§ 21, p. 83, the words "_da ferner Substanz_" down to "_das Wirken_ in concreto." (E. v., § 21, p. 90, "Substance and Matter" down to "_in concreto_.") § 29, p. 105, the words "_im Lateinischen_" down to "_erkannte_." (E. v., § 29, p. 116, from "In Latin" down to "κατ' ἐξοχήν.") § 34, p. 116, the words "_Ueberall ist_" down to "_Praxis und Theorie_." (E. v., § 34, p. 128, the words "Reasonable or Rational" down to "theory and practice.") § 34, p. 121, the verses from Göthe's "West-Östlicher Divan." § 34, p. 125, _Anmerkung_, the words "_Auch ist Brahma_" down to "_die erstere_," and p. 126, the quotation from I. J. Schmidt's "Forschungen." (E. v., § 34, p. 138, note, "Brahma is also" down to "first of these.") § 34, p. 127, the words from "_Aber der naive_" down to "_judaisirten gouverneurs_" (E. v., § 34, p. 150, sentence beginning "But the artless" down to "infancy," and the Greek quotation from Plutarch in the note.) § 34, p. 128, the words from "_Ganz übereinstimmend_" down to "_überflüssige sein soll_." (E. v., p. 151, from "J. F. Davis" down to "superfluous.") § 45, p. 147, the words "_Eben daher kommt es_" down to "_sich erhält_." (E. v., § 45, p. 163, "It is just for this reason too" down to "their possession.") § 45, p. 149, the words "_Man suche Das_," &c., down to "_gelesen haben_." (E. v., § 45, p. 164, from "We should" down to "read in books.") § 49, p. 154, the words "_Der bei den Philosophastern_," down to "_zu kontroliren sind_." (E. v., § 49, p. 169, from the words "The conception of our," &c., down to "by perception.") § 50, p. 156, the words "_Denn der Satz vom Grunde_" down to "_nur sich selbst nicht_." (E. v., § 50, p. 172, from "For the Principle of Sufficient Reason," &c., down to "everything else.") § 52, p. 158, the words "_Der allgemeine Sinn des Satzes vom Grunde_," down to "_der Kosmologische Beweis ist_." (E. v., § 52, p. 173, from "The general meaning" down to "the Cosmological Proof.") JULIUS FRAUENSTÄDT. BERLIN, _August, 1864_. EDITOR'S PREFACE TO THE FOURTH EDITION. The present Fourth Edition is of the same content as the Third; therefore it contains the same corrections and additions which I had already inserted in the Third Edition from Schopenhauer's own interleaved copy of this work. JULIUS FRAUENSTÄDT. BERLIN, _September, 1877_. ON THE FOURFOLD ROOT OF THE PRINCIPLE OF SUFFICIENT REASON. CHAPTER I. INTRODUCTION. § 1. _The Method._