Wolfhart Pannenberg is the the most important living German systematic theologian. Yet so far he has written no volume of systematic theology. His position on christological questions has been stated in Jesus -God and Man, but thoughts on other topics have been expressed largely in article form. A first aim of Dr Tupper's book is therefore to produce a lucid and comprehensive exposition of the areas so far covered by Pannenberg's theology. There is more to this work, however, than systematization. Having traced the background to Pannenberg's thought and described his theology, Dr Tupper goes on to raise questions about Pannenberg's current conclusions and future programme. Professor Pannenberg himself has written a postscript and comments on the success of the enterprise: Dr Tupper's book presents the most comprehensive report that has been published so far on my theology. His careful interpretation and balanced discussion of the numerous controversies surrounding it and the clarity of his presentation of the issues at stake will prove helpful, I hope, in urging substantial theological discussion. There are a number of points in my writings which are in need of clarification and further development, Dr Tupper mentions a few of them. They may indicate to the reader that theology is not something like a closed system, but an open and accumulative process of research.