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.

Moloney, C. (2021, December 30). Southern cancels London Victoria trains for two weeks over Covid. The Guardian. https://www.theguardian.com/uk-news/2021/dec/30/southern-cancels-london-victoria-trains-for-two-weeks-over-covid

https://www.youtube.com/watch?v=cHr9qGPHdiA&t=2856s

Well, this is an exciting prospect for 2026!

Benefits of electric trains.

Never book a long train ride without finding some reviews by people who took the same train recently.