I read How to Take Smart Notes by Sönke Ahrens recently which talks about Niklas Luhmann’s zettlekasten (English: slip-box) note-taking method. Luhmann was a prolific sociologist who came from humble beginnings.

Check out video of the relationships in my zettelkasten so far:

I highly recommend reading How to Take Smart Notes but to summarize the method:

  1. You want to keep notes unitary. Each note contains one idea, and one idea only. I’m targeting a maximum of 500 words per note. But some of them are only one sentence.
  2. Notes are written in mini-essay or article form. Full sentences and written as if to a stranger. This helps capture context, and context is critical to this method.
  3. Notes are then linked to other related notes to produce chains of ideas. This is where the context begins to become important. By linking notes you are describing relationships between ideas. If there’s a contradiction between two notes there might be an interesting error (which can be discussed in a new note). But maybe the same idea works differently in a different context (which again, should be discussed in a new note).
  4. Notes are permanent, though not necessarily read-only. You can think of the zettelkasten as an append-only graph of nodes. In my zettelkasten I try to minimize updating notes as much as possible. Only correcting typos, or updating to add links to other notes. The reason for this is that there’s often much of interest in why you got something wrong, or why an idea might work differently in another context.

The core insight behind this method I find so intriguing is we aren’t linear creatures, so why should we write to learn linearly? We learn in fits and spurts. We get bored of a topic and move on to another. Then come back to where we were again days, weeks later, or longer. We also learn by forming connections between related ideas. Ahrens even points out that this is why mnemics are such powerful devices for improving memory retention.

We have our ‘ah-ha’ insights most often when we’re thinking about something totally unrelated. That is because we make connections through analogy, “this thing is like this other thing” and we’re able to abstract learnings to fit other contexts. This method takes those seemingly serendipitous connections and makes them visible, and permanent through your linked notes. Those truly original ideas you have and their contexts are put on display right in front of you. And as a thinking device I think that is truly powerful.