Gall Sheehy made an impression on the popular consciousness by charting ""predictable"" life crises in Passages; now she's out to show us how to use our passages to best advantage--to reach a sense of ""well-being,"" ""a sustained background tone of equanimity."" So she's distributed ""Life History"" questionnaires far and wide (at her own lectures, to Redbook and Esquire readers); telephoned hundreds of recommended people to see who might measure up; and criss-crossed the country in search of the perfectly passaged. The results are somewhat less than breathtaking: more criteria for admission than a country club, with a similarly self-conscious style (as the setting for an ""ordinary man's"" story, we read: ""The Idaho sky was a shawl of uncombed wool stretched loosely across the frozen land""). To the criteria, then: ""pathfinders"" are those who confront life's crises, predictable or not, and make them into opportunities (the corporate wife who gets fed up and goes back to school, the corporation man who leaves to avert a heart attack and sets himself up in his own business). Their most essential attribute is a willingness to risk--for little is accomplished, we're told, when fear-of-change dominates a lifestyle. Other prevalent qualities include a good sense of timing (they set goals for five years from now); a ""flourishing circle of friendship and kinship""; the usual androgynous spectrum of strengths (evidenced particularly by pathfinders in the second half of life); the financial stability and self-knowledge of middle age(!); a sense of purpose and direction, etc. Sheehy's path-finders--illustrated by biographical profiles both pro and con--are primarily copers and survivors, people who may initially go down for the count but are soon up and at it again, in better shape than ever. They've got energy and optimism, and tend to view failure as a temporary setback rather than a sign of basic internal shortcomings. In short, they're the heroes of 99 percent of the self-help books ever written--but the readers of Passages may well give them another strong, if brief, chance to shine.