CNN Article on the value of “slacking off at work.” What they’re actually saying is that you need to take the time to think things through.

Remember the story of Archimedes lolling in his bathtub? To an observer, he’d have seemed to be wasting time. While ostensibly doing nothing, however, he discovered the principle of displacement, a cornerstone of physics. Would he have reached the same insight in a quick shower?

Unlikely. And while you might say that’s ancient history, don’t be too sure.

Consider that for most industries, the U.S. can’t hope to be the low-cost producer in a global economy. With innovation now our main competitive strength, creativity is crucial for anyone who wants to move up.

But it’s really, really hard, if not impossible, for the human brain to come up with fresh new ideas when its owner is overworked, overtired, and stressed out. And in today’s wonderful world of nonstop work, 40% of American adults get less than seven hours of sleep on weeknights.

“The physiological effects of tiredness are well-known. You can turn a smart person into an idiot just by overworking him,” notes Peter Capelli, a professor of management at Wharton.

Still, putting in more than 50 hours a week at the office has become routine — and that doesn’t count time spent doing paperwork at home, answering e-mail at the airport, or talking on the phone in the car.

Sooner or later, companies’ performance has to reflect that, Capelli says. “On the organizational level, what you get is, everyone is so focused on running flat-out to meet current goals that the whole company is unable to step back and think.”

Indeed, “the notion that busyness is the essence of business can only do us long-term harm,” writes consultant Tom DeMarco in a book called Slack: Getting Past Burnout, Busywork, and the Myth of Total Efficiency.

DeMarco knows the word “slack” has some not-so-hot connotations — slacking off, slacker, slack-jawed… — but his definition is different: the degree of freedom required to effect change.

“Companies need to respect the time it takes to do strategic thinking,” he says. “Task-oriented thinking is important too, of course. But bigger thinking is slow.”

The late Peter Drucker agreed. He wrote in The Effective Executive (an eerily prescient 40 years ago), “All one can think and do in a short time is to think what one already knows and to do as one has always done.” Gulp.

Moreover, in Drucker’s view, simply working longer and longer hours won’t help. “To be effective, every knowledge worker, and especially every executive…needs to dispose of time in fairly large chunks,” he wrote. “To have small dribs and drabs of time at his disposal will not be sufficient even if the total is an impressive number of hours.”

Hmm, small dribs and drabs of time…and, just think, the BlackBerry hadn’t been invented yet.