Frum’s book attempts to inform, and that’s an altogether different mission, one that traditional text is poorly suited to carry out. In a slightly more perfect world, the process of reading would be closer to the process of recording: we would scan words, and they would be retained, with perfect fidelity, in our neural pathways. The information would all be categorized, stored, and made available for future mental searches. A book would be virtually disposable, rendered utterly unnecessary after the first read. Sadly, our brains are more sieve than supercomputer. They absorb text much like the old child’s trick of pressing putty against newsprint: the information is initially imprinted with perfect clarity, then rapidly begins to fade, till only the faintest outline remains. There are the rare exceptions—my high school reading of The Grapes of Wrath still colors my understanding of power relations in a capitalist system—but they are too rare, and frankly, I sometimes wish I still had my notes on Steinbeck.

Still, hope springs eternal, and many of us pack our books away, filling spare rooms with bookshelves and attics with old titles. Those books hold what our minds cannot, and we hope that having read them once, we will be able to quickly rediscover their secrets if and when the need arises. To help us in this quest, we have margins. It is here that most of us make our stand against time’s inevitable fade to black. Notes, exclamation points, stars, doodles, complicated systems of acronyms and symbols—all serve as maps to intellectual lands we once traversed and may someday revisit. But they are spotty guides. Sometimes, the directions are illegible. Other times, we find that we forgot to mark a particular road or byway because we didn’t realize it was important. And without any real way of pinpointing our position, the search through this hazy mess of chicken scratch can be only marginally more efficient than rereading the book itself.

Compared to this, electronic text is a GPS system. You tell it where you want to go, it finds the route. The whole book is searchable. So, for that matter, are your notes, which can all be stored. Favored passages can be clipped and saved in a separate file to facilitate more rapid review. When text ceases to be fixed, when margins swell to an infinite expanse, when every word can be sorted and searched, the failings of our brains are hardly noticeable. Your bookshelf becomes your mind’s external hard drive. It’s a shiny new e-brain, a Google that searches your personal intellectual universe.

The point was driven home to me while reading William Powers’s brilliant essay “Hamlet’s BlackBerry: Why Paper Is Eternal,” which considers the evolution of paper and the way it has subtly shaped not only the way we read, but what we read. “The persistence of paper flies in the face of a widely held popular assumption about technology,” Powers writes, “propagated over the years by breathless futurists and science-fiction writers.” True enough. But it was at about that moment that I realized I was reading “Why Paper Is Eternal” paperlessly, on my computer. I had downloaded it for free, which could be done because there were no shipping or production costs associated with the electronic file, and I decided to read it in my PDF viewer (the wonderful freeware Skim, for those who are interested) so I’d be better able to jot down thoughts and pull quotes. Paper may be eternal, but for some purposes, it’s simply inferior.

Ezra Klein is an associate editor at The American Prospect.