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