nsult the complete
collection of all these catalogues and their indexes. But Heuristic is
still difficult, because these conditions are, unfortunately, still very
far from being adequately realised.

Firstly, there are depositories of documents (archives, libraries, and
museums) whose contents have never been even partially catalogued, so
that no one knows what is in them. The depositories of which we possess
complete descriptive catalogues are rare; there are many collections
preserved in celebrated institutions which have only been catalogued in
part, and the bulk of which still remains to be described.[32] In the
second place, what a variety there is among existing catalogues! There
are some old ones which do not now correspond to the present
classification of documents, and which cannot be used without
reference-tables; there are new ones which are equally based on obsolete
systems, too detailed or too summary; some are printed, others in
manuscript, on registers or slips; some are carefully executed and
clear, many are scamped, inadequate, and provisional. Taking printed
catalogues alone, it requires a whole apprenticeship to learn to
distinguish, in this enormous mass of confusion, between what is
trustworthy and what is not; in other words, to make any use of them at
all. Lastly, where are the existing catalogues to be consulted? Most of
the great libraries only possess incomplete collections of them; there
is no general guide to them anywhere.

This is a deplorable state of things. In fact, the documents contained
in uncatalogued depositories and collections are practically
non-existent for researchers who have no leisure to work through the
whole of their contents for themselves. We have said before: no
documents, no history. But to have no good descriptive catalogues of
collections of documents means, in practice, to be unable to ascertain
the existence of documents otherwise than by chance. We infer that the
progress of history depends in great measure on the progress of the
general catalogue of historical documents which is still fragmentary and
imperfect. On this point there is general agreement. Pere Bernard de
Montfaucon considered his _Bibliotheca bibliothecarum manuscriptarum
nova_, a collection of library catalogues, as "the most useful and most
interesting work he had produced in his whole life."[33] "In the present
state of science," wrote Renan in 1848,[34] "nothing is wanted more
urgently than a