@diogenes, a student of philosophy, psychology and history in Vienna, asked some questions on the forum. I’d like to elaborate a bit on that. There will be specific use cases for the Zettelkasten Method. The method itself is a meta method of knowledge work. It translates what we understand of knowledge acquisition into basic actions that can be incorporated into any (knowledge work) workflow. Here, I will show a couple of applications to a more specific case.

Personal Cognitive Work Load

Even though I would consider myself as a relatively good student I often struggle to process all the stuff that i’ve learn about during the lectures + processing the stuff for an upcoming exam. My maximal cognitive Work Load (=Capacity for Deep Work) seems to be only 3-4 Hours. But on most of the work-days the lectures alone require three hours of concentration. So therefore I run out of cognitive energy to process the stuff of previous lectures or stuff for an upcoming exam.

What are you’re experiences with your personal cognitive work load?

As a coach, I have one benchmark for my clients. Unless they are able to concentrate for six hours straight with an approximate 80–90% effort, I consider them to have attention and concentration issues. That means that there is work to do on this matter.

My personal capacity is, depending on the day, 6 to 10 hours at this level of effort. Of course, there are some days I cannot manifest this capacity fully. Christian’s capacity is, in my estimate, quite similar.

We have different bottlenecks in our attention system.¹ My orienting system is my bottleneck. I am quite sensitive to specific kinds of distractions. I am not so distracted by other people. But I tend to fall into rabbit holes. Sometimes, in my deep work sessions, I start with a paper on brain lateralization but end with pages on dog training. Christian stays way more on point, though he doesn’t rise to the same intensity as I and his bottleneck is getting up to speed at all.

Concentration is a special form of attention which is governed by the brains own attention system. We all have different bottle necks.

Is it possible to expand the capacity for deep work? Peterson and Newton estimate the maximal duration of focused knowledge work at 3-4 Hours per Day.

I explicitly added the measure of intensity to my comment. I think Peterson is referring to really pushing oneself. That is a different story. Most deep work shouldn’t be done at a hundred percent effort.

If you train for weightlifting or powerlifting in a Russian Style workout, you accumulate high volume with a moderate intensity. You stay very calm and don’t hype yourself up before any lift. It is quite different from our western style of training. See the video below for your own amusement.

Having said that, there are many ways to increase the possible capacity for deep work. At the same time, you will decrease the drain on yourself if you don’t use up all your capacity. Some methods:

1. Mindfulness Meditation, besides its spiritual aim, is a training method for attention control. Mindfulness is a special state of attention, as there are many others. Start with 5 minutes in the morning and increase it to at least 20 minutes. You will see results after six to twelve months. Though it could be that you feel improvements much earlier because of additional acute effects.
2. Eat very clean, and rich in micronutrients. Eating brain is not only for zombies. Brain is very nutrient-dense and healthy. There is a simple reason for it: The brain needs a lot of nutrients. Therefore, it is nutrient rich. You doesn’t have to eat brain explicitly. But you concentration will improve if you switch from a pizza diet to a paleo-type diet. Eat fatty fish a couple of times a week. Consume foods like kale, berries and stinging nettles. And consider supplementing creatine and some adaptogens.
3. Do a combination of strength and endurance training. Both are needed for a healthy brain. Train daily, but briefly. A short 30–45min workout per day (as part of your morning routine) is sufficient. Mix in very light days (one day could be very slow jogging for 30 Minutes)
4. Engage in temperature stress. Cold training and sauna.
5. Break up your deep work with small breaks to shake up the tension. 3–5 minutes of movement every 40 minutes of work is good enough.
6. If you cannot concentrate on specific material, change the subject or the mode. If you wrote on your computer on psychology, switch do drawing a diagram on paper about some historical event.
7. Drink water!
8. Consume coffee three times a week, tops. It is a real mental drain.
9. Block everything not needed. You smartphone needs to be in another room. Switch off the door bell etc.
10. Cool down. After an exhausting deep work session you should go into nature. Take a walk in a park if you don’t have woods or true nature available. Just walk as long as you need to feel refreshed.

There are many lifestyle choices that matter. The brain is an organ. It needs to be healthy to be able to concentrate.

Should I not consider lectures as deep work and therefore save some concentration?

It depends on how you structure your studying. I wouldn’t do it. I personally had a very hard time to even stay awake during lectures. I think they are way too slow and not very engaging. I can listen to recorded lectures speeded up to 1.5x the original speed. To me, lectures are a drag and would cost me a lot of energy in a very inefficient way. Therefore, I didn’t engage a lot. Obviously, when I slept through them. :)

Structuring Deep Work-Units

As some of you may know, as a student you’re free to organize your time spent studying (I call it Deep Work-Units). So therefore I would like to know how you organize your learn-sessions on a daily basis.

I had different schedules. Here is one example:

• 0600: Wake up, morning routine (meditation, mobility)
• 0700: Creative work like writing new stuff.
• 1100: Strength Training, eating, relaxing.
• 1400: Non-creative work like emails or appointments.
• 1800: Crossfit-Style Training.
• 1900: Dinner. Read till sleepy.

Would you recommend doing all your knowledge work in the morning in a four hour stretch (of course divided by short breaks) or would you recommend to do two hours in the morning and two hours in the afternoon/evening?

The latter. But aim for more work. Don’t accept those limits.

I have to admit that I’d like the idea of finish the knowledge work for the day in an four hour stretch in the morning but don’t know about the efficacy of this method.

It is not all about efficiency but also on motivation. It is the principle of front-loading. Here it is front-loading of the day. When you have done all the things you consider duty, the rest of the day will feel free and joyful. The same thing goes for the week. If you did most, or even all, of your duties in the beginning of the week you feel very light towards the end. Adopting this habit will make you feel you can get everything done, instead of being stuck in doubt if you will ever get anything done/instead of always thinking about what’s still left unfinished.

Structuring the Semester

Do you process the lectures immediately (on the same day or the day after) or do you wait until just before the exam to process the lectures?

Let’s say I didn’t sleep through the lecture. Let’s say it was a seminar or a recorded lecture that I listened at 1.5 times the normal speed while I am walking in the woods, sometimes stopping to make some notes.

In that case, I would process the notes twice. One time, on the same day to order them, rephrase the knowledge atoms and make an effort to write down possible open questions and connections to different topics.

Example: On a lecture on Freudian psychoanalysis, you can ask if there is differing relevancy in different countries for his work. Is there a difference between Anglo-Saxon and German ways to approach Freud’s work? How would a behaviorist tackle an issue differently? Do similarities exist?

The second time would be days or weeks later. Then I’d process the notes like any notes to integrate them into my Zettelkasten.

How do you take notes during the lectures? Do you just mark down possible connections for the zettelkasten, write down interesting informations or do you take notes at all?

I do drawings and key points. In lectures I tend to do more of engagement notes that notes I actually use. Engagement notes are those types of notes that you do to process the material at the moment but then won’t store them.

How to you process the lecture afterwards? Just processing your notes, processing the PowerPoint-Slides of the lectures and feed them in into the zettelkasten?

I have a problem with processing lectures to my Zettelkasten: The content you gather is what one person says another said. I always go to the primary source. So, I’d use the material that is produced during lectures in three ways:

1. I use engagement notes for better depth of processing.
2. I’d process them immediately after that. This increases depth of processing even further. (And in consequence recall).
3. Then I’d use them as a guide to primary sources to process them fully.

Christian’s Lament: My capacity to concentrate depends. During my favorite days, which are long, uninterrupted work-days, I dry up noticeably after about 5 hours of programming at around lunch time. After a break for exercise and, ideally, some food, I can easily put in another 3 hours. Took me a while to get there, though, and the years prior I was happy if I could squeeze 3–5 hours out of any given day in total. Back when I was going to uni, I was slogging through lecture-filled days most of the time. The first semester was the worst: everything was new, all the people were strangers, and I was attending classes for 2 majors at once. (Which was a bad idea.) It pushed me to stay awake during lectures, but I didn’t post-process much. I was just too happy to be done with the day, exhausted from all the new info (especially all the maths major courses!), and that was that. Most processing, if at all, I crammed into the mornings I had to myself when I didn’t have to commute to uni early. Not all was wasted, but neither did I preserve a lot for my future self. Then again, I learned how to read and how to learn effectively, got accustomed to the way academics write, including 18th century continental philosophers, and got introduced to interesting mental models like systems theory. I value all that, and it shapes my thinking. I’m happy I’m not 16 and stupid anymore. But boy am I curious what I’d be able to write today if had known the basic skills earlier in life, and then had the motivation in uni to actually adhere to all the meta-knowledge. :)

(Pictyre by Irina Logvinenko on Pixabay)

Please welcome Gerrit Scholle, aka gescho from the forums! Gerrit kindly took the time to write up his recent thoughts as a self-contained blog post, with colored pencil drawings and all! Enjoy.

A recent forum post led me to an idea that seemed to be brewing in my subconscious for a little while.

In a Zettelkasten, the individual notes contain (ideally) singular grains of knowledge, or ‘knowledge atoms’ (named after the principle of atomicity). Those are joined with connections of many kind and form strings of thought. Going with the nuclear physics imagery, I like to call those connected notes ‘knowledge molecules’. Graphically, this looks as follows:

The red, blue and green structures in the image above are individual knowledge atoms stringed together into molecules.

Those molecules are the discussion threads about individual topics – when you start at the first connected note, down the rabbit hole you go. Other times, a molecule has a lot of short, stubby branches with definitions and examples in individual notes. In that case, it acts more like a topic category or an index for a topic.

These Knowledge molecules emerge because of the way you assimilate knowledge into your note system. Most often, you will work through one or more sources of knowledge and then input it into the Zettelkasten. Because a source will talk about closely related topics, they form molecules naturally. Where this isn’t the case, they will be attached to already existing molecules, shining new light on a topic, which is why you’re encouraged to look through already existing Zettels when attaching notes. In either case, the following behavior will occur:

As the number of knowledge molecules increases, there will be more and more connections between individual knowledge molecules. These connections emerge between individual atoms of separate molecules. With enough connections, these interconnections gain a meaning of their own:

A new (pink) molecule appears!

And the same, looking at the emergent knowledge molecule from the its own perspective, with traversable paths to already existing molecules branching out to the side.

They will either form over time, naturally, or are actually separate, deliberate knowledge molecules that are just joined with already existing ones. They can also be manufactured by hand, for example if a source suggests a connection between already existing topics. The reverse can also be true, where a topic has a subset of topics that form their own knowledge molecules.

There are two more ways to connect new information: Sequential notes about a source, and combinatory notes about a topic. These are typical ways of writing notes and can’t connect ideas together. To see why, let’s have a look at each of them:

Theses are sequential notes about two different ideas from two different sources, separated into their own files, be it hand-written or electronic document. Typical for sequential notes are book notes/excerpts and lecture notes.

The notes don’t need to be sequential in the strictest sense – even mind-maps or sketch notes about a book/subject are still individual documents about one source. As you can see, the notes you have written for the sources are independent of each other. You have extracted individual knowledge atoms from the sources, but they remain segregated into the context of the source text. You can’t readily connect similar knowledge atoms of different sources together. For that, you need to use a combinatory note:

These are combinatory notes about one topic from different sources – you pooled all the information about a topic or part-topic into one document. This happens when you do research on a topic – when you think about it, theoretical texts have the same structure of combining different sources into a new document, as well. The Synopticon mentioned in the original forum post also falls into the category of ‘combinatory note’, pooling together many sources about one concept after another. With combinatory notes, you lose the context in which the ideas stood previously – important clues for knowledge work. Also, the researched topic stands on its own. It’s difficult to interconnect combinatory notes about different research topics.

In a Zettelkasten, you separate the knowledge atoms of a would-be sequential note into individual, small documents instead of using monolithic book notes. You can do this while reading, as described in Christian’s article about reading notes. Or you split notes after the fact with already existing sequential book notes.

You would do the same when researching a topic: Writing Zettels about your research, or dividing combinatory research documents into smaller notes. Then you just need to make a note of relevant Zettels in your Zettelkasten – using emergent structures.

This is the resulting network of knowledge atoms in the Zettelkasten which combines sequential notes about a topic into emergent, new structures.

The emergent lattice structures of vertical and horizontal strings of thought are the unique selling proposition of the Zettelkasten Method. The interconnections between the knowledge molecules are the breeding ground for new ideas. This idea formation wouldn’t be possible without free-moving connections and the atomicity of concept which is typical of the Zettelkasten principle.

A few implications for real-life knowledge work with the Zettelkasten that result from this:

1. Focus on presenting concepts and ideas in an atomic way. Convert already existing lecture/book/article notes into atomized bits.
2. Connect your thoughts – use Folgezettel, structure/hub notes and backlinks thoroughly.
3. Look for similar Zettels across topic boundaries. Maybe read a few (semi-)random notes and wait for any associations coming to mind. For me, doing that and then going for a walk helps immensely for ideation.
4. Don’t just connect structure/hub notes of similar topics. Go right down to the individual note level in the connection and specify how notes are connected, either in those notes or with a new inter-connection note.
5. Traverse those inter-topic connections. Look at their beginning and end. Do you have any associations with that note sequence? Make a Zettel of it, connect them to already existing Zettels, grow the molecule!
6. Connections between molecules won’t form if you separate your notes into categories with different Zettelkastens or folders, which is why your Zettelkasten should be monolithic.
7. Consider the emergent molecules as strong contenders for being writing material – they should be the most novel ideas in your Zettelkasten.

This is a recent highlight from the forums. @nickmilo22 posted this the other day; we’d like to feature his essay on the blog so you don’t miss it. The following is a verbatim copy of his forum post, plus a link to @daneb’s post that @nickmilo22 added for context.

Something I read by @daneb on a recent post made me want to reflect on what the meaning and the purpose of knowledge processing is to me. I’m curious what others might think…

The Process forces us to think critically, categorize ideas, relate them to similar ideas, come up with metaphors/analogies/stories to better convey those ideas. The Process improves Thinking.

The Process solidifies thoughts you deem worthy of remembering, and by working The Process, you strengthen the ability to recall those worthy things in your life. The Process strengthens Memory.

Most importantly, it’s not the destination but the journey. Or put another way, the journey IS the destination. When I was young, my dad said we could open presents a day early if we solved his riddle. I chewed on the riddle trying to solve it. It was riveting to have a good riddle. Then my brother emerged from the computer room (having just been on the internet) and he blurted out the answer. You’d think I would have been happy to open presents; but instead I was disappointed because I was robbed of a juicy riddle. It’s not the answer, it’s the riddle itself that matters. Or put another way, the riddle IS the answer. It’s a means unto itself, full of its own joy and fulfillment. The Process is Fulfilling.

Trust the Process. The Process is the Answer.

Discuss this on the forum in its original thread.

We’d like to introduce to you the latest update to The Archive. It comes with multiple tabs and windows! You can now search for different things in different windows without losing the context of your previous work.

Multiple windows were an oft-requested feature since the early beta. The benefit is obvious: you can write a note, then search for a note to link to in a new tab without losing the context of the note you were writing.

So far, Sascha and I have used the Q-Trick to get back to a note quickly. You leave qqq in the note right where you are, which is a unique search string that works much like a bookmark. Browse around in the archive, copy some links, then search for “qqq” again to paste them where you left off. Multiple windows and tabs make this hack almost unnecessary. Working with a lot of notes just got simpler for everyone!

Download the new version from our website and check it out. This update is free for existing customers, as per our update policy and feature promise!

We’re proud to announce the latest big update to The Archive! It adds browser-like navigation, so you can get back to the results of an old search quickly.

This will be super useful in your workflow, especially when you often get lost in a rabbit hole. When you’re done following links, hit the back button to get to your starting point. No need to remember what exactly you did search for; no need to keep note IDs in the clipboard to get back to the start.

Download the new version from the website and check it out. This update is free for existing customers, as per our update policy and feature promise!

Here’s today’s fun story.

Sascha asks me if I remember the connection between an author (Heinrich von Kleist) and a concept (Maieutics). I hesitate a bit but then agree: yes, it’s his concept. The association feels just so familiar.

I look up the concept in my archive, searching for “midwifery” (“Hebammenkunst” is the German term Sascha suggested). I indeed stumble upon a note about a text by Heinrich von Kleist about the spontaneous and sequential creation of thoughts during conversation.

The note is from 2012. It’s not about the technique of midwifery at all. It’s more closely related to the topic of social systems.

Then I find the actual term I was looking for.

It’s at the very bottom, separated from the rest of the note by a series of dashes. It’s in an aside, if you will.

There I find the following line, probably added in 2014¹:

Sascha did look for this in association with the labels “midwifery”/maieutics.

Turns out Sascha and I embarked on this exact same search for Heinrich von Kleist’s concept about 5 years ago already. Why did I add this? Maybe last time we didn’t recall the author immediately and it felt safer to add this as a tag of sorts.

Even though we did recall the author this time, I’m glad I left the breadcrumb behind. The practice seems to produce surprises indeed :)

In a Zettelkasten – if done correctly – there will emerge layers of evidence. These layers represent the necessary processing steps from data to knowledge. It is very rare that raw data is put into the archive. You can do it. But normally, you will process the data outside your archive. So I will ignore this possibility. The three layers are:

1. Data description and patterns.
2. Interpretation of descriptions and patterns.
3. Synthesis of patterns, descriptions and interpretation.

First Layer: Patterns

The first layer of evidence is a description of data. I will call that the phenomenological layer. This description is limited to meaningful patterns in the data – or a meaningful lack of patterns, which could be considered as a pattern in itself. If you read an empirical study, for example, you come up with patterns that you can observe and the conditions on which the patterns can be observed.

The most common example is a correlation between two variables. An example is the very strong 0.9 correlation of people who drown while in a swimming-pool and the power output of US nuclear power plants between 1999 and 2009:

Correlation has very little to do with causality. Even a correlation as high as in the example above means nothing. It is just a quantified pattern. In this case, the observation of the pattern is as follows: with a positive correlation (pattern: If more then more, if less then less) of 0.9 (quantified value of the pattern) the power generated by US nuclear power plants changed at the same time people drowning in a swimming-pool changed. Correlation is a pattern extracted from data or a pattern imposed on the data, depending on the epistemological dogma you follow.¹ Either way, you only have data and patterns.

Second Layer: Interpretation

The next layer of evidence is the interpretation of data patterns. The phenomenological layer meant you describe what you saw. Here, you interpret why you saw it.

Now the concept of causality can come into play. You can explain the correlation above by saying: Drowning people in swimming pools generates amplifiers for the nuclear power plants in the U.S, and that’s why when more people drown in swimming pools, more energy is generated in nuclear power plants.

This layer often breaks and needs regular maintenance. In the words of Nassim Taleb:

Theories are superfragile; they come and go, then come and go, then come and go again; phenomenologies stay, and I can’t believe people don’t realise that phenomenology is “robust” and usable, and theories, while overhyped, are unreliable for decision making – outside physics.²

I don’t go as far as Taleb in saying that theories are unreliable,³ yet in practice it proves to be true . The explanation for correlation above is ridiculous. But it appears ridiculous only because we operate in a field of many knowns and don’t need to scrutinize the explanation. If we operate in the field of the unknown, though, or worse: in field of unknown unknowns, it is very likely that we come up with theories that in hindsight will look ridiculous, too.

A very common mistake I have made a lot of times is ignoring the difference between those two layers. I processed empirical studies but then mainly wrote zettels in the layer of interpretation. This was not a problem as long as I could remember the individual studies. But with time I couldn’t recall the conditions of the studies any longer and wasn’t confident in using those notes. Nowadays, I always write down what the actual study design was.

Example: When I did research on the effects of the low carb diet on blood cholesterol, I didn’t consider the effects of the calorie content of the tested diets. So I had to go back to the studies and filter them for the calories tested. For you non-dieters: If you have a high cholesterol and you lower the calories and lose weight, your cholesterol comes down – no matter which diet you followed before the study. But that doesn’t mean that you just have to control for the calorie content between the tested groups. You have to decide if you test a high calorie or a low calorie diet (caloric surplus or deficit). You have to decide if you have a high or low g-flux (high = train a lot, eat a lot; low = train less, eat less). And you have to decide what you test. If you instruct the participants to eat a certain diet, you don’t test the diet but the instructions of the diet. And so on and so forth … You need to be meticulous with processing studies on nutrition. It pays off a lot if you note what the researchers actually did. :)

Another Example: Very few journalists have the ability to understand science (or humanities, or anything at all sometimes). If you read an article written by a journalist you can be sure that it barely scratched the second layer. My advice: Don’t consume this kind of media at all if you want to be informed on facts instead of opinion. (Most documentaries are just propaganda!) Even though this problem with media seems to be a very recent development, it is as old as mass media itself.⁴ A journalist who did an excellent job is Johann Hari in his book Lost Connections: Uncovering the Real Causes of Depression – and the Unexpected Solutions.

Last Example: If you read a book, you mostly read secondary literature. That means that you read a text that is about texts. Scientific reviews, self-help literature, history books, you name it. Most of what we read is second-hand knowledge. In the beginning of my Zettelkasten work I once read all the studies mentioned in footnotes of a book on nutrition that was famous back then. I was quite surprised at the bias and flawed approaches of the authors. So I pledged myself I would never rely on someone else’s interpretation of phenomena. (See first example.) To this day, I am happy with that pledge and its consequences. It takes some time to process a book, but with the barbell method of reading I am happy with my productivity.

Third Layer: Synthesis

The third and last layer of evidence is the level of synthesis. This layer is to the second what the second is to the first. You take the entities as building blocks for the bigger picture. You string together hypothesis, theories, models and more create something that is useful, interesting, entertaining and what not.

Christian pointed out that this section is suspiciously short. That is because this layer is on the edge between your Zettelkasten and your writing environment. We are about to leave knowledge work and approach writing. I want to focus on the former.

Further Examples

Here are examples of my own work for illustration.

In Fiction Writing

1. Phenomenon: There is an increasing number of sex doll brothels that open around the world.
2. Theory/Interpretation: The interaction between the relatively free market and the modern hedonistic materialism generates products and services that aim for profit by maximizing hedonistic pleasures for as many people as possible.
3. Entertaining/Speculations: I created a cyberpunk world that explores the consequences of a world in which sex doll brothels are the norm, no natural food exists, no physical labor is necessary etc. Then through characters with different backgrounds I explored if one can, would, or even has to rebel against the tyranny of comfort and lack of challenge.

In Health and Fitness

1. Phenomenon: One study showed that some training can increase the relation of fat to carbohydrate you use for up to 24 hours.⁵ Another study showed that in overweight people, fasted training in the morning results in a ad libitum reduction of calories reduction of carbohydrates.⁶
2. Interpretation: There is an acute effect on the metabolic flexibility that is distinct from the general metabolic flexibility one has and that is used as a model in current science.
3. Tool: You could do very brief and intensive exercise before your breakfast: One set to failure of each exercise: pushup, rowing in rings and squats. After that you do a maximum one-minute-sprint on an ergometer-bike. That will increases you ability to stay away from carbs and should reduce your cravings.

In Psychology

1. Phenomenon: Serotonin is part of the physiological substance that constitutes status.⁷ Cooperations and alliances are integral part of status.⁸
2. Interpretation: Serotonin is a regulator of negative emotion and emotion in general can be optimized via dominance and cooperation.
3. The broader picture: You cannot have optimized serotonin while being weak (lack of dominance) or being alone and only dominant (lack of altruistic behavior). Depression as a side effect of deregulated serotonin can only be considered a physiological disorder if there is no disorder in the rest of one’s life, like being isolated or lacking competitiveness. Therefore, self-development depends partly on the correct (factually and morally) application of status principles in your life. Computer game addiction is an example of pathology and developing your (creative knowledge work) business to support your loved ones is an example of healthy behavior.

In Business

1. Phenomenon: Feature Requests are truly that. Users normally express their wishes in the form of a specific app behavior. E.g.: The Archive should allow for multiple tabs. The Archive should allow for multiple windows.
2. Interpretation: Feature Requests depend on the individual representation of the problem. They are the concrete manifestation of more abstract problem. User say “I want multiple tabs and multiple windows!” rather than “I have difficulty to handle complex projects with a lot of notes and layers. I think that multiple tabs and windows would help me.”
3. Practical Application: Ask for the specific use cases. Ask for the perceived problem and try to get the actual problem and not the individual representation of the problem that manifests in a specific feature request. You can decide which steps you need to take much better once you understand the problem in this context.

What Can You Do to Improve How You Deal With Those Layers?

That was a lot of theory and examples. Let’s dive into some of the practical implications for creative knowledge work.

1. Divide those layers

Your notes should always reflect those different layers of evidence. They build on each other, not only in an abstract way. Either a note belongs to one of the layers, or it itself is divided according to those three layers. In the first case, it only contains phenomena, interpretations, or integrations. The notes are then linked to each other: An interpretation note links to a phenomenon note as reference, the integration notes link to the interpretation notes. In the second case, the note contains a description of phenomena at the top, followed up with the interpretation of the phenomena and the integration into the bigger picture.

It is not always possible to be that clean. But take it as an ideal to strive for. It is also a tool for thinking which is not an incidence. The Zettelkasten Method is the concrete manifestation of the abstract principles of good thinking practices and knowledge creation.

2. Read and learn with those layers in mind

The principle of layered evidence is either correctly applied or violated. You can read and learn from both. Sometimes, authors don’t care if they reference secondary or primary literature. If you want to work correctly, you’ll have to deal with this behavior. If you read something interesting but the facts are not derived from primary literature, you can’t trust those facts. Always – at least at random – check if the primary literature is used correctly. I fell flat on my face after I first discovered how widespread mishandled and misused primary resources are. There are a lot of people who want to sound scientific as a means of marketing.

So, always check the primary literature if there is any. Take texts that cite only secondary literature with a great heap of salt.

Christian’s Comment: One of my first real Zettelkasten projects was in 2009, at University, when I read Kant’s Critique of Pure Reason. I didn’t understand a lot. The language was weird, it took ages to extract any meaning at all, and it was an overall cumbersome undertaking. (Funnily, nowadays my brain seems to have adapted to more complex literature and weird sentence structures and I can read similar texts quicker.) Still, I found parts to be inspiring, thought-provoking, or irritating. I often could not pin down what was going on in my head and why a sentence struck me as relevant. So I ended up re-stating what Kant said in my own words, but not really: I just rephrased what I thought he wrote, but since my understanding was sub-par, I could not get creative and summarize the content properly. I was also afraid to lose information in the process. Sascha’s post and separation of layers reminds me of my struggle and I think that I could’ve used this approach for non-empirical reading of Kant as well: (1) What does Kant say, quoted? (2) What do I think does this mean? Why is it interesting? How does secondary literature interpret the part? (3) … well, there’s not much practical application of Pure Reason, besides beginning to think differently about the universe and everything of course.