“What happens when you want to add a new note between notes 1/1 and 1/1a?”
asked at least a dozen times in the Reddit fora related to zettelkasten and note taking, on zettelkasten.de, or in other places across the web.
From a mathematical perspective, these numbering or alpha-numeric systems are, by both intent and design, underpinned by the mathematical idea of dense sets. In the areas of topology and real analysis, one considers a set dense when one can choose a point as close as one likes to any other point. For both library cataloging systems and numbering schemes for ideas in Zettelkasten this means that you can always juxtapose one topic or idea in between any other two.
Part of the beauty of Melvil Dewey’s original Dewey Decimal System is that regardless of how many new topics and subtopics one wants to add to their system, one can always fit another new topic between existing ones ad infinitum.
Going back to the motivating question above, the equivalent question mathematically is “what number is between 0.11 and 0.111?” (Here we’ve converted the artificial “number” “a” to a 1 and removed the punctuation, which doesn’t create any issues and may help clarify the orderings a bit.) The answer is that there is an infinite number of numbers between these!
This is much more explicit by writing these numbers as:
0.110
0.111
Naturally 0.1101 is between them (along with an infinity of others), so one could start here as a means of inserting ideas this way if they liked. One either needs to count up sequentially (0, 1, 2, 3, …) or add additional place values.
The problem most people face is that they’re not thinking of these numbers as decimals, but as natural numbers or integers (or broadly numbers without any decimal portions). Though of course in the realm of real numbers, numbers above 0 are dense as well, but require the use of their decimal portions to remain so.
The tough question is: what sorts of semantic meanings one might attach to their adding of additional place values or their alphabetical characters? This meaning can vary from person to person and system to system, so I won’t delve into it here.
One may find it useful to logically chunk these numbers into groups of three as is often done using commas, periods, slashes, dashes, spaces, or other punctuation. This doesn’t need to mean anything in particular, but may help to make one’s numbers more easily readable as well as usable for filing new ideas. Sometimes these indicators can be confusing in discussion, so if ever in doubt, simply remove them and the general principles mentioned here should still hold.
Depending on one’s note taking system, however, when putting cards into some semblance of a logical, sort-able order (perhaps within a folder for example), the system may choke on additional characters beyond the standard period to designate a decimal number. For example: within Obsidian, if you have a “zettelkasten” folder with lots of numbered and named files within it, you’ll want to give each number the maximum number of decimal places so that when doing an alphabetic sort within the folder, all of the numbered ideas are properly sorted. As an example if you give one file the name “0.510 Mathematics”, another “0.514 Topology” and a third “0.5141 Dense Sets” they may not sort properly unless you give the first two decimal expansions to the ten-thousands place at a minimum. If you changed them to “0.5100 Mathematics” and “0.5140 Topology, then you’re in good shape and the folder will alphabetically sort as you’d expect. Similarly some systems may or may not do well with including alphabetic characters mixed in with numbers.
If using chunked groups of three numbers, one might consider using the number 0.110.001 as the next level of idea between them and then continuing from there. This may help to spread some of the ideas out as surely one may have yet another idea to wedge in between 0.110.000 and 0.110.001?
One can naturally choose almost any any (decimal) number, so long as it is somewhat “near” the original behind which one places it. By going out further in the decimal expansion, one can always place any idea between two others and know that there will be a number that it can be given that will “work”.
Generally within numbers as we use them for mathematics, 0.100000001 is technically “closer” by distance measurement to 0.1 than 0.11, (and by quite a bit!), but somehow when using numbers for zettelkasten purposes, we tend to want to not consider them as decimals, as the Dewey Decimal System does. We also have the tendency to want to keep our numbers as short as possible when writing, so it seems more “natural” to follow 0.11 with 0.111, as it seems like we’re “counting up” rather than “counting down”.
Another subtlety that one sees in numbering systems is the proper or improper use of the whole numbers in front of the decimal portions. For example, in Niklas Luhmann’s system, he has a section of cards that start with 3.XXXX which are close to a section numbered 35.YYYY. This may seem a bit confusing, but he’s doing a bit of mental gymnastics to artificially keep his numbers smaller. What he really means is 3000.XXXX and 3500.YYYY respectively, he’s just truncating the extra zeros. Alternately in a fully “decimal system” one would write these as 0.3000.XXXX and 0.3500.YYYY, where we’ve added additional periods to the numbers to make them easier to read. Using our original example in an analog system, the user may have been using foreshortened indicators for their system and by writing 1/1a, they may have really meant something of the form 001.001/00a, but were making the number shorter in a logical manner (at least to them).
The close observer may have seen Scott Scheper adopt the slightly longer numbers in the thousands (like 3500.YYYY) as a means of remedying some of the numbering confusion many have when looking at Luhmann’s system.
Those who build their systems on top of existing ones like the Dewey Decimal Classification, or the Universal Decimal Classification may wish to keep those broad categories with three to four decimal places at the start and then add their own idea number underneath those levels.
As an example, we can use the numbering for Finsler geometry from the Dewey Decimal Classification wikipedia page shown as:
500 Natural sciences and mathematics
510 Mathematics
516 Geometry
516.3 Analytic geometries
516.37 Metric differential geometries
516.375 Finsler geometry
So in our zettelkasten, we might add our first card on the topic of Finsler geometry as “516.375.001 Definition of Finsler geometry” and continue from there with some interesting theorems and proofs on those topics.
Of course, while this is something one can do doesn’t mean that one should do it. Going too far down the rabbit holes of “official” forms of classification this way can be a massive time wasting exercise as in most private systems, you’re never going to be comparing your individual ideas with the private zettelkasten of others and in practice the sort of standardizing work for classification this way is utterly useless. Beyond this, most personal zettelkasten are unique and idiosyncratic to the user, so for example, my math section labeled 510 may have a lot more overlap with history, anthropology, and sociology hiding within it compared with others who may have all of their mathematics hiding amidst their social sciences section starting with the number 300. One of the benefits of Luhmann’s ad hoc numbering scheme, at least for him, is that it allowed his system to be much more interdisciplinary than using a more complicated Dewey Decimal oriented system which may have dictated moving some of his systems theory work out of his politics area where it may have made more sense to him in addition to being more productive on a personal level.
Of course if you’re using the older sort of commonplacing zettelkasten system that was widely in use before Luhmann’s variation, then perhaps using a Dewey-based system may be helpful to you?
As both a mathematician working in the early days of real analysis and a librarian, I wouldn’t be surprised if some of these loose ideas may have occurred tangentially to Gottfried Wilhelm Leibniz (1646 – 1716), though I’m currently unaware of any specific instances within his work. One must note, however, that some of the earliest work within library card catalogs as we know and use them today stemmed from 1770s Austria where governmental conscription needs overlapped with card cataloging systems (Krajewski, 2011). It’s here that the beginnings of these sorts of numbering systems begin to come into use well before Melvil Dewey’s later work which became much more broadly adopted.
The German “file number” (aktenzeichen) is a unique identification of a file, commonly used in their court system and predecessors as well as file numbers in public administration since at least 1934. We know Niklas Luhmann studied law at the University of Freiburg from 1946 to 1949, when he obtained a law degree, before beginning a career in Lüneburg’s public administration where he stayed in civil service until 1962. Given this fact, it’s very likely that Luhmann had in-depth experience with these sorts of file numbers as location identifiers for files and documents. As a result it’s reasonably likely that a simplified version of these were at least part of the inspiration for his own numbering system. [†] [‡]
At the end of the day, the numbering system you choose needs to work for you within the system you’re using (analog, digital, other). I would generally recommend against using someone else’s numbering system unless it completely makes sense to you and you’re able to quickly and simply add cards to your system with out the extra work and cognitive dissonance about what number you should give it. The more you simplify these small things, the easier and happier you’ll be with your set up in the end.
Krajewski, Markus. Paper Machines: About Cards & Catalogs, 1548-1929. Translated by Peter Krapp. History and Foundations of Information Science. MIT Press, 2011. https://mitpress.mit.edu/books/paper-machines.
Munkres, James R. Topology. 2nd ed. 1975. Reprint, Prentice-Hall, Inc., 1999.
Featured photo by Manson Yim on Unsplash
Coming soon to a theater near you…
In the preface to the novel Penguin Island (L’Île des Pingouins. Calmann-Lévy, 1908) by Nobel prize laureate Anatole France, a scholar is drowned by an avalanche of index cards which formed a gigantic whirlpool streaming out of his card index (Zettelkasten)!
Translation via:
France, Anatole. Penguin Island. Translated by Arthur William Evans. 8th ed. 1908. Reprint, New York, NY, USA: Dodd, Mead & Co., 1922.
Small changes in the translation by me, comprising only adding the word “index” in front of the occurrences of card to better represent the historical idea of fiches used by scholars in the late 1800s and early 1900s, are indicated in brackets.
The walls of the study, the floor, and even the ceiling were loaded with overflowing bundles, paste board boxes swollen beyond measure, boxes in which were compressed an innumerable multitude of small [index] cards covered with writing. I beheld in admiration mingled with terror the cataracts of erudition that threatened to burst forth.
“Master,” said I in feeling tones, “I throw myself upon your kindness and your knowledge, both of which are inexhaustible. Would you consent to guide me in my arduous researches into the origins of Penguin art?”
“Sir,” answered the Master, /“I possess all art, you understand me, all art, on [index] cards classed alphabetically and in order of subjects. I consider it my duty to place at your disposal all that relates to the Penguins. Get on that ladder and take out that box you see above. You will find in it everything you require.”
I tremblingly obeyed. But scarcely had I opened the fatal box than some blue [index] cards escaped from it, and slipping through my fingers, began to rain down.
Almost immediately, acting in sympathy, the neighbouring boxes opened, and there flowed streams of pink, green, and white [index] cards, and by degrees, from all the boxes, differently coloured [index] cards were poured out murmuring like a waterfall on a mountain-side in April. In a minute they covered the floor with a thick layer of paper. Issuing from their in exhaustible reservoirs with a roar that continually grew in force, each second increased the vehemence of their torrential fall. Swamped up to the knees in cards, Fulgence Tapir observed the cataclysm with attentive nose. He recognised its cause and grew pale with fright.
“ What a mass of art! ” he exclaimed.
I called to him and leaned forward to help him mount the ladder which bent under the shower.
It was too late. Overwhelmed, desperate, pitiable, his velvet smoking-cap and his gold-mounted spectacles having fallen from him, he vainly opposed his short arms to the flood which had now mounted to his arm-pits . Suddenly a terrible spurt of [index] cards arose and enveloped him in a gigantic whirlpool. During the space of a second I could see in the gulf the shining skull and little fat hands of the scholar; then it closed up and the deluge kept on pouring over what was silence and immobility. In dread lest I in my turn should be swallowed up ladder and all I made my escape through the topmost pane of the window.
Les murs du cabinet de travail, le plancher, le plafond même portaient des liasses débordantes, des cartons démesurément gonflés, des boîtes où se pressait une multitude innombrable de fiches, et je contemplai avec une admiration mêlée de terreur les cataractes de l’érudition prêtes à se rompre.
—Maître, fis-je d’une voix émue, j’ai recours à votre bonté et à votre savoir, tous deux inépuisables. Ne consentiriez-vous pas à me guider dans mes recherches ardues sur les origines de l’art pingouin?
—Monsieur, me répondit le maître, je possède tout l’art, vous m’entendez, tout l’art sur fiches classées alphabétiquement et par ordre de matières. Je me fais un devoir de mettre à votre disposition ce qui s’y rapporte aux Pingouins. Montez à cette échelle et tirez cette boîte que vous voyez là-haut. Vous y trouverez tout ce dont vous avez besoin.
J’obéis en tremblant. Mais à peine avais-je ouvert la fatale boîte que des fiches bleues s’en échappèrent et, glissant entre mes doigts, commencèrent à pleuvoir. Presque aussitôt, par sympathie, les boîtes voisines s’ouvrirent et il en coula des ruisseaux de fiches roses, vertes et blanches, et de proche en proche, de toutes les boîtes les fiches diversement colorées se répandirent en murmurant comme, en avril, les cascades sur le flanc des montagnes. En une minute elles couvrirent le plancher d’une couche épaisse de papier. Jaillissant de leurs inépuisables réservoirs avec un mugissement sans cesse grossi, elles précipitaient de seconde en seconde leur chute torrentielle. Baigné jusqu’aux genoux, Fulgence Tapir, d’un nez attentif, observait le cataclysme; il en reconnut la cause et pâlit d’épouvante.
—Que d’art! s’écria-t-il.
Je l’appelai, je me penchai pour l’aider à gravir l’échelle qui pliait sous l’averse. Il était trop tard. Maintenant, accablé, désespéré, lamentable, ayant perdu sa calotte de velours et ses lunettes d’or, il opposait en vain ses bras courts au flot qui lui montait jusqu’aux aisselles. Soudain une trombe effroyable de fiches s’éleva, l’enveloppant d’un tourbillon gigantesque. Je vis durant l’espace d’une seconde dans le gouffre le crâne poli du savant et ses petites mains grasses, puis l’abîme se referma, et le déluge se répandit sur le silence et l’immobilité. Menacé moi-même d’être englouti avec mon échelle, je m’enfuis à travers le plus haut carreau de la croisée.
In yesterday’s post on Chris Aldrich’s overview of zettelkasten techniques, I asked about seeing the zettelkasten itself. He replied saying most of the content was in his Hypothesis account, and sent me a pointer to an entry. I read through a bunch of pages on zettelkasten stuff yesterday, ...
Historically, Zettelkasten as used to describe both Luhmann’s notes and his method is patently in the minority compared to the vast prior Zettelkasten tradition, dating back at least to Konrad Gessner in 1548, which could be broadly framed as a commonplace book kept on index cards, usually organized by topic or subject headings and kept in a card index.
If you’ve been watching the tools for thought space, the note taking space, or the productivity spaces over the past several years, you’ve run across the seemingly foreign idea of Zettelkasten if not possibly tried it out for yourself. Surely by now there are several hundred short one page blog posts that make cursory, but excited attempts to describe what a zettelkasten is, how it works, and why you might want one. Aside from the excitement they all share, nearly all of them will mention the now famous example of Nicholas Luhmann’s collection of over 90,000 notes, and his prolific writing output of hundreds of papers and scores of books. Almost all of them will also inevitably make the error, courtesy of the availability heuristic compounded by the lack of appropriate history and context, of stating that Niklas Luhmann invented the idea of Zettelkasten.
However, in the growing amounts of literature about zettelkasten online there is a massive swath of history and knowledge often missing from what could and should be a broader discussion. The so-called “Zettelkasten Method” you hear about in 99% of the cases is specifically the variation of that method practiced by Niklas Luhmann. Historically, however, the idea of a zettelkasten (or slip box) as practiced by the vast majority of people—and there have assuredly been many—from the mid 1500s to now—is really that of the idea of a commonplace book kept using index cards. Some will be organized by subject headings while others won’t. Some of these will have indexes and some won’t. Some, surprisingly, aren’t even kept in boxes.
So what was a Zettelkasten before we were overwhelmed with all the conversation about Niklas Luhmann’s instantiation?
Since antiquity, writers and thinkers have used what has come to be called the commonplace book tradition. They typically collected quotes (sententiae), thoughts, and ideas in books and notebooks for later review and potential reuse in their own writing. From the 8th to the 12th centuries there was a closely related practice of keeping florilegium that was used in Christian settings and particularly popular within the mendicant orders of the Catholic church. These were focused more on religious topics and ideas and were often used for creating sermons as their ultimate output.
In the 16th century, Swiss physician Konrad Gessner (1516 – 1565), building on the commonplace tradition, realized that one’s notes or excerpts might be easier to use if they were cut out of their places on the page and re-arrangeable. Gessner’s method in brief:
- When reading, everything of importance and whatever appears useful should be copied onto a good sheet of paper.
- A new line should be used for every idea.
- “Finally, cut out everything you have copied with a pair of scissors; arrange the slips as you desire, first into larger clusters which can then be subdivided again as often as necessary.”
- As soon as the desired order is produced, arranged, and sorted on tables or in small boxes, it should be fixed or copied directly.
—Gessner, Konrad. Pandectarum sive Partitionum Universalium. 1548. Zurich: Christoph Froschauer. Fol. 19-20 (Tr. Markus Krajewski via Paper Machines) 1
Subsequent note takers and composers eventually realized that, while useful, Gessner’s method could be improved by using “slips of equal size” (thus making it easier to flip through and prevent smaller slips from getting lost) and by indexing them or cross referencing them internally. Because note taking was frequently done on scraps of paper which were often kept in piles by topic, if one didn’t file or properly manage them, they came to be known as “scrap heaps”, a phrase which has linguistically gained the meaning of “trash”, as lack of indexing or coherence made them useless to anyone but their originator.
Indexing of commonplace books became much more common with the publication of John Locke’s Méthode nouvelle de dresser des recueils in Le Clerc’s Bibliothèque universelle vol. 2 (1685) (cf. Catalogue générale des livres imprimés (Paris, Bibliothéque nationale. Département des imprimés) v. 99, col. 192-195) which was translated with Le Clerc’s Observations (Lond., 1697, Lowdnes. v.4, p. 1379-1380) and was posthumously published as the stand alone text A new method of making common-place-books (1706).2
Using cards of equal size became more common following the “invention” of the index card by Carl Linnaeus (1707-1778) who hand cut his own cards used and reused his research materials throughout his career.3 Of course, taking notes on index cards was far easier in the early 20th century with the rise of library card catalogs, the Dewey Decimal System, and Melvil Dewey’s Boston-based company Library Bureau. Mass manufacturing of these cards improved both quality and pricing making it much easier to source one’s own cards. Dewey’s push for profits included expanding his library wares into the business sector, a practice which became more common after his own company adopted a card file-based system for its own office work.
In addition to early popular handbooks on commonplace book methods by Desiderius Erasmus, Rudolph Agricola, and Phillip Melanchthon, which were written for both teachers and students, one can find a growing number of texts which are either dedicated to note taking practices which heavily feature slips of paper or index cards or give them significant discussion. Some of these include:
This brief, but limited collection, shows that there was certainly a long and illustrious note taking tradition using slips or index cards. It doesn’t highlight the fact that often these methods were also handed down from teacher to student, which was also a major mode of transmission and somewhat similar to current messy person-to-person transmission on the internet using examples and conversation on various fora and social platforms.
Of course, the most recent resurgence of these commonplace and older zettelkasten ideas comes to us courtesy of a handful of interesting practitioners who have kept the memory alive as well as helped to push some of them into digital form. A limited selection of some of these include:
While there are thousands upon thousands of practitioners of the commonplace book tradition using the notebook format, there is a smaller less well known set who have used these methods with index cards or other slip-like formats. I’ll present just a handful of some that I’m aware of, but I’m sure that there are thousands upon thousands more.
Niklas Luhmann has, for the last several years, almost entirely defined much of popular culture’s conceptualization of the idea of what a zettelkasten is, when, in fact, he represents only the tiniest tip of the iceberg of a much broader tradition.
Rather than spend our time on rehashing what is already a massive and still growing volume of words, work, and available research on Luhmann’s particular practice, perhaps a more productive question is how his version manages to capture so much mind share? In large part, I attribute it to the fact that the prior tradition has significantly waned from cultural consciousness, making it seem like the idea is new while pitches for Luhmann’s system simultaneously tout it as being almost wholly responsible for Niklas Luhmann’s outsized productivity.
To some extent, our “new” definition (at least in the English language) of a Zettelkasten is driven by a several factors:
Given some of the basic discussion above outlining some of this history will point out a fraction of some of we’ve all been missing. I’ll leave the aphorism “Those who cannot remember the past are condemned to repeat it” here to gild this lily. Hopefully those in the space will look more closely at the well-worn cow paths of analog history in deciding how to pave our (digital) futures. Students looking to improve upon their own practices will hopefully have more examples to examine and use as models.
It bears mention that Vannevar’s influential essay “As We May Think” in the July 1945 issue of The Atlantic is entirely underpinned by the commonplace book and zettelkasten traditions pervading Western thought and culture. Rather than acknowledge this tradition explicitly, he creates the neologism “Memex” which stands in for a networked and connected zettelkasten. Given that his essay appears at the cusp of the waning of these older traditions and that following technologists would not have been as knowledgeable of them, Bush did a massive disservice to the computing field by specifically leaving the earlier words out of his essay. Had he mentioned them, designers and programmers would have had them as more explicit examples to emulate in their work.
Many of our note taking traditions were explicitly taught and learned from either handbooks, transmitted from teacher to student, or from practitioner to practitioner. (We definitely see a lot of this mode online now via blogposts, Twitter, YouTube, and fora (including https://zettelkasten.de, r/zettelkasten, and r/antinet, amongst a slew of productivity writers and influencers who make a living promoting variations of these ideas.) But historically, outside of older phrases like florilegia and commonplace books, there weren’t concrete names or brands for these practices.
Compare the traditional zettelkasten to the ideas of a “card catalog” or a “rolodex”. The card catalog has an immediate definition as a physical object consisting of wooden filing cabinets specifically for index cards containing information about the subjects, titles, and authors of books. The rolodex is now a generic term (like Kleenex is for tissues or Xerox for photocopies) stemming from the company product Rolodex for a previously ubiquitous piece of office furniture. Having both explicit terms for their physical instantiations and their specific uses helped to drive the ubiquity of both compared to the humble, generic card index, which while ubiquitous in physical form in early 20th century offices was never defined explicitly with respect to a specific form of note taking practice. Just as academics in English speaking countries referred to their generic card indexes, those in Germany and France talked about their Zettelkasten and fichier boîte, respectively. The linguistic shift occurs broadly with the transmission of zettelkasten from German into English spheres around the time of the German exhibition “Zettelkästen. Machines of Fantasy” at the Museum of Modern Literature, Marbach am Neckar in 2013 where we begin to equate the physical objects with a particular method. It bears noting that the Marbach exhibition featured a number of very similar Zettelkasten (the physical item consisting of boxes and slips), but with a variety of zettelkasten methods, the majority of which were more similar to each other than the “different” one represented by Luhmann’s.
One can’t help but notice the proliferation of specific method names for slightly different practices within the now growing space. These specific names for practices literally give both a name and power to the space and help to make it grow. Some of these names include: Zettelkasten itself as a name for Luhmann’s method; Smart Notes (Sönke Ahrens’ delineation of Luhmann’s method, Linking Your Thinking (aka LYT, Nick Milo’s method); Building a Second Brain (BaSB, Tiago Forte’s method); ANTInet (Scott P. Scheper’s analog branded version of Luhmann’s method); and even Pile of Index Cards (PoIC, Hawk Sugano’s productivity-based method from 2006). The naming tends to expand here as many of these examples have a commercial need to differentiate these practices to make them sellable to a larger audience. Should one really consider it a coincidence that Obsidian is so heavily used by those in Tiago Forte’s Building a Second Brain camp when Obsidian’s tag line on their home page boldly declares “A second brain, for you, forever.”?
This naming craze even extends to a proliferation of names for note types within each system including fleeting notes, permanent notes, literature notes, atomic notes, evergreen notes, source notes, point notes, concept notes, claim notes, etc. Of course the power of naming begins to wane here as the over-proliferation of names causes semantic collisions and worries when these systems and their adherents talk about related ideas online in broader overlapping publics. One would presume that over time this list of names will settle down and roughly standardize around a much smaller (dare I say atomic?), possibly mutually exclusive set.
The lack of a specific name to distinguish the methods and uses of card indexes from each other in the early 20th century further muddles the picture of their use. How does one specifically differentiate the use of a card index for business versus note taking versus a library card catalogue? The library card catalogue has a both a named object and a method (verb) and is much more easily distinguished than the card index being used for either business or note taking use, and in fact there may have been reasonable overlap of business and note taking use making their distinct uses less clear. As an example, in The Crown season 1 episode 4 “Act of God” (Netflix, 2016) there is a scene portraying former British Prime Minister Clement Atlee in his office in which he is prominently bookended in the background by two four drawer card indexes: one 3 x 5″ and the other 4 x 6″. Are these for general business filing use and document tracking or were they full of ideas from his reading and thinking?
Tangential names exist for practices in the German part of the tradition. For example there is the phrase Wissenschaftliches Arbeiten which translates as “scientific work”. This phrase arises out of Ernst Bernheim’s framing of the zettelkasten practice within his formulation of historical method, or how a professional historian might scientifically approach their work. The phrase not only pops up in the title of the book which likely inspired Niklas Luhmann’s practice, but curiously and even surprisingly, searching on the term within the Internet Archive reveals 106 works, predominantly textbooks in the English language, about research methods, note taking, and writing geared toward masters and Ph.D. students.
The lack of a named method, generally makes finding written examples of these practices in the historical record more difficult as one must search for generic words (index cards, slips, notes) used within the practice rather than specific method words with dramatically higher signal-to-noise ratios.
Knowledge about these note taking practices has almost always been geared toward academic settings and even there it has been primarily geared toward masters and Ph.D. level students who would more profitably use them over extended time horizons for not only their thesis work, but their extended careers. While early manuals on commonplace methods were written for broader student audiences, it’s exceedingly rare to find works written for non-specialist or popular audiences. It’s only within the last decade or so that one finds general note taking advice or practices for knowledge workers or those interested in greater productivity in their work. Advice of the sort and form given by Twyla Tharp or Anne Lamott is the exception rather than the rule.
Beyond the modes of written transmission of these practices and methods which have been geared toward academics, the primary mode of transmission is from either teacher to student or from practitioner to practitioner. This transmission mode is often much “quieter” and ostensibly hidden from historical view without significant work. There are media studies and history scholars who look at the notebooks and records of students and teachers to follow some of these methods, so some of these specific practices may surface over time.
These “manual” transmission modes are “high touch” (requiring a lot of work) and as a result are very slow to diffuse. Quite often they fail to adequately inspire or communicate their immense long term value. In a zettel in his second zettelkasten entitled “Does Spirit hide in the filing cabinet” (literally, though one could translate it as “Is there a Ghost in the machine?”), Niklas Luhmann wrote a note about people disappointed in seeing his system in person: “People come, they see everything [his boxes, slips, and notes] and nothing more than that, just like in porn movies; consequently, they leave disappointed.” 9
In Appendix C of her autobiography, Beatrice Webb found difficulty in explaining the massive value she found in her note taking practice and resorted to telling the reader to trust her experience:
“What is the use of this pedantic method of note-taking, involving masses of paper and a lot of hard thinking, not to mention the shuffling and reshuffling, which is apparently the final cause of this intolerable elaboration?” will be asked by the post-graduate student eager to publish an epoch-making treatise on the History of Government, or, perchance, on the History of Freedom, within the two years he has allotted to the taking of his doctorate. The only answer I can give is to cite our own experience.
My own anecdotal experience of research and note taking with index cards dates to 1985 when, in sixth grade, I was admonished to take my notes on index cards so that I could later string them together in outline form to create a narrative. While this was done with good intentions, there was no indication of doing this as a life-long practice nor was there any discussion of potential long term uses or potential beneficial affordances or effects. To make matters worse, my natural memory for storing ideas for a 3 page essay with only a handful of sources was strong enough that note taking seemed a waste of time. Never anticipating the need to be able to think and write over a lifetime, I filed the idea into the proverbial circular bin. I suspect this is the case for the vast majority students in the latter half of the twentieth century.
These historically hidden transmission modes can be contrasted directly with a more public facing and readily visible transmission mode of these practices which now occurs online. Social media, blogs, online fora and video platforms makes it dramatically easier for individual users to write about and pass along their particular experiences and affordances they find in specific methods, tools, and modes of use.
The hidden value proposition of the older methods can be contrasted with the incessant drumbeat of the value and productivity inherently “promised” by those describing Niklas Luhmann’s system. Look at all the books and papers he wrote in his lifetime! The system explains it all! It’s so simple. You can do this too! Reframed, one could almost visualize Ron Popeil pitching the idea of Luhmann’s zettelkasten and having his audience chant “Set it and forget it!”
The rise of the Zettelkasten as a name for both a specific object and a specific practice (Luhmann’s) in English started roughly in 2007. The first instances come from the work of Manfred Kuehn on note taking with his blog Taking Note starting in 2007 and ending in 2018, though large portions are still fortunately archived on the Internet Archive. He was definitely aware of Niklas Luhmann’s note taking practices and even translated Luhmann’s 1981 article “Kommunikation mit Zettelkästen” into English. This is supplemented on March 4, 2013 with the opening of the Marbach exhibition followed closely by the launch on June 20, 2013 and subsequent growth of the website https://zettelkasten.de begun by Christian Tietze and featuring both a blog as well as a forum for questions and further discussion of the practice. While these started a low brew of Luhmann’s method within the productivity and writing communities in the mid 2010s, things continued to heat up with the release of Sönke Ahrens’ English language book How to Take Smart Notes in 2017. Full boil was reached after 2018 and during the COVID-19 pandemic as a massive swath of note taking applications like Roam Research, Obsidian, and Notion came to the forefront of internet culture which was ostensibly idle enough to need ideas and tools like these to fill their new found free time and distract them from their pandemic worries.
In addition to all these applications, which could be used to implement digital versions of Luhmann’s method, a lot of the hype behind the idea of this particular Zettelkasten Method (again, the one specifically practiced by Luhmann) is driven by the often quoted prolific writing output of Luhmann. It’s as if no one prior to him had been creative or productive within the history of ideas. Surely his output is notable for its size, but he also had more freedom and flexibility by being employed full time as a research professor at a German University where it was both his life-long vocation and avocation to produce this output. Certainly his modification of earlier commonplacing techniques helped him along, but if one looks at the historical record, nearly every famous writer or researcher in the Western tradition had some sort of note taking or commonplace book practice upon which to build. In a handful of cases, we see well known intellectuals of their day writing down some of these ideas and influential methods in handbooks, addenda to other works, or in autobiographies including Erasmus, Agricola, Melanchthon, John Locke, Beatrice Webb, Jacques Barzun, and Umberto Eco.
Of course, there are surely other uses of the term zettelkasten in various places and languages—this is a well known feature of ever-evolving words in active use. One which comes quickly from my old word horde is the current use of zettelkasten within German speaking countries of an office product consisting of a stack of slips of note paper held in a box. There are a variety of these available for sale within the German version of Amazon.
It also bears pointing out that card indexes were used in the early 1900s for a variety of business use functionalities including for accounting, general back office management and file maintenance, as indexes for larger filing systems, as early proto-rolodexes, and what would now be known as customer relationship management purposes.
I’ve made some presumptions about the level of familiarity readers may have with the commonplace book tradition and that of Niklas Luhmann’s practice. It may be helpful for those missing parts of one or both to have some quick resources to fall back on as well as to describe the broad differences.
For the commonplace tradition, I can heartily recommend Earle Havens’ Commonplace Books: A History of Manuscripts and Printed Books from Antiquity to the Twentieth Century (Yale, 2001) short but reasonably wide ranging text as a crash course on the topic. Additionally Colleen Kennedy has an excellent 12 page primer she developed for classroom use on how to actively implement and create one’s own commonplace book which takes into account some of the historical practices seen in the literature.
Broadly, the commonplace book tradition involves excerpting ideas (ars excerpendi), quotes, or writing one’s own ideas into a notebook either pre-broken into topical categories (love, war, civility, productivity, etc.), or indexed after the fact with cross-references to particular pages. In index card or early zettelkasten form, this process is easier as each idea is placed on its own card and placed behind a tabbed card with a single topic heading written on it. As a result, one might have dozens of cards (generally unordered) on the topic of “Hope”, for example, and when writing about that topic, one would ostensibly go to that section of their index, pull out those related cards, sort through them, identify one appropriate for the piece, and insert the relevant idea(s) into their writing. One might thus look at the essays of Montaigne and discern that he’d taken years of reading and excerpting and formed essays around topics in his collection based on his experience and thinking.
While broadly similar, Luhmann’s practice puts far less emphasis on the index portion of the work, but relies on juxtaposing ideas that are close in thought next to each other. This means that he needs a method for both ordering and finding specific cards. He chose a decimal numbering system, which (mathematically) allows for infinite internal branching and growth and was likely based on Melvil Dewey’s system from half a century prior. One could frame his system as building a book in reverse, so he would take an idea, create a single index entry for it, and then number it and place it in his system. Rather than indexing each further related idea, he would visit the index, find that idea and then find the section of related prior cards. He could then install his new idea behind the most closely related idea already in the system. Repeating this thousands and thousands of times creates a complex branching tree structure of inter-related ideas. Once a particular interesting branch becomes large enough, one can reverse the process and turn it into a paper or book. Traversing one’s tree and its branches of knowledge regularly generates not only reminds one of prior knowledge, but also tends to generate new ideas.
While the method is very simple in form, it can generate a great deal of complexity. One will notice that instead of having a single card index tab labeled “Sociology” with thousands of (unordered) cards behind it, as would be likely in the earlier tradition, Luhmann’s index only contains a few links into the idea of sociology from whence things branch out into multiple directions. Thus his index can focus on the more specific to find what he needs rather than the broad. This also allows for greater levels of inter-disciplinarity across ideas which may have otherwise been split into different topic headings.
In the near future, I expect to write out a theory of how Niklas Luhmann may have evolved his practice from the older zettelkasten practice which will surely point out a number of differences in the practices as well as affordances each provides. While we have some indications of where Luhmann’s practice originated historically, it is presently unknown whether he evolved his own practice from the prior or if someone else did that work and communicated the method to him personally and from which he continued to use and evolve it.
For those interested in more specifics on Luhmann’s practice, I might recommend the Getting Started page at zettelkasten.de, the first seven chapters of Dan Allosso and Salvatore Allosso’s book How to Make Notes and Write, or Sönke Ahrens’ book. Looking directly at the digital archive of Luhmann’s zettelkasten can be of immense value. Similarly the digital archives of Jonathan Edwards’ commonplace book (which are known as “the Miscellanies” rather than the traditional commonplace book) and its surrounding research as well as the digitized hybrid notebook/index card version of H. Ross Ashby’s notes can provide some fabulous insight as to how one might structure or use their own notes.
Using some of this history, I’ve previously outlined a progressive zettelkasten method with levels of slowly increasing complexity which may be an easier method for people to immediately begin working towards some creative goal without getting bogged down in the weeds. It combines the older traditions with Luhmann’s traditions to provide the practitioner with a potential formula to determine the level of complexity that may be right for them. Different practices and levels of complexity can be used for different end goals. (Why go “full-Luhmann” when “stacking ammo” is useful enough and fits your lifestyle and goals?)
Other variations of these two broadly different traditions might include keeping a traditionally indexed commonplace slip box with quotes, aphorisms, summaries of others’ ideas, and even fleeting notes in one box while maintaining a more densely linked version of a Luhmannian-based zettelkasten of one’s own best thoughts with refinements in a separate box.
Naturally the methods and instantiations one could arrive at are far richer and potentially more useful and practical if one is aware of more of the possibilities involved in the fuller spectrum of historical practices.
Editor’s note: I wrote this essay of approximately 7,000 words in about half a day’s work, including outlining, footnoting, and editing by drawing material directly from my own hybrid commonplace books/Luhmann-based Zettelkasten.
Allosso, Dan, and S. F. Allosso. How to Make Notes and Write. Minnesota State Pressbooks, 2022. https://minnstate.pressbooks.pub/write/.
Ahrens, Sönke. How to Take Smart Notes: One Simple Technique to Boost Writing, Learning and Thinking – for Students, Academics and Nonfiction Book Writers. Create Space, 2017.
Bernstein, Mark. “Hypertext Gardens: Delightful Vistas.” Hypertext essay. Eastgate Systems, 1998. http://www.eastgate.com/garden/Enter.html.
Bush, Vannevar. “As We May Think.” The Atlantic, July 1, 1945. https://www.theatlantic.com/magazine/archive/1945/07/as-we-may-think/303881/.
Havens, Earle. Commonplace Books: A History of Manuscripts and Printed Books from Antiquity to the Twentieth Century. Beinecke Rare Book and Manuscript Library New Haven, CT, 2001.
Kennedy, Colleen E. “Creating a Commonplace Book (CPB).” Accessed August 31, 2021. https://www.academia.edu/35101285/Creating_a_Commonplace_Book_CPB_.
Lamott, Anne. Bird by Bird: Some Instructions on Writing and Life. 25th Anniversary. 1994. Reprint, Anchor, 1995. https://www.penguinrandomhouse.com/books/97395/bird-by-bird-by-anne-lamott/.
Luhmann, Niklas. “Kommunikation mit Zettelkästen.” In Öffentliche Meinung und sozialer Wandel / Public Opinion and Social Change, edited by Horst Baier, Hans Mathias Kepplinger, and Kurt Reumann, 222–28. Wiesbaden: VS Verlag für Sozialwissenschaften, 1981. https://doi.org/10.1007/978-3-322-87749-9_19. – Luhmann, Niklas. “Communicating with Slip Boxes: An Empirical Account.” Translated by Manfred Keuhn. kuehnm on scriptogr.am, December 6, 2014. https://web.archive.org/web/20150825031821/http://scriptogr.am/kuehnm.
Tharp, Twyla. The Creative Habit: Learn It and Use It for Life. Simon & Schuster, 2006. https://www.simonandschuster.com/books/The-Creative-Habit/Twyla-Tharp/9780743235273.
Deniz Cem Önduygu (denizcemonduygu.com)A summary of the history of philosophy showing the positive/negative connections between ideas
Interestingly it has not only a spatial interface and shows spatial relationships between people and ideas over time using a timeline, but it also indicates—using colored links—the ideas of disagreement/contrast/refutation and agreement/similarity/expansion.
What other (digital) tools of thought provide these sorts of visualization affordances?
Here’s a surprisingly useful thinking tool for anybody interested in the history of Western philosophy: a sort of garden of forking paths of argument. https://t.co/AH1ophVXH8
— Daniel Dennett (@danieldennett) October 9, 2018
After some research, I landed on the Stockroom+ Grid Ruled Index Cards (4×6 Inches, White, 300 Pack), which I purchased for $12.99 from Amazon.
This is a great quality index card for one of the best prices/values for this size and grid ruling.
It’s a noticeably thicker index card stock compared to most (~0.0106″ compared to Oxford’s 0.0072″ or Amazon Basic’s 0.0078″). Most of my pens and pencils weren’t visible through the Stockroom+ card even when held up to a standard room light, something which I couldn’t say about the thinner Oxford or Amazon cards. Only a thick Sharpie pen was slightly visible held up to a light, but none of them came remotely close to bleeding through. These cards write smoothly and take fountain pen ink well without any feathering.
The grid is 1/4″ and printed on both sides. The lines are a light grey which doesn’t overwhelm black ink lines in the 0.4-0.5mm range. The printed grid is also very standard from card to card, so if you need to line the patterns up or are OCD, you’re not going to have problems. The second line down matches up well with the top red lines on most other standard index cards.
I got mine for about $0.043/per card, so it’s a fantastic value.
I can’t wait to use them more and expect them to hold up incredibly well over time. This should be useful given that some of the math, engineering, and science topics I’ll use them for are some of the more well-traveled pathways in my slip box.
Have you used 4 x 6″ grid index cards that you like? I’d be curious to hear comparisons.
Gotthard Deutsch (1859–1921) taught at Hebrew Union College in Cincinnati from 1891 until his death, where he produced a card index of 70,000 ‘facts’ of Jewish history. This article explores the biography of this artefact of research and poses the following question: Does Deutsch’s index constitute a great unwritten work of history, as some have claimed, or are the cards ultimately useless ‘chips from his workshop’? It may seem a curious relic of positivistic history, but closer examination allows us to interrogate the materiality of scholarly labor. The catalogue constitutes a total archive and highlights memory’s multiple registers, as both a prosthesis for personal recall and a symbol of a ‘human encyclopedia’. The article argues that this mostly forgotten scholar’s work had surprising repercussions: Deutsch’s student Jacob Rader Marcus (1896–1995) brought his teacher’s emphasis on facticity to the field of American Jewish history that he pioneered, catapulting a 19th-century positivism to the threshold of the 21st century. Deutsch’s index was at an inflection point of knowledge production, created as historians were shifting away from ‘facts’ but just before new technologies (also based on cards) enabled ‘big data’ on a larger scale. The article thus excavates a vision of monumentality but proposes we look past these objects as monuments to ‘heroic’ scholarship. Indeed, Deutsch’s index is massive but middling, especially when placed alongside those of Niklas Luhmann, Paul Otlet, or Gershom Scholem. It thus presents a necessary corrective to anointing such indexes as predecessors to the Internet and big data because we must keep their problematic positivism in perspective.
Brodart is a library services company based in Pennsylvania that supplies materials to institutional libraries that still has a variety of supplies not only for libraries and book lovers alike, but for amateur and professional zettelmacher(in) as well.
Most of their focus is on 3-by-5 inch index card sized material, but maybe with the re-popularization, they might add more support for the 4-by-6 inch card enthusiasts?
Perhaps if the demand for these older systems goes up, they’ll not only have more offerings, but the price will come down through economies of scale?
Let’s look at what they’ve got available.
On the card side, they’ve got a variety of options that aren’t as readily available at most office supply stores. If you’ve got an old school library card catalog with rods, you’re probably going to want cards with holes pre-punched. Of course they’ve got them in colors as well as without holes too.
With a sizeable card collection you’re likely to want some card guides, so they offer the traditional A-Z 1/5 Cut Card Guides as well as Blank Catalog Card Guides, with those holes pre-punched for convenience.
Dewey Decimal Catalog Card Guides
Most may already have an indexing system built into their system, but if you don’t and want to go with a classic Dewey Decimal set up, they’ve got you covered.
Perhaps you’ve got a sizeable digital card collection already, and have been jonesing to make the jump to analog? They’ve got printable card sheets so you can print out your digital cards relatively easily and continue without losing all that work. Or maybe you’re the mid century/ Umberto Eco purist who wants typewritten cards, but don’t want to retype them all? They’ve got both 4-up and 3-up versions as well.
Let’s say you’ve got a long standing practice of making bibliographic cards. You need some cards to hold not only your meta data about the materials you’re reading, but you want to add your fleeting notes to them the way Luhmann and others have. Brodart has a wide variety of pre-printed cards that could serve this purpose. Some have printed sections which say “Date Loaned” and “Borrowers’s Name”, with sections for data below, but these could just as easily stand for page number and lined space for your important notes.
Brodart White Book Cards with Author, Title, Date Loaned, and Borrower’s Name
There are also a number of other versions of this sort of card depending on what you want. Try these or search for the many others which may suit your fancy:
Maybe you haven’t made that slip box purchase yet, but want something shiny and new? Brodart has you covered here as well. They’ve got a few different options for a small desktop slip box or a fully modular system that you can add to over time.
Brodart has at least two desktop boxes, with 12 and 9 drawers respectively.
Want to design your own system that’s expandable with your card collection? They’ve got a five drawer wide system with options for 1, 2, or 3 row tall sections that you can build up to suit your needs. Start with their table and legs, add a one or more sections of card files, and then top it off with a cover. If you’d like, they’ve also got an interstitial piece with drawer pulls so that you’ve got a writing surface built into your zettelkasten. Build that system up to your ceiling!
Brodart is a bit thin on the 4-by-6 inch category, but for the beginning zettelmacher(in), they do have some nice sized, portable, archive quality boxes you might like to start your collection. See their Postcard Boxes.
Of course there are lots of other options in the space. Some of these box systems can become pretty expensive, and for the price you might be as well off purchasing a used card catalog which you can restore or you can find restored ones online. Some of them even go to the level of fine furniture and can quickly go for over $5,000.00.
If you prefer the vintage 20 gauge steel esthetic (you know I do!), you can find lots of used, but still great condition slip boxes online in places like eBay or on Craigslist.
I and others have written some advice about other card storage options on a Reddit community targeted at analog zettelkasten in the past.
What do you use? What do you want to use? Are you going to custom build your own? Have you seen other companies like Brodart that still support the manufacturing of these sorts of tools for thought? Please share your ideas and supplies below.
Originally published in French in 1897 as Introduction aux études historiques and then translated into English by George Godfrey Berry, Henry Holt and Company published Introduction to the Study of History in 1898 by authors Charles Victor Langlois and Charles Seignobos. Along with Ernst Bernheim’s popular Lehrbuch der historischen Methode mit Nachweis der wichtigsten Quellen und Hülfsmittelzum Studium der Geschichte (Leipzig: Duncker & Humblot, 1889), Langlois and Seignobos’ text is one of the first comprehensive manuals discussing the use of scientific techniques in historical research.
Primarily written by Seignobos, Book II, Chapter IV “Critical Classification of Sources” has several sections on the zettelkasten method under the section headings:
- Importance of classification—The first impulse wrong—Thenote-book system not the best—Nor the ledger-system—Nor the “system” of trusting the memory
- The system of slips the best—Its drawbacks—Means ofobviating them—The advantage of good “private librarian-ship”
This section describes a slip method for taking notes which is ostensibly a commonplace book method done using slips of paper (fiches in the original French) instead of notebooks. Their method undergirds portions of the historical method they lay out in the remainder of the book. Seignobos calls the notebook method “utterly wrong” and indicates that similar methods have been “universally condemned” by librarians as a means of storing and maintaining knowledge. Entertainingly he calls the idea of attempting to remember one’s knowledge using pure memory a “barbarous method”.
The slip method is so ubiquitous by the time of his writing in 1897 that he says “Every one admits nowadays that it is advisable to collect materials on separate cards or slips of paper.”
The book broadly outlines the note taking process:
The notes from each document are entered upon a loose leaf furnished with the precisest possible indications of origin. The advantages of this artifice are obvious : the detachability of the slips enables us to group them at will in a host of different combinations ; if necessary, to change their places : it is easy to bring texts of the same kind together, and to incorporate additions, as they are acquired, in the interior of the groups to which they belong. As for documents which are interesting from several points of view, and which ought to appear in several groups, it is sufficient to enter them several times over on different slips ; or they may be represented, as often as may be required, on reference-slips.
Seignobos further advises, as was generally common, “to use slips of uniform size and tough material” though he subtly added the management and productivity advice “to arrange them at the earliest opportunity in covers or drawers or otherwise.”
In terms of the form of notes, he says
But it will always be well to cultivate the mechanical habits of which professional compilers have learnt the value by experience: to write at the head of every slip its date, if there is occasion for it, and a heading in any case; to multiply cross-references and indices; to keep a record, on a separate set of slips, of all the sources utilised, in order to avoid the danger of having to work a second time through materials already dealt with.
Where the Luhmann fans will see a major diversion for the system compared to his internal branching system is in its organization. They describe a handful of potential organizations based on the types of notes and their potential uses, though many of these use cases specific to historical research are now better effected by databases and spreadsheets. As for the broader classes of more traditional literature-based textual notes, they recommend grouping the slips in alphabetical order of the words chosen as subject headings. Here, even in a French text translated to English, the German word Schlagwörter is used. It can be translated as “headwords”, “catchwords” or “topical headings” though modern note takers, particularly in digital contexts, may be more comfortable with the translation “tags”.
While there are descriptions of cross-linking or cross-referencing cards from one to another, there is no use of alpha-numeric identifiers or direct juxtaposition of ideas on cards as was practiced by Luhmann.
The authors specifically credit Ernst Bernheim’s Lehrbuch der historischen Methode several times in the book. While a lot of the credit is geared toward their broader topic of historical method, Bernheim provides a description of note taking very similar to their method. I’ve found several copies of Bernheim’s text in German, but have yet to find any English translations.
Both Bernheim and Langlois/Seignobos’ work were influential enough in the areas of history specifically and the humanities in general that Beatrice Webb (an influential English sociologist, economist, socialist, labour historian, and social reformer who was a co-founder of the London School of Economics, the Fabian Society, and The New Statesman) cites their work in Appendix C “The Art of Note-Taking” in her 1926 autobiographical work My Apprenticeship, which was incredibly popular and went through multiple reprintings in the nearly full century since its issue. Her personal use of this note taking method would appear to pre-date both books (certainly the Langlois/Seignobos text), however, attesting to its ubiquity in the late 1800s.
Scott Scheper has recently written that personal communication with Luhmann’s youngest son Clemmens Luhmann indicated that Luhmann learned his method in 1951 from the Johannes Erich Heyde text Technik des wissenschaftlichen Arbeitens (with several German editions from 1931 onward). This book’s note taking method is broadly similar to that of the long held commonplace book maintained on index cards as seen in both Langlois/Seignobos (1897) and Webb (1926). One of the few major differences in Heyde was the suggestion to actively make and file multiple copies of the same card under different topical headings potentially using carbon copy paper to speed up the process. While it’s possible that Luhmann may have either learned the modifications of his particular system from someone or modified it himself, it is reasonably obvious that there is a much longer standing tradition as early as Konrad Gessner in 1548 to the middle of the 20th century of a zettelkasten tradition that is more similar to the commonplace book tradition effectuated with index cards (or slips “of a similar size”). Luhmann’s system, while seemingly more popular and talked about since roughly 2013, is by far the exception rather than the rule within the broader history of the “zettelkasten method”. With these facts in mind, we should be talking about a simpler, historical zettelkasten method and a separate, more complex/emergent Luhmann method.
