Puer aeternus is Latin for eternal boy, used in mythology to designate a child-god who is forever young; psychologically, it is an older man whose emotional life has remained at an adolescent level. The puer typically leads a provisional life, due to the fear of being caught in a situation from which it might not be possible to escape. He covets independence and freedom, chafes at boundaries and limits, and tends to find any restriction intolerable. Senex (“old man”): associated with attitudes that come with advancing age. Negatively, cynicism, rigidity, conservativism; positively, responsibility, order, self-discipline. The elder pole of the spirit archetype. A healthy personality balances senex with puer. In this lecture, Dr. Lavin discusses the experience of Puer and Senex in midlife.