BOOK I
PRELIMINARY STUDIES
CHAPTER I
THE SEARCH FOR DOCUMENTS (HEURISTIC)
The historian works with documents. Documents are the traces which have been left by the thoughts and actions of men of former times. Of these thoughts and actions, however, very few leave any visible traces, and these traces, when there are any, are seldom durable; an accident is enough to efface them. Now every thought and every action that has left no visible traces, or none but what have since disappeared, is lost for history; is as though it had never been. For want of documents the history of immense periods in the past of humanity is destined to remain for ever unknown. For there is no substitute for documents: no documents, no history.
In order to draw legitimate inferences from a document to the fact of which it is the trace, numerous precautions are