This book engages one of the liveliest theological debates at the turn of the twenty-first century: the significance of the doctrine of the Trinity to the Christian concept of God and to its life of faith. Juergen Moltmann's social trinitarian theology constitutes the most substantial Protestant contribution to this debate. In this book, Joy McDougall offers a reading of Moltmann's major theological writings over the past thirty years from his first major book, The Theology of Hope, to the present, tracing the development of Moltmann's doctrine of the Trinity and its implications for ethics broadly understood.