Jüngel's magnum opus to date is the lengthy study Gott als Geheimnis der Welt, and themes from this book will be explored in the next three chapters. Gott als Geheimnis is a diffuse work whose main thrust is not easily identified from a cursory reading: it is indeed a ‘Studienbuch’ which makes considerable demands on the student. Jüngel has three main areas of concern in the course of the book: language about God, thought about God, and the nature of God himself. He is led to range over such a breadth of issues in prolegomena and substantive dogma because of the book's underlying conviction that issues of method and content cannot be separated. Indeed, in some ways the book is an object lesson in the many-sidedness of serious theological work. Stylistically, too, it is a curious piece, blending together historical analysis with highly abstract writing on metaphysical and dogmatic themes. Once again, the juxtaposition conveys a conviction about ‘the bond between systematic thinking and historical analysis’. There are certainly times when the reader is left wondering whether the book operates on so many different fronts that its energy is dissipated. Nevertheless, it is a book of very considerable strength, with passages of real brilliance. We turn to the first of its main themes, that of Christian speech about God.