And he’s not alone. Just about everyone I know complains about the same thing when they’re being honest—including, maybe especially, people whose business is reading and writing. They mourn the loss of books and the loss of time for books. It’s no less true of me, which is why I’m trying to place a few limits on the flood of information that I allow into my head. The other day I had to reshelve two dozen books that my son had wantonly pulled down, most of them volumes from college days. I thumbed idly through a few urgently underlined pages of Kierkegaard’s “Concluding Unscientific Postscript,” a book that electrified me during my junior year, and began to experience something like the sensation middle-aged men have at the start of softball season, when they try sprinting to first base after a winter off. What a ridiculous effort it took! There’s no way for readers to be online, surfing, e-mailing, posting, tweeting, reading tweets, and soon enough doing the thing that will come after Twitter, without paying a high price in available time, attention span, reading comprehension, and experience of the immediately surrounding world. The Internet and the devices it’s spawned are systematically changing our intellectual activities with breathtaking speed, and more profoundly than over the past seven centuries combined. It shouldn’t be an act of heresy to ask about the trade-offs that come with this revolution.