There’s a sentence in a book you read two years ago that you’ve been trying to remember all week. You know roughly what it said. You know it was about patience, or maybe about doors. You can’t tell which book it was in, and you can’t remember why it stopped you.
Collecting lines from what we read is the easy part. Keeping them in a way that lets you return to them, and remember why you kept them, takes a little method. Readers worked this out a long time ago. They called the result a commonplace book, and it’s still one of the best ideas in the history of reading.
This is a guide to keeping one: what it is, the small habit that makes it work, and how to do it on paper or on a screen.
What a commonplace book actually is
A commonplace book is a notebook where you copy out passages worth keeping, from anything you read, and gather them in one place. The name comes from the Latin locus communis, a “common place” to collect what you’d otherwise lose.
For centuries it was a standard tool of education. In the Renaissance, Erasmus set out how students should build one, and schoolboys across Europe copied passages from their reading under headings they could come back to. Milton kept one. So did Thomas Jefferson, whose literary commonplace book of poets and philosophers was later published.
What sets it apart from a reading log is the direction it faces: a log follows one book from start to finish, and a commonplace book follows an idea across many books. A line about grief from a novel can sit beside a line about grief from an essay, and the two begin to talk to each other.
That’s also how it differs from a reading journal, which keeps a small record of each book as you finish it. Both are worth having, and they don’t compete. If you already keep the four-line journal, you don’t need to replace it. A commonplace book is a second notebook, organized around what you’re thinking about rather than what you’ve read.
The one field you care about
Copying a passage isn’t the valuable part, anyone can copy a passage.
A highlighter does it faster, and most highlights are never opened again.
The part that makes a commonplace book yours is a single sentence in your own words, written beside the passage: why it matters. Not a summary of the quote. Why you stopped on it, or what it touches in your own life.
The passage reminds you of the book.
The sentence beside it reminds you of you.
The habit is an old one. Jefferson wrote to a friend that as a law student he had abridged what he read and sometimes mixed in his own reflections.1 That small act of mixing in your own voice is the whole difference between a pile of excerpts and a notebook you want to open.
It also solves the problem from the start of this post. Two years from now, the passage will remind you of the book. The sentence you wrote will remind you of why it was worth keeping.
The smallest version, with a template
You don’t need ruled pages, a special pen, or a system. Each entry has three parts and one optional one:
- The passage. Copy it exactly, and keep it short. A sentence or two is usually plenty.
- The source. Title, author, and a page number if you have one. A passage without its source is hard to trust and impossible to share.
- Why it matters. One sentence, in your own words, written now rather than later.
- A heading (optional). One or two words for the idea it belongs to: patience, home, attention.
Here’s a commonplace book template you can paste into a notes app or copy onto a page:
Passage:
Source: (title, author, page)
Why it matters:
Heading: (optional)
Write the first entry tonight, from whatever book is on your nightstand. A commonplace book with five entries is a commonplace book.
Resist the urge to keep every line that’s merely good. The test isn’t whether a sentence is well written. It’s whether you’ll want to meet it again. Most readers end up keeping one or two passages per book, and that restraint is what makes the notebook worth rereading.
How to find things again
Locke’s whole method was an answer to one problem: a notebook is only useful if you can get back to what’s in it.
On paper, that’s genuinely hard. Entries pile up in the order you wrote them, so finding “the one about patience” means turning pages. This is where headings earn their place. If you use them, keep the list short, a dozen words at most, and add a new one only when an entry truly doesn’t fit anywhere. A long list of narrow headings is how most notebooks get abandoned by spring. A short index of your headings on the last page, with the page numbers beside each, is all Locke’s system really asks of you.
On a screen, you get something Locke would have envied: search. Type a word you half remember and the passage comes back. That changes how you should keep the notebook. When you can search, headings stop being a filing system and become an optional extra, a way of noticing patterns rather than a way of finding things. The sentence under “why it matters” does most of the work, because it’s in your own words, and your own words are what you’ll search for.
So the practical advice is simple:
On paper, use a few headings and keep a short index.
On a screen, write the sentence and trust search.
Either way, give yourself a reason to return. Once a month, open the notebook and read the last few entries without doing anything to them. A passage often lands differently after a few weeks, and the second sentence, the one you wrote, is sometimes the part you needed.
Doing it on a screen
Plenty of tools work. A notes app, a single document you keep adding to, or a spreadsheet with one row per entry all fit the template above. Pick the one you already open without thinking about it.
If you’d rather have something built for it, Kiveo is one option. When you save a quote, it stays attached to the book it came from, with the page number and date. Beside it sits an optional reflection field, which is the “why it matters” sentence. You can search across every quote and reflection you’ve saved, and export them whenever you like. Your notes are yours alone: nothing is published, and there’s no feed.
What Kiveo doesn’t do is group quotes by theme (yet 😉 ). Your quotes live with their book, and you find them across books by searching. If you want a notebook organized by idea, with headings and tags, a flexible notes app will suit that better. If you’d rather keep the line, the book and your own sentence together, and find the rest with search, that’s the shape Kiveo was made for. You can see how it works here.
Start with one passage
Pick the last book you finished, or the one beside your bed. Find one line that stayed with you. Copy it, note where it came from, and write one sentence about why it matters.
That’s a commonplace book. It started today, and it gets a little more useful with every entry you add. There’s no schedule to keep and nothing to catch up on.
If this sounds like the kind of reading space you’ve been looking for, Kiveo is free on the App Store. You can read more about why we built it the way we did.