Zettelkasten without the graveyard
by Andreas Tissen · · updated
Say you started a Zettelkasten in spring. By autumn it holds a few hundred notes: highlights, summaries, ideas from the train. Each one was meant to be linked to the notes it relates to, and on busy days that step waited. The unlinked notes only turn up when you search for a word you happen to remember.
This post looks at what Niklas Luhmann's original box did to keep its notes connected, and at how the same three moves work in Pando, the outliner I built, where Claude can take over the searching for related notes.
What Luhmann's box did
Luhmann (1927 to 1998) was a sociologist at Bielefeld University. The university's Niklas Luhmann archive describes his note box of about 90,000 slips, written between the early 1950s and 1996, as the centre of his theoretical work, and counts nearly 600 publications by him, more than 40 of them monographs (archive page at uni-bielefeld.de, read on 14 November 2026). It is really two boxes. A 2018 talk by Johannes Schmidt of the archive gives about 24,000 slips for the first, from 1952 to 1962, and about 66,000 for the second, from 1963 to 1996.
The same talk names the principles that held the box together. Three of them do the connecting:
- A fixed place. A new slip went directly behind the slip it continued and got a branching number, so a thought that continued 21/3d18 became 21/3d18a. Filing a note meant deciding which earlier note it followed.
- References. Slips carried the numbers of other slips anywhere in the box, which is how a note on one subject pointed at a note filed under another.
- A keyword register. The second box had one with about 3,200 entries, used as entry points: a keyword led to a few slip numbers, and from there you followed the sequence and the references.
In a 1981 essay, "Kommunikation mit Zettelkästen", Luhmann described the box as a partner he communicated with, one that could surprise him with connections he had not been looking for.
Sönke Ahrens's How to Take Smart Notes (2017) made the method popular again and split notes into kinds: fleeting notes you jot down quickly, literature notes on what you read, and permanent notes that hold one idea in your own words.
Why digital boxes fill up with unlinked notes
In most note apps, writing a note and connecting it are separate steps. On the train you jot down "cities grow along their transport lines, not around their centres". Linking it to your older note on suburban rail means searching for that note and pasting a link, and that can wait until later.
If later does not come, the box turns into a flat pile. Search still finds a note when you remember a word from it, but the box no longer brings up anything you were not already looking for, which was the part Luhmann valued.
The same three moves in an outline
Pando is an outline of bullets inside bullets, and each of Luhmann's three connections has a counterpart in it.
The fixed place is a child. A note that continues another goes directly under it, which keeps the follow-up behind the thought it extends, as the branching numbers did.
A reference is a bullet link. The bullet menu has Copy a link to it; paste that link into the text or the note of another bullet and it shows as a link wearing the first bullet's own words. The same menu has What links here, which lists every bullet pointing at this one. On paper that reverse direction only existed if Luhmann wrote the reference on both slips.
The register is a set of topic bullets with mirrors under them. A mirror is one bullet standing under several parents at once; edit it in one place and every place shows the edit, because it is the same bullet.
In the picture, the train capture still sits in Fleeting as a question. The permanent note it became, "Cities grow along their transport lines, not around their centres", stands under Permanent notes with an Evidence line and a Counter-case under it, and the same bullet, children included, stands under Urbanism and under Infrastructure in Topics. A topic placement like this works as an entry point, as the register did, and it is closer to a tag than to a link: it says what the note is about, not which other note it answers. The note-to-note links are still the bullet links, and those are the ones worth writing when you file a note. Mirrors also help when you cannot decide where a note goes.
The Zettelkasten template has three lanes. Fleeting is the inbox for quick captures, emptied once a week; Permanent notes hold one idea each, in your own words, with the evidence as children; Topics collect the mirrors. The link shows the branch read-only, and its Show in my Pando button copies it to the top of your Home after you sign in.
Emptying Fleeting with Claude
Claude, once connected to Pando, has the tools you have here: it can create a bullet, mirror it under a topic and write a link to another bullet into a note. You can ask it to go through Fleeting each week. It suggests which captures are worth a permanent note, drafts a first version, searches the box for notes the new one relates to and proposes the links and the topics.
The wording of a permanent note should stay yours, because rephrasing is how you find out whether you understood the idea; the reading-notes post makes the same point about highlights. What Claude takes off your hands is the search for related notes, which is the step that kept waiting.
Pando is free up to 5,000 bullets with every feature, agents included, and Pro costs 3 EUR a month. To try a Zettelkasten where Claude does the searching, create a free account and connect Claude.