Do you want to learn how to take better notes while reading?
Are you looking for a proven method to come up with original ideas?
If these questions apply to you, then let me tell you about the Zettelkasten system or the Slip-box method of note-taking. For decades, people have been using this method to enlarge their understanding of the world and to produce original thoughts.
This will be an overview of the Zettelkasten note-taking system. I will show you why you should consider this method to get more out of your reading notes.
What Is The Zettelkasten System
Zettelkasten is a German word for “slip-box” or “note box.” The core idea of the system is a single repository for your notes, which is called a slip-box.
One of the founders of the Zettelkasten method was an academic named Niklas Luhmann. Born in 1927, Luhmann was a prolific writer and scholar. He wrote 70 books and over 400 scholarly articles during his lifetime. His work touched many subjects and was widely read and cited.
How was he able to write so many influential papers? It might be simpler than you think. It was his note-taking system.
Luhmann said “I… do not think everything by myself. It happens mainly within the slip-box.” As you will read below, Luhmann’s system was an external brain, which aided his work. By organizing his notes in a certain way he let his notes do most of the thinking for him.
The note-taking system Luhmann created was revolutionary. His system serves as the model for the Zettelkasten Method.
How The Zettelkasten Method Works
Here is a simple diagram of the workflow behind the Zettelkasten Method.

There are four main steps
- Find Ideas
- Take Notes
- Make Permanent Notes
- Slip-Box
Finding Ideas
For most of us, we already have this step in place. We have our favorite sources for ideas and information. For me, reading books is the biggest source of new ideas. But, I have also found great information from other sources such as Twitter and YouTube Videos.
Take Notes
The next step is to take notes about the ideas we’ve come across. There are two categories of notes at this stage; fleeting notes and literature notes.
Fleeting notes can be thought of as the place where you record any ideas you have. It might be on a napkin or a notebook. It doesn’t matter. These aren’t permanent notes, but rather a place where we can quickly jot down an idea that comes into our mind.
Don’t overthink note-taking at this stage. Capturing information is all that’s important.
Literature Notes
The next type of note is Literature notes. These notes are based on where the idea came from. After you’ve read a great book, take the time to review what you read. You can transfer underlined passages from the book into these literature notes. Ask yourself: What don’t I want to forget about this book?
Make Permanent Notes
Finally, we are at the most important part of the Zettelkasten – making permanent notes. We will do our best thinking at this stage. We will review notes and ideas from our fleeting notes and literature notes. We will think about what notes are the best. One criterion I use, is I look for ideas that inspire me and move me to want to do something. These are the golden ideas.
We also review previous permanent notes we have made in our slip-box. You are looking for how these new ideas connect with previous ideas you’ve noted and recorded. This is where the magic happens. When we make connections between ideas we begin to develop new and original thoughts. We transcribe these new insights into “permanent notes.”
In a physical Zettelkasten system, you would do this on an index card. Each note is based on one idea and should be concise enough to be contained on one card. Write the note in your own words and be as clear and precise as possible.
Filing Notes in the Slip-box
After we’ve created the note we then file it in our Slip-box.
If the new note was inspired by a previous note in the Slip-box then you would file the new note behind the inspirational note. Luhmann would number each note. He went in numerical order and when a new note was built off of a previous note his numbering would branch off to show this.
Why Would You Want To Keep A Zettelkasten System?
Because of the workflow described above, you will have a system that creates ideas. It forces you to consider how each new idea you come across relates to other quality ideas you’ve had and making connections between ideas can inspire new ideas.
If you are trying to create content, the Zettelkasten system can be a repository for your next content idea. Over time you will begin developing thoughts around certain topics. These are topics that have previously inspired you and have been filed neatly together because of the Zettelkasten Method. Then when you are looking for the next idea to structure your content around go to your slip-box.
Digital vs. Paper System
So how do you implement a Zettelkasten system? Luhmann used 3 x 5 index cards. Today, there are dozens of software for Zettelkasten note-taking.
Personally, I prefer a paper Zettelkasten system. I worry about the longevity of software programs (will it still be receiving updates in 3 years?). I don’t want to waste time creating notes in a format that could become obsolete in a few years.
That being said, I still do take digital notes. I make highlights and take notes on my Kindle. If I come across an interesting idea anywhere on the Internet I will email it to myself. I then take my Kindle notes and emailed notes and make them into permanent notes on 3×5 index cards.
This is a simple box I purchased from Amazon. It holds up to 1,000 3×5 index cards. I use it as my slip-box and I’m very happy with it.
I also started an index of my notes in Google Sheets. This is a newer idea, so I haven’t been able to thoroughly test it out yet. The general goal is to have a digital record of what thoughts I’ve had. It just contains the reference number and the subject of the card in the Zettelkasten.
If you haven’t used paper for years, then there is plenty of Zettelkasten software. I haven’t used them much, but some of the popular Zettelkasten Softwares are:
- Obsidian
- Roam
- Zettlr
Next Steps
If you want to learn more about the Zettelkasten method then you should read How To Take Smart Notes by Sönke Ahrens. This is the book that introduced me to the Slip-box method. The primary audience for this book is academics and those who write non-fiction.
Hopefully, this overview of the Zettelkasten system has inspired you to take your note-taking to a higher level.