Book Club on Cataloging the World and Index, A History of the

Dan Allosso has been hosting a regular book club for a few years centered around sense making, note taking, and topics like economics, history, and anthropology. Our next iteration over the coming month or so will focus on two relatively recent books in the area of intellectual history and knowledge management:

This iteration of the book club might be fruitful for those interested in note taking, commonplacing, or zettelkasting. If you’re building or designing a note taking application or attempting to create one for yourself using either paper (notebooks, index cards) or digital tools like Obsidian, Logseq, Notion, Bear, TinderBox etc. having some background on the history and use of these sorts of tools for thought may give you some insight about how to best organize a simple, but sustainable digital practice for yourself.

The first session will be on Saturday, February 17 24, 2024 and recur weekly from 8:00 AM – 10:00 Pacific. Our meetings are usually very welcoming and casual conversations over Zoom with the optional beverage of your choice. Most attendees are inveterate note takers, so there’s sure to be discussion of application of the ideas to current practices.

To join and get access to the Zoom links and the shared Obsidian vault we use for notes and community communication, ping Dan Allosso with your email address. 

Happy reading!

On The Interdisciplinarity of Zettelkasten: Card Numbering, Topical Headings, and Indices

As humans we’re terrifically spectacular at separating things based on perceived categories. The Dewey Decimal System systematically separates mathematics and history into disparate and distinct locations, but your zettelkasten shouldn’t force this by overthinking categories. Perhaps the overlap of math and history is exactly the interdisciplinary topic you’re working toward? If this is the case, just put cards into the slip box closest to their nearest related intellectual neighbor—and by this I mean nearest related to your way of thinking, not to Melvil Dewey’s or anyone else. Over time, through growth and branching, ideas will fill in the interstitial spaces and neighboring ideas will slowly percolate and intermix. Your interests will slowly emerge into various bunches of cards in your box. Things you may have intially thought were important can separate away and end up on sparse branches while other areas flourish. If you make the (false) choice to separate math and history into different “sections” it will be much harder for them to grow and intertwine in an organic and truly interdisciplinary way. Universities have done this sort of separation for hundreds of years and as a result, their engineering faculty can be buildings or even entire campuses away from their medical faculty who now want to work together in new and exciting interdisciplinary ways. This creates a physical barrier to more efficient and productive innovation and creativity. It’s your zettelkasten, so put those ideas right next to each other from the start so they can do the work of serendipity and surprise for you. Do not artificially separate your favorite ideas. Let them mix and mingle and see what comes out of them.

If you feel the need to categorize and separate them in such a surgical fashion, then let your index be the place where this happens. This is what indices are for! Put the locations into the index to create the semantic separation. Math related material gets indexed under “M” and history under “H”. Now those ideas can be mixed up in your box, but they’re still findable. DO NOT USE OR CONSIDER YOUR NUMBERS AS TOPICAL HEADINGS!!! Don’t make the fatal mistake of thinking this. The numbers are just that, numbers. They are there solely for you to be able to easily find the geographic location of individual cards quickly or perhaps recreate an order if you remove and mix a bunch for fun or (heaven forfend) accidentally tip your box out onto the floor. Each part has of the system has its job: the numbers allow you to find things where you expect them to be and the index does the work of tracking and separating topics if you need that.

The broader zettelkasten, tools for thought, and creativity community does a terrible job of explaining the “why” portion of what is going on here with respect to Luhmann’s set up. Your zettelkasten is a crucible of ideas placed in juxtaposition with each other. Traversing through them and allowing them to collide in interesting and random ways is part of what will create a pre-programmed serendipity, surprise, and combinatorial creativity for your ideas. They help you to become more fruitful, inventive, and creative.

Broadly the same thing is happening with respect to the structure of commonplace books. There one needs to do more work of randomly reading through and revisiting portions to cause the work or serendipity and admixture, but the end results are roughly the same. With a Luhmann-esque zettelkasten, it’s a bit easier for your favorite ideas to accumulate into one place (or neighborhood) for easier growth because you can move them around and juxtapose them as you add them rather than traversing from page 57 in one notebook to page 532 in another.

If you use your numbers as topical or category headings you’ll artificially create dreadful neighborhoods for your ideas to live in. You want a diversity of ideas mixing together to create new ideas. To get a sense of this visually, play the game Parable of the Polygons in which one categorizes and separates (or doesn’t) triangles and squares. The game created by Vi Hart and Nicky Case based on the research of Thomas Schelling (Dynamic Models of Segregation, 1971) provides a solid and visual example of the sort of statistical mechanics going on with ideas in your zettelkasten when they’re categorized rigidly. If you rigidly categorize ideas and separate them, you’ll drastically minimize the chance of creating the sort of useful serendipity of intermixed and innovative ideas. A zettelkasten isn’t simply the aggregation repository many use it for—it’s a rumination device, a serendipity engine, a creativity accelerator. To get the best and most of this effect, one must carefully help to structure their card index to generate it.

It’s much harder to know what happens when you mix anthropology with complexity theory if they’re in separate parts of your mental library, but if those are the things that get you going, then definitely put them right next to each other in your slip box. See what happens. If they’re interesting and useful and they’ve got explicit numerical locators and are cross referenced in your index, they are unlikely to get lost. Be experimental occasionally. Don’t put that card on Henry David Thoreau in the section on writers, nature, or Concord, Massachusetts—especially if those aren’t interesting to you. Besides, everyone has already worn down those associative trails, paved them, and re-paved them. Instead put him next to your work on innovation and pencils because it’s much easier to become a writer, philosopher, and intellectual when your family’s successful pencil manufacturing business can pay for you to attend Harvard and your house was always full of writing instruments from a young age. Now you’ve got something interesting and creative. (And if you really must, you can always link the card numerically to the other transcendentalists across the way.)

In case they didn’t hear it in the back, I’ll shout it again:

ACTIVELY WORK AGAINST YOUR NATURAL URGE TO USE YOUR ZETTELKASTEN NUMBERS AS TOPICAL HEADINGS! MIX IT UP INSTEAD.

Featured image by Michael Treu from Pixabay

Bookmarked Indxd (indxd.ink)
Filling up notebooks is great - but what happens when you need one obscure factoid that's stashed somewhere among dozens of notebooks? Searchability is Analog's Achilles heel.

Introducing Indxd
I wanted a simple, searchable index of all the topics in all my notebooks. So I built it, and you can use it too. Indxd lets you quickly enter notebooks and their topics, then search and browse everything.
INDXD is a digital, web-based index tool for your analog notebooks.

Ostensibly allows one to digitally index their paper notebooks (page numbers optional). It emails you weekly text updates, so you’ve got a back up of your data if the site/service disappears.

This could potentially be used by those who have analog zettelkasten practices, but want the digital search and some back up of their system.


sgtstretch in @Gaby @pimoore so a good friend of mine makes INDXD which is for indexing analog notebooks and being able to find things. I don’t personally use it, but I know @patrickrhone has written about it before. ()

Creating a commonplace book or zettelkasten index from Hypothes.is tags

I thought it might be useful to have a relatively complete list of cross linked topical headings in my digital notebook (currently Obsidian) which is a mélange of wiki, zettelkasten, journal, project management tool, notebook, and productivity tool. First, let’s be honest that mélange is too poetic based on what I see of how others use Obsidian and similar tools. My version is structured to have very clear delineations between these forms even though I’m using the same tool for various functions.

I find that indexed subject headings can be useful for creating links between my wiki-like pages as well as links between atomic ideas in my digital zettelkasten. Gradually as one’s zettelkasten becomes larger and one works with it more, it becomes easier to recall individual ideas and cross link them. Until this happens or for smaller zettelkasten it can be useful to cross reference subject headings from one zettel to see what those link to and use those as a way to potential create links to other zettels. This method can also be used as a search/discovery aide for connecting edge ideas in new areas to pre-existing portions of one’s zettelkasten as well. Of course at massive scale with decades of work, I suspect this index will have increased value as well.

I don’t hear people talking about these types of indices for their zettelkasten in any of the influencer spaces or on social media. Are people simply skipping this valuable tool? For those enamored of Niklas Luhmann, we should mention that having and maintaining a subject index was a powerful portion of his system, even if the digitized version of his zettelkasten hasn’t yet been fully digitized. I haven’t seen the whole collection myself, but based on the condition of some of the cards in his index, Luhmann heavily used his subject index. (Note to self: I wonder what his whole system would look like in Obsidian?) Having a general key word/subject heading/topic heading index of all the material in one’s system can be very useful for general search and discovery as well. This is one of the reasons that John Locke wrote about a system for indexing one’s commonplace book in 1685. His work here is likely the distal reason Luhmann had one in his system.

Systems that have graphical knowledge graphs may make this process easier as one can look from one zettel out one or two levels to see where those link to.

Since such a large swath of my note taking practice starts by using Hypothes.is as my tool of choice, I’m able to leverage several years of using it to my benefit. Within it I’ve got 9,314 annotations, highlights, and bookmarks tagged with over 3,326 subject headings as of this writing.

To get all my subject heading tags, I used Jon Udell’s excellent facet tool to go to the tag editing interface. There I entered a “max” number larger than my total number of annotations and left the “tag” field empty to have it return the entire list of my tags. I was then able to edit a few of them to concatenate duplicates, fix misspellings, and remove some spurious tags.

An alternate way of doing this is to use a method described in this GitHub issue which shows how to get the tags out of local storage in your web browser. Your mileage may vary though if you use Hypothes.is in multiple browsers, which I do.

I moved this list from the tag editor into a spreadsheet software to massage the list a bit, clean up any character encodings, and then spit out a list of [[wikilinked]] index keywords. I then cut and pasted it into my notebook and threw in some alphabetical headings so that I could more easily jump around the list.

Now I’ve got an excellent tool and interface for more easily searching and browsing the various areas of my multi-purpose digital notebook.

I’m sure there are other methods within various tools of doing this, including searching all files and cutting and pasting those into a page, though in my case this doesn’t capture non-existing files. One might also try a search for a regex phrase like: /(?:(?:(?:<([^ ]+)(?:.*)>)\[\[(?:<\/\1>))|(?:\[\[))(?:(?:(?:<([^ ]+)(?:.*)>)(.+?)(?:<\/\2>))|(.+?))(?:(?:(?:<([^ ]+)(?:.*)>)\]\](?:<\/\5>))|(?:\]\]))/ (found here) or something as simple as /\[\[.*\]\]/ though in my case they don’t quite return what I really want or need.

I’ll likely keep using more local search and discovery, but perhaps having a centralized store of subject headings will offer some more interesting affordances for search and browsing?

Have you created an index for your system? How did you do it?

Replied to Monks, a polymath and an invention made by two people at the same time. It’s all in the history of the index by Aaron DavisAaron Davis (Read Write Collect)
Anna Kelsey-Sugg and Julie Street discuss Dennis Duncan research in the index. He explains how the practice evolved separately in Paris and Oxford during 1230. Although the two inventions were not connected, they were both associated with the rise of the university and the lecture. In the early 13th...
Great find Aaron. Thanks for the ping.

I’ve gone back further than this for the commonplace and the florilegium which helped to influence their creation, though I’ve not delved into the specific invention or general use of indices in the space heavily. I suspected that they grew out of the tradition of using headwords, though I’m not sure that indices became more popular until the paper by John Locke in 1689 (in French) or 1706 (in English).

I’ll put Dr. Duncan’s book into the hopper and see what he’s got to say on the topic.

An Index for My Digital Commonplace Book

In reading about the history of commonplace books, I figured it’d be nice to have a full listing of all the categories and tags on my website for public reference. So I’ve now added an Index page.

I must admit that with a tiny amount of research and set up, I’ve now got something that even John Locke could be jealous of.

For my future self or others interested, I’m using Multi-column Tag Map which has a variety of short codes for implementing various forms of output. Sadly it wasn’t tagged with the word index, so it took some time to find it.

I’ve always had my own administrative interface for this data as well as search and even programmatic tag completion which makes writing and posting easier. However since a lot of what I do is in the public, perhaps it will be useful for readers to have access to the same full list instead of the abbreviated ones that appear as tag clouds or in various sidebars on the site?

Currently I’ve got over 9,000 different tags on the site. Perhaps displaying them publicly will help motivate me to curate and manage them a bit better. I already see a handful of repeated versions based on spelling, spacing, or typos that could be cleaned up. Let’s go crazy!