(FORTUNE Magazine) – Society is sailing into an era of ''discontinuous change,'' declares British consultant Charles Handy in The Age of Unreason (Harvard Business School Press, $18.95). Corporations and business folk face a choice: Embrace this truth and cast about for new ways of thinking, or risk ending up like the Peruvian Indians who, after glimpsing the sails of their Spanish invaders on the horizon, put it down to a freak of the weather and went about their business. ''Assuming continuity,'' Handy cheerily explains, ''they screened out what did not fit and let disaster in.'' Catchy stuff. But just who or what are the paradigm-shattering Pizarros dreamt of in Handy's futurology? They include information technology, global competition, the rise and rise of the service sector, and the shift to ''knowledge-based'' organizations, among other things. Oh, you may be thinking at about this point, them again. Handy's main theme is how these familiar forces will alter ''the way our work is organized.'' Corporations will continue casting off layers of management and support activities to concentrate on a ''professional core'' of executives. That inner circle will increasingly function -- and compensate itself -- the way ad agencies, consultancies, and law firms do now. Early retirement and part-time work will proliferate. By 2000, a quarter of the working population may toil at home. Which leads to the really good news: With only a few hardy souls pursuing traditional corporate careers, ''the early morning crush in the commuter train will one day be a thing of the past.'' Much of this will seem old hat to regular readers of Peter Drucker, Tom Peters, or the pages of the better business magazines. That's my biggest gripe about this book. Still, anyone coming into this intellectual country for the first or second visit will find this urbane, avuncular Brit an appealing guide. For one thing, unlike most of his American counterparts -- particularly the ones who teach in business schools -- Handy can write. His distaste for jargon is matched by a keen appreciation for how, as he puts it, ''words are the bugles of social change.'' Example: With the growing appeal of working at home, ''homeworker,'' a term still redolent of arthritic spinsters knitting in dimly lit rooms, is disappearing. Such people are now ''telecommuters.'' Similarly, now that ''typing'' has become ''keyboard skills,'' Handy observes, ''everyone can learn to use ((the computer)) without loss of face or dignity.'' HE CAN ALSO BE delightfully imaginative. We're all vaguely aware, for instance, that people spend less of their lifetimes fully employed than they did, say, 30 years ago. But Handy does his sums and comes up with a number -- roughly 50,000 hours less per life -- that should prompt even the most dedicated corporate climber to begin pondering how he might fill that time. I was particularly taken with Handy's musings on how changes in the workplace could affect policymakers. Government has traditionally relied on big corporations as sources of economic data, collectors of taxes, and administrators of social welfare programs, such as medical insurance. But with the shift to ''more fee work, more telecommuting, more self-employment,'' business will be increasingly less suited to playing those roles. He suggests ! substituting a federally guaranteed income for the vast structure of government benefits and wiping out the income tax, which ''will become progressively harder to collect,'' replacing it with a consumption tax. Handy is not interested in making detailed arguments for his immodest proposals. He's more eager to play the role of intellectual bomb-thrower. His target: the cast of mind epitomized by a speaker at the Church of England General Synod in the 1980s, who asked, ''Why cannot the status quo be the way forward?'' Rare is the successful top manager these days who would echo that heartfelt cry -- at least publicly. Even so, when it comes to grappling with issues such as how you train and compensate a ''flexible labor force'' chockablock with part-timers, few companies have begun to walk their talk. Handy's goal, he says at the outset, is to help people ''look at things in a different way.'' Measured against that aspiration, this modest little book succeeds.

BOX: EXCERPT: The telephone and its attachments make it possible for people to work together without being together . . . not an unmixed blessing. As Pascal once said, ''All the world's ills stem from the fact that a man cannot sit in a room alone.'' Increasingly he, and she, may have to.