In preparation for the volume on Christianity to be published in `The Religious Situation of Our Time', Hans Kung here presents, in the same lucid style as his recent best-selling Credo, a study of seven of the greatest Christian thinkers. After 'A Brief Introduction to Theology' he begins with Paul, as a result of whose activity Christianity broke through to become a world religion. Then come Origen, who made a controversial synthesis between the Christian spirit and the spirit of antiquity, and Augustine, the father of Western, Latin theology. Thomas Aquinas represents the learning of the universities and papal court theology, and Martin Luther is introduced as representing a return to the gospel in a classic case of a paradigm shift. Schleiermacher is a theologian at the dawn of modern times, and the book ends at the opposite pole from him, with Karl Barth, standing on the threshold of post-modernity. An epilogue explains what theology is all about