How to Mark a Book Mortimer Adler

How to Mark a Book: A Guide by Mortimer Adler


In his essay “How to Mark a Book,” Mortimer Adler discusses the importance of active reading and provides valuable insights on marking books as a means to enhance comprehension and engagement. Adler, a renowned philosopher and educator, argues that marking books is not an act of vandalism but rather an act of respect for the ideas contained within. This article aims to delve into Adler’s thoughts on marking books and provide practical tips on how to do so effectively.

I. Understanding the Purpose of Marking Books:

Adler begins by emphasizing the significance of active reading. He asserts that reading should not be a passive activity but an interactive process between the reader and the text. By marking books, readers actively engage with the material, making connections, highlighting important points, and leaving personal notes. Adler believes that this form of interaction is essential for comprehension and critical thinking.

II. The Different Methods of Marking:

1. Underlining and Highlighting: Underlining key phrases or passages helps draw attention to significant points. Highlighting with different colors can be used to categorize ideas or mark different types of information, such as examples, quotes, or arguments.

2. Margin Notes: Writing notes in the margins allows readers to express their thoughts, make connections, and ask questions. Marginal notes serve as a personal dialogue with the author and enable readers to revisit their initial impressions and insights.

3. Symbols and Abbreviations: Developing a system of symbols and abbreviations can facilitate efficient and concise marking. For instance, using an asterisk (*) to mark important ideas, or an exclamation mark (!) to highlight surprising or controversial statements.

4. Indexing: Creating an index or table of contents at the beginning or end of a book can be immensely helpful. This allows readers to easily locate specific sections or ideas within the text.

III. Addressing Concerns:

1. Isn’t marking a book an act of vandalism? Adler dismisses this notion, arguing that marking books is an act of respect and an acknowledgement of the value of the author’s ideas. It is a personal conversation with the text, enhancing the reading experience.

2. What if I want to sell or lend the book later? Adler suggests that the value of a marked book surpasses its resale value. A marked book reflects the reader’s intellectual journey and can be an invaluable resource for future reference or discussion.

3. Can’t I just use sticky notes or digital annotations? While these alternatives are valid, Adler believes that physically marking a book fosters a deeper connection with the text. The act of writing itself enhances engagement and memory retention.


Q1. Should I mark every book I read?
A1. Adler suggests marking books that have value to you, whether due to their content, significance, or personal interest. Not every book needs to be marked, but those that resonate with you should be engaged with actively.

Q2. What if I make a mistake while marking?
A2. Mistakes are a natural part of the process. Embrace them as opportunities to learn and grow. If you make an error, you can always cross it out or correct it later. Remember, the purpose is to enhance your understanding, not to achieve perfection.

Q3. How can I balance marking with the preservation of the book’s condition?
A3. It is essential to strike a balance between marking and preserving the physical integrity of the book. Use a light touch with pens or pencils, and avoid excessive pressure. If concerned about preserving the book’s condition, consider using removable adhesive flags or bookmarks.


Mortimer Adler’s essay “How to Mark a Book” serves as a valuable guide for readers seeking to actively engage with the material they read. Marking books is a means to enhance comprehension, foster critical thinking, and establish a personal connection with the author’s ideas. By following Adler’s advice on different methods of marking, readers can transform their reading experience into an interactive and enriching journey. So, next time you pick up a book, remember Adler’s words and embrace the act of marking as a tool for deepening your understanding and engagement with the text.

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