Stewart Brand -- '60s whole-earth philosopher, '80s new-media chronicler, '90s new-economy consultant -- is stirring his coffee with a hunting knife, telling us that we ought to slow down. He's dressed comfortably, in jeans and a rough-hewn burnt-orange shirt, and he's talking about his current obsession -- time, speed, the ever-accelerating pace of life -- while sitting next to a prototype of what promises to be the world's strangest clock. (That timepiece, called the Clock of the Long Now, will tick once a year, gong once a century, and cuckoo once a millennium.) Brand, 62, is moving at his own sweet pace, pausing to think for 10 or 20 seconds before he answers each of my questions.

When did it first occur to you that we might be moving too fast for our own good?

(Long, long pause.)

Lately, Brand has been mulling over the rewards and the perils of "Internet time." That's a slogan, to be sure, but it's something real too -- something technological, something physiological, something personal. Money moves around the world at the speed of light. Product cycles are measured in months, rather than in years. People find it unremarkable to spend time on three different continents in the space of a week. And in-the-trenches Web workers feel like God's new chosen people. But Brand is worried. One thing that worries him is Moore's Law. Early doublings of computing power (and hence of speed) were manageable, he says. But the doublings of speed and power that are under way now could cause the whole Web fun house to come crashing down. "The Internet is a runaway plague," says Brand. "It's a self-accelerating system that makes itself go faster and faster and faster and faster. And if it's not framed properly, it will overleap itself, as Shakespeare would say."

Hence his "infrequently asked question": Can we make the world safe for Internet time?

Brand's 30-year history of intellectual achievement includes launching the legendary Whole Earth Catalog and cofounding the influential Global Business Network. But right now, he's just eyeing his clock and palming his knife. He looks simultaneously terrified and thrilled. "If the AIDS virus had been airborne, it would have been a runaway plague. Well, the Internet virus is airborne -- and it's running away. Engineers say that a tenfold quantitative change is a qualitative change. Well, through Moore's Law alone, we're getting three of those revolutions every decade now. That rate of change is tremendously exciting and rewarding, especially to the young, but if we don't take the long view, the fallout could be pretty intense."

Ever an optimist, Brand isn't troubled with Woody Allen-esque anxiety about the effects of relentless acceleration on the human psyche. He saves his worrying for global issues: for the natural environment in particular and for the cultural infrastructure in general; for ecosystems, for languages, for the bedrock institutions of civilization -- for luxuries that most of us mistakenly believe we no longer have time for.

To illustrate, Brand pulls out a diagram consisting of concentric circles. (Picture a sketch of the earth's crust along with various interior layers.) The two outer layers are labeled "fashion" and "commerce"; the two inner ones are labeled "nature" and "culture." He calls his diagram "a pace-layering cross section of a healthy civilization." Spinning it around for me, Brand explains how the outer, ephemeral layers move very rapidly, while the inner, bedrock layers move very slowly but very powerfully.