Dietrich Bonhoeffer is now well known to the English-reading public. His Posthumous works, the Ethics and Letters and Papers from Prison, have caught the imagination of writers and artists, philosophers and theologians, far beyond the normal circles in which theology is read. But very little substantial work has so far appeared in English on the profound questions of faith and its understanding which Bonhoeffer raises. In this symposium an attempt is made to analyse and clarify some of the key ideas in Bonhoeffer's thought. The enigmatic theme of the 'world come of age' receives special attention. An essay by Professor Rudolf Bultmann of Marburg, as well as the famous letter by Karl Barth, are importance contributions. The Chicago lectures of Eberhard Bethge, friend of Bonhoeffer and recipient of most of the famous letters from prison, together with the contributions from America, Scotland, Denmark and Germany, make an illustrious addition to the study of Bonhoeffer's ideas.