Visiting cards, playing cards, business cards, notecards, index cards (even trade cards) all possessed a crucial role in predigital information processing. They were only partially replaced at the start of the twenty-first century by the email signature and other small personalized media—except for the visiting card, which had its heyday from the *Renaissance to the Belle Époque, while the trade card enriched modern marketing campaigns in the second part of the nineteenth century. They both belong to the category of *dead media, however, since invitations to visits or appointments are now initiated by *digital text messages, and advertisements for brands and products have been circulated differently long since. Among others, cards functioned as handheld representatives and manageable paper-based proxies. The early use of notecards and card index boxes, especially, illustrates the card’s importance as an inconspicuous, though indispensable, medium of information processing and knowledge transfer. For centuries, cards were made from paper, which afforded the allegedly modern features of mobility, portability, flexibility, modularity, representativity, transitivity, manageability, updateability, legibility, combinability, and, last but not least, the organization of information in terms of *big data, long lists, and vast amounts of accumulated knowledge. (For a closer examination of those ten properties, see Krajewski, “Cards,” in the further reading section.)
Ever since the Swiss doctor, *polymath, and mountaineer Conrad Gessner (1516–65) recommended the index card as an aid for scholarly and textual production in his Pandectae of 1548, this medium has been set on a unique, albeit often secluded career. The main advantage of discrete cards consists in their mobility, which enables the words and text modules stored on them to be combined and reordered. Although others might have used the technique of cutting up pieces of information on paper so as to (re)arrange them more readily, Gessner’s explicit description and reflection of this process may constitute the earliest account of conveniently generating extensive lists in alphabetical and systematic order. In this sense, Gessner is the inventor of index cards for scholarly purposes, and he marks the beginning of both the history of the card catalog and the thinking with index cards.
Next to mobility, the simple portability of a stack of cards is what makes working with the individual elements incomparably easier, especially in comparison to the difficulty of working with a catalog in book form. As a consequence of portability, a book no longer needs to be present on the shelf—a circumstance that deeply altered the scholarly community’s modus operandi to date. In 1790 Albrecht Kayser, librarian to the German prince of Thurn and Taxis, explained, “For librarians, the second advantage of writing down the titles of all the works on hand in a library on individual slips of paper and then laying these out in alphabetic order is that they can now produce a general-purpose alphabetic catalog whenever and wherever they want. They no longer need to pick up a book itself, and whenever they do need one, they can specify its location at a distant site from their own homes.” In other words, the slip of paper, or notecard, becomes a proxy of the actual text, a procedure that would prove to be extraordinarily practical for information processing and knowledge production. Notecards consequently represent an entire personalized system of symbols consisting of flexible vehicles for signs whose combinatorics serve to produce surprising constellations and to create completely new connections between the cards themselves by pointing to other parts of the card collection. It resembles a deeply interwoven *hyperlink system on a paper basis.
Card catalogs serve mainly two purposes. On the one hand they were installed and curated in libraries since the end of the eighteenth century, where they gathered the book collection in both alphabetical and systematic order. On the other hand, a card catalog is operated by an individual scholar who compiles excerpts, ideas, references to books, data about persons, and notes of any kind. No doubt the task of a library catalog consists in referring to all addresses of available books in as complete and logically consistent an order as is feasible at any given time. Questions to the catalog—whether asked by the mediating librarian or later by readers themselves—customarily comply with this general schematized form: whether and where a text is to be found (author catalog), or which text can be found in the stacks (subject catalog). Thus, the catalog may be expected to be able to answer if the pattern is followed, regardless of how peculiar a query might be. In other words, the library catalog, built on cards, serves as a dynamic, collective search engine. Its data input comes from numerous sources, but it always works in accordance with strictly regulated instructions, so that it can be queried by anyone. Owing to its flexible order it may be always up-to-date. The difference between the collective search engine and the learned box of paper slips lies in the latter’s contingency, and the resulting possibility that queries in one’s own terms can be posed to the arrangement. While a search engine is designed to register everything randomly, the scholar’s machine makes the determination whether or not to record a piece of information, and whether or not to draw a connection from a new entry to an old one. With the aid of these connections, the user succeeds in tracking down new connections following the reference structure of entries, uncovering unintended readings.
On the basis of keywords and short forms, every point of the index card box can refer precisely to another. In contrast to a book with its fixed connections and unchangeable format defaults, every slip of paper represents a finite, extendable information unit, an expandable, elementary piece of information that can easily be cited—for every index card carries an unequivocal address thanks to its position in the set order or in the form of a call number others can refer to. A card always remains a pure reference and a relation to something else: it refers to something beyond itself. This logic also seems to apply in the case of knowledge proxies such as the library: a card catalog simultaneously makes one curious and provides information, occasionally to the extent that consulting the source documented on an index card may seem superfluous. References always refer to something else, be it a keyword on an index card, a catalog entry, books in a library, names on other notecards, absent interlocutors, or overarching structures, all of which get gathered together in bundles of notes. The principle of transitivity or relationality always prevails. Consequently, surprises pop up, thanks to an unexpected reference to aspects not previously considered. Thus, the advantage of the index card box consists not only in its ability to deliver precise answers to specific inquiries, but above all in its infallible ability to remember associations, to say nothing of the value added that is offered by (semi)automatic associative linking. Every input is preserved and retrievable, either as an isolated piece of information or as a building block for a larger line of argument. Equipped with sufficient (material) flexibility, the notecard as a single information carrier can enter into circulation; mixed forms can now be created out of the heterogeneous material recorded on them; and new orders can emerge out of cards that had not previously been located next to each other. Getting involved in constant communication with such a *secondary memory means trusting not only in the fact that the apparatus faithfully returns the stored information—there is also the reliable fact that information successively fed in over time will generate future knowledge.
In the apparatus’s connectivity of preformed elements, it achieves a configuration of potential states of knowledge that are merely actualized by the user at a given time in certain combinations—when they are called up. “The text knows more than its author,” as one of the basic assumptions of *philology has it. One could transfer this statement easily to the relation between constellations of index cards and their users. Text fragments held at the ready by the apparatus in their potential connectivity offer incomparably more connection points than the user is aware of at any given moment. Thus, the interface offers a range of possible connections, and along with them it delivers potentially new lines of argumentation. Storing states of knowledge and (via their contacts with the interface) helping to catalyze future thoughts, index cards know more than their author. One might say that the communication between database and user is purely theoretical, in the etymological sense of the word theoria, “view.” For the arrangements of paper slips allow their user an instant view, an overview of possible constellations or different arguments. The variety of the slips of paper opens a perspective onto different possible considerations at the same time, allowing one to see various mental constellations in their contingency. Theory is nothing else, at least in etymological terms. It is up to the users to commit themselves to a view, to select certain lines of arguments or readings according to scientific practice as the basis of their own textual production.
If modularity depends on the statistical completeness of information, each card must constitute a distinct, self-contained data container with limited storage space. A card is a fundamental unit of meaning. Conrad Gessner made a similar observation in his stipulation that each discrete thought be recorded on a new line, which should then be put on its own slip of paper. This is how information grows—through the accumulation of scattered thoughts and the formation of discrete modules. One of the most well-known examples of this approach can be found in Niklas Luhmann’s theory and in his own note-taking system. Niklas Luhmann (1927–98) was a German sociologist who developed Talcott Parsons’s system theory into a very subtle and all-encompassing theory of society. Less known, though no less efficient, was Johann Jacob Moser, an eighteenth-century figure who, like Luhmann, had been trained as a legal scholar. In both cases, the patchwork system of juridical knowledge seems to favor a card-based organization scheme. What Moser and Luhmann had in common was not only their immense productivity but also their emphasis on the reusability of their note-taking systems. While there has recently been much scholarship on Luhmann’s note-taking system, Moser’s practices remain underappreciated in spite of detailed information about the secret of his productivity. The advantage of a modular notecard, in comparison to an entire notebook consisting of collectanea, is that it can “be used right away, as it is; whereas if collected passages are entered into books, they need to be written down again.” For this reason, modular loose leaves make drafting a new text easier than working with books. Moser’s process is also more conducive to selecting specific information or even concealing it: “If I wish to communicate only one of my collected passages to other people, or to have someone transcribe something without seeing the rest of the material, then I need only take out the sheets I wish to retain. If, on the other hand, the collected passages have been entered into books, then I have to provide the entire volume, or multiple volumes, in which things might be located that I would not want to be made known to just anybody.”
A module is something self-contained, self-enclosed, which can be understood as a unit. Moser also describes, again in detail, his practice of rereading his excerpts, and effortlessly generating a new text out of them. Out of all his notes, Moser would first select only those slips of paper that seemed most auspicious for his present argument and then arrange them according to some specific classification scheme. Next, he would refine the order of the slips of paper for each subpoint and subsequently furnish them with additional marginal notes. With the aid of this outline, Moser would then search through his library for further quotations, references, and new ideas, noting these down on their own slips of paper, which he would combine with the previously selected slips of papers into a new order. After further review, additions, and a round of self-editing, he would finally add a table of contents to this entire bundle, consisting only of little slips of paper, and hand the whole thing over to a printer’s shop, or the censorship board, without expending any further effort on the material. Two things would come back in return—a new book, which would get put back on his bookshelf, and the box containing the old slips of paper, which would get refiled into his note-taking system, allowing the loop to repeat. Thus, Moser’s data stream alternates between two different media: An excerpt from a book turns into a card, which represents a book, which will be turned back into more cards, which will, in turn, become new books.
Ultimately, the historical analysis of index cards and card catalogs is able to bridge the gap between premodern principles of knowledge production and modern modes of data distribution as they (at least partly) fulfill common functions: Both, paper cards and electronic data in specific formats, are unified in their performance as standardized knowledge carriers. Though their specific formats differ—information requires formats—their status as proxies resembles each other as does their ability to accomplish organizational tasks, and finally their main function as placeholders—or rather representatives—that have the potential to create ever new connections—even out of the smallest pieces of information.
Markus Krajewski
See also accounting; bibliography; books; book sales catalogs; databases; documentary authority; excerpting/commonplacing; indexing; inventories; knowledge; notebooks