Plagiarism and borrowings by authors from each other--The filiation of statements--The investigation of sources 93 Importance of investigations of authorship--The extreme of distrust to be avoided--Criticism only a means to an end 98 CHAPTER IV CRITICAL CLASSIFICATION OF SOURCES Importance of classification--The first impulse wrong--The note-book system not the best--Nor the ledger-system--Nor the "system" of trusting the memory 101 The system of slips the best--Its drawbacks--Means of obviating them--The advantage of good "private librarianship" 103 Methods of work vary according to the object aimed at--The compiling of _Regesta_ or of a _Corpus_--Classification by time, place, species, and form 105 Chronological arrangement to be used when possible--Geographical arrangement best for inscriptions--When these fail, alphabetical order of "incipit"--Logical order useful for some special purposes--Not for a _Corpus_ or for _Regesta_ 107 CHAPTER V CRITICAL SCHOLARSHIP AND SCHOLARS Different opinions on the importance and dignity of external criticism--It is justified by its necessity--But is only preliminary to the higher part of historical work 112 Distinction between "historians" and "critical scholars" [Fr. "_érudite_"]--Expediency, within limits, of the division of labour in this respect--The exceptional skill acquired by specialists--Difference of work the corollary of difference of natural aptitudes 115 The natural aptitudes required for external criticism--Fondness for the work, which is distasteful to the creative genius--The puzzle-solving instinct--Accuracy and its opposite--"Froude's Disease"--Patience, order, perseverance 121 The mental defects produced by devotion to external criticism--Its paralysing effect on the over-scrupulous--Hypercriticism--Dilettantism 128 The "organisation of scientific labour" 135 The harshness of judgment attributed to scholars, not always rightly--Much of it a proper jealousy for historic truth--Bad work nowadays soon detected 136 SECTION II.--INTERNAL CRITICISM CHAPTER VI INTERPRETATIVE CRITICISM (HERMENEUTIC) Internal criticism deals with the mental operations which begin with the observation of a fact and end with the writing of words in a document--It is divided into two stages: the first concerned with what the author meant, the second with the value of his statements 141 Necessity of separating the two operations--Danger of reading opinions into a text 143 The analysis of documents--The method of slips--Completeness necessary 145