Zettelkasten notes

A Zettelkasten ("slip box") is a collection of short notes, each holding one idea in the writer's own words, each with a fixed ID, and each linked to the notes it relates to. The sociologist Niklas Luhmann kept one for decades and credited it with much of his output. It works because the value sits in the links: a new note is only finished when it has been placed among the old ones, so over time the box starts suggesting connections the writer did not plan.

The method, as Sönke Ahrens lays it out in How to Take Smart Notes, uses three kinds of note. Fleeting notes are quick captures that get thrown away once processed. Literature notes record what a source says, briefly and with a reference. Permanent notes are the writer's own ideas, written to stand alone and linked into the box. This skill does the processing: it turns raw material into literature notes and proposes permanent notes linked to what the person already has.

When to use it