In March 1998, Hans Kung celebrated his seventieth birthday. Over the years his books have been read by millions throughout the world, and they represent a quite remarkable achievement. The Church, a prophetic vision of the church written at the time of the Second Vatican Council and still read widely today, was followed by On Being a Christian?, Does God Exist?, Eternal Life, and then both by magisterial volumes like Judaism and Christianity and classic popular studies like Credo and Great Christian Thinkers, Global Responsibility led also to his indefatigable work for a global ethic, marked most recently by A Global Ethic for Global Politics and Global Economics. This study by Hermann Haering, a former pupil and colleague of Hans Kung, offers a comprehensive guide to all Hans King's work and shows how his concerns, from his call for reform of the Catholic Church and his questions about infallibility to his work in inter-faith dialogue and ethics, all belong together and all stem from a deep and truly Catholic faith. It makes as exciting reading as the books of the author it describes and shows him to be one of the great theologians of the twentieth century. Hermann Haering is Professor of Dogmatic Theology in the Catholic University of Nijmegen.