ABSTRACT
Historians like to think that their work is shaped by some consistent idea of what is important. In practice it has to be admitted that their choice of topics and the methods of dealing with them depend heavily on what sources are available The nature of the evidence that existed and has survived is itself part of the history of a period. But survival is not the only thing that matters. Even the most assiduous writer of scholarly monographs is unlikely to be able to make use of everything that would help. For all but the narrowest topics what is ‘available’ is mainly that part of the relevant material that has been assembled, classified, and indexed. There are taking place at the moment changes – greater than any since the invention of printing – in methods by which we can make use of historical sources. Microphotography and electronic devices for recording, sorting and extracting information may some day make the researcher who ploughs through inadequate indexes and travels with pencil and notebook round collections of archives look as inefficient as the monk copying out a chronicle. But so far we still rely mainly on what the individual worker can find and read. Sources that are printed, in full or in summarized ‘calendars’, are bound to have more influence than others of their kind that are not. Countries and towns where a large proportion of manuscripts can be seen in libraries and record offices get better historical treatment than those with fewer facilities.
