What if you could hold a conversation with your book notes?
This was the idea that first tempted me to try the Zettelkasten Method, developed by Niklas Luhmann in the 1950s.
The basic method is deceptively simple…
The Zettelkasten Method
Here is the Zettelkasten method, in its simplest form:
- Assign each index card a unique number.
- Write a “nugget” of information on each card.
- Cross-reference cards using their unique numbers.
+ a few more nuances:
- Title each card to make it easy to see the topic at a glance.
- Insert a card between two numbers using alphanumerics (e.g. 1a, 1b, 1c…) or a slash followed by further numbers (e.g. 1/1, 1/2, 1/3…).
- Create indexes (or “registers”) that collate multiple cards under a keyword or tag.
This article describes my (physical) implementation of the method. Niklas Luhmann’s Zettelkasten was, of course, more developed and intricate, and tended toward different aims. Please see Further Reading below for more information.
A Brief History of Note-Taking
“Early compilations involved various combinations of four crucial operations: storing, sorting, selecting, and summarizing, which I think of as the four S’s of text management. We too store, sort, select, and summarize information, but now we rely not only on human memory, manuscript, and print, as in earlier centuries, but also on computer chips, search functions, data mining, and Wikipedia, along with other electronic techniques.” – Ann Blair
The dream of organised book notes has haunted writers and readers for millennia.
In Too Much to Know, Ann Blair details the concerns of scholars facing the flood of information following the invention of the printing press, and the increased availability of books, and of paper. During this period, the art of memory was replaced by the art of excerpting, which consigned information to paper in order to forget rather than to remember it.
What struck me was how little the problem and the attempted solutions have changed since that time. Early Modern writers and readers were employing all of the same techniques we use today:
- Annotating books
- Copying out interesting excerpts
- Organising information using headings (we might call them “folders”)
- Cross-referencing
- Dividing information into manageable nuggets (“files”)
- Creating keyword registers or indexes (“tags”)
They struggled with the difficulty of knowing how to categorise information, and having categorised it, of retrieving it, just as we do. Every scholar had his or her own variation of a solution, ranging from notebooks, to “files” (strings on which notes were strung by categories), to custom cabinets (also called “machines”).
One frequent technical issue was knowing how much space to allocate to a particular topic, which anyone who has ever created a bullet journal collection will surely attest to. Many scholars found the solution in moving away from their notebooks and using small pieces of paper instead. This not only made their commonplaces infinitely (outwardly) extendible, it also made the possibilities for combination all the plainer.
But for the most part, Renaissance scholars directed their efforts towards trying to recreate in their notes, the order they found (or expected to find) in the world. Their excerpts were saved under the Grand Headings of Knowledge (much like today’s Dewey Decimal System), and the structure was supported by elaborate alphabetical and topical indexes.
With regret and second thoughts, they were finally compelled to admit that the order of knowledge does not necessarily mirror the order of nature. – Alberto Cevolini
Arborescent vs. Rhizomatic
One of the chief concerns that led Luhmann to devise his Zettelkasten Method was a desire to avoid hierarchical structures. Every hierarchy imposes a top-down limit on information and seeks to reduce complexity. Luhmann, a systems theorist, sought instead to increase complexity without succumbing to structure.
In 1980, two post-structuralist philosophers, Gilles Deleuze and Felix Guattari, suggested an alternative to the dominant hierarchical “arborescent” structure: the heterarchical rhizome.
A rhizome is a type of plant root like that of ginger or potato. Deleuze and Guattari used it as an analogy for a way of thinking that, similar to a map, could have multiple entries, and multiple paths, but without reference to a unifying “whole” or centrality.
The rhizome is not structured. Like Luhmann, Deleuze and Guattari note that structure dampens the possibility of combination, and thereby the generation of new ideas.
I think the difference between the rhizome and the branching tree root illustrates the essential shift that the Zettelkasten provides:
- Each card can be connected to every other card.
- There is no hierarchy. Even the order of branching cards is arbitrary.
- There is no unity of meaning. The Zettelkasten can cover any and all subjects.
- A line of inquiry (or “line of flight”) can change the nature of the cards. In other words, connecting the cards in different ways — or even along the same line but with different intent — yields different results.
- A line of inquiry can break off at one card, only to start up again at another.
- Unlike book pages that are brought together by a central spine, the cards can all exist on a “plane of consistency”.
I realise that this is all very theoretical, but hopefully it conveys some of the power behind the seemingly simple “thinking tool” that is the Zettelkasten.
By the way, if you’ve never encountered literary theory before, you might be interested in reading my article on deconstruction for writers.
A Paper Conversation Partner*
“Als Ergebnis längerer Arbeit mit dieser Technik entsteht eine Art Zweitgedächtnis, ein alter Ego, mit dem man laufend kommunizieren kann.” – Niklas Luhmann
As a result of working longer with this technique, there arises a sort of second memory, an alter ego, with whom one can communicate regularly.
Luhmann referred to himself and his Zettelkasten as “us”. I think that gives a good indication of the sort of relationship one might develop with a box of cards that, with time, comes to resemble an alter ego. An alter ego with whom you’ve spent quality time, with whom you have a reciprocal (give and take) relationship, who remembers things you may have forgotten (or who remembers them differently), and who is always there to surprise and delight you with new ideas.
I couldn’t help wondering whether Luhmann’s wife wasn’t a little jealous of his relationship with his Zettelkasten (a massive collection that is now being digitised).
After all, your Zettelkasten is a partner with whom YOU have the closest connection, even if other people can read a superficial meaning or two on the face of it.
“When the user stores his thoughts in his own filing cabinet, these thoughts are no longer his own but those of his filing cabinet… It is not simply another Ego for enacting a user’s soliloquy but a true Alter Ego with whom the user communicates. Additionally, when the machine is started, the user does not simply refresh his memory; the filing cabinet actually speaks. To achieve this practical outcome, the card index must be provided with a ‘life of its own’ (Eigenleben) which should be as independent of the life of its educator as possible.” – Alberto Cevolini
Part of the Zettelkasten’s success as a conversation partner lies in its resemblance to a human in the way it stores information. The cards that are connected to other cards are more likely to be accessed, whereas cards that aren’t cross-referenced will eventually be lost — just like a person who hasn’t formed the necessary neural connections to sustain a piece of information — and can only be re-discovered by accident.
When you want to initiate a conversation, you can search the index (“register”) for a relevant card, and then follow on to any cross-referenced cards. Or you can pick a selection of cards from the constellation of topics relating to the main subject, and create new cards that link them together.
Thus the conversation is never one-sided, and never a simple matter of information retrieval, but one of information creation.
“…in general, one man’s Notes will little profit another, because one man’s Conceit doth so much differ from another’s; and because the bare Note itself is nothing so much worth, as the suggestion it gives the Reader.” – Sir Francis Bacon
A few story ideas that resulted from personifying the Zettelkasten:
- A spouse becomes jealous of their partner’s relationship with their Zettelkasten.
- A Zettelkasten becomes “self-aware”.
- Two people decide to cross-reference their Zettelkästen. 🖤
- A scholar steals a rival’s Zettelkasten and then tries to make sense of it.
- A biographer tries to reconstruct a person’s life from their cards. (see Jean Paul’s Fixlein)
* Technically, Luhmann referred to his Zettelkasten as a “communication partner” (Kommunikationspartner) rather than a “conversation partner”.
Things You Can Put in Your Zettelkasten
The box of index cards offers an interface that is more than just a stimulating sight, as the apparatus, upon the lightest touch, delivers keywords that stimulate the protagonist to further production of thought. – from Paper Machines by Markus Krajewski
Any information you want to link to other information can find a place in your Zettelkasten, but you should also consider what you want to get OUT of your notes.
Why are you taking notes in the first place?
I know, I know, “to remember things”. But why remember things?
I think answering this question alone can make your reading more purposeful. You might begin to consider how the books and articles you read are tied together, what sorts of ideas you’re drawn to, and what patterns emerge from your life experiences.
Then, taking this store of knowledge, you might apply it to your writing and explore your oeuvre as a whole, how you fit into the larger literary tradition, and in which ways you can expand.
Or you can just have fun! ;)
Here are some ideas of things to put in your Zettelkasten:
- Examples of passages you like in books you’ve read, especially with an eye to imitating them, stealing from them, or alluding to them.
- Anecdotes, stories, observational details, or “snippets of life” that you can draw on in order to round out your characters or your story world. These are precisely the sorts of things that are so difficult to find a place for in a notebook!
- Your thoughts about people you meet, places you visit, foods you try, and any other interactions that go towards creating the rich tapestry of your life experience.
- Information about writing techniques and tools you’d like to try, such as story structures, warm-up exercises, and writing prompts.
- Story ideas and scene ideas. Cross-referencing these with other ideas can be epiphanic!
- Research for writing projects, especially to build up a picture of a particular milieu, culture, or social situation.
- Names, name meanings, words, terms, and etymologies that you find interesting and potentially useful for future projects.
- Placeholders for subjects you want to research, and stories you want to write.
- Theme or leitmotif indexes that collect examples of particular themes you’d like to develop (especially life themes).
- Metaphor/simile indexes that collect examples of comparisons you like, or that are pertinent to the thinking of the milieu or character you’re researching. Conceptual metaphors in particular can be very enlightening. For example, try collecting metaphors that connect texts with textiles. You can find several CLUES in this article alone!
Lady Writers
If you follow my plot, character, and worldbuilding frameworks, here’s how you might incorporate them into your Zettelkasten:
- Create cards for each of the 8 stages of the One Page Novel. Note down your favourite generic scene ideas, or scenes from your reading that you feel exemplify a particular stage.
- Create cards for ARTs (Abilities, Resources, and Traits) that you use to develop a character. Use them to note down any examples you encounter in your reading.
- Create cards for specific occupations, and list the ARTs that they might require.
- Create indexes for specific characters, and use them to collate information that can help you in their depiction.
- Create cards for your World Figures and note down cultural references, symbolism, instructions, or instances of these objects you encounter “in the wild”.
- Create placeholder cards for FIATs (Forces, Ideas, Affects, and Things) that you’d like to research further.
- Pick two cards, and use the combination spells in your Worldbuilding Spell Book to transmute them.
You can also expand your One Page Novel, Heroine Frame or World Building exponentially by simply referencing your Zettelkasten cards!
Drafts & Writing Journals
I know that many writers use index cards to plot, and Vladimir Nabokov even wrote his novels and poems on them. Watching writers using digital Zettelkästen, I’ve noticed that many people also enjoy creating daily cards that collate their reading, conversations, and thoughts.
I haven’t tried any of these approaches myself, but if the idea of using your Zettelkasten for drafting or journalling appeals to you, please experiment and let me know what you discover!
Story Bibles
Personally, I don’t think a Zettelkasten is the ideal place to keep a story bible. Writers like to include many different sorts of unwieldy knowledge material in their story bibles, from novel outlines to moodboards, to ephemera and family trees. Furthermore, the material you gather in a story bible is often very specific to the story, and can’t be linked to anything outside the project.
However, cross-referencing your Zettelkasten from INSIDE your story bible can be an efficient way of accessing your story research, and “connecting the dots” between different ideas. To make it clear that you’re referencing a Zettelkasten card and not a page number, you might want to prepend a “Z” to your card number.

Project Indexes
“The card index is a historical machine with no limits to either outer (i.e., physical) or inner (i.e., structural) expansion…” – Alberto Cevolini
Much as I enjoy the ease and speed of taking reading notes, the moment I created a project index for my story, then I could feel the neurons connecting!
An index (or “register”) in the Zettelkasten is a card that lists all of the other cards related to a particular topic.
Once I had amassed a number of research cards, I created an index for my story, Black Grammar. It felt like a dénouement. Suddenly, all of the disparate threads that I had been trying to hold onto in my mind were tied together in one place where I could grasp them.
I then created project indexes for future projects (even mere story sparks), to keep track of relevant information or ideas I come across.
See A Working Example below to see how I use the indexes while writing.
Master Index
I enjoy my Zettelkasten in its physical form, but I’ve decided to supplement it with a digital master index that I keep in a Google Docs spreadsheet. In this spreadsheet, I list every single card I’ve created. Right now it only has 3 columns:
- No (the reference number/letter of the card)
- Title (the card heading)
- Tags (hashtags that I might use to search for a particular card)
My Zettelkasten (Zosimos) is only a month old, so I’m not yet sure what other information I want to index.
Luhmann himself only had a master index for keywords, the idea being that the index would allow him to find the first card, after which he could follow the thread of cross-references.
See the section on (Possible) Best Zettelkasten Practices for some suggestions.

A Working Example
Here is a project index I created for a story I’m working on, titled, Black Grammar:
0c BLACK GRAMMAR
- Writing tables
- erasure – 1
- as gifts – 1a, 1
- used during hunt – 1b
- small & secret – 20a
- Literary closet – for collab – 20a (ark & chest)
- Group study – 22 (reading aloud)
- Selling notes – to collaborator – 24
- Writing tables
It’s a fantasy story but I’m drawing in a lot of research on Renaissance scholarly practices (which overlapped conveniently with my research for this article!).
Even simply listing some of the uses for writing tables sparked many ideas, mingled with the pleasure of having all of this information in a safe and accessible place. But this collection will truly come into its own when I’m writing. Then I can pick out this index card (0c) and find the information I need in the linked cards.
For example, when I come to write a hunting scene, I can follow the relevant reference and remember to mention that my character notes something down in her writing table, as Sir Philip Sidney was wont to do (1b).
Later on, if a character needs money, perhaps they can consider selling their notes, as Conrad Gesner did on his deathbed (24).
I can also follow the cross-reference to 12 (Papers After Death) and consider what happens to a scholar whose papers are distributed among her students after she dies. This might lead me to develop another character and subplot.
If I need some guidance on crafting my subplot, I can search my digital master index for #subplot and find references to books I’ve read where I thought the subplots worked well. Then I might look for a name for my scholar and search for #names or #surnames. The names I choose may have further cross-references which I can follow, and so on and on…
Hopefully that example gives you some idea of what it’s like to work with a Zettelkasten as a writing companion.
(Possible) Best Zettelkasten Practices
You may prefer to keep a digital Zettelkasten, in which case I would refer you to some of the resources at the end of this post. If you’d like to start a physical Zettelkasten, however, here are some pointers:
- Card takes up more space than paper, but it is more durable.
- It’s a good idea to start out with a size of card or paper that you can easily procure.
- It can help to write cross-references in a contrasting colour, so that they attract notice.
- I’ve found it helpful to write indexes on different-coloured cards so that they’re easy to distinguish.
- It might also be useful to keep indexes separate from “regular” cards. I number my indexes 0 (zero) and keep them at the front of my box. I’m not sure how this will evolve as my Zettelkasten grows. As far as I understand, Luhmann sometimes created indexes for long branches of cards and stored these at the beginning of the branch for an easy overview.
- Write only on one side of your cards. This allows you to see everything at a glance when you’re working with them.
- Keeping a master index in a digital spreadsheet is a good alternative to a digital Zettelkasten, because it allows you to perform quick searches. However, you will need to consider how you set up your index, and how you maintain it. Ultimately, I recommend figuring out problems as you go, rather than trying to perfect a system before you even begin collecting. Also, figure them out in a way that satisfies YOU, that makes sense to YOU, and that YOU will be eager to keep up in the long-term.SET-UP QUESTIONS:
- How and when will you want to access this index? Where should you store it, how can you back it up, and how easy will it be to update?
- Do you want to list cross-references?
- How do you want to list book titles, and book authors?
- Do you want to include mentions of people, places, and dates?
- How do you decide on which tags to use?
- Is the date you created a card important? What if you update one?
MAINTENANCE CONCERNS:
- Indexing your cards isn’t as simple as listing the latest cards, because you may also be adding branching cards in between existing ones. As your Zettelkasten grows, this can become more difficult to track…
- In which case, I recommend keeping new cards in an “inbox” until you index them. Once indexed, you can sort them into their correct position.
- Regular indexing can also encourage you to review your cards and find new cross-references.
- Giving your cards interesting (and informative) headings can spark new ideas, reframe your “knowledge” on a subject, and make you more likely to pick the cards up again. It does require pausing to think, but (along with indexes) it’s been the most rewarding aspect of this method for me. Admittedly, you can also easily employ this technique in your notebooks: leave a wide margin on your page (à la Cornell) to enter your titles afterwards.
- It can help to find a way to distinguish your own thoughts, interpretations, or reactions from those that come from your reading. I decided to use a unique bullet point for this purpose, but Luhmann recommends keeping a separate Zettelkasten for reading notes.
- Only transpose your previous notes into your Zettelkasten as you need them. Any cards that aren’t linked to other cards in the box are forgotten, so there’s no value in adding more information unless it can form productive links with some other notes.
- Avoid the instinct to use your index cards as bookmarks.
Demands & Commitments of a Zettelkasten
“From 1952 or 1953 on, I started the index card file because it was obvious to me that I would have to plan for a lifetime not for a book.” – Niklas Luhmann (quoted by Johannes F.K. Schmidt)
- Weigh up the value of keeping a piece of information with the time it will take you to manage your Zettelkasten. If the idea of choosing titles, cross-referencing, and regular indexing don’t excite you, this probably isn’t the method for you.
- Consider the space that a Zettelkasten will take up in your life. It’s quite possible you’ll have this collection of papers FOR LIFE, and that means finding it a home where it’s easy to access, and has room to grow.
- How will you access a physical Zettelkasten while travelling? Short of carting it along and exposing it to the dangers of the world, the only solution that occurs to me is to set someone to “babysit” or “steward” your collection.
Surprise Yourself
“Für Kommunikation ist eine der elementaren Voraussetzungen, daß die Partner sich wechselseitig überraschen können.” – Niklas Luhmann
One of the premises for communication is that the partners can mutually surprise each other.
Did you know that a packet of information is called a “surprisal”? (Thanks to this excellent article for pointing that out!)
Here are some ways you can have fun and surprise yourself with your Zettelkasten:
- Paste a picture onto one of your index cards. Sketch a scene, a storyboard frame, a map, a mind map, a quick diagram, or a symbol.
- Write encouraging or cryptic notes to yourself on the back of the cards. I think it’s good practice NOT to use the back of the cards except for fun.
- Once your Zettlekasten grows a little, you can draw a random card to use as a writing prompt, or for a spot of bibliomancy.
- Pick two cards at random and try to find a link between them, even if they aren’t cross-referenced.
- Include false links between your cards to encourage you to subvert your logical assumptions. This was a technique Diderot employed to radical effect in his Encyclopedia:
“… in his Encyclopédie, Denis Diderot had intentionally ‘false’ references recorded in order to stimulate thought, as with the famous cross-reference from ‘cannibalism’ to the ‘Eucharist’.” – Alberto Cevolini
Zettelkasten Quick Start
- What is the quickest tool you can use right now to create a note? Use that.
- Write the number “1” in the top left-hand corner.
- Write down a topic title that interests you, a question that’s been going around in your mind, or the last “fun fact” you picked up and why it interested you.
You’ve begun your Zettelkasten! Keep up the practice over the next few days and see what you learn about using the system, and about your tendencies in gathering and processing knowledge.
Consider the difficulties you encounter, the decisions you need to make, and the mistakes you fall into. Improve the system incrementally to suit your needs.
And if it doesn’t work for you… forget it!
Further Reading
- Zettelkasten — How One German Scholar Was So Freakishly Productive – an excellent and in-depth explanation of the Zettelkasten method.
- Communicating with Slip Boxes by Niklas Luhmann – a translation of Luhmann’s article on his Zettelkasten.
- Where Does Niklas Luhmann’s Card Index Come From? by Alberto Cevolini – a really interesting paper that explores the history behind the Zettelkasten.
- Niklas Luhmann’s Card Index: Thinking Tool, Communication Partner, Publication Machine by Johannes F.K. Schmidt – a thorough description of Luhmann’s method.
- Too Much Information by Ann M. Blair – a detailed history of “information overload”.
- Forgetting Machines ed. by Alberto Cevolini
- Paper Machines by Markus Krajewski
- Tiago Forte’s notes on How to Take Smart Notes
- LessWrong – another interesting article that discusses some technical concerns.
- A Thousand Plateaus by Gilles Deleuze and Felix Guattari – the book which expounds (and confounds) the “rhizome” theory.