A commonplace book is the notebook for everything worth keeping that didn't come from you. A paragraph from a novel, a statistic from a report, a line a friend said at dinner, an idea from a lecture — copied down, filed under a heading, and findable years later.
It's an old practice. Students at Oxford and Harvard were taught to keep commonplace books for centuries, and it has come back because the problem it solves hasn't gone away: most of what we read disappears within a week.
Quick answer
A commonplace book is a personal notebook for collecting things worth keeping from what you read and hear — quotes, passages, facts, ideas — organised by subject rather than by date. To keep one: copy the passage and its source, add a line on why it matters, file it under a broad heading, and keep an index at the front so every heading can be found again.
What a commonplace book is
The name comes from "commonplaces", the stock arguments and quotations that students of rhetoric collected to use in their own writing. Over time the notebook outgrew that purpose. According to Wikipedia's history of the commonplace book, they have held notes, proverbs, quotes, letters, poems, recipes, tables of weights and measures, prayers and legal formulas — essentially anything the owner found useful enough to keep.
Two features separate a commonplace book from other notebooks.
It collects outside material. A diary records your day and a journal records your thinking. A commonplace book records what you encountered — the best of what you read, heard and noticed — with your own thinking added as commentary.
It's organised by subject. Entries are filed under headings like work, language or grief, not by the date you wrote them. That's what makes it a reference you can use, rather than a log you'd have to read from the start.
The distinction from a diary is worth a moment, because the words get blurred: we covered the difference between a diary and a journal separately, and a commonplace book is a third thing again — a library rather than a record.
How to keep a commonplace book
The method fits on an index card. Five steps:
1. Pick one notebook and number the pages. A hardback A5 is the usual choice because it survives years of use. Leave the first four pages blank for the index.
2. Copy only what you'd want to find again. The bar is not "interesting" — almost everything is interesting. The bar is "I'll want this later": a passage that changed how you see something, a sentence you'll want to quote, a fact you keep looking up.
3. Always write the source. Author, title, page or link. A commonplace entry without a source is a quote you can't use and can't check.
4. Add one line of your own. Why did this matter? What does it connect to? This line is where a collection becomes thinking. Weeks later it's often more valuable than the quote itself, because it tells you what you were working out at the time.
5. File it and index it. Write the entry under an existing heading, or start a new heading on the next blank page and add it to the index at the front. If an entry fits two headings, file it under one and add a cross-reference under the other.
That's the whole method. The most common failure is spending a month designing categories before writing anything. Start with five broad headings and let the book tell you where it needs more.
Commonplace book ideas: categories to start with
Good categories are broad enough to fill and specific to what you actually read. A starting set that works for most people:
| Heading | What goes there |
|---|---|
| Ideas about work | Management, craft, decisions, career |
| Writing & language | Sentences you admire, words, style notes |
| People | Relationships, friendship, family, conversation |
| Mind & health | Psychology, habits, sleep, mental health |
| Money & time | Spending, saving, attention, priorities |
| History & places | Facts and stories worth retelling |
| Lines worth quoting | Short sayings that don't belong anywhere else |
| Unsorted | Anything you're not sure about yet |
The Unsorted heading matters more than it looks. Without it, the hard-to-categorise entries — often the most interesting ones — don't get written down at all.
Beyond quotes, a commonplace book can hold recipes, packing lists, gift ideas, book recommendations and favourite poems. If the notebook starts to feel like a bullet journal's collections, that's because collections are a modern descendant of the same idea.
How John Locke indexed his commonplace book
The most famous method came from the philosopher John Locke. He wrote a treatise on commonplace books in French in 1685, published in English in 1706 as A New Method of Making Common-Place-Books.
Locke's problem was the index. A commonplace book kept for decades has hundreds of headings, and an alphabetical list breaks down when you can't predict how many headings will start with each letter. His solution indexed every heading by two letters: the first letter of its key word and the vowel that follows it. In his own example, a heading on Epistle is filed under E-I. The index becomes a compact grid of letters against vowels, and each cell lists the pages where headings with that pattern begin.
John Locke's 1706 New Method of Making Common-Place-Books indexes each heading by its first letter and the vowel that follows, so one compact grid can point to hundreds of headings. Publishers later sold blank commonplace books pre-printed on Locke's principles, and one copy passed from Erasmus Darwin to his grandson Charles.
For a personal notebook, a plain alphabetical index is usually enough. Locke's grid earns its keep once a book runs to several volumes.
Famous commonplace book examples
Commonplace books were standard equipment for educated readers for several hundred years. Some survivors:
- Ralph Waldo Emerson and Henry David Thoreau were both taught to keep commonplace books at Harvard, and both continued the habit; their notebooks have been published.
- Erasmus Darwin kept one printed on Locke's principles from 1776 to 1787. Charles Darwin later used the same book, which he called "the great book", when writing his grandfather's biography.
- Thomas Jefferson kept both a literary and a legal commonplace book; Princeton University Press has published each.
What the examples have in common is that the notebooks fed the owners' own work. That's the strongest argument for keeping one: reading becomes material you can draw on, not just time spent.
Commonplace book vs zibaldone vs journal
Three notebook traditions sit close together.
A commonplace book collects outside material, organised by subject so it can be retrieved.
A zibaldone — Italian for "hodgepodge" — was a fifteenth-century Italian miscellany kept in the vernacular rather than Latin, mixing poems, accounts, letters and recipes in whatever order they arrived. The poet Giacomo Leopardi later used the word as the title of his enormous notebook of thoughts, the Zibaldone di pensieri.
A journal records your own experience and thinking, usually in date order.
The useful question is whether you need to find things again. If yes, you need subject headings and an index, and that makes it a commonplace book whatever you call it.
Keeping a digital commonplace book
Paper has one real advantage: copying by hand is slow, and the slowness makes you choose. Digital has a bigger one: search. A digital commonplace book can be searched for any word, which replaces most of what an index does, and a passage can be filed under several headings at once.
The workable compromise is to keep the selection step and let software do the filing. Photograph the page or paste the passage, add the source, and write your one line of commentary in your own words — the commentary is the part that shouldn't be outsourced.
In 3 pages daily, search covers text inside uploaded images, so a photographed book page can be found later by the words printed on it, alongside anything you typed. Topics work as commonplace headings: assign a page to Writing & language or People, and every entry under that heading is gathered across dates. The free plan includes three topics, which is enough to test whether the habit sticks.
Start with one heading and one passage
A commonplace book is a notebook of things worth keeping from what you read and hear, organised by subject so you can find them again. Copy the passage, write the source, add one line of your own, and file it under a heading in the index.
Start small. Five headings, one notebook, and the next passage that makes you stop reading for a second. Within a few months you'll have a reference built entirely from your own reading — the thing most reading never leaves behind. If you'd rather keep it alongside a daily journal, 3 pages daily holds both in one place.
Jonas Weber
I like practical systems that bring order to everyday life without turning it into another project.
Frequently asked questions
A commonplace book is a personal notebook for collecting things worth keeping from what you read, hear and think — quotes, passages, facts, ideas, recipes, lists — organised so you can find them again. Unlike a diary, it isn't arranged by date or about your day. It's arranged by subject, and it grows into a private reference library built from your own reading.
Start with five to eight broad headings that match what you actually read: ideas about work, writing and language, people and relationships, health, money, history, and a catch-all for things that don't fit yet. Broad headings work better than narrow ones at the start — you can split a category once it grows past a few pages, but empty narrow categories just sit there.
A commonplace book is organised: entries are filed under subject headings so they can be retrieved. A zibaldone — Italian for a hodgepodge — was a miscellany notebook kept in the vernacular in fifteenth-century Italy, mixing poems, accounts, recipes and notes in no fixed order. The poet Giacomo Leopardi later used the word for his own vast notebook of thoughts.
A journal records your own thinking and experience, usually in date order. A commonplace book records material from outside you — what you read and hear — organised by topic. In practice they overlap: most good commonplace entries include a line of your own reaction, and a journal often quotes things. The test is the organising principle: date for a journal, subject for a commonplace book.
Yes. Search is the main advantage — a digital commonplace book can be searched by any word, which replaces most of the work an index does on paper. The trade-off is that copying by hand forces you to choose and slows you down enough to think about the passage. Many people photograph a passage and add a typed note, which keeps the selection step.
Anything you'd want to find again: a passage that changed how you think, a striking sentence, a statistic you keep needing, a line from a conversation, an idea from a podcast. Write down the source and page, then one or two sentences of your own on why it mattered. That last line is what turns a pile of quotes into something useful.
Number the pages, keep the first few blank, and each time you start a new heading, write it and its page number in that front index. John Locke published a more compact system in which each heading is indexed by its first letter and the vowel that follows, so one small grid covers the whole book. For most people a simple alphabetical list of headings is enough.
