Thomas Harrison invented a wooden filing cabinet in the 1640's for storing slips of paper. Each slip could be hooked onto tin plates which contained the topical or subject headings that were arranged in alphabetical order.

Harrison's description was anonymously published with corrections and improvements by Vincent Placcius in De arte excerpendi. Vom gelehrten Buchhalten liber singularis (Stockholm/Hamburg, 1689), 124–59, in his hand-book on excerpting systems.

Update 2024-03-18: The 1740s reference here must be a misprint and is perhaps 1640s as Harrison was a 17th century person and Placcius published results in 1689.

example of a note from King's zettelkasten

reply to m_t_rv_s__n/ at https://www.reddit.com/r/Zettelkasten/comments/164n6qg/is_this_overkill/

First, your system is historically far more traditional than Luhmann's more specific practice. See: https://boffosocko.com/2022/10/22/the-two-definitions-of-zettelkasten/

If you're taking all the notes/highlights from a particular book and keeping them in a single file, then it may be far quicker and more productive to do some high level tagging on the entire book/file itself and then relying on and using basic text search to find particular passages you might use at a later date.

Spending time reviewing over all of your notes and tagging/indexing them individually may be beneficial for some basic review work. But this should be balanced out with your long term needs. If your area is "sociology", for example, and you tag every single idea related to the topic of sociology with #sociology, then it will cease to have any value you to you when you search for it and find thousands of disconnected notes you will need to sift through. Compare this with Luhmann's ZK which only had a few index entries under "sociology". A better long term productive practice, and one which Luhmann used, is indexing one or two key words when he started in a new area and then "tagging" each new idea in that branch or train of though with links to other neighboring ideas. If you forget a particular note, you can search your index for a keyword and know you'll find that idea you need somewhere nearby. Scanning through the neighborhood of notes you find will provide a useful reminder of what you'd been working on and allow you to continue your work in that space or link new things as appropriate.

If it helps to reframe the long term scaling problem of over-tagging, think of a link from one idea to another as the most specific tag you can put on an idea. To put this important idea into context, if you do a Google search for "tagging" you'll find 240,000,000 results! If you do a search for the entirety of the first sentence in this paragraph, you'll likely only find one very good and very specific result, and the things which are linked to it are going to have tremendous specific value to you by comparison.

Perhaps the better portions of your time while reviewing notes would be taking the 150 highlights and finding the three to five most important, useful, and (importantly) reusable ones to write out in your own words and begin expanding upon and linking? These are the excerpts you'll want to spend more time on and tag/index for future use rather than the other hundreds. Over time, you may eventually realize that the hundreds are far less useful than the handful (in management spaces this philosophy is known as the Pareto principle), so spending a lot of make work time on them is less beneficial for whatever end goals you may have. (The make work portions are often the number one reason I see people abandoning these practices because they feel overwhelmed working on raw administrivia instead of building something useful and interesting to themselves.) Naturally though, you'll still have those hundreds sitting around in a file if you need to search, review, or use them. You won't have lost them by not working on them, but more importantly you'll have gained loads of extra time to work on the more important pieces. You should notice that the time you save and the value you create will compound over time.

And as ever, play around with these to see if they work for you and your specific needs. Some may be good and others bad—it will depend on your needs and your goals. Practice, experiment, have fun.

Topical headings in Phyllis Diller's gag file

Some of the topical headings in Phyllis Diller's gag file

Phyllis Diller's gag file was arranged alphabetically by subject and ranged from "accessories" to "world affairs".

According to Jacques Barzun (and possibly written in the volumes itself), while the Syntopicon has 102 ideas, there are "some three thousand subheadings."

Joan Rivers card index of jokes is categorized by topical headings like "Parents hated me", "Las Vegas", and "No sex appeal". The largest subject category in her collection was "Tramp" with 1,756 jokes.

quote by Journey Gunderson, the executive director of the National Comedy Center

Zettelkasten - How Categories Emerge by Nicolas Gatien

Gatien uses Scheper's suggested top level categories, but shows that it doesn't take long for things to end up in dramatically disparate areas. As a result, why bother with a pre-defined set of categories in the first place?

https://www.youtube.com/watch?v=tdHH3YjOnZE

Luhmann indicates that there are different methods for keeping note collections and specifically mentions categorizing things by topics first. It's only after this that he mentions his own "open" system as being a possible or successful one.

Q: Can I use a card index for note taking?

ChatGPT does a reasonable bit of advice on how one would use a card index for note taking.

http://www.pearltrees.com/barockschloss/knowledge-management-germany/id12863560

Knowledge Management in Germany by Barockschloss

Example of someone using the social bookmarking application Pearltrees as a form of digital zettelkasten. They've created a collection of cards about zettelkasten.

The fact that Luhmann changed the structure of his zettelkasten with respect to the longer history of note taking and note accumulation allowed him several useful affordances.

In older commonplacing and slip box methods, one would often store their notes by topic category or perhaps by project. This mean that after collection one had to do additional work of laying them out into some sort of outline to create arguments and then write them out for publication. This also meant that one was faced with the problem of multiple storage or copying out notes multiple times to file under various different subject headings.

Luhmann overcame both of these problems by eliminating categories and placing ideas closest to their most relevant neighbor and numbering them in a branching fashion. Doing this front loads some of the thinking and outlining work which would often be done later, though it's likely easier to do when one has the fullest context of a note after they've made it when it is still freshest in their mind. It also means that each note is linked to at least one other note in the system. This helps notes from being lost and allows a simpler indexing structure whereby one only needs to use a few index entries to get close to the neighborhood of an idea as most other related ideas are likely to be nearby within a handful or more of index cards.

Going from index to branches on the tree is relatively easy and also serves the function of reminding one of interesting prior reading and ideas as one either searches for specific notes or searches for placing future notes.

When it comes to ultimately producing papers, one's notes already have a pre-arranged sort of outline which can then be more easily copied over for publication, though one can certainly still use other cross-links and further rearranging if one wishes.

Older methods focused on broad accretion of materials into subject ordered piles while Luhmann's practice not only aggregated them, but slowly and assuredly grew them into more orderly trains of thought as he collected.

Link to: The description in Technik des wissenschaftlichen Arbeitens (section 1.2 Die Kartei) at https://hypothes.is/a/-qiwyiNbEe2yPmPOIojH1g which heavily highlights all the downsides, though it doesn't frame them that way.

an elegant little statement

Categorizing ideas (and or indexing them for search) can be useful for quick bulk storage, but the additional work of linking ideas to each other with in a Luhmann-esque zettelkasten can be more useful in the long term in developing ideas.

Storage by category means that ideas aren't immediately developed explicitly, but it means that that work is pushed until some later time at which the connections must be made to turn them into longer works (articles, papers, essays, books, etc.)

As humans we're good at separating things based on categories. The Dewey Decimal System systematically separates mathematics and history into disparate locations, but your zettelkasten shouldn't force this by overthinking categories. Perhaps the overlap of math and history is exactly the interdisciplinary topic you're working toward? If this is the case, just put cards into the slip box closest to their nearest related intellectual neighbor—and by this I mean nearest related to you, not to Melvil Dewey or anyone else. Over time, through growth and branching, ideas will fill in the interstitial spaces and neighboring ideas will slowly percolate and intermix. Your interests will slowly emerge into various bunches of cards in your box. Things you may have thought were important can separate away and end up on sparse branches while other areas flourish.

If you make the (false) choice to separate math and history into different "sections" it will be much harder for them to grow and intertwine in an organic and truly disciplinary way. Universities have done this sort of separation for hundreds of years and as a result, their engineering faculty can be buildings or even entire campuses away from their medical faculty who now want to work together in new interdisciplinary ways. This creates a physical barrier to more efficient and productive innovation and creativity. It's your zettelkasten, so put those ideas right next to each other from the start so they can do the work of serendipity and surprise for you. Do not artificially separate your favorite ideas. Let them mix and mingle and see what comes out of them.

If you feel the need to categorize and separate them in such a surgical fashion, then let your index be the place where this happens. This is what indices are for! Put the locations into the index to create the semantic separation. Math related material gets indexed under "M" and history under "H". Now those ideas can be mixed up in your box, but they're still findable. DO NOT USE OR CONSIDER YOUR NUMBERS AS TOPICAL HEADINGS!!! Don't make the fatal mistake of thinking this. The numbers are just that, numbers. They are there solely for you to be able to easily find the geographic location of individual cards quickly or perhaps recreate an order if you remove and mix a bunch for fun or (heaven forfend) accidentally tip your box out onto the floor. Each part has of the system has its job: the numbers allow you to find things where you expect them to be and the index does the work of tracking and separating topics if you need that.

The broader zettelkasten, tools for thought, and creativity community does a terrible job of explaining the "why" portion of what is going on here with respect to Luhmann's set up. Your zettelkasten is a crucible of ideas placed in juxtaposition with each other. Traversing through them and allowing them to collide in interesting and random ways is part of what will create a pre-programmed serendipity, surprise, and combinatorial creativity for your ideas. They help you to become more fruitful, inventive, and creative.

Broadly the same thing is happening with respect to the structure of commonplace books. There one needs to do more work of randomly reading through and revisiting portions to cause the work or serendipity and admixture, but the end results are roughly the same. With the zettelkasten, it's a bit easier for your favorite ideas to accumulate into one place (or neighborhood) for easier growth because you can move them around and juxtapose them as you add them rather than traversing from page 57 in one notebook to page 532 in another.

If you use your numbers as topical or category headings you'll artificially create dreadful neighborhoods for your ideas to live in. You want a diversity of ideas mixing together to create new ideas. To get a sense of this visually, play the game Parable of the Polygons in which one categorizes and separates (or doesn't) triangles and squares. The game created by Vi Hart and Nicky Case based on the research of Thomas Schelling provides a solid example of the sort of statistical mechanics going on with ideas in your zettelkasten when they're categorized rigidly. If you rigidly categorize ideas and separate them, you'll drastically minimize the chance of creating the sort of useful serendipity of intermixed and innovative ideas.

It's much harder to know what happens when you mix anthropology with complexity theory if they're in separate parts of your mental library, but if those are the things that get you going, then definitely put them right next to each other in your slip box. See what happens. If they're interesting and useful, they've got explicit numerical locators and are cross referenced in your index, so they're unlikely to get lost. Be experimental occasionally. Don't put that card on Henry David Thoreau in the section on writers, nature, or Concord, Massachusetts if those aren't interesting to you. Besides everyone has already done that. Instead put him next to your work on innovation and pencils because it's much easier to become a writer, philosopher, and intellectual when your family's successful pencil manufacturing business can pay for you to attend Harvard and your house is always full of writing instruments from a young age. Now you've got something interesting and creative. (And if you must, you can always link the card numerically to the other transcendentalists across the way.)

In case they didn't hear it in the back, I'll shout it again: ACTIVELY WORK AGAINST YOUR NATURAL URGE TO USE YOUR ZETTELKASTEN NUMBERS AS TOPICAL HEADINGS!!!

Oppenheimer doesn't keep track of specific cards (he didn't discuss how he files them, other than loosely together, potentially for specific projects) and finds that this creates a greater amount of surprise for him when searching for ideas within his system.

Missing here is any sort of topic or subject headings.... double check this as it's a key to most systems.

that he used it little in later years. His author-title entries usually went into the main file, after the appropriate subject index cards.

This is a curious pattern and not often seen. Apparently it was Paxson's practice to place his author-title entries into his main file following the related subject index cards instead of in a completely separate bibliographical file. He did apparently have one comprised of six scantily filled drawers which he kept in his coat closet, but it was little used in his later years.

What benefits might this relay? It certainly more directly relates the sources closer in physical proximity within one's collection to the notes to which they relate. This might be of particular beneficial use in a topical system where all of one's notes relating to a particular subject are close physically rather than being linked or cross referenced as they were in Luhmann's example.

A particular color of cards may help in this regard to more easily find these sources.

Also keep in mind that Paxson's system was topical-chronological, so there may also be reasons for doing this that fit into his chronological scheme. Was he filing them in sections so that the publication dates of the sources fit into this scheme as well? This may take direct review to better known and understand his practice.

Frederic L. Paxson kept a collection of 3 x 5 " slips of thin paper that filled eighty wooden file drawers which he organized using topical-chronologic headings spanning 4639 BCE to 1949.

Lustig provides a description of some of the order of Gotthard Deutsch's zettelkasten. Most of it seemed to have been organized by chronological, geographical and thematic means, but often there was chaos. This could be indicative of many things including broad organization levels, but through active use, he may have sorted and resorted cards as needs required. Upon replacing cards he may not have defaulted to some specific order relying on the broad levels and knowing what state he had left things last. Though regular use, this wouldn't concern an individual the way it might concern outsiders who may not understand the basic orderings (as did Lustig) or be able to discern and find things as quickly as he may have been able to.

related, but not drawn from as I've been thinking about the continuum of taxonomies and subject headings for a while...

On the Spectrum of Topic Headings in note making

Any reasonable note one may take will likely have a hierarchical chain of tags/subject headings/keywords going from the broad to the very specific. One might start out with something broad like "humanities" (as opposed to science), and proceed into "history", "anthropology", "biological anthropology", "evolution", and even more specific. At the bottom of the chain is the specific atomic idea on the card itself. Each of the subject headings helps to situate the idea and provide the context in which it sits, but how useful within a note taking system is having one or more of these tags on it? What about overlaps with other broader subjects (one will note that "evolution" might also sit under "science" / "biology" as well), but that note may have a different tone and perspective than the prior one.

This becomes an interesting problem or issue as one explores ideas in a pre-designed note taking system. As a student just beginning to explore anthropology, one may tag hundreds of notes with anthropology to the point that the meaning of the tag is so diluted that a search of the index becomes useless as there's too much to sort through underneath it. But as one continues their studies in the topic further branches and sub headings will appear to better differentiate the ideas. This process will continue as the space further differentiates. Of course one may continue their research into areas that don't have a specific subject heading until they accumulate enough ideas within that space. (Take for example Daniel Kahneman and Amos Tversky's work which is now known under the heading of Behavioral Economics, a subject which broadly didn't exist before their work.) The note taker might also leverage this idea as they tag their own work as specifically as they might so as not to pollute their system as it grows without bound (or at least to the end of their lifetime).

The design of one's note taking system should take these eventualities into account and more easily allow the user to start out broad, but slowly hone in on direct specificity.

Some of this principle of atomicity of ideas and the growth from broad to specific can be seen in Luhmann's zettelkasten (especially ZK II) which starts out fairly broad and branches into the more specific. The index reflects this as well and each index heading ideally points to the most specific sub-card which begins the discussion of that particular topic.

Perhaps it was this narrowing of specificity which encouraged Luhmann to start ZKII after years of building ZKII which had a broader variety of topics?

This discussion seems to miss the broader intellectual historical background of tags in prior generations. There's not even a nod to commonplaces, topic headings, subject headings, indices, etc.

following the commonplace tradition, the keyword gets pride of place...

Watch here the word "address" and double check the original German word in translation. What was it originally? Seems a tad odd to hear "address" applied to a keyword which is likely to be just one of many. How to keep them all straight?

A specific reference to the commonplace book tradition and in particular the practice of segmenting note books into pre-defined segments with particular topic headings. This practice described here also ignores the practice of keeping an index (either in a separate notebook or in the front/back of the notebook as was more common after John Locke's treatise)

What are the potential different affordances allowed by giving cards titles versus giving them topic keywords or other taxonomic links?

Card titles may be useful in analog settings, but they can be even more valuable in digital settings where one can transclude "cards" (read: ideas) into outlines.

Both of these two patterns have some similarities. Is Allosso differentiating between them? As his notes don't seem to have titles otherwise, one would presume that he's solely referring to topic categories.

Forte frames things primarily from a digital perspective so he talks about folders and tags, but seems to wholly forget the grand power of having an subject index. While they're broadly the same, it's as if he's forgoing two thousand years of rhetorical tradition to have something that seems new and innovative, but which are paths that are incredibly well travelled.

Most people born since the advent of the filing cabinet and the computer have spent a lifetime using a hierarchical folder-based mental model for their knowledge. For greater value and efficiency one needs to get away from this model and move toward linking individual ideas together in ways that they can more easily be re-used.

To accomplish this many people use an index-based method that uses topical or subject headings which can be useful. However after even a few years of utilizing a generic tag (science for example) it may become overwhelmed and generally useless in a broad search. Even switching to narrower sub-headings (physics, biology, chemistry) may show the same effect. As a result one will increasingly need to spend time and effort to maintain and work at this sort of taxonomical system.

The better option is to directly link related ideas to each other. Each atomic idea will have a much more limited set of links to other ideas which will create a much more valuable set of interlinks for later use. Limiting your links at this level will be incredibly more useful over time.

One of the biggest benefits of the physical system used by Niklas Luhmann was that each card was required to be placed next to at least one card in a branching tree of knowledge (or a whole new branch had to be created.) Though he often noted links to other atomic ideas there was at least a minimum link of one on every idea in the system.

For those who have difficulty deciding where to place a new idea within their system, it can certainly be helpful to add a few broad keywords of the type one might put into an index. This may help you in linking your individual ideas as you can do a search of one or more of your keywords to narrow down the existing ones within your collection. This may help you link your new idea to one or more of those already in your system. This method may be even more useful and helpful for those who are starting out and have fewer than 500-1000 notes in their system and have even less to link their new atomic ideas to.

For those who have graphical systems, it may be helpful to look for one or two individual "tags" in a graph structure to visually see the number of first degree notes that link to them as a means of creating links between atomic ideas.

To have a better idea of a hierarchy of value within these ideas, it may help to have some names and delineate this hierarchy of potential links. Perhaps we might borrow some well ideas from library and information science to guide us? There's a system in library science that uses a hierarchical set up using the phrases: "broader terms", "narrower terms", "related terms", and "used for" (think alias or also known as) for cataloging books and related materials.

We might try using tags or index-like links in each of these levels to become more specific, but let's append "connected atomic ideas" to the bottom of the list.

Here's an example:

• broader terms (BT): [[physics]]
• narrower terms (NT): [[mechanics]], [[dynamics]]
• related terms (RT): [[acceleration]], [[velocity]]
• used for (UF) or aliases:
• connected atomic ideas: [[force = mass * acceleration]], [[$$v^2=v_0^2​+2aΔx$$]]

Chances are that within a particular text, one's notes may connect and interrelate to each other quite easily, but it's important to also link those ideas to other ideas that are already in your pre-existing body of knowledge.

See also: Thesaurus for Graphic Materials I: Subject Terms (TGM I) https://www.loc.gov/rr/print/tgm1/ic.html

https://openknowledgemaps.org/

Open Knowledge maps is a visual literature search tool that is based on keywords rather than on a paper's title, author, or DOI. The service was founded in 2015 by Peter Kraker, a former scholarly communication researcher at Graz University of Technology.

in print.33

1. Moss (1996), 54–55. For Guarino’s methods, see the treatise by his son Battista in Guarino (2002); Erasmus discusses commonplacing in De copia and De ratione studii (Basel, 1512), in Erasmus (1978), 605–6, 636–38, 672; Vives does so in De tradendis disciplinis (1531), in Vives (1971), 108, 133

Double check what Erasmus has to say as it would seem that Earle Havens contradicts this in Commonplace Books (Yale University Press, 2001). Perhaps its a difference of degree? I seem to recall that he indicated that Erasmus helped to popularize commonplacing practice.

Early modern reference works, handbooks, and pedagogical practices created a sort of standardized set of subject headings amongst note takers.

A similar sort of effort could have been seen in the blogosphere of the early 2000s in which Technorati and their search functionality may have helped to standardize some of these same sorts of taxonomic issues within their product which was widely used at the time.

Even in the western tradition, the earliest methods of mnemonics tied ideas to locations, from whence we get the ideas of loci communes (in Latin) and thence commonplaces and commonplace books. The idea of loci communes was koinos topos in Greek from whence we have derived the word 'topic'.

Was this a carryover from other local oral traditions or a new innovation? Given the prevalence of very similar Indigenous methods around the world, it was assuredly not an innovation. Perhaps it was a rediscovery after the loss of some of these traditions locally in societies that were less reliant on orality and moving towards more reliance on literacy for their memories.

An example here of a misconception. The zettle may be given a number, but it is also given a topic tied into an index. Because it isn't put into a "folder" or "hierarchy" isn't the same thing as not giving it a topic.

The important part of permanent notes are generating your own ideas and connecting (linking them densely) into your note system. The linking part is important and can be the part that most using digital systems forget to do. In paper zettelkasten, one was forced to create the first link by placing the note into the system for the first time. This can specifically be seen in Niklas Luhmann's example where a note became a new area of its own or, far more likely, it was linked to prior ideas.

By linking the idea to others within the system, it becomes more likely that the idea can have additional multiple contexts where it might be used and improve the fact that context shifts will prove more insight in the future.

Additional links to subject headings, tags, categories, or other forms of taxonomy will also help to make sure the note isn't lost completely into the system. Links to the bibliographical references within the system are helpful as well, especially for later citation. Keep in mind that these categories and reference links aren't nearly as valuable as the other primary idea links.

One can surely collect ideas and facts into their system, but these aren't as important or as interesting as one's own ideas and the things that are sparked and generated by them.

Asking questions in permanent notes can be valuable as they can become the context for new research, projects, and writing. Open questions can be incredibly valuable for one's thinking and explorations.

Drexel, Aurifodina, 135

The question of the correct taxonomies isn't an easy one and certainly isn't new.

Placcius, De arte excerpendi, 84–5;

Niklas Luhmann's zettelkasten had three different forms of links.

• The traditional keyword index/link from the commonplace book tradition
• A parent/child link upon first placing the idea into the system (except when starting a new top level parent)
• A direct link (Verweisungen) to one or more ideas already in the index card catalog.

Many note taking systems are relying on the older commonplace book taxonomies and neglect or forego both of the other two sorts of links. While the second can be safely subsumed as a custom, one-time version of the third, the third version is the sort of link which helps to create a lot of direct value within a note taking system as the generic links between broader topic heading names can be washed out over time as the system grows.

Was this last link type included in Konrad Gessner's version? If not, at what point in time did this more specific direct link evolve?

A great quote, but this is likely a nebulous statement to those with out the experience of practice. Definitely worth expanding on this idea to give it more detail.

Luhmann indicated that one must keep a register of keywords to assist in the rediscovery of notes. This had been the standard within the commonplacing tradition for centuries before him. The potential subtle difference is that he seems to place more value on the placement links between cards as well as other specific links between cards over these subject headings.

Is it possible to tell from his system which sets of links were more valuable to him? Were there more of these topical heading links than other non-topical heading links between individual cards?

aliases for "topical headings": headwords keywords tags categories

https://tracydurnell.com/2021/10/20/digital-garden-index/

Quoted in Vernon F Snow “Ftrancis Bacon's Advice to Fulke Greville on Research Techniques," Huntington Library Quarterly 23, no.4 (1960): 370.

Ryan Holiday's system is a more traditional commonplace book approach with broad headings which can feel project-based or bucket-based and thus not as flexible or useful to some users.

The design of Carl Linnaeus' specimen cabinets mirrored that of the bilateral tables and the ways he arranged his heads in his notes and books.

Linnaeus used the logic of topical headings in commonplace books as an intellectual framework for designing a better filing system for his physical plant specimens. This was in marked contrast to the sorts of contemporary curiosity and medical cabinets that others were using at the time.

Note here the idea of being able to file things away, reorder them, and find them quickly. Search was a likely motivator.

He's essentially created an early form of zettelkasten, but for plants.

Oh the times I wish this were easier to do in English without the gymnastics.

In much the way one might move around portions of ideas under heads in a commonplace book, Carl Linnaeus was moving around bigger ideas/chapters within books and moving from one book to another.

Carl Linnaeus' classification method in Systema Naturae, his famous nomenclature system, was informed by the traditional topical headings of commonplace books.

[16] The content of Methodus and the nature of the heads is addressed in S. Müller-Wille, ‘Introduction’, in C.Linnaeus, Musa Cliffortiana: Clifford’s Banana Plant, translated by S. Freer (Liechtenstein: A.R.G. Gantner VerlagK.G., 2007), 33