In the last halfof the 20th century, a consensus emerged that Christian theology inthe Western tradition had failed to produce a viable doctrine of the HolySpirit, and that Augustine's trinitarian theology bore the blame for much ofthat failure. This book offers a fresh rereading of Western trinitariantheology to better understand the logic of its pneumatology. Ables studies thepneumatologies of Augustine and Karl Barth, and argues that the vision of thedoctrine of the Spirit in these theologians should be understood as a way oftalking about participating in the mystery of God as a performance of the lifeof Christ. He claims that for boththeologians trinitarian doctrine encapsulates the grammar of the divineself-giving in history. The function of pneumatology in particular is toarticulate the human reception and enactment of God's self-giving as itselfpart of the act of God; this "self-involving" logic is the special grammar ofthe doctrine of the Holy Spirit.