"Why is marking a book indispensable to reading it? First, it keeps you awake — not merely conscious, but wide awake. Second, reading, if it is active, is thinking, and thinking tends to express itself in words, spoken or written...Third, writing your reactions down helps you to remember the thoughts of the author...Marking a book is literally an expression of your differences or your agreements with the author, It is the highest respect you can pay him."