We consider that the entire floating body of documents at large in the world—books, paper ephemera, electronic texts, et al.—constitutes a huge, siteless library.

You are already using this library. You have been using it all your life.

This library is perpetually engaged in an unpredictable, irregular, slow circulation, via the used book trade, the remainder business, and the borrowing and lending, bequeathing and inheriting, stealing, copying, quoting, discussing, plagiarizing and simple mentioning done by ordinary readers. We consider this process not secondary to commercial or scholarly methods of dissemination but in fact the primary way documents are circulated.

Knowledge is widely understood as held in trust for ordinary readers by expert institutions with superior standards, methods of conservation, retrieval systems, and dedication to its preservation. In fact, the slow circulation of books through private collections, the revival and reinvigoration of institutionally overlooked or despised works through the efforts of fans, the accidental preservation of ephemera through carelessness and packrattyness, as well as of other out-of-favor, idiosyncratic, and variously sub-radar texts, all represent a vast and sometimes superior resource.

Experts (variously, librarians, scholars, publishing professionals) are largely seen as the arbiters and guardians of culture. Certainly, market forces, contemporary taste and intellectual fashions largely dictate what can be published, in what quantities it will be sold, and how widely it will circulate in its brief commercial lifespan. However the long-term survival of the vast majority of texts is principally due to inexpert readers, casual collectors, the used book business, and the slow mulching of time.

Ordinary libraries with limited shelf-space and a commitment to contemporary relevance are subject to periodic culls and purges according to values whose relevance is necessarily limited to a particular historical and cultural context. Books that have not been checked out in a given number of years, or attained canonical status, will be withdrawn from the collection and discarded. A few years, however, is a short time compared to the lifespan of a book and the evolving interests of a changing readership. A book that has been out of favor for a century may suddenly prove to be of great interest to a new readership. Fortunately, the books discarded by libraries reenter the slipstream as used books, where they can be resurrected—thanks to the Interstitial Library.

Readers are generally seen (by libraries and publishers alike) as having a specific title, author, or subject in mind; as falling into particular types, with particular needs and tastes. As a result, publishing/marketing aims to fit itself to that particular need or taste, while information retrieval systems aim to make it possible to zero in, with increasing specificity, on a particular book. These approaches require that somebody else have anticipated your need, written, published, preserved and catalogued the book you want, and defined its subject in the way that corresponds to your need. In fact, readers are often hoping to find out something they don't yet know, experience something they have not yet experienced.

Browsing and other accident-based encounters with books must be redefined as a primary, not marginal method of "information retrieval."

Again: What we need is not to get what we're looking for, but what we don't know we're looking for.

Consequently, waste, excess, accident are crucial "collection-refining" techniques. Misshelving leads to serendipitous discoveries. Indiscriminate hoarding leads to preservation of books with qualities to which the present day may be blind. In the Interstitial Library, information will circulate unpredictably, disappearing and reappearing, rather than being located in a centralized, stable place.

However, the Interstitial Library embraces all consequences of the circulation of books, including their decay and eventual disappearance. Literature is too often regarded as possessing value only in so far as it is (or seems) immortal. But books too have bodies; books too die. We believe that their vulnerability to change is not their failure but essential to their being in the world.

The traditional library has a transcendental aspect, both as the representative of official authority and as the material embodiment of of an ideal, eternal archive. Our relationship with the Interstitial Library proper evokes this metaphysical structure only to refuse it. The Circulating Collection posits an immanent sublime, a literal and everyday infinity.

In turning our attention away from idealized structures of knowledge and towards our everyday dealings with books, we find ourselves reconsidering the librarian. The librarian is a medium between the transcendental realm of knowledge and the materiality of the book. (So, of course, are the writer and the reader, but the librarian is an often overlooked third intervening in this binary.)

As such the librarian has evolved material practises of peculiar specificity. Theatrical elements include steering carts, climbing rolling ladders, reaching and lifting. shushing, card-drawer opening, file-flicking, stamping, generating library cards, receiving fines, etc. Elements of handcraftsmanship include covering and binding of library books, gluing in book pockets and inserting book cards—a specific practise designed to make books last, which paradoxically damages them so irreparably that for a book to be "ex-lib" is considered, in the rare book business, a severe handicap.

As a group, librarians have features in common with the secret society. Librarians, stereotypically women of a certain age, occupy an unusual position between self-effacement and performance, service and mastery. The piercing Shhh! is symptomatic of this troubled relationship between repression and self expression. The Interstitial Library has drawn forth this element of stealth, refiguring the librarian as dashing secret agent. Her trademark gestures—stamping, shushing, shelving—are in fact the covert signals of a secret society.

We contend that every reader is an amateur librarian, with a mental library organized according to a private cataloguing system that is never identical with that prescribed by the AACR2R (the Anglo-American Cataloguing Rules, Revised). Since every system of organization highlights some kinds of information and obscures others, we contend that these idiosyncratic catalogues have advantages—advantages that could be shared.

We do not consider the "authoritative" taxonomies of the Library of Congress (or Barnes & Noble) to be superior to private ones. We are suspicious of taxonomies that appear self-evident, unbiased, objective. All taxonomies are interpretations. All interpretations are valuations. We ask, how does a given taxonomy, which is always a reduction and a generalization, come to be associated with objective or ideal categories of knowledge? We contend that the question of what matters and what does not is a political and philosophical one that should be open to the input of individual readers.

The catalog of the Circulating Collection is organized by its visitors, who are also its librarians. Over time, it will evolve into a vast alternative system of reference, which will double as a map of the mind of a collective reader. (We expect that this map will converge in unexpected ways with the canon. All books, regarded from a certain angle, are potentially interstitial.)

It would be impossible to catalog all books—all texts, in fact—in circulation. The Interstitial Library’s Circulating Collection aspires to catalog only a portion of this collection. We believe that the "complete" collection pretends to an impossible universality. It obscures not only its gaps, but also its excrescences—those anomalies that put its taxonomies to the test. Instead, we aspire to build an incomplete collection of interstitial books—those books that occupy curatorial blind spots, fall between categories, or are notable for qualities not catalogued in ordinary libraries. We serve those readers who are looking for unusual books, in unusual places, by unusual methods.

We believe, furthermore, that the universalist aspirations of the AACR2R not only imposes an uneasy hegemony of logic on the patrons of libraries, but subtly shepherds publishers, booksellers and even writers toward those books that fit into a preexisting category. In the long run, therefore, we hope to influence not only what books are read, but also what books are written. The Interstitial Library, therefore, not only archives the past. It archives the future.