How a Commonplace Book Differs From a Journal

A friend asked me about the difference between keeping a journal and keeping a commonplace book: “Aren’t they two words for the same thing?”


At the moment I didn’t have a good answer. Then I stumbled on to a website from the University of Chicago about the history of books. There I found a page about Commonplace Thinking with this passage:

A commonplace book is at once a book form and a method of reading. Commonplacing was a system of using books in which readers digested the books they read by extracting, ordering and recording particular phrases or passages in notebooks of their own. This process encouraged readers to atomize books by isolating units that might later be useful in one or another discursive context….

This gets to the heart of the distinction between a journal and a commonplace book. I see three activities that a commonplace book emphasizes more.

A commonplace book preserves the best of your reading

Think back to the times when books were not widely available, and when libraries were few. When people did manage to get their hands on a book, it was truly an event.

To aid their memory, people copied out—by hand—their favorite passages from an author into a blank, bound set of papers. This served as a portable mini-library to savor at any moment.

This is how commonplace books began. And it’s still a powerful application of the concept. When filled with quotations—the “greatest hits” from the your favorite authors—a commonplace book distills all your reading into a single, personally-curated collection.

A commonplace book promotes creative thinking

The beautiful thing about a collection of quotations is that you can read them in any order and move them around.

Each individual quotation is an “atom” of thought. When you collect quotations from several books by different authors on the same topic, you see these atoms in a broader context. Your individual way of combining them can lead to new insights.

In his book The Act of Creation, Arthur Koestler referred this way of thinking as bisociation. For him, it was the essence of creativity.

A commonplace book is a step toward making ideas public

Commonplace books are more output-oriented and outward-facing than journals. They’re used to create things that go out into the world, such as:

  • Articles, blog posts, books, and other publications (literally, ideas made public)
  • Services based on the exchange of information, such as training, consulting, and coaching
  • Businesses and other organizations that are closely tied to a mission

Each of these starts as an idea in someone’s head. A commonplace book is the perfect system for capturing such ideas, developing them, refining them, and making plans to implement them.