The ongoing argument about whether the Internet is a boon or a bust to civilization usually centers on the Web’s abundance. With so much data and so many voices, we each have knowledge formerly hard-won by decades of specialization. With some new fact or temptation perpetually beckoning, we may be the superficial avatars of an A.D.D. culture.David Weinberger, one of the earliest and most perceptive analysts of the Internet, thinks we are looking at the wrong thing. It is not the content itself, but the structure of the Internet, that is the important thing. At least, as far as the destr...