“We must develop a compelling vision of later life: one that does not assume a trajectory of decline after fifty, but one that recognizes it as a time of change, grown, and new learning; a time when ‘our courage gives us hope.’” —from The Third Chapter At a key moment in the twenty-first century, demographers are recognizing the significance of a distinct developmental phase: those years following early adulthood and middle age when we are “neither young nor old.” Whether by choice or not, many in their “third chapters” are finding ways to adapt, explore, and channel their energies, skills, and passions in new ways and into new areas. It’s this process of creative reinvention that the renowned sociologist Sara Lawrence-Lightfoot details in The Third Chapter, which redefines our views about the casualties and opportunities of aging.