It might seem absurd that something as simple as a method of highlighting could be so important to a person’s productivity and learning. Even I’m surprised that’s turned out to be the case.

But as testimonials and stories have streamed in from people putting it to use around the world, I’ve become convinced that it is the beginning of a sea change in how we consume information. Just as mindless materialism has given way to mindful consumption, as we’ve realized that more is not always better, I believe we’re starting to see a parallel shift in our attitude toward information consumption. We’re learning that making is often more satisfying than consuming.

“Economic development is based not on the ability of a pocket of the economy to consume but on the ability of people to turn their dreams into reality”

–Cesar Hidalgo, Why Information Grows

College students have said they will never take notes any other way (“You mean my class notes could be useful even after I graduate?!”). Elite consultants have used it to help their clients make sense of the massive amount of data they have at their disposal. I’ve been happily surprised to hear experienced content creators tell me that Progressive Summarization has reinvigorated their reading and writing.

Even if you decide not to adopt the summarization method as I’ve described it in this series, I want to outline what I believe to be the universal principles of knowledge capture in the digital age.

In no particular order:

  1. Interaction over consumption
  2. Balance detail with discoverability
  3. Opportunistic compression
  4. Intuition over analysis
  5. Focus most of your attention on the most valuable information
  6. Tacit knowledge over explicit knowledge
  7. Value questions over answers

Interaction over consumption

Most organizing focuses on containers and categories, obsessing over where things should be stored. But the digital world is changing too fast to justify all this upfront work of questionable value. We need quick, lightweight methods of annotating and saving content in the stream of our daily work.

The best way to do this is to maximize the time spent interacting directly with the content itself. This deep engagement helps us learn at the same time as we organize, forcing us to make snap decisions about what to keep and what to ignore. This mirrors how our biological brains work: we don’t “look up” our memories by name or folder or tag; we reach directly for the content itself.

There is a parallel here to the early days of the world wide web. Yahoo created an empire by manually categorizing the pages they thought were important into an index, like a front page to the web. But Larry and Sergei took a very different approach with Google: their PageRank algorithm showed that the web did have a structure, but not one created by humans. The structure could emerge from the content itself, and the links between content. We can use the same technique by allowing our highlights to reveal the structure inherent in our notes, saving us the effort of creating it ourselves.

Balance detail with discoverability

Having the right knowledge is no longer our biggest challenge. Finding it is. We solved the problem of preservation – we can now keep all our data forever. But in the process created a new one – there’s now so much data the task of finding what you’re looking for is hopeless.

Important research is going stale in university libraries because scientists have no idea it’s there. Business problems that others have already solved linger on for years, because the time it would take to discover those solutions is untenable. The most proven methods for self-improvement, which could change the lives of millions, remain buried deep in books and courses. The knowledge is out there, but the need for greater discoverability has never been greater.

We should take every opportunity to shift our efforts from acquiring ever more detailed notes, to surfacing the keywords, key ideas, and other meta-data of the notes we already have. Progressive Summarization encourages us to shed details at every stage of compression, so the truly unique points can shine brighter.

Opportunistic compression

As with P.A.R.A., we can’t afford to be doing multiple passes on sources that might never be used. We need to add value to our notes every time we touch them, allowing these touches to accumulate over time into a highly compressed artifact that can be used in different contexts.

There is a parallel to how ant colonies work. Instead of a central leader who directs where each ant should go, they use a decentralized solution. Every time an ant finds food in its random wanderings, it brings it back to the nest, leaving a special trail of pheromones in its wake. Other ants come across this trail, and follow it to the source of food, leaving even more pheromones as they bring some back. Over time, the paths to food are brightly marked for all to see, with no central direction required.

Pheromone trail on the left, which is picked up by ants as they come across it on the right

Similarly, by “leaving a mark” of highlights every time you read a note, you allow your Future Self to pick up instantly where you left off, whether it was yesterday or a year ago. You could view this as a “collective intelligence” of all your selves working together across time. By continually “designing” notes for your Future Self, you follow a “pay it forward” strategy that you yourself get to collect on at every future point!

Intuition over analysis

The best-selling book Thinking Fast and Slow by Daniel Kahneman made waves when it was published in 2011. It presented a dizzying array of experiments over many years showing that there are actually two decision-making systems in the brain: System 1 was intuitive, fast-acting, and decisive, while System 2 was slower, more rigorous, and more considered.

But I think the conclusion many people took away – that they shouldn’t trust the quick decisions made by System 1 – was the wrong one. Another interpretation is that we can use System 1 where it excels, making decisions as quickly and intuitively as possible, because we know that System 2 will come along afterward to clean up our mistakes.

There is great value in “low fidelity” (rough and low-resolution) pictures. Think about why a quick sketch on the back of a napkin is such a universal symbol of creativity. By its nature, no one expects it to be accurate. You can see through to the essence of the idea, because you’re not getting distracted by the details.

Because knowledge capture takes place so early in the creative process, before you have any idea how the knowledge will be used, it must be low fidelity. You can’t afford the time and energy to minutely analyze and critique every idea that comes in the door. This will only create a backlog of ideas you don’t have time to process.

PS is designed to allow you to use the lightning-fast System 1 as your filter, instead of dropping into (System 2) analysis mode. It recognizes that “saving” a piece of information is just the beginning of capture. By staging the distillation process in a series of discrete layers, it allows the main idea of the source to slowly emerge. Each of these layers allows you to “leave behind” the parts that are good, but not great.

Focus most of your attention on the most valuable information

One of the deepest principles in all of Building a Second Brain is that the value of information is not evenly distributed. This is why most organizational schemes and tagging systems are so flawed: if they force you to apply equal attention to every bit of information you consume, you’re behind before you’ve even begun.

The value of information is concentrated in very particular places: the throwaway line at the end of a chapter that completely changes you how view something; the one painting in the museum that leaves you transfixed; the one scene in a movie that brings you to tears. I would argue that the purpose of all the other stuff – the backstory, the examples, the details – are just to provide context to these pinnacle moments.

This is what distinguishes PKM from its precursor, PIM (Personal Information Management). PKM concerns itself less with comprehensive sources. The initial batch of information you bring into your PKM system (Layer 1) includes only the best excerpts and snippets. You then build on that foundation with your own interpretations, observations, and experiences. Even something as simple as boldfacing (Layer 2) starts to add your own interpretation.

What you are really doing as you add the layers of PS is structuring your attentional environment. You are creating affordances and signposts that signal to your Future Self where to concentrate their attention for maximum return. This is a feature of all successful visualization tools. Think of Google Maps: it offers 18 separate levels of detail, from your street to the entire globe. Each level serves a very specific purpose, only showing the detail that’s relevant to that elevation. But with a simple pinch, new levels of detail come seamlessly into view. PS seeks to do the same with text.

At a minimum, focusing your attention on the most interesting knowledge is more enjoyable. At best, it allows you to greatly increase the density of knowledge you can hold in your head, potentially allowing you to take on much bigger intellectual challenges.

Tacit knowledge over explicit knowledge

In the age of Google, it might seem futile to carefully curate and summarize a personal store of knowledge. With the latest and greatest answer to any question right at our fingertips, why is it worth “collecting” our own answers?

What you are doing in creating a “second brain” is not rivaling Google Search, but creating an alternative: a collection of tacit knowledge, instead of explicit knowledge. Explicit knowledge can be programmed and categorized by a computer. It includes formal, systematic, rational knowledge that can be expressed in numbers and transferred electronically.

But over time, it will be tacit knowledge that has the most value. This includes personal insights, intuitions, and hunches. It is the knowledge of bodily experience, the “senses” that are impossible to describe, except through art and music. Tacit knowledge is not visible or easily transferrable, since it is rooted in an individual’s experiences and emotions.

PS is a training ground for identifying tacit knowledge. It starts off with the most basic form: recognizing something you know in the experience of another. Using resonance as your filter, you will often highlight things you “already know,” but never quite were able to express. Everything you read or watch becomes a mirror, prompting what you already know tacitly to emerge into consciousness as explicit knowledge, which you can then write down and make use of.

Value questions over answers

In the mid-1960s, researchers Jacob Getzels and Mihaly Csikszentmihalyi studied students at the School of the Art Institute of Chicago to discover what led to successful creative careers. Giving them a variety of objects and asking them to compose a still life drawing, two distinct groups emerged: those who hastily chose an object and proceeded straight to drawing, and those that took much more time, carefully considering different arrangements.

In their view, the first group was trying to solve the problem that had been given to them: “How can I produce a good drawing?” The second group was trying to find a problem in the situation they were presented with: “What good drawing can I produce?” A panel of art experts reviewed the drawings and rated the latter group of “problem finders” works as much more creative than the “problem solvers.” Following up on the students 18 years later, they found that the problem finders “were 18 years later significantly more successful–by the standards of the artistic community–than their peers who had approached their still-life drawings as more craftsman-like problem solvers.”

The researchers went on to conclude that “The quality of the problem that is found is a forerunner of the quality of the solution that is attained…It is in fact the discovery and creation of problems rather than any superior knowledge, technical skill, or craftsmanship that often sets the creative person apart from others in his field.”

A “second brain” is not meant to be launched fully formed from day one. It is meant to be born as a child: endlessly curious, always asking “why?”, and never quite satisfied with the answers it’s given. A profound and troubling question is worth far more than a mere answer, because it can fuel a lifetime of creative exploration.

“The Purpose of the Commons (and of my Library): To be a repository that contains, not just glimpses of the truth, but fragments of the false, the possible, the impossible, the mystic, the concrete, the ludicrous, the believable, the unbelievable, the unspeakable, the beautiful, the ugly, and the uncategorisable. It should not be a source of confirmation and certainty, but a generator of disquiet, doubt, confusion and uncertainty.”

–Umberto Eco, The Name of the Rose

Working with others

Progressive summarization may seem like a solitary activity, and it can be if you want. But I think it also enables cooperation and collaboration at a deep level. Summarizing a text for your Future Self is remarkably similar to summarizing it for someone else. Sharing the compression you’ve done now and asking someone if they can “get the gist” is an excellent test of how well you’ve done it.

But it goes beyond this: what you are creating with progressively summarized notes is a durable building block of knowledge. The context you’ve preserved through multiple layers, and preserved in the form of original titles and links, allows it to survive through time and across projects. It lies somewhere between pithy one-liner takeaways and full-scale book reviews, giving you hints and suggestions of insights while inviting you to dive deeper if needed.

Millions or billions of people have solved some of the very same problems again and again throughout history. It’s amazing to me to think that every human being has to, in some respects, start from nothing, building up their core knowledge from scratch before they can do anything useful. How many years are wasted because we don’t have ways of delivering succinct packets of knowledge right at the moment they’re needed? How much time and money is wasted dumping vast amounts of material on students upfront, hoping they’ll somehow remember it for years until it’s actually needed?

Progressive Summarization is just one small building block in a new way: Just-in-Time Learning. Breaking education down into small parts, and distributing it across time to match where it’s needed. PS concerns itself with how these small parts are constructed, making them solid building blocks in an edifice that future generations can build up over time.

As MIT economist Cesar Hidalgo says in his book Why Information Grows, “our ability to crystallize imagination, to build products, gives us access to the practical uses of the knowledge and knowhow residing in the nervous systems of other people.” By publishing our packets of knowledge in the form of products, we make them available for others to stand on, whether they are alive now, or 100 years from now.

Emergent self-organization

The holy grail of digital organization is a system that is “self-organizing.” That is, all the mundane administrative tasks of sorting and categorizing are done for you, freeing you to focus on creating.

I don’t think we have to wait for advanced artificial intelligence to create this effect. We can use simple associative tools, designed to consistently put in front of us combinations of ideas that yield productive thinking.

I’ve noticed that, with all the most potent triggers I’ve come across over years exposed, my “second brain” does indeed seem to have an emergent intelligence of its own.

Notes seem to pop up at serendipitous times, to seek each other out across boundaries, to conspire together to push my thinking in certain directions. It’s almost like my second brain has its own beliefs, its own priorities, its own conclusions.

You could almost say, it’s almost like my second brain has a mind of its own.

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