Concepts
Commonplace Book – The centuries-old practice of collecting quotes, ideas, and observations in a single place. A historical ancestor of personal knowledge management. Extended Mind Thesis – The philosophical argument that cognition isn’t limited to our brains – tools and environments are part of how we think. Generation effect – Information you generate yourself is remembered significantly better than information you passively receive. Levels of processing model – The depth of cognitive engagement with information determines how well it is retained. Writing, summarizing, and connecting ideas produces stronger, more durable memory than passive reading. The Magical Number Seven, Plus or Minus Two – George Miller’s landmark 1956 paper establishing that working memory can hold only a handful of items at once. Personal Knowledge Management – The broader field of practices and tools for capturing, organizing, and retrieving what you know. Zeigarnik effect – Uncompleted tasks occupy mental bandwidth disproportionately – the mind keeps returning to open loops. Zettelkasten – Niklas Luhmann’s slip-box method for building a network of atomic, interlinked notes.Books
Core methodology
The Bullet Journal Method by Ryder Carroll – An analog system for tracking the past, organizing the present, and planning for the future. Getting Things Done by David Allen – The classic methodology for capturing, organizing, and executing on everything that has your attention. The Organized Mind by Daniel Levitin – How the brain handles information overload, and why externalizing your thinking matters. Thinking, Fast and Slow by Daniel Kahneman – How the mind works, its limits, and its biases. Essential context for understanding why external systems matter. A New Method of a Common-Place-Book by John Locke – A system for categorizing ideas so they could be retrieved when needed – not just recorded and forgotten. Leonardo da Vinci by Walter Isaacson – Specifically Chapter 5: Leonardo’s Notebooks. An example of what it looks like to externalize a restless, relentlessly curious mind.Philosophical foundations
These following entries may cause you to pause. None of them are books about note-taking, productivity, or knowledge management. If the connection to an extended mind system isn’t immediately obvious, that’s fair – let me explain why they’re here. All three are asking the same underlying question: what does it actually mean to think? And more urgently – are we doing it? On the Shortness of Life by Seneca – Written around 49 AD, Seneca’s argument is deceptively simple: life isn’t actually short. We just squander most of it – on distraction, on busyness, on obligations we never questioned, on other people’s priorities we absorbed without noticing. The person who lives with intention and protects time for genuine thought lives far more than the person who merely stays busy. Leisure: The Basis of Culture by Josef Pieper – Written in 1948 in the rubble of postwar Germany, Pieper looked at the modern world and saw a society that had collapsed all of human life into work. Not just physical labor – but a posture of relentless utility, the sense that every moment must be productive and every thought must serve some function. He called this “total work.” His argument: genuine thinking – the kind that produces wisdom, culture, and meaning – requires a fundamentally different mental posture. One of stillness, receptivity, openness. The ancient Greeks called it scholē. We get the word “school” from it, which tells you something about how far we’ve drifted from the original idea. Pieper makes the case that the frenzied need to always be doing, producing, and optimizing is itself a kind of spiritual poverty – and that a society that can’t protect space for genuine contemplation will eventually hollow itself out. That’s the problem this system exists to help solve, at least in part. Modern life is not designed for deep thinking. The notifications, the obligations, the endless grind – they’re not going away. So you have to be intentional about creating the conditions Pieper is describing. An extended mind system offloads the cognitive overhead of daily life – the tracking, the remembering, the deciding – so that your mind can actually be free to think. It gives you your scholē back. The Great Conversation by Robert Maynard Hutchins – The introductory essay to Great Books of the Western World (1952), a 54-volume collection compiling the foundational texts of Western thought from Homer and Plato through Darwin and Freud. Hutchins’s argument is that Western civilization isn’t a fixed inheritance – it’s an ongoing conversation across centuries. Each generation engages with the ideas of those who came before, challenges them, builds on them, adds its own voice. That conversation is both an intellectual inheritance and a civic responsibility. Hutchins makes clear that the conversation doesn’t continue on its own. It requires people who think, who read, who form views, and who bother to articulate them. The extended mind system is one way to participate. You can’t join a conversation you know nothing about. This system carves out a space for recording what you know and writing down what you think – an honest record of whether you’re actually engaging with ideas at any depth, or just moving through days.Last update: 2026.03.07