(Image: Jack Kerouac’s copy of Dostoevsky’s An Unpleasant Predicament)

I truly appreciate the existence of libraries, which provide many people access to books that their budgets would not allow them to purchase.

But the thing is, I rarely check out books from them. The reason why? I love to mark up books.

Since high school—thanks to the advice of my English teacher—my reading has routinely been accompanied by a mechanical pencil that I use to underline significant passages, write comments and questions in the margins, and put asterisks next to truly profound quotations.

The author of the famous How to Read a Book, Mortimer Adler, also advocated marking up books, and gives three reasons it’s an important accompaniment to reading:

1) It Keeps You Awake.

“A great book, rich in ideas and beauty, a book that raises and tries to answer great fundamental questions, demands the most active reading of which you are capable… If, when you’ve finished reading a book, the pages are filled with your notes, you know that you read actively.”

2) It Helps You Think.

“Reading, if it is active, is thinking, and thinking tends to express itself in words, spoken or written…

Reading a book should be a conversation between you and the author… And marking a book is literally an expression of your differences, or agreements of opinion, with [him].”?

3) It Helps You Remember.

“The physical act of writing, with your own hand, brings words and sentences more sharply before your mind and preserves them better in your memory. To set down your reaction to important words and sentences you have read, and the questions they have raised in your mind, is to preserve those reactions and sharpen those questions.”

Of course, one doesn’t need to mark up every single book. With a few exceptions I tend not to write in fiction books, and I have a few beautiful editions of books (which are works of art in themselves) that I avoid defacing with my pencil lead.

But we live in an age where some really great books can be ours for a few dollars. And, for the sake of thoroughly engaging with them, I say “Mark ‘em up!”