Zettelkasten is German for “slip-box”, and it’s a note-taking method that originally involved putting literal index cards in a box. These days a lot of people implement it digitally, in note-taking sotware. The fundamentals of the method are:

  1. Each card gets an alphanumeric string as its “address”. You might have top-level cards “1”, “2”, etc.
  2. Want to add a new card? Great. If it’s a continuation of, or building on, one of your existing cards, its address will be based on that address. Two methods: the dot method (“1.1.1”, “1.1.2”…) or the alphanumeric one (1a1, 1a2…). If it’s a fresh idea or you’re not sure where to slot it in, you can give it a top-level number. Don’t overthink it too much or you’ll probably never write any notes because you’ll be paralysed by indecision over how to address it. Zettelkasten is definitely a hierarchical method.
  3. You can create cross-links by adding something like: “See card: 1.1.2” if it turns out you had a related thought on, say, card 2.7.4.
  4. The benefit of using cards is that thoughts should be “atomic”. That is, one thought = one card. If you want to add more thoughts, make more cards!!
  5. You can later create “index cards” at, say, 0. Like if you end up with “1.1.1” all the way up to “1.1.15”, you might want a card at 1.1.0 that lists all of them. Another type of “index” might be a fresh top-level card that just lists all the cards you keep going back to (especially if you struggle to locate them when you do). Obviously I guess computerisation makes this easier…
  6. You can also later create a “bottom-up” map… like, look at all the children of e.g. 1.1, and map out the most important ones. Then later look at all the maps of all the children of 1, and create a map for that. Then eventually look at all the maps of all the top-level cards, and create a top-level map. This gives you a guide to where all your most important ideas ended up being.
  7. Generally each card would end in a “references” section, with a citation for the idea (remember, atomicity = one idea) that your card was about.

The method seems to have been popularised by Niklas Luhmann, to the point that he’s sometimes believed to have been the “creator” of the method (including by me, previously). However, variations of this method – which is also known as the “commonplace book” – have been used at least as far back as the 16th century (at which time slips of paper were used, with index cards not having been invented yet).

At any rate, Niklas Luhmann intended the method to be used for taking notes while reading. Others use it for making notes while thinking. If you want both types of notes, apparently it makes sense to maintain different collections for them.

I’ve also seen this idea that you might have four different types of notes: fleeting (to be thrown away once you’ve translated them into “permanent” notes – if worthy – or decided not to, if not); literature notes (with citations for things you’ve read), permanent notes (to be kept forever) and project notes (which you can throw away once done with a project).

Digital Zettelkasten

The ideal format for a digital zettelkasten is a single-level folder (no subdirectories) full of plain-text (or markdown) files. They should use addresses, like “1a1”, “1a2”, etc. (I’ve seen some people have cards named like “1a1 Cats”, “1a1a Origins”, “1a1b Domestication” – with a title as well as an address – but strictly the method only uses addresses.) You should use wiki-links that expressly state the address to link between them – like [[1a1]] not [[1a1|Cats]].

That said, I’ve seen various “Zettelkasten editors” (including Zettlr) use timestamp addresses/filenames instead, and this section of this page(external link) states that there are at least four acceptable systems for addressing cards in a digital zettelkasten:

  1. Luhmann’s method
  2. timestamps
  3. any arbitrary UUID
  4. give cards titles

The main thing is that the title just needs to be unique and should be immutable.

Other than that, anyway, the method seems basically the same. You should still be creating atomic cards, cards should still link to one another (e.g. “Cats” should link to all those subpages under “Cats” no matter what the filename is)…

An alternative might be to use blocks as “cards”, if you’re using some kind of software that allows linking to and maybe transclusion of specific blocks (Roam, Notion, TiddlyWiki, and even I think Obsidian although it’s a newer feature seem to allow this). This is probably more readable at the end of the day.

Overall, it seems a lot easier to manage a Zettelkasten digitally – however…

My Opinion

When I first created a Notion account I thought the word “Zettelkasten” was really cool so I decided to call my personal wiki that. However, my current opinion is that the Zettelkasten method is just way too rigid for me. I feel like it was probably a genius idea back before computers, when your main alternative was scouring a notebook desperately trying to work out where you jotted down that one all-important note. But in the modern day, where we have wikilinks, backlinks, tags, folders, and most importantly of all search bars, the constraints no longer make anything easier in the long run. I don’t really see the point in having my digital notes be immutable, or adhering to a rigid structure of “one note = one idea”.

The idea of eventually discarding all non-permanent notes also doesn’t sit right with me, but I think that’s because I like to make my notes cover every facet of my life, and not just professional work.

See Also / References