Liwen Knight-Zhang

Liwen Knight-Zhang

Emacser, Coder, Husband & Lifelong Learner

Zettelkasten & Org-Roam

Why Taking Notes At All

I started taking notes when I was in elementary school. I am absolutely convinced that it is a good habit in learning new subjects.

The action of writing things down involves multiple senses working together to create stronger memory.

Taking notes in your own words forces you to think deeply about the ideas beyond the passages. To truly understand an idea is not the same as to merely comprehend the written text itself. The ’translation’ process is the essence of note-taking. It integrates the newly-learned idea with your existing knowledge network. The benefit of linking your knowledge is more like compound interests instead of linear addition. On the other hand, copying text word by word doesn’t automatically make you understand the ideas.

Taking notes in meetings and conversations help us concentrate and avoid daydreaming, this is particularly useful in the age of working remotely with back-to-back Zoom calls.

Notes crystallise our thoughts in the precise moment when they emerge. Any form of coming-back-later is a waste of time. Repetition doesn’t guarantee better understanding of the ideas because our memory is very selective. The action of highlighting-for-later is the same as putting things on your back-burner. It’s better to deal with them now or discard them completely. Wasting mental energy to manage more back-burners is counterproductive. Our short-term memory and focus are all limited, overloading them will only cause us stress.

Taking notes empties our short-term memory. This means we can use our main focus to think about the order, the relationship and the clarity between the ideas we are trying to make sense of. Writing down thoughts doesn’t mean we are going to forget about what we have learned. The action of linking the ideas strengthens our understanding. The idea of freeing out short-term memory is also used in David Allen’s book Getting Things Done.

However, I always felt I am not taking notes the right way, or perhaps I just have really bad memroy. There are times I couldn’t remember much about the books I’ve spent days reading about a couple of months ago. The volumes of notebooks on my bookshelf often felt foreign to me, as if they were from somebody else.

It all changed when I learned about Zettlekasten.

What is Zettelkasten

Zettelkasten (German: “slip-box”) is a note taking method for knowledge management and writing. It is what made Niklas Luhmann, a self-made public servant to sociologist professor who wrote 58 books and over 400 papers during his lifetime - with more published based on his manuscripts after his death, a prolific scholar. Zettelkasten seems to have gained popularity in the past few years, especially with the popular not-taking application Roam Research.

As a result of extensive work with this technique a kind of secondary memory will arise, an alter ego with who we can constantly communicate. It proves to be similar to our own memory in that it does not have a thoroughly constructed order of its entirety, not hierarchy, and most certainly no linear structure like a book. Just because of this, it gets its own life, independent of its author.

— Niklas Luhmann

The idea of communicating with your second brain is very powerful. It’s like you have a Google with all your own ideas and writings. I find it’s particularly interesting as it resonates with my idea of ’searching over organising’. I believe we should be able to have dialogues with our brain and notebooks to ask questions.

The method itself is very simple to practice. You use small index cards for note taking. Each card (“Zettel” in German) has an ID, a set of contexts (tags) and references to other cards. All the cards are stored in a slip-box. You then create indexes with key terms of important notes as entry points for querying your knowledge (the second brain). Luhman also has a slip-box dedicated for bibliography.

The Zettelkasten Manifesto explains the concept very well.

Key Principles of Zettelkasten

In order to truly realise the effectiveness of the Zettelkasten method, there are few key principles (or at least the ideas behind them) need to be followed religiously.

  • Each card holds a single idea - an atomic concept that can be understood by itself. This makes each card useful in more than one context and it increases the surface area for enquiry.
  • Use specific and contextual tags, avoid categories. ’Finance’ or ’Holiday’ are not good tags in Zettelkasten. In what context would you want to find information about ’Finance’? It’s too wide. A better version would be ’Money Saving Tips’ or ’Places I Want to Visit in Africa’. When you tag the notes, don’t automatically link them to the most obvious and most commonly used tags. Think hard about in what contexts this note may be useful. This deliberate practice of linking is the essence of Zettelkasten. The existing keywords are warnings, they are not cues.
  • Build the links among cards through references. The practice of deliberately building links helps you connect ideas. Building links from bottom-up means you have to constantly update your links as you gain new knowledge and insights.

How to Take Smart Notes

Apart from reading articles from zettelkasten.de, I’ve also read the book How to Take Smart Notes from Sönke Ahrens. There are plenty of resources on the Internet about Zettelkasten but none explains the idea as in depth as Ahrens’ book.

The core idea of the book is that there are two parts in note-taking. The first one is to write a summary of the main ideas in your own words. The second part is to create links between the new ideas and the existing concepts in your slip-box. They are equally important.

If you want to give the book a try, I recommend at least try Zettelkasten at the same time while reading the book. I learnt about slip-boxes on the Internet, bought the book and started to use the Zettelkasten method to read this very book about Zettelkasten. I kept improving my Zettelkasten note taking techniques as I went through the book. There were many aha moments which I probably would not be able to get from reading the book for the first time if I didn’t practice this technique at all.

The book categorised notes into a few types. Below is my own interpretation of how Zettels should be organised.

Five Types of Notes

Fleeting notes
Your scrawls on serviettes, brown bags, or coffee shop receipts. They are random ideas you jolted down while you were reading, waiting in the queue or talking with a friend. Make sure you process them within a day or two while the memory is still fresh. You can bin these after you’ve turned them into permanent notes.
Permanent notes
Notes that represent atomic ideas which can be understood in their own contexts. I occasionally create notes only to connect related ideas when they are too big to fit into one zettel. The title of the Zettel should be descriptive. The first sentence or paragraph should be the summary of the idea.
Literature notes
Summarise the content of a book, publication or blog post and give the citation, in the format of “on page X of Y, it says Z”You can keep a separate bibliography slip-box with tools such as Zetora or org-ref.
Index notes
Index notes are the entry points to the universe inside your slip-box. Each index should link as few notes as possible (Luhmann links maximum three). Index notes are not tables of contents which have links to everything in the slip-box. The key idea is to use the key links to discover more notes by traversing through the network. If you use a digital Zettelkasten system this type of notes may not be necessary - back-links can be discovered by the software easily
Project notes
Notes that serve as ’folders’ for specific projects. You can archive them or bin them once the projects are done. You draw ideas from your permanent notes but you don’t change them for the projects - keep the modifications for the project specific context inside the project notes.


As a dedicated Emacser, the first thought in my mind was that I have to implement the idea with Emacs. Fortunately you have the wonderful Org-Roam. It’s straightforward to get started.

This article itself is a result of my Zettelkasten with Org-Roam. This wonderful video taught me how to outline an article with Zettels in 20 minutes.