Marginalia: how to take notes in the margin of a book

Marginalia is the oldest reading journal there is: the notes readers leave in the margins of their books. Underlinings, stars, arguments, the occasional furious 'no'. For centuries it was how serious readers thought — the margin was where the book stopped being a monologue and became a conversation.

The problem with margin notes is not taking them; it's finding them again. A pencil tick on page 41 of a paperback is invisible the moment the book goes back on the shelf. Digital marginalia — a quote and a note kept beside the book in your reading journal — keeps the conversation findable. Here's a method that works in either medium.

The line, the reason, the mark

• The line: copy the sentence exactly as printed. Don't paraphrase — the wording is usually the point.
• The reason: one sentence of your own, beginning with why. 'This is the argument the whole chapter was hiding.' 'I disagree, because…'
• The mark: where it lives — page, chapter, or percent. Future you will want the way back.

The reason is the part everyone skips and the only part that matters later. A bare quote is a photograph with no caption; the reason is what makes it a memory.

Three kinds of margin note worth keeping

• Agreements — the line that said what you'd been circling for years. Keep the wording; you'll quote it.
• Arguments — the sentence you pushed against. These age the best: reread them in five years to see if you still disagree.
• Doors — the reference to another book, author or idea. Marginalia is how reading lists actually grow.

A note on writing in physical books

If the book is yours, write in it. A paperback you argued with is worth more than a pristine one, and readers have known this since the first margins existed. But copy the best of it into the journal too — the shelf is where notes from every book meet, and a note you can't search is a note you'll lose.

The margin is where the book stops being a monologue and becomes a conversation.

In khoshra, every book on the shelf holds a quote and a note beside it, and the homepage lifts your latest ones back into view as 'notes from the margin' — so a line you copied in March is still findable in November.