Yves Conngar's great three volume work I Believe in the Holy Spirit (Geoffrey Chapman 1983) has found world-wide acclaim. In the present volume this distinguished Dominican theologian returns to the subject of the Holy Spirit, the Breath of God, in particular the Holy Spirit in action together with Jesus Christ, the Word of God. He writes with a distinctive combination of depth of scholarship, breadth of reference and a very personal style. Congar considers the Spirit at work jointly with the Word: building up and developing the Church; intervening in the spheres of personal initiatives, the unfolding of revelation, the charisms and prophecy; the Spirit in Christology; the theology of the Spirit in the Eastern and Western Churches; and the Spirit at work in the universe.