Considered the standard work on note-taking and the Zettelkasten (slip box) concept, How to Take Smart Notes is a must-read for anyone who wants to make optimal use of their external second brain.
The slip box notes system
When first hearing about the Zettelkasten notes system, people generally want to first know what the system is, so let us start there.
In this system there are three types of notes:
- Start with capturing fleeting notes in your inbox. These are simple reminders of anything you want to do something with. Process them later in the day when you have time for it. This way you keep your mind free for thinking, and you can maintain your focus on your current task. Do not use your brain for remembering things1.
- When you read or listen to something, note down enough bibliographic information so you can find the source again if you need it (reference note), and make literature notes of the parts that were really interesting2. Not in the book, but you can apply progressive summarization here to drill the note down to its essentials with little effort while maintaining a certain level of context3.
- Process fleeting notes and literature notes into permanent notes. These permanent notes are your own thoughts, elicited by your notes and the relationships between them. Your goal is to gather not just any information in your slip box, but focus on those things that triggered you. This way, over time, you get to a critical mass of high quality notes, that will support your thinking. For findability and discoverability, it is important to create links from this note to other notes and vice versa. In the original system, the advice is to either link from an index note, or a note that is linked from the index note4.
Ahrens starts from the basic assumption that writing is all that matters. To him, writing is not just that thing you do in the end for publication, but writing is part of the reading, thinking and reflecting process. When your goal is to write about interesting open questions that give new insight, you will need to understand so you can write about it in your own words (through writing you will quickly identify where understanding is lacking), you will need to focus on the most relevant points, and you will need to think on what you read or discuss so your writing will contribute something new. Writing helps clarify your own thoughts and argumentation as contradictions and inconsistencies will become visible. Plus, when you do publish, you can get feedback and actually help others. As Ahrens says: “An idea kept private is as good as one you never had. And a fact no one can reproduce is no fact at all.”5
Ahrens also discusses a few other important principles: don’t make the system any more complicated than necessary6, work on what you find interesting and let arguments develop bottom-up, and the more notes you have developed, the more motivating, inspiring and easier it will become to continue to add new information and get inspired to new thoughts by the connections already in your system. Your brain and notes system will start to interact to bring your thinking to new heights.
Summaries by others
But honestly, just go read the book. It is written by somebody who uses Zettelkasten to write, so it is quite information dense and difficult to do justice in a summary.
If this idea is new to you, Getting Things Done by David Allen will be an eye-opener. ↩
In a digital system this is easy to combine. You can also keep this external in a system like Zotero. ↩
In progressive summarization (developed by Tiago Forte) you (1) capture and make notes, (2) later when you review the note (naturally, when you encounter it for some project for example) you make the parts that strike you most bold, and (3) again later you highlight the most essential sentences. This way you still have all your notes, but it is also very easy to scan your notes for the most relevant information. To further process the note, (4) you can write an executive summary at the top of the note in your own words, and if the note is really important, (5) you can create your own remix in the form of sketchnotes (notes with sketches, graphs, etc.). Steps 4+5 are the most valuable in terms of internalizing the material (see the critical notes on progressive summarization by Nick Milo). ↩
In a digital system, I think it matters a bit less that it is no more than 2 links away. It probably results in artificial hierarchical structures if you would really want to enforce that. Perhaps 3 links? Like a Kevin Bacon number for notes? ↩
If you need more convincing to share your work publicly, I recommend Show Your Work! by Austin Kleon. ↩
In an interview with Ahrens, he again emphasized that the system should be as simple as possible, with little friction to use. Whenever you are in doubt, choose the easy path. That is the only way to ensure continued use of the system! ↩