# Zettels should capture an atomic concept
The core intention of practicing Zettelkasten is so that you can connect and build on top of other concepts, generating insights. To make this happen, naturally, every notes that you write should be oriented around a concept. Capturing notes by concept will also force you to elaborate what you have read (Write about what you read).
Capturing your notes by books, in contrast, is straightforward but will not encourage notes linkage and therefore will not generate new ideas (see also: Zettels should not have ephemeral tags).
The concept that you capture must be atomic, meaning it must not have multiple ideas in one note. Not only atomic notes are easier to be read in the future, but also most importantly, it will increase the link-ability of the note.
Ahrens, How to Take Smart Notes (pp. 18-19).
He then would turn to the main slip-box and write his ideas, comments and thoughts on new pieces of paper, using only one for each idea and restricting himself to one side of the paper, to make it easier to read them later without having to take them out of the box. He kept them usually brief enough to make one idea fit on a single sheet, but would sometimes add another note to extend a thought.
It’s not just about accumulation. There’s also no pressure to synthesize your new ideas on the concept with your prior thoughts about it.
- Zettels should be optimised for retrieval strength
- Zettels should capture an atomic concept. Not only a well thought concepts are more linkable, they are also more retrievable as the title itself is a cue
- Limiting the length of your zettels can make them atomic
- Zettels should capture an atomic concept, but knowing whether the concept that you have captured is atomic may be difficult. Limiting the length of your zettels will help make them atomic. When you can't fit your note into a predefined length, it's a good indicator that your concept contains multiple ideas and should be split into multiple zettels.