The Commonplace Book: An Ancient Practice for Modern Thinkers

Before Evernote, before Notion, before the internet, thinkers had commonplace books. Marcus Aurelius kept one (his “Meditations” grew from it). John Locke developed an indexing system for his. Thomas Jefferson filled volumes. Virginia Woolf, H.P. Lovecraft, and Ralph Waldo Emerson all maintained them throughout their creative lives.

A commonplace book is a personal collection of ideas, quotations, observations, and fragments gathered from reading, conversation, and experience. It’s not a diary. It’s not a journal. It’s a curated library of thought—your intellectual autobiography written one fragment at a time.

What Goes in a Commonplace Book

Anything that strikes you. The only criterion is that it resonated enough for you to want to keep it. Common entries include:

Quotations from reading. The passage from a novel that stopped you cold. The argument from an essay that changed your thinking. The sentence from a biography that illuminated something about human nature. Copy them by hand—the act of transcription engages your memory differently than highlighting in a Kindle.

Your own observations. An idea that occurred to you on a walk. A connection between two seemingly unrelated things. A question you can’t answer. These original thoughts sit alongside the borrowed ones, and over time, the distinction between the two blurs productively.

Facts and data. A historical date. A scientific finding. A statistic that surprised you. The commonplace book as a factual reference has a long history—before search engines, these personal knowledge bases were how educated people stored and retrieved information.

Poems and lyrics. Verse that moved you, copied in full or in fragment. Poetry is compressed wisdom, and having it in your own handwriting makes it feel more personally yours.

Overheard dialogue and conversation fragments. A stranger’s comment on the train. A friend’s off-hand remark that carried unexpected weight. These bits of real speech often spark creative ideas or illustrate human truths better than any polished quote.

Definitions and word discoveries. New vocabulary, interesting etymologies, words from other languages that name something English doesn’t.

How to Organize (or Not)

The traditional commonplace book has no organization. Entries go in chronologically—whatever you encountered today goes on the next blank page. This creates a pleasingly random quality: a passage from Seneca sits next to a recipe, which sits next to an overheard conversation, which sits next to a scientific paper’s conclusion.

If this randomness bothers you, there are structural options:

The Locke method. John Locke developed an indexing system where you create a two-page index at the front of the book, organized alphabetically by the first letter and vowel of each entry’s keyword. When you add an entry, you note the page number in the index under the appropriate letter-vowel combination.

Color-coded sections. Use different colored inks for different types of entries: blue for quotations, black for personal observations, green for facts, red for ideas to develop. This creates visual categorization without separate sections.

Thematic collections. Start a new spread for each theme or topic that interests you: creativity, death, humor, economics, nature. Add to each spread as you encounter relevant material.

The digital hybrid. Keep a physical commonplace book but maintain a digital index (a simple spreadsheet) that lets you search by keyword, source, or date.

For writers, the unstructured approach often works best. The random juxtaposition of ideas from different sources is where creative connections happen. You flip through looking for a quote and stumble across an observation that sparks an essay. That serendipity is a feature, not a limitation.

Choosing Your Book

A commonplace book should feel permanent and substantial. This is a volume you’ll keep for years and return to indefinitely.

Leuchtturm1917 A5 hardcover (~$20): Numbered pages and a table of contents make organization easy. The 249 pages will last most people six months to a year of regular collecting. See [INTERNAL: leuchtturm1917-notebook-review] for details.

Midori MD Notebook A5 (~$12): Cream-colored paper with a beautiful texture. The minimalist design lets the content be the focus. Excellent for fountain pen users.

Moleskine Large Expanded (~$25): 400 pages in a slim-ish hardcover. If you fill commonplace books quickly, the extra pages mean fewer volumes to store.

Handmade or leather-bound journals: A commonplace book is perhaps the one context where a beautiful journal is justified. You’ll keep this book for decades. A $40 leather journal that makes you want to open it and write is money well spent.

Whatever you choose, use good paper. You’ll be writing in this book with whatever pen you have on hand, and it should handle everything from fountain pen ink to ballpoint. See [INTERNAL: best-paper-for-fountain-pens] if fountain pens are your primary tool.

The Commonplace Book as a Writing Tool

For writers, a commonplace book is more than a collection—it’s a creative reservoir. Here’s how it feeds your work:

Style development. Copying great sentences by hand teaches you sentence construction the way copying master paintings teaches art students. The physical act of reproducing good prose trains your own instincts.

Idea cross-pollination. The random juxtaposition of entries from different sources creates unexpected connections. A passage about whale migration sitting next to a quote about loneliness might spark a metaphor you’d never have found otherwise. This associative thinking is the engine of creative work.

Research accumulation. If you’re writing about a particular subject, relevant passages naturally accumulate in your commonplace book over months or years. By the time you start a project, you’ve already gathered material without trying.

Voice collection. Recording dialogue, speech patterns, and distinctive phrasings builds a catalog of human voices that enriches your fiction. See [INTERNAL: character-voice-development] for why this matters.

The Practice

Always carry something to capture with. A pocket notebook, your phone’s notes app, even index cards. You can’t predict when you’ll encounter something worth saving. Transfer these captures to your commonplace book during a regular session.

Transcribe by hand. I know it’s slow. That’s the point. Typing a passage takes seconds and leaves almost no memory trace. Hand-copying a paragraph takes minutes and embeds it in your mind. You’ll remember passages you’ve hand-copied in ways you never remember highlighted e-book passages.

Record the source. Author, title, page number. Future you will want to find the full context. Getting this habit right from the start saves enormous frustration later.

Date your entries. Not because the date matters to the content, but because it creates a timeline of your intellectual interests. Looking back through a commonplace book is like seeing the evolution of your mind.

Don’t curate too aggressively. If something struck you, write it down. Even if you’re not sure why. Even if it doesn’t seem important. Your subconscious may be collecting material your conscious mind hasn’t found a use for yet.

The Long View

A commonplace book gains value with time. Your first volume might feel like a random collection. Your fifth volume is a map of your mind—your evolving interests, your deepening understanding, and the invisible threads connecting everything you’ve ever read and thought.

Writers like Ryan Holiday and Maria Popova have discussed how their commonplace books (physical and digital) are the foundations of their creative output. Every essay, every book, every idea starts as a fragment captured in the moment of encounter.

Start one today. You don’t need a system. You don’t need a plan. You need a good notebook, a pen, and the willingness to pay attention to what moves you. The rest happens by accumulation.

If you’re interested in a more structured approach to capturing reading specifically, [INTERNAL: reading-journal-guide] covers systems designed for processing books and articles.