. It is not really clariWed by Bruno’s august formulation that God is the Nature making Nature (natura naturans) while the universe is the Nature made by Nature (natura naturata). Two features of Bruno’s system have caught the attention of historians and scientists: his adoption of the Copernican hypothesis, and his postulation of multiple universes. Bruno accepted that it was the earth that went round the sun, and not the sun that went round the earth. He went on to develop Copernicus’ ideas in a bold and dramatic manner. The earth was not the centre of the universe: but neither was the sun. Our sun is just one star among others, and in boundless space there are many solar systems. No sun or star can be called the centre of the universe, because all positions are relative. Our earth and our solar system enjoy no unique privilege. For all we know, there may be intelligent life at other times and places within the universe. Particular solar systems come and go, temporary phases in the life of the single inWnite organism whose soul is the world-soul. Within the universe each intelligent being is a conscious, immortal atom, mirroring in itself the whole of creation. If in his interfusing of God and Nature Bruno anticipated Spinoza, in his account of rational atoms he anticipated Leibniz. Bruno’s championship of Hermetism and his theory of multiple universes challenged the orthodox teaching that God was incarnate uniquely in Jesus and that Christianity was the deWnitive divine revelation. Nonetheless, 21 SIXTEENTH-CENTURY PHILOSOPHY after leaving England he was accepted for a while as a Lutheran at Wittenberg and in 1591 was lecturing in Zurich. Unwisely, he accepted an invitation from the Doge of Venice, and found himself in the prison of the local Inquisition in 1592. A year later he was passed on to the Roman Inquisition, and after a trial that dragged on for nearly seven years in 1600 he was burned as a heretic in the Campo dei Fiori, where his statue now stands. There is no doubt that the ideas expressed in Bruno’s writings were unorthodox. The remarkable things about his trial are that he showed such constancy in defending his ideas and that it took his inquisitors so long to Wnd him guilty of heresy. But although theories of multiple universes are once again popular with cosmologists today, it is a mistake to think of Bruno as a martyr to science. His speculations were based not on observation or experiment but on occult traditions and on a priori philosophizing. He was condemned not because he supported the Copernican system, but because he practised magic and denied the divinity of Christ. Galileo Matters are very diVerent when we turn to another Italian philosopher who suVered at the hands of the Inquisition, Galileo Galilei. Galileo, twelve years younger than Bruno and an exact contemporary of Shakespeare, was born in Pisa and studied at the university there, eventually becoming professor of mathematics in 1589. In 1592 he moved to Padua, and held a professorship there for eighteen years, which he would recall as the happiest period of his life. Already as a young man Galileo had begun to criticize the still dominant physics of Aristotle, not, like Bruno, on the basis of Neoplatonic metaphysics, but as a result of observation and experiment. His years at Pisa became famous for one observation that he made and one experiment that he probably did not make. Observing the motion of a chandelier in the cathedral he discovered that the length of time taken by the swing of a pendulum depends only on its own length, not on its weight or the scope of its swing. He almost certainly did not, as legend tells, drop balls of diVerent weights from the cathedral’s leaning tower to prove that Aristotle was wrong to say that heavier bodies fell faster than light ones. His contemporary Aristotelian opponents, however, did carry out such 22 SIXTEENTH-CENTURY PHILOSOPHY an experiment, and their results were closer to his prediction than to Aristotle’s: a 100 lb ball hit the ground very little sooner than a 1 lb ball. It was in Padua that Galileo did conWrm by experiment—with balls rolling down inclined planes—that bodies of diVerent weight, in the absence of resistance, take the same time to fall a given distance, and that they accelerate at the same uniform rate. His experiments also tended to show the falsity of the principle, fundamental to Aristotelian physics, that nothing moves unless acted on by an external source of motion. On the contrary, he maintained, a body in motion will continue to move unless acted on by a contrary force, such as friction. This thesis enabled him to dispense with the notion of impetus, which earlier critics of Aristotle such as Philoponus had invoked to explain the continued motion of projectiles.11 It prepared the way for the principle of inertia stated later by Descartes and Newton, that any moving object, unless acted on from outside, tends to move in a straight line at a constant speed. Galileo himself did not quite arrive at this principle, since in order to explain the orbits of the planets, he postulated that inertial motion was basically circular. On its own, Galileo’s work in mechanics would entitle him to a place among the great scientists, and he also made important discoveries in hydrostatics. But it was his research into astronomy that brought him fame and tribulation. Using the newly invented telescope, which he himself substantially improved, he was able to observe four moons of Jupiter, which he named ‘Medicean Stars’ in honour of Grand Duke Cosimo II of Tuscany. He discovered the mountains of the moon and the variable spots on the sun; discoveries which showed that he heavenly bodies were not, as Aristotle thought, made out of a uniform crystalline quintessence, but consisted of the same sort of material as our own earth. These discoveries were published in 1610 in a book entitled A Messenger from the Stars (Sidereus Nuncius). The book was dedicated to Duke Cosimo, who forthwith gave him a lifetime appointment as philosopher and mathematician to the court of Tuscany. Shortly afterwards, Galileo observed that the planet Venus went through phases similar to the phases of the moon. This could only be explained, he concluded, if Venus was orbiting the sun and not the earth: it provided a powerful argument in favour of the Copernican hypothesis. 11 See vol. II, p. 180. 23 SIXTEENTH-CENTURY PHILOSOPHY The discovery of the moons that revolved around Jupiter in its planetary orbit had already disposed of one of the strongest arguments urged against heliocentrism, namely that the moon would only be able to orbit the earth if the earth itself was stationary. Galileo was initially cautious in publicly expressing the conclusions he drew from his astronomical discoveries. However, after an ecclesiastical commission in Rome had taken oYcial notice of his major observations, he began to propagate heliocentric ideas to a wide circle of friends, and in 1613, in an appendix to a book on sunspots, he declared his adherence to Copernicus. A Dominican friar in Florence, in a sermon on Acts 1: 11 (‘Ye Galileans, why stand ye gazing up to heaven?’) denounced heliocentrism as being in conXict with biblical texts, such as the one in which Joshua tells the sun to stand still so that the Israelites may complete their victory over the Philistines. Galileo decided to travel to Rome to clarify his theological status. In advance he wrote to the powerful Jesuit cardinal, St Robert Bellarmine, urging that the sacred authors who spoke of the sun as moving were merely using popular idiom and were not intending to teach geometry. Bellarmine referred the matter to a committee of the Inquisition who determined that the opinion that the sun was the centre of the cosmos was heretical, and the opinion that the earth moved was at the least erroneous. On the instructions of Pope Paul V, Bellarmine instructed Galileo that he must not hold or defend either of these opinions. If there was a real proof of heliocentrism, he told one of Galileo’s friends, then we would have to re-examine the biblical texts which appeared to contradict it; but as matters stood, Copernicus’ theory was only an unproved hypothesis. And indeed, Galileo’s own heliocentric system, though it Wtted the phenomena better, was almost as complicated as the geocentric system of his opponents, demanding constant appeal to epicycles.12 The evidence he had discovered did not justify the degree of certainty with which he maintained his thesis. It is often said that in this exchange Bellarmine showed a sounder grasp of the philosophy of science than the age’s greatest scientist and Galileo showed a sounder grasp of biblical exegesis than the age’s most famous theologian. The paradox is an agreeable one, but it is not really a fair 12 Galileo did not incorporate Kepler’s discovery of the elliptical orbits of the planets, which was needed to achieve the appropriate simpliWcation of heliocentrism. 24 SIXTEENTH-CENTURY PHILOSOPHY representation of the debate on either side. And whatever the merits of the case, the upshot was that while Galileo’s writings were not condemned, he was silenced for several years to come. In 1624 Galileo travelled to Rome once more. Paul V and Bellarmine were now dead, and there was a diVerent pope wearing the tiara: Urban VIII, who as Cardinal Barberini had shown himself an admirer of Galileo’s astronomical discoveries. Galileo was given permission to write a systematic treatment of the Ptolemaic and the Copernican models, on condition that he presented them both impartially without favouring heliocentrism. In 1632 Galileo published, with the approval of the papal censor, Dialogue on the Two Chief World Systems. In the book one character, Salviati, presents the Copernican system, and another, Simplicius, defends the traditional one. ‘Simplicius’ was an appropriate name for the defender of Aristotelianism, since it had been borne by the greatest of Aristotle’s Greek commentators. However, it could also be interpreted as meaning ‘simpleton’ and the pope was furious when he found some of his own words placed in the mouth of Simplicius. He concluded that Galileo had presented the Copernican system in a more favourable light than its opponent, and had therefore deviated from the terms of his licence to publish. In 1633 Galileo was summoned to Rome, tried by the Inquisition, and under the threat of torture forced to abjure heliocentrism. He was condemned to life imprisonment, a sentence that he served out until his death in 1642, in conWnement in the houses of distinguished friends and eventually in his own home at Bellosguardo outside Florence. While under house arrest he was allowed to receive visitors. Among them was John Milton, who in Areopagitica recorded: ‘I found and visited the famous Galileo grown old, a prisoner of the Inquisition, for thinking in Astronomy otherwise than the Franciscan and Dominican licensers thought.’ The newly founded college at Harvard in the commonwealth of Massachusetts made an oVer of a visiting professorship, which was politely declined. Even though going blind, Galileo continued to write, and incorporated the fruit of his lifetime’s work in Discourses and Mathematical Demonstrations Concerning Two New Sciences. This was published in Leiden in 1638 and became the most widely inXuential of his works. Galileo was treated more humanely than Bruno and many another prisoner of the Inquisition, but the evil eVects of his condemnation were felt throughout Europe. ScientiWc investigation in Italy went into decline: 25 SIXTEENTH-CENTURY PHILOSOPHY ‘nothing has been there written now these many years,’ Milton could complain, ‘but Xattery and fustian.’ Even in Protestant Holland, Descartes was for many years deterred by Galileo’s fate from publishing his own scientiWc cosmology. When in 1992 Pope John Paul II publicly acknowledged the injustice the Church had done to Galileo, the apology came 350 years too late. Bacon An English contemporary of Galileo, Francis Bacon, shared his antipathy to Aristotle, but was more interested in the theory than in the practice of scientiWc method. Born in London in 1561, Bacon was educated at Trinity College, Cambridge, and studied law at Gray’s Inn. He entered Parliament in 1584 and later became a client of Queen Elizabeth’s favourite, the Earl of Essex. When, in 1598, Essex plotted an insurrection, Bacon took a leading part in his prosecution for treason. On the accession of James I he became solicitor-general and was knighted. In 1606 he published the Wrst of his major philosophical writings, The Advancement of Learning, a systematic classiWcation of scientiWc disciplines. The climax of Bacon’s career was his appointment in 1618 as Lord Chancellor with the title Lord Verulam. He planned a massive work, the Instauratio Magna (The Great Instauration), which was to take all knowledge for its province. Only two parts of this were completed: the Wrst was a revision of The Advancement of Learning, and the second was the Novum Organum which was his principal work on scientiWc method. In 1621, in the course of a parliamentary inquiry, he pleaded guilty to charges of accepting bribes, and was disgraced and brieXy imprisoned. He wrote other scientiWc and historical works and also the essays for which he is nowadays best remembered. He died at Highgate in 1626. Legend represents him as a martyr to science, oVering his life in the cause of experimental refrigeration; for he died, it is said, from a chill caught stuYng a hen with snow to see whether the cold would preserve the meat. ‘The parts of human learning’, Bacon says in Book Two of The Advancement, ‘have reference to the three parts of Man’s Understanding, which is the seat of learning: History to his Memory, Poesy to his Imagination, and Philosophy to his reason’ (AL, 177). Poesy, which includes not only poetry 26 SIXTEENTH-CENTURY PHILOSOPHY The title page of the Oxford edition of Bacon’s Advancement of Learning (1640) 27 SIXTEENTH-CENTURY PHILOSOPHY but prose Wction, is treated only perfunctorily by Bacon: the kind of poesy he most admires is a story with a moral message, like Aesop’s fables. But history and philosophy are addressed at length, and given further subdivisions. The most important parts of history are Natural and Civil. ‘Civil history’ is what we would nowadays call history: Bacon himself contributed to it a narrative of the reign of Henry VII. ‘Natural history’ is a discipline of broad scope with three subdivisions: the history of ‘nature in course, of nature erring or varying, and of nature altered or wrought’. It will include, then, treatises of natural science, records of extraordinary marvels, and manuals of technology. Bacon’s own contribution to natural history consisted of two compilations of research material, a History of the Winds, and a History of Life and Death. The ‘history of nature erring’, he thought, should include records of superstitious narrations of sorceries and witchcrafts, in order to ascertain how far eVects attributed to superstition could be attributed to natural causes. But the third subdivision, ‘history mechanical’, was the most fundamental and useful for natural philosophy, whose value, according to Bacon, was above all in its practical application and utility. In his classiWcation of philosophy, Bacon Wrst puts on one side ‘divine philosophy’ or natural theology: it suYces, he tells us, to refute atheism but not to inform religion. He then divides philosophy into natural and human. Natural philosophy may be speculative or operative: the speculative kind includes both physics and metaphysics, and the operative kind includes both mechanics and magic. Mechanics is the practical application of physics, and magic is the practical application of metaphysics. This brisk and provocative anatomy of philosophy is not as neat as it seems, and many of the names Bacon gives to the various disciplines are employed in idiosyncratic ways. His ‘natural magic’, he tells us, must be sharply distinguished from the ‘credulous and superstitious conceits’ of alchemy and astrology. It is not at all clear what he has in mind: the one thing he seems to oVer as an example is the mariner’s compass. Why, we may ask, is this a matter of ‘magic’ rather than ‘mechanics’? An answer suggests itself when we read that physics deals with the eYcient and material causes of things, while metaphysics deals with the Wnal and formal causes. So the sail, which gives the boat its motion, operates in the realm of physics, while the compass, which guides the boat’s 28 SIXTEENTH-CENTURY PHILOSOPHY direction, operates in the realm of metaphysics. Bacon admits candidly that he is using ‘metaphysics’ in a novel way. What others call metaphysics he calls ‘Wrst philosophy’ or ‘summary philosophy’: it is a receptacle, he tells us, for all the universal principles that are not exclusive to particular disciplines. (An example is ‘If equals be added to unequals the result will be unequal,’ an axiom which he believes applies in law as well as in mathematics.) But the distinction made between physics and metaphysics on the basis of the Aristotelian four causes is itself misleading. Bacon’s scheme for natural magic leaves no real room for teleology: ‘inquiry into Wnal causes’, he tells us, ‘is sterile, and like a virgin consecrated to God, produces nothing.’ And when he speaks of ‘forms’ he is not thinking of Aristotle’s substantial forms—such as the form of a lion, or of water—because these, he believes, are too varied and complicated to be discovered. Instead of studying these, we should look rather for the simpler forms which go into their composition, in the way that letters go to make up words. The task of metaphysics is to investigate the simpler forms which correspond to individual letters: To enquire the forms of sense, of voluntary motion, of vegetation, of colours, of gravity and levity, of density, of tenuity, of heat and of cold, and all other natures and qualities, which like an alphabet are not many, and which the essences (upheld by matter) of all creatures do now consist. (AL, 196) Bacon’s elementary forms are obscure characters in comparison with the mathematical shapes and symbols which Galileo declared to be the alphabet in which the book of the world is written. But most probably when he talked of forms he had in mind hidden material structures underlying the overt appearance and behaviour of things. So much for natural philosophy. Human philosophy, the other great branch of the subject, has two parts, Bacon tells us, one which considers ‘man segregate’ and another which considers ‘man congregate’. The Wrst part corresponds to anatomy, physiology, and psychology, and the second embraces what would nowadays be called the social sciences. The detailed subdivisions Bacon enumerates appear arbitrary and haphazard. The sciences of the body include medicine, ‘cosmetic’, ‘athletic’, and the ‘Arts Voluptuary’, which include practical joking. The study of the nature of the soul is a matter for theology, but there is a human science which studies 29 SIXTEENTH-CENTURY PHILOSOPHY the operations of the soul. These fall into two classes, one set belonging to the understanding or reason, whose function is judgement, and the other set belonging to the will or appetite, whose function is action or execution. What of the imagination, which had a privileged place in Bacon’s initial classiWcation of human faculties? The Imagination is an agent or nuncius in both provinces, both the judicial and the ministerial. For sense sendeth over to Imagination before Reason have judged: and Reason sendeth over to Imagination before the Decree can be acted; for Imagination ever precedeth Voluntary Motion: saving that this Janus of Imagination hath diVering faces; for the face towards Reason hath the print of Truth, but the face towards Action hath the print of Good. (AL, 217) But imagination is no mere servant of the other faculties, Bacon insists: it can triumph over reason, and that is what happens in the case of religious belief. It is clear that Bacon envisioned the mind as a kind of internal society, with the diVerent faculties enshrined in a constitution respecting the separation of powers. When he comes to treat of the social sciences themselves he oVers another threefold division, corresponding to associations for friendship, for business, and for government. Political theory is a part of civil philosophy, that branch of human philosophy that concerns the beneWts that humans derive from living in society. Having Wnished his classiWcation, Bacon can boast ‘I have made as it were a small globe of the intellectual world’ (AL, 299). The various sciences which appear in his voluminous catalogue are not all at similar stages of development. Some, he thinks, have achieved a degree of perfection, but others are deWcient, and some are almost non-existent. One of the most deWcient is logic, and the defects of logic weaken other sciences also. The problem is that logic lacks a theory of scientiWc discovery: Like as the West-Indies had never been discovered if the use of the mariner’s needle had not been Wrst discovered, though the one be vast regions and the other a small motion; so it cannot be found strange if sciences be no further discovered if the art itself of invention and discovery hath been passed over. (AL, 219). Bacon set out to remedy this lack and to provide a compass to guide scientiWc researchers. This was the task of his Novum Organum. Bacon’s project of introducing discipline into research had a negative and a positive component. The researcher’s Wrst, negative, task is to be on 30 SIXTEENTH-CENTURY PHILOSOPHY his guard against the factors that can introduce bias into his observations. Bacon lists four of these, and calls them ‘idols’ because they are fetishes which can divert us from the pursuit of truth: there are the idols of the tribe, the idols of the den, the idols of the marketplace, and the idols of the theatre. The idols of the tribe are temptations endemic in the whole human race, such as the tendency to judge things by superWcial appearances, the tendency to go along with popular belief, and the tendency to interpret nature anthropomorphically. The idols of the den, or cave, are features of individual temperaments which hamper objectivity: some people, for instance, are too conservative, others too ready to seize on novelties. Each person has ‘a certain individual cavern of his own, which breaks and distorts the light of nature’. The idols of the marketplace (or perhaps ‘idols of the courts’—idola fori) are snares lurking in the language we use, which contains meaningless, ambiguous, and ill-deWned words. Finally the idols of the theatre are false systems of philosophy which are no more than stage plays, whether ‘sophistical’, like Aristotle’s, or ‘empirical’, like contemporary alchemists, or ‘superstitious’ like the Neoplatonists who confuse philosophy with theology. The positive task of the researcher is induction, the discovery of scientiWc laws by the systematic examination of particular cases. If this is not to be rash generalization from inadequate sampling of nature, we need a carefully schematized procedure, showing us how to mount gradually from particular instances to axioms of gradually increasing generality. Bacon oVers a series of detailed rules to guide this process: Suppose that we have some phenomenon X and we wish to discover its true form or explanation. We must Wrst make a table of presences—that is to say, we list the items A, B, C, D . . . which are present when X is present. Then we make a table of absences, listing items E, F, G, H . . . which are present when X is absent. Thirdly, we make a table of degrees, recording that J, K, L, M . . . are present to a greater degree when X is present to a greater degree, and present to a lesser degree when X is present to a lesser degree. This is only the preparatory step in the method. The real work of induction comes when we start the process of eliminating candidates for being the form of X. To be successful a candidate must be present in every case occurring in the table of presences, and absent in every case occurring in the table of absences. Bacon illustrates his method with the example of 31 SIXTEENTH-CENTURY PHILOSOPHY heat. We list cases when heat is present (e.g. the rays of the sun and the sparks of a Xint) and cases in which it is absent (e.g. in the rays of the moon and the stars). Since light is present in cases listed in the table of absence, we can eliminate light as being the form of heat. After some further eliminative moves, and making use also of the table of degrees (e.g. that the more exercise animals take the hotter they get), Bacon concludes that heat is a special kind of motion (‘an expansive motion held in check and pushing its way through tiny particles’). Bacon never completed the series of guidelines that he set out to present in the Novum Organum, and it cannot be said that his system adds up to a ‘logic of induction’. However, he did establish the important point that negative instances are more signiWcant, in the process of establishing laws, than positive ones. Twentieth-century philosophers have been willing to give him credit for being the Wrst person to point out that laws of nature cannot be conclusively veriWed, but can be conclusively falsiWed. Bacon’s insistence on the importance of precise and repeated observations went hand in hand with an appreciation that natural science could make progress only by a massive cooperative endeavour. In the New Atlantis, an unWnished fragment published posthumously, a ship’s crew in the South Seas land on an island containing a remarkable institution known as Salomon’s House. This turns out to be a research establishment, where scientists work together to embody Bacon’s utilitarian ideal of science as the extension of men’s power over nature for the betterment of the human race. Their projects include plans for telephones, submarines, and aeroplanes. The president of the institute described its purpose thus: The End of our Foundation is the knowledge of Causes, and secret motions of things, and the enlarging of the bound of Human Empire, to the eVecting of all things possible. (B, 480) Salomon’s House was a Utopian fantasy; but it was given a counterpart in the real world when, thirty-Wve years after the New Atlantis, Bacon’s compatriots of the next generation founded the Royal Society of London. 32 2 Descartes to Berkeley Descartes he seventeenth century, unlike the sixteenth century, was fertile in the production of philosophers of genius. The man who is often considered the father of modern philosophy is René Descartes. He was born in 1596, about the time when Shakespeare was writing Hamlet, in a village in Touraine which is now called after him La-Haye-Descartes. A sickly child, he was exempted at school from morning exercises and acquired a lifelong habit of meditating in bed. From his eleventh to his nineteenth year he studied classics and philosophy at the Jesuit college of La Flèche. He remained a Catholic throughout his life, but chose to spend most of his adult life in Protestant Holland. In 1616, having taken a degree in law at Poitiers, Descartes gave up his studies for a while. In the wars of religion that divided Europe, he enlisted in both camps. First, he was an unpaid volunteer in the army of the Protestant Prince of Orange; later he served in the army of the Catholic Duke Maximilian of Bavaria, who was then at war with the Palatine Elector Frederick, son-in-law of King James I of Britain. After he left the army he did not adopt a profession. Unlike the great philosophers of the Middle Ages he was a layman in both the ecclesiastical and the academic sense. He never lectured in a university, and he lived a private life as a gentleman of means. He wrote his most famous work not in the Latin of the learned world, but in good plain French, so that it could be understood, as he put it, ‘even by women’. While serving in the army, Descartes acquired a conviction that he had a call to philosophy. He spent a winter’s day of 1619 huddled beside a stove, T DESCARTES TO BERKELEY engrossed in meditation. He conceived the idea of undertaking, singlehanded, a reform of human learning that would display all disciplines as branches of a single wonderful science. His conviction of vocation was reinforced when, that night, he had three dreams that he regarded as prophetic. But it was not until some years later that he settled permanently to philosophical studies. From 1620 to 1625 he travelled in Germany, Holland, and Italy, and from 1625 to 1627 he mixed in society in Paris, gambling heavily and becoming involved in a duel over a love aVair. His surviving early writings show his interest in mechanical and mathematical problems, and include a brief treatise on music. In 1627 he intervened impressively in the discussion of a grand public lecture in Paris: a cardinal who was present exhorted him to devote himself to the reform of philosophy. A year later Descartes left for Holland, where he lived until 1649, shortly before his death. He chose the country for its climate and its reputation for tolerance: he looked forward to a life free from the distractions of the city and from morning callers. He dwelt in thirteen diVerent houses during his twenty-year sojourn and kept his address secret from all but close friends. Amid Protestant surroundings, he continued to practise as a Catholic. Descartes kept in touch with the learned world by letter. His principal correspondent was a Franciscan friar, Father Marin Mersenne, who was the centre of an erudite international network. Mersenne acted as Descartes’ literary agent, handling the publication of his works and keeping him informed of recent scientiWc discoveries. Of the ten volumes of the standard edition of Descartes’ works, Wve are taken up by his letters, which are a highly important source for the development of his thought. In Holland Descartes lived comfortably and quietly; he was not wholly without company, and in 1635 he had an illegitimate daughter, Francine, who lived only Wve years. He brought a few books with him from Paris, including the Summa Theologiae of Thomas Aquinas. He claimed that he spent very little time reading: he had no great admiration for classical languages and he boasted that he had not opened a scholastic textbook once in twenty years. When a stranger asked to see his library, he pointed to a halfdissected calf. Besides purchasing carcasses from the butcher for dissection, he ground his own lenses in order to make experiments in optics. He trusted experiment rather than learning, but more than either he trusted his own philosophical reXection. 34 DESCARTES TO BERKELEY During his Wrst years in Holland his work was mainly mathematical and physical. He laid the foundations of analytical geometry: the Cartesian coordinates that every schoolchild learns about derive their name from the Latin form of his surname, Cartesius. He studied refraction and propounded the law of sines, the result of careful theoretical and experimental work on the nature of light and of the eye. He also worked on meteorology, trying to ascertain the true nature of rainbows. By 1632 Descartes had in mind to publish a substantial volume which would explain ‘the nature of light, the sun and the Wxed stars which emit it; the heavens which transmit it; the planets, the comets and the earth which reXect it; all the terrestrial bodies which are either coloured or transparent or luminous; and Man its spectator’. The system that it propounded was a heliocentric one: the earth was a planet, moving around the sun. The treatise was entitled The World and it was ready for the press when Descartes learned that Galileo had been condemned for upholding the Copernican system. Anxious to avoid conXict with ecclesiastical authority, he returned the treatise to his desk. It was never published in his lifetime, although much of its material was incorporated twelve years later in a textbook called Principles of Philosophy. Instead of publishing his system, in 1637 Descartes decided to make public ‘some specimens of his method’: his dioptrics, his geometry, and his meteorolgy. He prefaced them with ‘a discourse on the right way to use one’s reason and seek truth in the sciences’. The three scientiWc treatises are nowadays read only by specialists in the history of science, but the Discourse on Method has a claim to be the most popular of all philosophical classics. In signiWcance it compares with Plato’s Republic and with Kant’s Critique of Pure Reason, but it has the advantage of being much briefer and more readable than either. Among other things, the Discourse is a witty and urbane piece of autobiography, as the following extracts illustrate: Good sense is the most fairly distributed thing in the world; for everyone thinks himself so well supplied with it, that even those who are hardest to satisfy in every other way do not usually desire more of it than they already have. . . . As soon as my age allowed me to pass from under the control of my instructors, I entirely abandoned the study of letters, and resolved not to seek after any science but what might be found within myself or in the great book of the world. . . . I spent nine years in roaming about the world, aiming to be a spectator rather than an actor in all the comedies of life. 35 DESCARTES TO BERKELEY Amidst a great and populous nation, extremely industrious and more concerned with their own business than curious about other people’s, while I do not lack any conveniences of the most frequented cities, I have been able to live a life as solitary and retired as though I were in the most remote deserts. (AT VI. 2, 9, 31; CSMK I.111, 115, 126) But the Discourse is much more than Descartes’ intellectual autobiography: it presents in minature a summary of his philosophical system and his scientiWc method. Descartes had an extraordinary gift for presenting complicated philosophical doctrines so elegantly that they appear fully intelligible on Wrst reading and yet can provide material for reXection to the most expert philosophers. He prided himself that his works could be read ‘just like novels’. There are two key ideas that are presented in the Discourse and elaborated in later works. First: human beings are thinking substances. Second: matter is extension in motion. Everything in his system is to be explained in terms of this dualism of mind and matter. If we nowadays tend naturally to think of mind and matter as the two great mutually exclusive and mutually exhaustive divisions of the universe we inhabit, that is because of Descartes. Descartes reaches these conclusions by the application of a method of systematic doubt. To prevent being ensnared in falsehood, the philosopher must begin by doubting whatever can be doubted. The senses sometimes deceive us; mathematicians sometimes make mistakes; we can never be certain whether we are awake or asleep. Accordingly: I decided to feign that everything that had entered my mind hitherto was no more true than the illusions of dreams. But immediately upon this I noticed that while I was trying to think everything false, it must needs be that I, who was thinking this, was something. And observing that this truth ‘I am thinking, therefore I exist’ was so solid and secure that the most extravagant suppositions of sceptics could not overthrow it, I judged that I need not scruple to accept it as the Wrst principle of philosophy that I was seeking. (AT VI. 32; CSMK I.127) This is the famous Cogito, ergo sum, which achieves the second task of the philosopher, that of preventing the systematic doubt from leading to scepticism. But from it Descartes goes on to derive the principles of his system. If I were not thinking, I would have no reason to believe that I existed; hence I am a substance whose whole essence is to think; being a body is no part of my essence. The same goes for every other human being. So Descartes’ Wrst main thesis is established. 36 DESCARTES TO BERKELEY What assures me that the Cogito is correct? Only that I see clearly that it is true. Whenever I conceive something clearly and distinctly, I am assured of its truth. But when we turn to material objects, we Wnd that of all their properties the only ones we clearly and distinctly perceive are shape, size, and movement. So Descartes gains his second main thesis, that matter is extension in motion. But what guarantees the principle that whatever I see clearly and distinctly is true? Only the truthful nature of the God to whom I owe my existence as a thinking thing. So establishing the existence of God is a necessary part of Descartes’ system. He oVers two proofs that there is a God. First, I have in myself the idea of a perfect being, and this idea cannot be caused in me by anything less than a being that is itself perfect. Second, to be perfect a being must include in itself all perfections; but existence is a perfection, and therefore a perfect being must exist.1 Like Bacon, Descartes compared knowledge to a tree, but for him the tree’s roots were metaphysics, its trunk was physics, and its fruitful branches were the moral and useful sciences. His own writings, after the Discourse, followed the order thus suggested. In 1641 he wrote his metaphysical Meditations, in 1644 his Principles of Philosophy, which is a pruned version of the physical system of The World, and in 1649 a Treatise on the Passions, which is largely an ethical treatise. The Meditations contain a full statement of the system sketched in the Discourse. Before publication the text was sent to Mersenne to circulate for comment to a number of scholars and thinkers. Six sets of objections were received. They were printed, with replies from Descartes, in a long appendix to the Wrst edition of 1641, which thus became the Wrst peer-reviewed work in history. The objectors were a varied and distinguished group: apart from Mersenne himself they included a scholastic neighbour in Holland, an Augustinian theologian from Paris, Antoine Arnauld, plus the atomist philosopher Pierre Gassendi, and the English materialist and nominalist, Thomas Hobbes. Criticisms of the Meditations continued to come in after publication, and critical reaction was not only literary. The rector of Utrecht University, Gisbert Voetius, denounced Descartes to the magistrates as a dangerous 1 Descartes’ natural theology is considered in detail in Ch. 10. 37 DESCARTES TO BERKELEY Princess Elizabeth of Bohemia, one of Descartes’ first readers and shrewdest critics propagator of atheism, and the University of Leiden accused him of the Pelagian heresy. Descartes wrote two tracts, which survive, to defend his orthodoxy; but it was really the intervention of inXuential friends that prevented him from being arrested and having his books burnt. One of his most supportive friends was Princess Elizabeth, the daughter of the Elector Frederick against whom he had once soldiered. He corresponded with her from 1643 until his death, answering (and sometimes failing to answer) her acute criticisms of his writings. He gave her much medical and moral advice, and consoled her on the execution of her uncle King Charles I. It was to her that he dedicated The Principles of Philosophy. The Wrst part of that book summarizes the metaphysics of the Meditations and its three remaining parts deal with physical science, propounding laws of motion and explaining the nature of weight, heat, and light. The account given of the solar system is disguisedly heliocentric and discreetly 38 DESCARTES TO BERKELEY evolutionary. Descartes explains that he is describing not how the world was actually made, but how God might have made it otherwise, if he had so pleased. Descartes’ correspondence with Princess Elizabeth led him to reXect further on the relationship between the body and the soul, and to construct an ethical system resembling ancient Stoicism. He developed these reXections into The Passions of the Soul. When the treatise was published, however, it was dedicated not to Elizabeth, but to another royal lady who had interested herself in philosophy, Queen Christina of Sweden. The queen was so impressed that she invited Descartes to be her court philosopher, sending an admiral with a battleship to fetch him from Holland. Descartes was reluctant to sacriWce his solitude and the appointment proved disastrous. He felt lonely and out of place: he was employed in writing a ballet and forced to rise at 5 a.m. to instruct the queen in philosophy. Descartes had immense conWdence in his own abilities, and still more in the method he had discovered. Given a few more years of life, he thought, and given suYcient research funding, he would be able to solve all the outstanding problems of physiology and learn thereby the cures of all diseases. At this point he fell a victim to the rigours of the Swedish winter. While nursing a sick friend he caught pneumonia, and died on 11 February 1650. There was an ironic Wttingness about the motto which he had chosen for himself as an epitaph: No man is harmed by death, save he Who, known too well by all the world, Has not yet learnt to know himself. Descartes was a man of extraordinary and versatile genius. His ideas on physiology, physics, and astronomy were superseded within a century: they enjoyed a much shorter currency than the Aristotelian system they were designed to replace. But his work in algebra and geometry entered into the abiding patrimony of mathematics; and his philosophical ideas remain—for better or worse—enormously inXuential to the present day. No one can question his claim to rank among the greatest philosophers of all time. We should not, however, take him altogether at his own valuation. In the Discourse he insists that systems created by an individual are to be preferred to those created by communities: 39 DESCARTES TO BERKELEY As a rule there is not such great perfection in works composed of several parts, and proceeding from the hands of various artists, as in those on which one man has worked alone. Thus we see the buildings undertaken and carried out by a single architect are generally more seemly and better arranged than those that several hands have sought to adapt, making use of old walls that were built for other purposes. Again, those ancient cities which were originally mere boroughs, and have become towns in process of time, are as a rule badly laid out, as compared with those towns of regular pattern that are laid out by a designer on an open plan to suit his fancy. (AT VI. 11; CSMK I.116) This is not merely the expression of a taste for classical rather than Gothic architecture: laws too, Descartes goes on, are better if devised by a single legislator in a single code. Similarly, he thought, a true system of philosophy would be the creation of a single mind; and he believed himself to be uniquely qualiWed to be its creator. It is true that Descartes initiated a new, individualistic, style of philosophizing. Medieval philosophers had seen themselves as principally engaged in transmitting a corpus of knowledge; in the course of transmission they might oVer improvements, but these must remain within the bounds set by tradition. Renaissance philosophers had seen themselves as rediscovering and republicizing the lost wisdom of ancient times. It was Descartes who was the Wrst philosopher since Antiquity to oVer himself as a total innovator; as the person who had the privilege of setting out the truth about man and his universe for the very Wrst time. Where Descartes trod, others followed: Locke, Hume, and Kant each oVered their philosophies as new creations, constructed for the Wrst time on sound scientiWc principles. ‘Read my work, and discard my predecessors’ is a constant theme of seventeenth- and eighteenth-century thinkers and writers. With medieval philosophers like Aquinas, Scotus, and Ockham, a student has to read the texts closely to realize the great degree of innovation that is going on: the new wine is always decanted so carefully i