The essential element in the renewal of the Catholic Church is to make the Christian message relevant to 20th century man-to somehow break down the invisible wall that has grown up between the abstract statement of principles of the life that is being lived by individual Christians. For today’s moral theologians this task of forming a synthesis of authoritative teaching and individual freedom in the lived circumstances of the person’s life requires, at times, a rethinking of the entire structure of the Church’s teachings. This is the work that Father Curran has engaged in here. He deals both with broad concepts-conscience, freedom, teaching authority, law - and specific applications - Sunday observance, mixed marriages, and birth control. The essays thus provide an introduction to the new moral theology, indicating the lines to be followed in forming a responsible individual conscience, as well as suggesting new frontiers for the professional theologian.