But, while I have only too much reason to solicit the indulgence of my readers, conscious as I am of the many defects of this translation, I feel that no apology is needed for bringing that of which it is a translation within the reach of the English-speaking public. We live in times when the intimate relation between the natural sciences and social questions is increasingly felt. Old landmarks are disappearing, new foundations are being laid, new problems are constantly arising, generating doubts and perplexities for which the solutions of other days supply no adequate answer. Meanwhile, as the facts of science reveal to us more of the conditions of human life, we give, more or less consciously, a larger place to sociology in our mental preoccupations. Thus renewed interest is being felt in the writings of the Founder of the Science of Sociology. The most conflicting schools of thought study the works of Auguste Comte and many ask: who is that man whose ideas appear to contain a clearer message to our generation than they did to his own? For such inquirers Professor Lévy-Bruhl’s book should prove singularly useful and timely. It is a plain, independent account of what Comte really taught, written by one possessed of the fullest qualifications for such a task, and no work of recent date will enable students to understand so clearly the solution given by the French philosopher to the perplexing moral, social, and religious problems of our time. Here, as elsewhere, “il s’agit de tout comprendre, non de tout admirer,” and Professor Lévy-Bruhl is himself too much of a philosopher to forget that golden rule; but, nevertheless, by his free, independent judgment of Comte’s teaching, he helps us to realise to what an extent, in these days, Comte is inspiring many who are not perhaps conscious of following him. KATHLEEN DE BEAUMONT-KLEIN. CONTENTS PAGE Note by Mr. Frederic Harrison v. Translator’s Preface xiii. Introduction by Professor Lévy-Bruhl 1 BOOK I. CHAPTER I.--The Philosophical Problem 23 “ II.--The Law of the Three States 35 “ III.--The Classification of the Sciences 49 “ IV.--Science 60 “ V.--Science (continued) Phenomena and Laws 79 “ VI.--Science (continued) Positive Logic 103 BOOK II. INTRODUCTION.--The Philosophy of the Sciences 121 CHAPTER I.--Mathematics 125 “ II.--Astronomy 142 “ III.--Sciences of the Inorganic World 154 “ IV.--Biology 171