was possible to consult 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. 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