Visionaries Dream Electric Sheep.

The year 2001 seems like the perfect time to appraise whether predictions about the future were accurate, relevant, and, the highest of all honors, self-fulfilling.

Two authors' prognostications are worthy of consideration by CEOs not only for their content, but as a sort of production script to the current economy.

Both are written by men whose names are well-known to CEOs, especially those who traffic in technology. That's as far as the similarities go, though, because the books, Telecosm by George Gilder and What Will Be by Michael Dertouzos, are as different as a business plan for selling land on the moon and a kindly professor's diary of musings.

George Gilder is one of the rarest and most important historical figures of our time. He's a framer of laws like Moses or Newton; one part moralist on a mountain, the other part scientific explorer. Gilder's view of the world has had arguably more influence on the technology marketplace than any other person's over the past five years. He's made a certain class of technologists into celebrities and has even glamorized technology itself. Case in point: Technologies like DWDM (laser for fiber) are now famous for being famous.

From his own private Mount Olympus in western Massachusetts, Gilder has caused billions of dollars to swing into companies that fit his umbrella concept of the "telecosm" as a world of, and about, communications technology. The problem with a bold techno-growth prediction, however, is that it blooms across all financial radar screens and tends to attract big, well-funded competitors who cross industry borders to flood the market with exponentially improving product that drives down prices, dries up future profits, and pushes down stock prices. Gilder shares a claim to fame--and part of the blame.

Although Gilder is very well-versed in physics, he's less so in the fundamentals of feedback loops, especially relating to supply and demand. In the end, it's simply not true that infinite appetite exists for bandwidth or that there's truly a smooth logarithmic elegance to demand for processing power, bandwidth, and storage. Yet the essential arguments of Telecosm were so firmly held by the marketplace that "Gilded" investors would pay any price for celebrity tech companies such as JDS Uniphase, QUALCOMM, or Sun.

In Telecosm, Gilder seeks to make a religion out of technology with talk of angels and cathedrals of light. But pride goeth before the fall. There's no free lunch after all. With trillions in market values lost to Wall Street last year and again this year, Telecosm is Exhibit A in the case against overhyping the tech sector.

One decent antidote to telecosmic cheerleading is Michael Dertouzos' What Will Be, though it was published a few years ago. The longtime director of the MIT Laboratory for Computer Science shows how, like Woody Allen's character Zelig, he was present and in the picture frame for many, if not most, computing breakthroughs related to universities in the past 20 years. Contrary to Gilder, Dertouzos argues that many of the most usefuL technologies still await discovery.

In one brilliant section, Dertouzos describes how and why computers need to be able to function without human input: "Imagine what would have happened if the companies making the first steam engine and internal combustion engines of the Industrial Revolution had made them so they could work together only if people stood between them and continued to labor with their shovels and horse-drawn plows. What an absurd constraint! Yet that is what we do today."

Ultimately, the choice between a Gilderian vision of unlimited abundance with no constraints other than the speed of light and span of life, and Dertouzos' impatience with our backwardness, in which we humans are the constraints, can serve as inspiration for investment and invention. But it's the vision and action of CEOs that will determine how successful our collective efforts are.

Alex Lightman is CEO of Charmed Technology (www.charmed.com), which develops wearable computers and augmented reality. He is writing Brave New Unwired World for John Wiley and is a graduate of MIT.