One of the following chapters has appeared in print, and selected parts of two others. Chapter VIII on Karl Barth was presented as a symposium of philosophers and theologians at Princeton Seminary in December 1962, and was printed among the papers of this conference in Faith and the Philosophers, edited by Professor John Hick and published by St Martin's Press and the Macmillan Company. It is reprinted with the publishers’ permission. An article based on Chapter VI, on Kierkegaard, appeared in the winter number of The Personalist in 1968, and permission has been granted by the editor for the re-use of this material. The substance of Chapter XI on ‘The Ethics of Belief’ was used in a presidential address to the American Theological Society in 1956, and was printed by the Center for Philosophic Exchange in its journal Philosophic Exchange, Vol. 1, No. 2, issued in 1972; it is here reprinted with the permission of the editor. These permissions are gratefully acknowledged.

In a work so largely critical as this, it has been necessary for the sake of accuracy to make numerous quotations from the books and authors dealt with. I have sought to make due acknowledgement for these in the notes at the end of the book by giving the publisher, place, and date of each volume on the occasion of the first reference to it.