There is a lot of discussion in the personal knowledge management (PKM) world about zettelkasten method and a collection of new tools for implementing the method. (See my post here about getting started with zettelkasten method.) Some of those tools include what are, essentially, hyperlinked outlining applications, the most popular being Roam Research and RemNote. Discussion about if and how to use these tools resurfaces a longstanding debate in the zettelkasten world about whether or not so-called "folgezettel" or "sequence notes" as used by Niklas Luhmann in his paper-based implementation of the zettelkasten method are still necessary and, if so, what their purpose is. After some additional reading and thinking about the implementation of the zettelkasten method in this new generation of networked note-taking applications, I think that they do have the possibility of implementing Luhmann’s system faithfully, including the folgezettel, and that the folgezettel are still potentially valuable. We just need to understand where they (likely) come from and their purpose in the overall system. In short, I believe that they are an artifact of Luhmann’s legal education and serve the purpose of synthesis.
I have written before that Luhmann’s particular implementation of zettelkasten method should not necessarily be seen as a universal model for all knowledge work because his implementation was tailored to his own project and research questions–i.e. the production of big social theory by drawing on disparate literatures from many disciplines. We can further contextualize Luhmann’s use of zettelkasten method by remembering that he first trained in law before later switching to sociology.
Remembering Luhmann’s time in law might help us to make sense of his use of folgezettel. In American legal education, the creation of outlines of topical areas of law (e.g. torts, contracts, etc.) that break down the main issues and legal rules along with supporting caselaw and statutes for each is a time-honored tradition. Students might listen to a lot of lectures, read and brief lots of individual cases, but they will then work to synthesize all of that material around the high-level topics of concern, breaking them down into their component parts and related rules.
I do not know if German law students do the same, or if they do, whether they used that method when Luhmann was a law student. Given that there is a long history of German influence in at least some disciplines of American higher education, such as history, it is possible that German law students do the same thing and that perhaps the American tradition of outlining has come from, or at least has been influenced by, the German tradition (or vice versa). This would be an interesting question to explore.
Some argue that Luhmann did not use categories. That is not entirely correct. He did have high level subject areas that emerged over time based on his interests (see PDF). He used these to broadly classify his final, "permanent" notes, as Ahrens calls them. But instead of just dumping them in these large categories or buckets, he organized them as best he could within each bucket using a combination of index notes and folgezettel. For example, he might have assigned the number "1" to a top-level category of "Biological systems." (Note: I do not know if this was the actual topic for the "1" category; this is merely a hypothetical example.) He would then add notes to this collection using an ID that starts with "1". A child note within that bucket might be "1a" and address "basic definitions of biological system." He might then have continuations of that definition note, say 1a1 – Biological systems are nonlinear and 1a2 – Biological systems evolve over time. He might further have sub-notes about how biological systems are nonlinear or exhibit evolutionary behavior, say, 1a1a – Biological systems exhibit emergence and 1a1b – Biological systems are sensitive to small changes in initial conditions, etc. This, my friends, makes an outline:
- 1 – Biological systems
- 1a – Definitions of biological systems
- 1a1 – Biological systems are nonlinear
- 1a1a – Biological systems exhibit emergence
- 1a1b – Biological systems are sensitive to small changes in initial conditions
- 1a2 – Biological systems evolve over time
Of course, saying that biological systems are nonlinear, evolve, exhibit emergence, etc. begs for cross references to notes in other parts of the system where those concepts are defined and explained in more detail. This is where the cross-links between individual notes (or we may say bullet points or "blocks" in the outline) come into play.
But why do this on individual "slips" (e.g. cards of slips of paper, a.k.a. "zettel")? The first reason was likely the material, technological limitation of slipping new bullet points into an existing outline written on paper. As soon as you realize a new point needs to be inserted as either a sibling or child, the entire outline would have to be re-written. That’s pretty inconvenient when, as in Luhmann’s case, he is trying to create a whole new area of knowledge that did not exist before and do it over the course of decades. Outlining a largely pre-existing area of knowledge already worked out for the most part by others might work on paper. But when you’re creating something new over such a long period of time, doing it on sheets of paper is likely to fail. Essentially, then, each zettel is a point in an ever-evolving outline of an emerging area of knowledge-in-the-making.
The second likely reason for Luhmann using individual slips for each note is that this was already common practice in the humanities and social sciences, including sociology, where Luhmann ultimately found his intellectual home. Contemporary and preceding sociologists, like C. Wright Mills and Beatrice Webb, wrote about their note-taking systems. Mills wrote in detail about the creation and maintenance of "the file" for scholarly research in his appendix to The Sociological Imagination. Webb wrote in particular about how she used notecards organized by topics, dates, etc. so that she could organize and re-organize them later (see "APPENDIX C – The Art of Note-Taking" in My Apprenticeship from 1926). She and Mills were certainly not the only ones to use this method, nor did they invent it. Webb, for example, cites works from historical methods texts in both French and German from the late 19th and early 20th century that advocate the use of such a method. In short, writing "atomic" notes, as some call them today, had a long history in precisely the new disciplines that Luhmann was entering.
Thus, I think we can say that Luhmann’s unique approach is the result of his unique life circumstances and long-term research project. Though I don’t know for certain, it seems possible that his system is a hybrid of the outlining method from law and the notecard method from history and sociology. The use of copious cross-links between the individual notes stems from his particular project of synthesizing knowledge from multiple disciplines, thus making it difficult to ever place most cards in one and only one spot in the ever-growing outline.
Of course, Luhmann did say that there are no privileged positions for individual notes in the folgezettel structure (see https://omxi.se/2015-06-21-living-with-a-zettelkasten.html). Again, this is because of the interdisciplinary nature of his overall project. But this does not mean, as some suggest, that there was no rhyme or reason at all, that notes can go just anywhere. We do know that Luhmann had top-level subjects or topics to which his numbering system corresponded. He didn’t just put his notes anywhere, but rather, in a place that made sense at the time, near something related, even if this was not the only or even best place for the note to go in the long term. Again, this difficulty of there being no one, best place for a particular note was addressed through the use of cross-links between notes, making it so that any given note could "exist" in more than one spot.
So how might this understanding clarify our understanding of the differences between so-called "permanent notes" and "literature notes?" I think the permanent notes are akin to the rules and definitions (i.e. the work of synthesis) one finds in a legal outline and the literature notes are akin to briefs of individual cases (i.e. the work of analysis). Advice on constructing good legal outlines says that one should organize the outline around broad topics and the related components, rules, and cases, not around individual cases. One reads and "briefs" cases to pull out and distill the most important facts and rules with the ultimate goal of better understanding the big picture. Those case briefs can then be slotted into various parts of different outlines as support or illustration for particular points related to that topic of law, which are the "permanent" notes in the outline.
In the case of non-legal research, we might be trying to come to terms with a particular area of knowledge, first figuring out what is already known, all with the goal of finding the gaps that we could explore further in our own work. Our "cases" to start might be the existing research literature, the books and articles already published on the topic. In examining this literature, we will "brief" these individual "cases" (i.e. articles, books, etc.), distilling them down to their essence (e.g. main argument, methods, etc.) in a collection of "literature notes." But the loop is not closed until we take those literature notes, our "source briefs," and use them to update our "permanent notes," our evolving outline of the topical area we are exploring. This could include adding explanatory bullet points under existing questions or problems identified in our outline, or even adding new questions/problems we had not encountered before. It could involve adding contradictory conclusions or examples. It could include adding or refining concepts and their definitions. And, of course, it could (and likely should) including thinking about and making explicit links to other broad topical areas of interest to us, or even to specific points in our evolving outlines of those areas.
In short, to understand Luhmann’s particular implementation of zettelkasten method, we likely need to understand the interdisciplinary nature of his own background and life’s work. Doing so suggests that the so-called folgezettel, which have been a source of controversy within the contemporary zettelkasten method community, could have been an artifact of Luhmann’s early education in law and public administration. His version of the zettelkasten method seems to be a hybrid of legal outlining with the well-known method of using notecards, which was already popular among academics in various disciplines of the humanities and social science, history and sociology in particular.
The ultimate take-away, I think, is that folgezettel served a particular purpose for Luhmann. That method may serve a purpose for some of us still today. I would not say that it is "wrong" to use folgezettel, nor that it is now obsolete because of changes in technology. Indeed, law students still use ever-growing outlines of the law over the course of their three years in school as vital tools for studying for individual classes, writing their law review articles, and studying for the Bar Exam. However, folgezettel-style outlines are also not required for everyone. Webb, Mills, and many other scholars over the last century or more who have relied on the use of notecards for taking "atomic notes" did quite well for themselves without necessarily putting those notes into ever-growing outlines (or, for what it’s worth, making copious links between individual notes as Luhmann also did). The most important element of zettelkasten method is ultimately the "principle of atomicity" combined with some method of broadly classifying each note based on emerging subjects of interest to the researcher. Beyond atomicity, whether one places them into an evolving outline and how extensively one links individual notes together must be based on the particular needs of the researcher. One need not slavishly copy exactly what Luhmann (or Mills or Webb, etc.) did to get at least some benefit from taking more atomic notes. That said, if your work aims towards synthesis across disciplines over a long period of time, then the incorporation of the folgezettel technique along with interlinking of individual notes may well allow you to take your work to a new level.