From Fleeting Notes to Project Notes – Concepts of "How to Take Smart Notes" by Sönke Ahrens

This is a guest post by our dear @ZettelDistraction. You can find his sketches and some (academia-)critical illustrations on Instagram @flengyel. And if you’re interested in seeing how a text evolves, check out the revisions of this post on the forums.

Terminological troubles beset the account of note categories in How To Take Smart Notes by Sönke Ahrens (Ahrens 2017). The book reads as though it emerged unedited from the author’s Zettelkasten. The most important type of note doesn’t have a name. This post aims to settle the record.

Note categories named and unnamed

Ahrens discusses five categories of notes: three main descriptive categories of notes: fleeting notes, permanent notes and project notes; and two subcategories of permanent notes, literature notes and Zettels, although the term Zettel occurs nowhere in Ahrens (Ahrens, 41). Italicized terms are defined in “Note categories in detail” below, after some remarks on the components of a Zettekasten and on workflow in the Zettelkasten Method according to Ahrens.

Zettelkasten components

A Zettelkasten consists of three components: a slip-box, which may be implemented in editing and note-linking software such as The Archive, Logseq, Obsidian, Roam Research, Zettel Notes, or Zettlr; a reference manager, such as Zotero or Mendeley; and, a pen and notebook or paper for so-called fleeting notes, to be defined (Ahrens, 29–30).

Ahrens includes a fourth component, an editor (Ahrens, 30). In software, the editor is usually combined with the slip-box function, so we refer to three components instead of four. When we refer to the slip-box, we mean the corresponding software component. Sometimes it is convenient to refer to the slip-box as the Zettelkasten, however it is (usually) clear from context whether one means the slip-box component or all of the components.


The Zettelkasten Method is a description of the standardized note formats used and of the workflow of those notes and source references among the components of the Zettelkasten (Ahrens, 23, 41, 45). The workflow starts with hand-written notes and ends either with permanent notes in slip-box or the reference manager, or with project notes for writing projects based on the contents of the Zettelkasten (Ahrens, 23, 41–45).

Niklas Luhmann’s workflow

In Ahrens’ account of Niklas Luhmann’s Zettelkasten workflow, Luhmann first wrote brief literature notes and used these to write self-contained permanent notes called Zettels, which Luhmann wrote carefully, as if for publication (Ahrens, 17–18, 43).

Ahrens’ workflow

For Ahrens, the Zettelkasten workflow begins with fleeting notes, which could be revised as literature notes, which are further developed as Zettels; otherwise the fleeting notes are revised directly as Zettels (Ahrens, 23). In the rare circumstance that one’s thoughts are fully formed as if for print, the preliminary fleeting and literature note steps can be skipped, and one writes a Zettel (Ahrens, 23).

Ahrens misses an opportunity to revisit Luhmann’s workflow in terms of the descriptive categories Ahrens identifies, and to relate Luhmann’s workflow to the workflow he presents in section 2.1 (Ahrens, 23). Examples and diagrams of the workflow would have been helpful. This should have presented no problem, as Ahrens states that “[s]implicity is paramount” (Ahrens, 38–40).

Note categories in detail

Fleeting notes

Fleeting notes are hand-written notes to be discarded after being recast for inclusion in the Zettelkasten as permanent notes (see below). Ahrens assigns the fleeting note to its own category to emphasize its function and to emphasize the habits that he wants users of the Zettelkasten Method to adopt. “Fleeting notes are there for capturing ideas quickly while you are busy doing something else” (Ahrens, 43).

Ahrens advises reading with paper and pen in hand and advises against highlighting or marking up books and leaving slips of paper around (Ahrens, 29, 85, 87). Ahrens also expects fleeting notes to be written judiciously on the spot, rewritten as Zettels or Literature Notes, and discarded within a day or two (Ahrens, 43). This is crucial: if you don’t cultivate the habit of reading with pen and paper in hand, then for Ahrens, you are not following the Zettelkasten Method (Ahrens, 146).

Ahrens refers to the “fleeting literature note” for the handwritten precursor to the literature note (Ahrens, 44). There is no name in Ahrens for the fleeting note that is rewritten as a Zettel, just as there is no name in Ahrens for the Zettel.

The fleeting note is more significant than its name suggests, because of its normative function in Ahrens’s account of the Zettelkasten Method. For Ahrens, the Zettelkasten Method is a systematic approach to academic research and non-fiction writing in which the first step is to jot down fleeting notes while reading or attending lectures and seminars, or when busy doing something else (Ahrens, 23, 41, 43). Also, Ahrens advises writers to act “[…] as if nothing counts other than writing” (Ahrens, 38). Taken literally, this maxim commits the writer to an instrumental approach to life, forever cycling through a workflow that begins with the fleeting note. We leave the topic of instrumentalism in Ahrens for another post.

Permanent notes

Permanent notes are self-contained notes that end up in the slip-box or in a reference manager. Quoting Ahrens [emphasis in boldface added]:

Permanent notes, which will never be thrown away and contain the necessary information in themselves in a permanently understandable way. They are always stored in the same way in the same place, either in the reference system or, written as if for print, in the slip-box.

(Ahrens, 41)

Ahrens recommends that permanent notes be written in “your own words.” (Ahrens, 23, 24, 37).

Literature notes: a subcategory of permanent notes

A literature note is a source reference in a reference manager, optionally with one or more attached notes.

The term ‘literature note’ derives from the note cards on which Niklas Luhmann, the prolific sociologist and originator of the Zettelkasten Method, recorded bibliographic references (Ahrens, 18). Occasionally Luhmann wrote a few brief remarks on the other side of these cards (Ahrens, 18, 43; Schmidt 2013, 170). Despite the ambiguous terminology, a literature note is a reference in a reference manager, such as Zotero. Ordinarily one doesn’t refer to bibliographic references as notes, although it is possible to attach notes to bibliographic entries in Zotero. In Ahrens, the reference manager is where those notes would go (Ahrens 43).

Zettels: a subcategory of permanent notes

What about the notes that go into the slip-box? Since Ahrens doesn’t give them a name, we’ll assign them a standard name that appears nowhere in the English translation of How to Take Smart Notes: the Zettel. Using only the descriptive categories Ahrens provides, the next definition will have to do, for now.

A Zettel is a permanent note that isn’t a literature note.

Ahrens refers to these notes as “the main notes in the slip-box” in exactly one place (Ahrens, 44). Since Ahrens doesn’t provide examples of Zettels or offer a standard template for notes, I offer a template for free at https://github.com/flengyel/Zettel.


Zettels are permanent notes, but not conversely. Moreover, neither Zettels nor Literature Notes are immutable as their name might suggest. They can be revised—however, I advise caution when revising permanent notes. There are trade-offs to be aware of. Zettels are supposed to be self-contained: revision could result in loss of context (Ahrens 44). Since Zettels are linked to other Zettels, changing one Zettel could affect any other note connected to it, directly or indirectly. There is also the risk of obliterating history; of losing track of mistakes and dead ends to avoid; and of creating a misleading record of ever-upward progress (Ahrens, 125–127).

[…] our culture is focused on success and how we neglect the important lessons from failure (Burkeman 2013).

(Ahrens, 125)

It is very good to know what has already proven to not work if we try to come up with new ideas that do work.

(Ahrens, 127)

Project notes

Project Notes are mentioned by Ahrens in four places (Ahrens, 42, 45, 46, 71). These notes don’t have a standard format and reside outside the Zettelkasten for writing projects that make use of the Zettelkasten (Ahrens, 23).

Acknowledgements. I wish to thank @taurusnoises for professional editorial assistance and encouragement. @zk_1000 alerted me to the term “fleeting literature note” and pointed out that permanent notes subsume literature notes. @ctietze suggested additional citations.


  • Ahrens, Sönke. 2017. How to take smart notes: one simple technique to boost writing, learning and thinking: for students, academics and nonfiction book writers. North Charleston, SC: CreateSpace.

  • Burkeman, Oliver. 2012. The Antidote: Happiness for People Who Can’t Stand Positive Thinking. New York: Faber and Faber.

  • Schmidt, Johannes F.K. 2013. “Der Nachlass Niklas Luhmanns – eine erste Sichtung: Zettelkasten und Manuskripte.” Soziale Systeme 19 (1): 167–83.

Christian’s Comment: Reading the first iteration of this text, I wanted to invite @ZettelDistraction to put this on the blog, because of one clever and interesting distinction he found in Ahrens’s book – and now the post turned into a much more thorough discussion of the concepts and terms used, and that’s even more useful to the Zettelkasten community! Thanks for taking so much care to make this piece.

Sascha’s Comment: This is the reason why the Zettelkasten Forum is the best community. I have nothing to add other than to thank @ZettelDistraction for his work. I hope this adds to the collective knowledge of the Zettelkasten community and clarifies some of the difficulties to understand of Ahrens’s concepts.