Sönke Ahrens's How to Take Smart Notes (2017) did for the Zettelkasten what a good manual does for a power tool: it turned a cryptic index-card practice into a workflow anyone can follow. If you've heard the phrase "smart notes," this is where it comes from.
The three kinds of note
The whole method runs on distinguishing three types:
- Fleeting notes — quick captures, thoughts in the moment. Disposable; they exist only to be processed within a day or two.
- Literature notes — what you took from something you read, in your own words, with the source. Never copy-paste — rephrasing is where understanding happens.
- Permanent notes — the payoff: atomic, concept-oriented evergreen notes written for your future self and linked into your existing notes. These are the slip box.
Fleeting and literature notes are feedstock; permanent notes are the product.
The insight
Ahrens's real argument is that writing isn't the last step of thinking — it's the medium of it. By turning every worthwhile input into a linked permanent note, your note system becomes a thinking partner: when you sit down to write, the essay is half-assembled from notes that already talk to each other. Ideas compound instead of resetting to a blank page.
Who it's for — honestly
Smart notes pay off richly if you write or research for a living — students facing theses, academics, non-fiction authors. For everyone else, the full three-tier workflow is more overhead than the return justifies; the durable takeaways are smaller and universal: capture fleeting thoughts fast, rephrase what you read, and link ideas so they compound. You can live those without the ceremony — which is the case for letting an app handle capture and connection for you while you keep the thinking.