Sonke Ahrens

How to Take Smart Notes reconstructs the method Niklas Luhmann used to produce seventy books, working from a slip-box of roughly ninety thousand index cards that were linked to each other rather than filed by topic.

The insistence is that writing is thinking, so notes must be written in full sentences and in your own words at the moment of reading, or they are worthless later.

Ahrens is a German academic writing about academic workflow, and what he produced is drier than the note-taking enthusiasm around it suggests. That is arguably the point.