PREFACE. THIS new edition may almost be considered as a new work, so many are the additions and so extensive the alterations. Seven new names have been added to the list of philosophers,-ABELARD, ALGAZZALI, GIORDANO BRUNO, HARTLEY, DARWIN, CABANIS, and GALL. An Introduction, setting forth the distinguishing characteristics of Philosophy and Science, replaces the original Introduction. Under the heads of SOCRATES, the SOPHISTS, ARISTOTLE, BACON, SPINOZA, HUME, CONDILLAC, KANT, and ECLECTICISM, considerable additions and alterations will be found; and, throughout, the revision has been such that scarcely a paragraph remains unaltered. The work was written ten years ago, and was addressed to a popular audience. Ten years have not been without their influence on the historian; and moreover, the success of the work has so greatly exceeded any thing that could reasonably have been anticipated-not only in respect to sale, but in the directions of its influence-that on undertaking this Library Edition I felt the necessity of modifying both the aim and scope of the work. A graver audience was to be addressed, a graver tone adopted. Without forgetting the general public, I had now to think also of what students would require. Many polemical passages, many ex tracts, and some digressions, have been removed; and the space thus gained has prevented the new matter from swelling the work to an inconvenient size. Many references and other bibliographical details have been added, although the principle of abstinence from unnecessary citation has still been preserved. The labor bestowed on this Edition will, I hope, render it more worthy of public acceptance. To my friend, the Rev. W. G. Clark, of Trinity College, Cambridge, an acknowledgment is due for the kindness with which he permitted me to profit by his accomplished scholarship and taste, in the revision of the proofs; but while thanking him publicly for his many suggestions and corrections, I must exonerate him from every iota of responsibility either as to the opinions or the statements in this volume. The Introduction explains the purpose of this History and the principles of its composition; let me therefore only add here that, although availing myself of the labors of other historians and critics, I have not restricted myself to them. The works of the various philosophers, with rare exceptions, have been studied at first hand, and have furnished the extracts and abstracts; that is to say, I have either collected the passages myself, or have verified them by reference to the originals, in almost all cases. While, therefore, this History makes no pretension to a place beside the many erudite and comprehensive Histories previously published, it claims to be regarded as something very different from a mere compilation. The novelty of its conception made direct acquaintance with the originals indispensable. Having to exhibit the Biography of Philosophy in its rise, growth, and development, I could not always have drawn my material from writers who had no such aim; many of the passages most significant for my purpose being totally disregarded by my predecessors. In another respect also I have innovated, namely, in the constant interweaving of criticism with exposition. This was necessary to my purpose of proving that no metaphysical system has had in it a principle of vitality; none has succeeded in establishing itself, because none deserved to succeed. In this way I have been led to express every conclusion to which the study of metaphysical problems has led me; in some places-especially in the refutation of Sensationalism, and in the physiological discussion of psychological questionsI have been forced to content myself with a brief and imperfect exposition of my own views; and the reader is requested to regard them rather in their bearing as criticisms, than as expressing what I have to say on such difficult topics. The following list comprises some of the many géneral Histories which the student will find useful, should he desire ampler detail than was consistent with the size and plan of this volume: In English.-Ritter, History of Philosophy, 3 vols.; Tennemann, Manual of the History of Philosophy, 1 vol.; Victor Cousin, Introduction to the History of Philosophy, 1 vol.; Morell, History of Speculative Philosophy in the Nineteenth Century, 2 vols. (2d edition, much improved). In French.-Degérando, Histoire Comparée des Systèmes de Philosophie, 4 vols. (2d edition); Renouvier, Manuel de la Philosophie Ancienne, 2 vols., and Manuel de la Philosophie Moderne, 1 vol.; Damiron, Histoire de la Philosophie en France au XIX Siècle, 1 vol.; Galuppi, Lettres Philosophiques, 1 vol. In German.-Ritter, Geschichte der Philosophie, 9 vols.; Tennemann, Geschichte der Philosophie, 11 vols. §. ; Hegel, Geschichte der Philosophie, 3 vols.; Zeller, Die Philosophie der Griechen, 2 vols.; Brandis, Geschichte der Griechisch-Römischen Philosophie, 2 vols. CONTENTS. PART I.—ANCIENT PHILOSOPHY. Speculations on the Nature of the Universe. PAGE CHAPTER II. THE MATHEMATICIANS.-Anaximander of Miletus.-Py- thagoras.-Philosophy of Pythagoras.-Translations from Aristotle's Intellectual Crisis.-The Insufficiency of all Attempts towards a Solution of the Problem of Existence, as well as that of Knowledge, produces the |