In twentieth-century industrial societies most of us live longer and healthier lives than ever before in history. Yet the social structures and institutions that provide opportunities for our lives are still marked by age constraints that were appropriate a century ago. Education is still primarily reserved for the young; work and family responsibilities are crowded into the middle years; while leisure and free time are allocated to the added decades of retirement. Even the many vital men and women past age 65, or even 55, who want or need paid jobs are regarded as "too old" to work. Lives...