Book collecting is the bringing together of books which in their contents, their form or the history of the individual copy possess some element of permanent interest, and either actually or prospectively are rare, in the sense of being difficult to procure. This qualification of rarity, which figures much too largely in the popular view of book-collecting, is entirely subordinate to that of interest, for the rarity of a book devoid of interest is a matter of no concern. On the other hand, so long as a book (or anything else) is and appears likely to continue to be easily procurable at any moment, no one has any reason for collecting it. The anticipation that it will always be easily procurable is often unfounded, but, so long as the anticipation exists, it restrains collecting, with the result that horn-books are much rarer than First Folio Shakespeares. It has even been laid down that the ultimate rarity of books varies in the inverse ratio of the number of copies originally printed, and though the generalization is a little sweeping, it is not far from the truth. To triumph over small difficulties being the chief element in games of skill, the different varieties of book-collecting, which offer almost as many varieties of grades of difficulty, make excellent hobbies. But in its essence the pastime of a book-collector is identical with the official work of the curator of a museum, and thus also with one branch of the duties of the librarian of any library of respectable age. In its inception every library is a literary workshop, with more or less of a garden or recreation ground attached according as its managers are influenced by the humanities or by a narrow conception of utility. As the library grows, the books and editions which have been the tools of one generation pass out of use, and it becomes largely a depository or storehouse of a stock, much of which is dead. But from out of this seemingly dead stock preserved at haphazard, critics and antiquaries gradually pick out books which they find to be still alive. Of some of these the interest cannot be reproduced in its entirety by any mere reprint, and it is this salvage which forms the literary museum. Book-collectors are privileged to leap at once to this stage in their relations with books, using the dealers shops and catalogues as depositories from which to pick the books which will best fit with the aim or central idea of their collection.
For in the modern private collection, as in the modern museum, the need for a central idea must be fully recognized. Neither the collector nor the curator can be content to keep a mere curiosity-shop. It is the collector’s business to illustrate his central idea by his choice of examples, by the care with which he describes them and the skill with which they are arranged. In all these matters many amateurs rival, if they do not outstrip, the professional curators and librarians, and not seldom their collections are made with a view to their ultimate transference to public ownership. In any case it is by the zeal of collectors that books which otherwise would have perished from neglect are discovered, cared for and preserved, and those who achieve these results certainly deserve well of the community.