TL;DR: Write atomic notes, link them together, and let structure emerge. This method helped Luhmann publish 70+ books.
The Zettelkasten (German for “slip box”) is a note-taking and knowledge management method developed by sociologist Niklas Luhmann.
Core Principles
1. Atomic Notes
Each note should contain one idea. This makes notes:
- Easy to link
- Easy to find
- Easy to combine
Atomic vs Non-Atomic
Non-atomic: “Notes about productivity and time management and goal setting” Atomic: Separate notes for each concept, linked together
2. Unique Identifiers
Every note gets a unique ID. Originally numbers like 1a2b, now often timestamps:
202401051430 - Zettelkasten Method
202401051445 - Atomic Notes
202401051502 - Progressive Summarization
3. Links Over Folders
Instead of organizing by category, organize by connection:
Traditional: Folder → Subfolder → Note
Zettelkasten: Note ↔ Note ↔ Note
This creates an emergent structure, similar to how the brain works.
How It Works
graph LR A[Fleeting Note] --> B[Literature Note] B --> C[Permanent Note] C --> D[Index/MOC] C --> E[Other Notes] E --> C
Note Types
| Type | Purpose | Lifespan |
|---|---|---|
| Fleeting | Quick captures | Temporary |
| Literature | Summarize sources | Reference |
| Permanent | Your own ideas | Forever |
Connection to Other Methods
The Zettelkasten integrates well with:
- Building a Second Brain - PARA for projects, Zettelkasten for ideas
- Evergreen Notes - Andy Matuschak’s modern interpretation
- Obsidian - Digital implementation
Luhmann’s Results
Using this method, Niklas Luhmann:
- Published 70+ books
- Wrote 400+ scholarly articles
- Built a system of 90,000+ notes
Luhmann on his Zettelkasten
“I don’t think everything on my own. It happens mainly within the slip-box.”
Getting Started
- Start with what you’re reading now
- Write one note about one idea
- Link it to existing notes
- Repeat daily
See Writing in Markdown for the technical aspects.