"BETWEEN now and the 21st century, millions of ordinary, psychologically normal people will face an abrupt collision with the future," Alvin Toffler (with a since-acknowledged assist from his wife, Heidi) prophesied at the start of the 1970 best seller "Future Shock." In diagnosing "a new and powerfully upsetting psychological disease," that book, along with works like the Club of Rome's neo-Malthusian tract "Limits to Growth" and Hal Lindsey's Christian jeremiad "The Late Great Planet Earth," helped to define the 70's as a period when smog, the Antichrist and insufferably long guitar solos threatened to destroy the global village as completely as Charlton Heston did at the apocalyptic climax of "Beneath the Planet of the Apes." But "Future Shock" was no typical Me Decade downer.

Robert Weingarten

For the Tofflers, "The Collapse of Hierarchy" and "A Superabundance of Selves" (to quote two section headings in "Future Shock") weren't the disturbing developments they were to appalled social critics like Daniel Bell in "The Cultural Contradictions of Capitalism" and Christopher Lasch in "The Culture of Narcissism." The Tofflers believed that rampant technological, economic and cultural innovation was mainly a good thing, or at least potentially liberating for most of us once we learned how to deal with it. When the shock wore off, said the Tofflers, who elaborated their case in "The Third Wave" (1980) and "Powershift" (1990), we'd appreciate a richer, freer, groovier world.

Now the Tofflers are again back from the near future. Their new book, "Revolutionary Wealth," builds on the framework of their previous writings, so there's a lot of talk about clashes among First Wave (agrarian), Second Wave (industrialized) and Third Wave (postindustrial, or "knowledge-based") societies. They argue convincingly that we are on the verge of a post-scarcity world that will slash poverty and "unlock countless opportunities and new life trajectories," at least if we avoid the rapidly escalating risks to such progress.

The Tofflers, whose penchant for neologisms remains unabated, spend much time discussing the booming "prosumer economy" (which involves unpaid work that nevertheless greatly increases quality of life; for example, cooking a lavish meal for friends or much of open-source computer coding) and fretting over "obsoledge" (obsolete knowledge). Terrorism, global warming and potential pandemics have done little to dampen their old optimism. "The long-term reality is that we, as a species, have been getting better" at producing wealth, they say. "If we hadn't, the planet would not now be able to support nearly 6.5 billion of us. We wouldn't live as long as we do. And, for better or worse, we wouldn't have more overweight people than undernourished people on earth — as we do." Life expectancy at birth in the world, they note, including the "poor world," increased 42 percent over the past 50 years.

The titular wealth they speak of comes from substituting "ever-more-refined knowledge for the traditional factors of industrial production — land, labor and capital." The United States is producing more stuff than ever with fewer workers. The Tofflers write that only 20 percent of the work force is now in the manufacturing sector, while some 56 percent (and growing) is engaged in what they call "knowledge work" — managerial, financial, sales-related, clerical and professional tasks. Even activities like agriculture have gone high-tech, through biotechnology and increasingly sophisticated use of global-positioning satellites to customize irrigation and fertilization down to the individual acre. Knowledge-based wealth, they argue, is revolutionary not just because it gets more output from fewer inputs. Unlike such physical resources as oil, knowledge can be shared by an infinite number of people, and its value and benefits are generally increased by wider circulation. (A network, after all, is only as powerful as the number of participants.) Just as important, the Third Wave wealth system "demassifies production, markets and society," creating space for unending experimentation, innovation and individuation.

Forgive the Tofflers their diction, which sometimes reads like the linguistic equivalent of a shag rug. Their schema helps to explain why air quality has improved in American cities over the past 30 years and why American culture has become remarkably more accepting of alternative lifestyles. Yet they are not Panglossian. "The list of potential horrors is seemingly endless," they write, citing a United States-China war, a 21st-century Great Depression, water shortages in the developing world and more. Any of these could slow or reverse today's generally positive trends.

Despite visionary passages about nanotechnology (the manipulation of objects at the atomic level) and potential moon-based helium energy, "Revolutionary Wealth" is less interesting for its specifics (most of which will be familiar to readers of publications like Wired, The Economist and Red Herring) than for its evidence of how far we've come since the 70's, when politics, economics and culture all seemed as played out as Richard Nixon's denials of criminality. In "Future Shock," the Tofflers warned that many people "will find it increasingly painful to keep up with the incessant demand for change that characterizes our time. For them, the future will have arrived too soon." These days, from Baghdad to Bangalore to Boston, it seems more likely that people worry that the future will arrive too late. That's no small change, and it's one on which the Tofflers have been shining a light for years. Nick Gillespie is the editor in chief of Reason magazine and the editor of "Choice: The Best of Reason."

Copyright 2006 The New York Times Company. Reprinted from The New York Times, Book Review, of Sunday, May 14, 2006.