The Commonplace Book: What It Is and How to Start One

Renaissance students learned it, and John Locke designed a widely copied index for it: a note-taking method that asks three things of every entry, namely the passage, where it came from and a heading to file it under. That method is the commonplace book, a notebook of quotations, facts and ideas sorted by subject rather than by date. The name translates the Latin locus communis, a “common place” or general theme, and the practice flourished in Renaissance Europe and again in the nineteenth century.¹ No study has tested commonplace books as such. What stands behind them is centuries of documented use, which the Harvard historian Ann Blair traces through early modern schools, manuals and keepers from Locke to Jefferson.² To start one:

1. Choose one home, paper or digital
2. Copy only what you would want to find again
3. Write the source on every entry
4. Add a line in your own words
5. File each entry under a heading and keep an index
6. Reread it once a week

Prefer to watch? The video covers the same ground as this article.

VideoHow to Keep a Commonplace Book (A Simple Method)WiserHours

What a commonplace book is, and why the headings matter

The defining feature of a commonplace book is the subject heading: entries are sorted by topic, so a line you copy today lands beside one you copied years ago on the same theme. Wikipedia’s overview of the tradition lists what keepers have filed this way, from proverbs, quotations and poems to recipes, letters, prayers, legal formulas and tables of weights and measures.¹

The heading is what makes it work. In her 2004 history of note-taking, Blair describes two basic ways of taking notes from a text: summarizing it in its own order, or picking out passages and sorting them under a heading so they are easy to retrieve. The headings and the notes gathered under them, she writes, are what were usually called commonplaces.² A heading pulls together things you met years apart in different places.

Picture a project manager who reads a line about deadlines in a novel, hears a sharp remark about them on a podcast and sees a contract dispute turn on one. In a diary those three moments sit months apart. In a commonplace book all three land on one page headed “Deadlines”, and when she drafts a project plan she opens that page instead of hunting through three sources. If you will mostly look things up by subject, sort by subject from the first entry. It is one of the older schools of personal knowledge management.

What goes into the book: passages, facts and lines of your own

Anything you would want to find again under a subject belongs in a commonplace book: quotations, facts, short examples and stories, references to books worth rereading, and ideas of your own. Jeremias Drexel, whose 1638 manual on excerpting Blair calls perhaps the most influential of its kind, named three sorts of note: references to useful books listed under a topic, passages copied out with their citation, and anecdotes or examples from history.²

Selectiveness was the old rule. In a note printed with the 1706 English edition of Locke’s method, the scholar Le Clerc advises copying only what is excellent in substance or expression, not what anyone could have said, and not breaking off your reading to copy: mark the place on a slip of paper and extract the passage later.³ A book stuffed with ordinary lines buries the few you will use.

The study

Limited evidence

Notes that stood in for the books, in Ann Blair's 2004 history of note-taking

Blair’s history of note-taking manuals and surviving notebooks found that notes often stood in for the books themselves. Drexel’s manual did not ask readers to mark whether an entry was an exact quotation or a paraphrase, and Blair suggests that this habit may explain some inaccurate quotation: Montesquieu, asked about a source, quoted from his notes, in which he had paraphrased and somewhat distorted the original.²

Blair’s account is a history of practices and tests no outcomes, but its lesson is direct. Your notes will often replace the source, so they need to show which words are the author’s and which are yours. Locke, for one, labelled excerpts with topic titles, sometimes added precise citations, and wrote in his own signed reflections and questions, according to Richard Yeo’s 2020 study of his notebooks; we read only its abstract.⁴ Put quotation marks around anything copied word for word, and you will never have to wonder later whether a line is a quote or your summary of one.

How to start a commonplace book in six steps

Starting a commonplace book takes a notebook or a notes app, a few headings and one rule for every entry: passage, source and your own line. The steps below follow how keepers worked for centuries; no controlled test has covered them.

1. Choose one home, paper or digital

Pick one notebook or one folder in one app, and keep everything there. A habit borrowed from trade helps: merchants kept one book of transactions in the order they occurred and a second that sorted the same transactions into categories, and early modern authors, Blair notes, held this up as a model for students.² Today that can be a phone note for catching lines during the day and the commonplace book itself, sorted at the weekend.

2. Copy only what you would want to find again

Use Le Clerc’s test before you copy: is this excellent, or something you could have said yourself? A teacher who copies every good line from a book on feedback ends up with a second copy of the book. One who copies the two lines she will quote at a staff meeting has a tool.

3. Write the source on every entry

Locke wrote down the author, title, volume, date and place of the edition and the book’s total number of pages, then recorded each passage’s page, so he could find roughly the same place in a different edition by simple proportion.³ Today, author, title and page, or a link and the date, are enough. Blair notes that modern conventions ask us to record sources more consistently than early modern scholars did.²

4. Add a line in your own words

Below the passage, add a sentence on why it matters to you or where you might use it, and sign it with your initials or a symbol. Even Montesquieu, whose notes mixed quotation and paraphrase, marked his own comments with an asterisk, Blair notes.² Restating ideas in your own words is one of the habits weighed in the guide to why notes help you remember and think.

5. File each entry under a heading and keep an index

Write the heading alone in the margin so you can scan it at a glance, as Locke did. His index sat on the first two pages: each heading was listed by its first letter and the vowel after it, so “Epistle” went in the box for E and i, which pointed to the page where all such headings lived.³ On paper, a contents page at the front listing headings and page numbers does the same job.

1. Heading: one key word, written alone in the margin so headings can be scanned at a glance, as Locke did
2. The passage: copied exactly and set off as a quotation, or clearly marked as a summary
3. The source: author, title and page, enough to find the place again
4. Your own line: why it matters to you or where you could use it, marked as yours
5. The index: a page at the front listing every heading and where it lives; in an app, a tag or a list of headings

6. Reread it once a week

Set a short, fixed time each week to open one heading, read what is there and add a line where an old entry connects with a new one.

Your first commonplace book entries

• Choose one notebook or one app folder
• Write five headings that match my work or reading
• Copy one passage I would want to find again
• Add the author, title and page
• Write one line in my own words, marked as mine
• Put a weekly rereading slot in my calendar

Why a commonplace book needs a weekly reread

A commonplace book that you only fill is a store, not a tool. The closest evidence comes from classrooms: Keiichi Kobayashi’s 2006 meta-analysis pooled 33 studies and reported substantial overall effects on school learning when students took notes and then reviewed them, compared with students who did neither. We saw only the abstract, and the studies were of students, not adults keeping notebooks for work.⁵

The old manuals knew this. Drexel told his readers that excerpting is not enough without remembering what you excerpted, and Blair cites the case of a scholar, Johann Caspar Hagenbuch, who put so much effort into indexing his notes that he never produced a book from them.² Searches of PubMed and ERIC in October 2026 turned up histories and classroom descriptions of commonplace books, but no controlled study of them.

The practical version is short. Each week, pick one heading, cover the passages and try to recall what you kept and why, then check. Recalling before you look is called retrieval practiceretrieval practice: Learning by recalling material from memory, for example by quizzing yourself, instead of rereading it. Pulling information out makes it easier to recall later, a result also known as the testing effect.Full entry in the glossary, and the guide to taking notes from books you want to remember explains why it beats rereading. A consultant with a heading on pricing, for example, might spend ten minutes on a Sunday recalling the three arguments filed there before a client meeting, then add the one she had forgotten to her slides.

Paper or app: keeping every entry findable

A commonplace book works in a notes app as well as on paper: Wikipedia’s overview notes that software now performs the functions paper commonplace books served.¹ A passage, its source and a heading move to any app; what changes is how you find things again.

Blair points out that a miscellany needs a finding aid, a search function on a computer or an index in a book, and both have weak spots: a mistyped word escapes search, and a wrong page number breaks an index entry. She also rates the book highly for reliability and long-term access compared with the computer, which needs technical infrastructure and runs into compatibility problems over time.²

So in an app, use one note per heading or a small set of tags, spell each one the same way every time, and export your notes to plain text now and then. On paper, keep the index current every time you start a new heading.

From Seneca to Locke: how the habit spread

Commonplace books grew out of classical rhetoric, became a standard study method in Renaissance Europe, and after Locke published his indexing method printers often sold blank books laid out for it. The Roman writer Seneca already compared collecting good sayings to a bee gathering pollen, and by the thirteenth century religious collections of excerpts were more commonly arranged under themes.¹

1. 1st centurySeneca likens collecting sayings to a bee gathering pollen
2. 13th centuryCollections of excerpts arranged under themes
3. 1500sErasmus teaches students to gather examples under headings
4. 1686Locke's indexing method printed in French
5. 1706The method appears in English
6. 1800sEmerson and Thoreau taught to keep them at Harvard

Renaissance teachers turned the habit into schoolwork. Erasmus advised students to build a tree of headings, with gratitude, say, under piety, and to copy examples beneath each; by the seventeenth century commonplacing was formally taught at universities such as Oxford, and Ralph Waldo Emerson and Henry David Thoreau were taught to keep commonplace books at Harvard.¹ Harvard Library’s collection on the history of reading now holds commonplace books used by Joseph Conrad, Washington Irving and Victor Hugo, among others.⁶

The idea was never only European. In China, the biji, literally “notebook” or “written notes”, collected stories, quotations, passing thoughts and learned asides over many centuries.⁷ Blair notes that the long continuities of European note-taking invite comparison with Chinese and Islamic scholarly methods. She also observes that young students were encouraged to take notes with no particular purpose, while older, more experienced readers took notes aimed at specific projects.² Give your book a job, such as the talks you give, the field you work in or the novel you are drafting, and choosing what to copy gets much easier.

How a commonplace book differs from a journal, a slip-box and a second brain

A commonplace book is sorted by subject and filled mostly from outside sources, while a journal or diary runs by date and records your own days, thoughts and feelings. The newer note systems differ in what they put first.

The slip-box is a descendant: Wikipedia’s account of the Zettelkasten traces it to the sixteenth-century scholar Conrad Gessner, who came from the commonplace tradition and devised notes he could rearrange at any time.⁸

Myth

A commonplace book is a journal with some quotes in it.

Fact

A journal runs by date and records your own life. A commonplace book runs by topic and records what you read, heard or saw, with its source.

Ask what you will do with the material. If you collect other people’s words and facts to quote, teach or decide with, a commonplace book fits. If you mostly develop your own arguments, a Zettelkasten built on linked notes suits better, and if you collect for deliverables, Forte’s second brain method does.

The historical support for each habit

Most of the support for the method is historical practice, which shows what worked for committed keepers but cannot show what would work for you.

The bottom line

No trial has tested the commonplace book; its support is centuries of keepers’ practice. Start small, with one home, a few headings and three parts to every entry, namely the passage, its source and a line of your own. Then open it once a week and reread one heading.