Middle of the night and your head teems with half-formed thoughts: Did I pay the car insurance? Where did I park the car? Is my best dress shirt at the dry cleaners? What time's the wedding on Saturday? Need a map of Vermont to get there. I should frame my vintage maps one of these days. Maybe start with that bird's-eye view of New Amsterdam, or the blue-tinted mariner's chart ...

How stop this ceaseless ticker tape? The mind's associative reflex is as rapid as it is circuitous, myriad things and things-to-do always unspooling in the brainpan. If you get out of bed, though, and grab a pen, you can at least slow it down by making a list. You can rank items in importance, annotate, categorize, and subcategorize—in short, you can give some material shape to and make some order of what Samuel Beckett dubbed "the big blooming buzzing confusion." So somewhere between penciling "Pick up prescription" and "Live a more examined life," a portion of calm might be found.

The notion that unwieldy consciousness can best be tamed by enumerative form has beguiled more than a few writers and artists. Umberto Eco, in The Infinity of Lists: An Illustrated Essay (Rizzoli, $45), recounts his own fascination with lists, lists of lists, and the infinite regress of adding up and counting down any- and everything. In compiling this roster—its own sort of metacollection—Eco ranges widely through Western civilization to include lists verbal (from Homer to Pynchon) and visual (from a fifth-century Greek shield to an installation by Christian Boltanski). Like any good cataloguer, Eco subdivides: His big two kinds of lists are those that evidence the "poetics of 'everything included'" and those that express the "poetics of the 'etcetera.'" The first aims for completeness and closure (provisionally so); the latter takes its cue from the mind's perpetual-motion association machine. It's the difference between a New York telephone directory and, say, J. A. S. Collin de Plancy's nineteenth-century Dictionnaire infernal, which offers a census of demons ("Aamon, Abigor, Abraace, Adramelech ... Xafan, Zagam, Zaleos, Zebos, Zepar"). The phone book includes the more or less fixed number of names of actual phone owners; the roster of devils is limited only by the imagination's disinclination to invent more.