I am indebted to a great many friends of widely differing philosophical and religious persuasions for help and encouragement in tackling the problems with which the following studies are concerned. To name them all would be impossible. Two, however, cry out to be mentioned. One is the head of the department in which I teach, Professor D. M. MacKinnon, whose deep interest in, and knowledge of, contemporary theology can surely be matched by few British philosophers today. The other is Professor Antony Flew, who gave generously of his time and logical skill in helping me to clarify and improve both argument and exposition at many points.
I am grateful to the following publishers for permission to quote certain passages: to Messrt T. & T. Clark for Church Dogmatics, by Karl Barth, and I and Thou by Martin Buber; to the Lutterworth Press for Essays in Christology for Karl Barth, by D. M. MacKinnon; to James Nisbet & Company for The World and God, by H. H. Farmer ; and to the S.C.M. Press for The Divine-Human Encounter, by Emil Brunner, Christian Apologetics, by Alan Richardson, and A Theological Word Book of the Bible.