As I write this, my personal library is somewhere between the Bay Area and New York, heading east. I don’t know if the truckers have read Kerouac, but the books themselves may be experiencing a sense of adventure. Some of them have made this American road trip before, though in the opposite direction; others are new to the road but confident that where I go, they go — my external, analogue hard drive, the picture of my consciousness, my personal library.

About two years ago, when my wife and I decided to move back east — or East, which is not the same thing — we began to take stock of our collection of books. This was in part the natural pruning of any flowering plant that had grown beyond its allotted space, but also an economic matter. We had been told that for every carton of books carried from the Left Coast to the Right, the cost would be $30. We calculated that we had about 100 cartons of books, so that came to $3,000, which seemed like a lot of money to carry around books that we had already read. So we decided to cut the number of books by half, a big effort, which resulted in some arguments and countless trips to our local used bookstore, the marvelous Logos Books and Music. This task was complicated by the fact, familiar to all bibliophiles, that even as we were selling off our library, we continued to buy more books. Particularly treacherous was the semiannual library book sale, where donated books are sold by the pound. Fill a shopping bag for $10. And why stop with one?

The irony of this is that for the past 20 years, I have principally made a living helping publishers publish e-books and journals and other forms of digital content. I am a signed-up member of the Gadget Society and carry a smartphone, Kindle, or iPad everywhere, all stocked with books, if “stocked” is the right word for ephemeral electrical charges that travel mysteriously from the Cloud to the device and back. I read print books because I already own thousands and cannot resist browsing in a used bookstore, which is in fact one of the few things that gets me to leave my study and its capacious desktop machine to venture out of doors.

Culling the library can be painful. There is no parting with “Ulysses” and “Middlemarch,” but Thackeray, Dickens, and Mrs. Gaskell? Tossing the complete Shakespeare is almost an impure thought, but Hart Crane, Byron, John Donne, and Emily Dickinson? The case for keeping poetry is strong if you have a propensity for rereading, but fiction is not such an easy call. Nonfiction is easier to toss, though there are some titles (“Civilization and Its Discontents,” “Understanding Media”) that I continue to return to. What makes this such an arduous task is that it is not about books at all but about a dialogue with your own mind. Is this volume something you want to engage again — load it into RAM, so to speak — or is this title so central to how you think about yourself, or how you want others to think about you, that parting with it is tantamount to giving up a piece of your self?

People have always culled personal libraries, of course, but the process is different in the age of the e-book. The literary classics that fill an entire book case are now all available electronically, most of them for free. Why carry “A Hazard of New Fortunes” or “The Brothers Karamazov” around when they can always be recalled from the Cloud, loaded onto a Kindle or the virtual shelf of the iBookstore? Thus do several hundred paperbacks make their way to the used bookstore, where groaning undergraduates will pick up copies of “Villette” and “Wuthering Heights” for a dollar or two. (I lie: I could never part with Emily Brontë.)

Prior to the advent of the e-book, there were few alternatives to carrying your library around with you, but now that digital books are mainstream, consituting perhaps 25% of all new trade books sales and about a third that amount for scholarly books, new aspects of the printed book come into view. For example, what are the environmental issues of owning a large library? If I were bookless, I could live in a house that was at least one full room smaller, perhaps two. That would require a less costly house and a lower heating bill. Or there is the aesthetic dimension of printed books. As we house-hunted, we stepped into a stunning house in Bronxville, NY, whose every room was lined with bookshelves. And the books! Perhaps the owner was a professor of political science or an editor at the New York Times. Or perhaps he or she was simply one of the thousands, millions of people who work in law and real estate and finance for whom books come second only to family. The books made a powerful and beautiful statement, but I could not help to think (as I checked email on my phone and posted to Twitter) that the house was a monument to a soon-to-be-bygone era. In a few years, that personal library will be as rare as a house with stables for horses.

So what are the books themselves thinking? I don’t mean their content — their tales of the lives of Einstein and John Stuart Mill or the fable of a distinguished intellectual who falls hopelessly and tragically in love with a young girl — but their private reflections on their role in the lives of their readers and owners. They are iconic — a picture of a human mind in five hundred or a thousand running feet — but not for much longer. They can feel themselves losing their hold on the imaginations of the reading public. Does “Howl” howl? Do we have a new candidate for the saddest story ever told?

Now a personal library is something that resides on a computer server somewhere, accessed through your Amazon account. You can sell your house and traipse across the country or overseas, but all that changes is the IP address from which you access your “library.” The books do not become dog-eared, they are never misfiled. A guest in your home will no longer note that Gibbon or Boswell lies next to your easy chair. If someone wants to know who you are through your books, the place to look is GoodReads and LibraryThing. The printed book is aware of the passage of time.

Reducing the size of my personal library made me aware that I had probably bought my last new print book. There may be exceptions to this, as when I purchase a gift for someone, but otherwise my new books will be e-books. Used books are a different matter, though, as the pleasure of browsing is something I will not give up until the last bookstore closes. I will continue to read print because I already own so many unread print books, but the e-book revolution is well on its way in this household. Oddly, it is easier to contemplate a world of e-books than a house without stuffed bookshelves.

Two footnotes to this tale. At the closing for our new house, I asked the seller what he had done with his extensive personal library as he prepared to move out. It was the wrong question — disposing of his library had pained him deeply. He talked feelingly about the books and with a sense of loss for the many volumes that he had had to consign to a rare book dealer. He will never have a library like that again, and he feels diminished, older, for it.

The new owner of our old house in California had a diferent take on things. He is a professional writer, with books and screenplays to his credit. As we walked around the house the last time, with me showing him all the intricacies of home ownership — the irrigation system, the pool filter, the solar panels — he turned to me and asked, “Could you recommend a good carpenter? I need to have a great many bookshelves built.”