We know we have to read "between the lines" to 1 the most out of anything. Marking up is also a useful practice, but you shouldn"t mark up a book 2 isn"t yours. Librarians who lend you books 3 you to keep them clean, and you should. 4 you decide that I am right about the usefulness of marking books, you will have to buy them. There are two ways 5 which one can 6 a book. The first is the property fight you establish by paying for it, just as you pay for clothes and furniture. But this act of purchase is only the prelude to possession. Full ownership 7 only when you have made it a part of yourself, and the best way to make yourself a part of it is by writing in it. An illustration may make the point clear. You buy a beefsteak and transfer it from the butcher"s icebox to your own. But you don"t own the beefsteak in the most important sense 8 you consume it and get it into your bloodstream. I am arguing that books, too, must be 9 in your bloodstream to do you any good.
There are three 10 of book owners. The first has all the standard sets and best sellers-unread, untouched. The second has a great many books—a few of them read through, most of them dipped into, but all of them 11 clean and shiny as the day they were bought. The third has a few books or many—every one of them dogeared and dilapidated.
12 is marking up a book indispensable to reading First, it 13 you awake. I mean wide awake. In the second place, reading if it is active, is thinking, and thinking tends to express itself in 14 . Finally, writing helps you remember the thoughts you 15 , or the thoughts the author expressed.