This volume integrates and makes sense of the growing body of theoretical and empirical research conducted on purpose across the lifespan. It opens with a comprehensive yet detailed discussion of the definitions of purpose most commonly used in studies on the topic. In addition to defining the construct, the author also discusses its philosophical roots and distinguishes it from related concepts, including meaning, goals, and ultimate concerns. This volume discusses the disparate perspectives on the construct and addresses the tendency to position purpose in the broader frame of positive psychology. It synthesizes distinct strands of research on purpose across the lifespan, it explores studies on the