The statements of authors, taken singly, do not rise above probability--The only _sure_ results of criticism are _negative_--To establish facts it is necessary to compare different statements 194 Contradictions between statements, real and apparent 198 Agreement of statements--Necessity of proving them to be independent--Perfect agreement not so conclusive as occasional coincidence--Cases where different observations of the same fact are not independent--General facts the easiest to prove 199 Different facts, each imperfectly proved, corroborate each other when they harmonise 204 Disagreement between documents and other sources of knowledge--Improbable statements--Miracles--When science and history conflict, history should give way 205 BOOK III _SYNTHETIC OPERATIONS_ CHAPTER I GENERAL CONDITIONS OF HISTORICAL CONSTRUCTION The materials of Historical Construction are isolated facts, of very different kinds, of very different degrees of generality, each belonging to a definite time and place, of different degrees of certainty 211 Subjectivity of History 214 The facts learnt from documents relate to (1) living beings and material objects; (2) actions, individual and collective; (3) motives and conceptions 217 The facts of the past must be imagined on the model of those of the present--Danger of error especially in regard to mental facts 219 Some of the conditions of human life are permanent--The study of these provides a framework into which details taken from documents are to be fitted--For this purpose systematic lists of questions are to be used, drawn up beforehand, and relating to the universal conditions of life 224 Outline of Historical Construction--The division of labour--Historians must use the works of their colleagues and predecessors, but not without critical precautions 228 CHAPTER II THE GROUPING OF FACTS Historical facts may be classified and arranged either according to their time and place, or according to their nature--Scheme for the _logical_ classification of general historical facts 232 The selection of facts for treatment--The history of civilisation and "battle-history"--Both needed 236 The determination of groups of men--Precautions to be observed--The notion of "race" 238 The study of institutions--Danger of being misled by metaphors--The questions which should be asked 241