For several years past the reading and collection of books on the Holy Spirit has been a matter of great interest to me, and when the invitation came to deliver the Stone Lectures at Princeton it seemed a favourable opportunity for putting together the available material. The object I had cherished for some time was to provide a Monograph for students, with references and Bibliography. In The London Quarterly Review for April, 1905, Dr. W. T. Davison, in an article on ' The Person and Work of the Holy Spirit,' described almost exactly what had been in my mind.

'The treatise for which the Church waits must be comprehensive enough to include branches of it which have been treated in a disconnected and fragmentary way, whilst sufficiently instinct with spiritual life to blend them into one having and organic whole. It should briefly trace the development of revelation through the Old Testament, showing what fresh highs on the Person and Work of the Holy Spirit is shed by the New. The bearing of the doctrine on the interior relations of the Godhead should be expounded, so far as Scripture gives guidance on a profoundly mysterious subject. The offices of the Spirit in relation to Christ and the believer can more easily be explained and illustrated. On the question of the relation between the Spirit and the Church widely different opinions are held by different sections of Christendom, and it is on this ground that so many divergent paths have been taken by " heretics " of various schools.... A complete treatise on the work of the Holy Spirit should show the significance of these several religious movements and the measure of truth and falsity in each.'

'This kind of work has, however, been undertaken, and more or less imperfectly accomphshed. What has not been attempted is a study of the chief " building eras of religion," under the guidance of the Spirit, as this is understood by Protestants and all who do not accept the Romanist doctrine of infallibility.... With these topics should be combined a careful inquiry into the relation between the illumination bestowed by the Spirit on the living Church of each generation on the one hand, and Holy Scripture as inspired by the same Spirit on the other. The measure of height and grace granted to the world outside the Christian Church, the operation of the Spirit in convicting the world of sin by the proclamation of the Gospel, and the work of the same Spirit in the initiation and conduct of all aggressive enterprise, are themes which greatly need to be thought out and expounded afresh by wise Christian teachers. Closely connected with them is the question of intermittent operation to which we have referred. The hindrances which prevent the Church of Christ from being " filled with the Spirit," and which therefore terribly retard the accomplishment of the great task of evangelization entrusted to her, together with the ways in which the Spirit Himself is seeking to remove these obstacles, need to be studied as a portion of the same great theme — manifold in its diversified parts, but one in its central conception and significance.

It will be said that the sketch thus outlined covers almost the whole field of dogmatics and Church history.... The answer is obvious. Only those aspects of Church thought and life should be considered which concern the direct operation of the Holy Spirit, and they should be treated from that point of view alone.... They have not been sufficiently considered from one special point of view and in the unity which that would give them.'

It was only after working for some time at the subject that I came across this article, and I desire to acknowledge with gratitude the help and guidance found in it. Of course, I make no claim to the realisation of this splendid ideal, but I have kept the aim before me and have endeavoured to frame my work on these lines. The plan is here reproduced in an available form for others, in the hope that they may bring the issue to fuller success.

It will soon be seen that there is no attempt at originality, but only the effort to call attention, within the compass of one volume, to some of the most important aspects of the truth. In the list of books found at the beginning of each chapter, in the numerous quotations scattered throughout the work, and in the Bibliography, the character and extent of my indebtedness will readily be noticed. Indeed, I should like to forestall some criticism by saying that the definite purpose of my book is to be seen from the frequent and full quotations especially in the earlier chapters. As the ground had already been so adequately and ably covered by writers of the eminence of Dr. Swete and others, I felt that it would have been wholly superfluous to re-state what had been thus effectively set forth. Instead of this, therefore, I have endeavoured, by means of quotations and references, to direct students to works in which the particular topics have been thoroughly discussed.

Another point seems to call for special mention. My lectures were delivered at Princeton and the substance of the book was completed before I read Dr. Forsyth's Faith, Freedom, and the Future and The Principle of Authority, and Dr. Mullins' Freedom and Authority in Religion. But I am particularly glad to be able to include quotations from and references to these valuable works, and especially to find some of my own conclusions confirmed by two such great authorities. Even though Dr. Forsyth's distinction between the Word of the New Testament and the Word of the Gospel is not here followed, there does not seem to be any fundamental difference between the position for which he and I contend in regard to the constant and close association of the Word and the Spirit.

I had hoped to be able to utilise the latest and best works in French and German on the subject of the Holy Spirit, and in order to make the book as complete as possible I wrote to several leading theologians for information and guidance. Unfortunately, time has prevented me from doing what I wished, unless the issue of this volume were to be seriously delayed, but I have included all the recommendations in the Bibliography for the guidance of other students, and I desire to express my obligations to Dr. Forsyth, Professor H. R. Mackintosh, Professor Denney, and Professor Knowling, for their valuable information and suggestions.

It remains to add two matters of a more personal nature. I am deeply indebted to the Faculty of the Princeton Theological Seminary for the invitation to deliver the Stone Lectures, and not least for the honour of being, I believe, the first Anglican to lecture on that Presbyterian Foundation. My visit to Princeton and my intercourse with the Faculty and the students were a privilege and an enjoyment which will long be a happy memory. Then, again, I have inscribed this volume to seven well-known names, first, in order to acknowledge with thankfulness my great indebtedness in various ways to their writings; and, second, to call attention to and emphasise something of that essential unity of Christian scholarship which is perhaps doing more than anything else to pave the way for the still larger unity of the Churches for which our Master prayed, and without which the world will not be impressed with the things of the Spirit. In this connection, I would like to make my own the closing words of the Times' notice of Professor Swete's book. The Holy Spirit in the Ancient Church:

'It is part of the irony of history that whereas all Christians have believed that the Holy Spirit was given to the Church in order to bind its members together into one Body, the disputes which arose concerning the Person or Persons through Whom the Spirit was given to the world were a chief cause of the disruption of the Church. We would fain believe that the increasing recognition of the work of the Holy Spirit within the Christian Church and throughout the world which has been a marked characteristic of recent years will prove to be the prelude to the complete reunion of Christendom.'

POSTSCRIPT TO PREFACE

Since the above lines were written the Rev. Dr. Orr has passed away, and I have had regretfully to make the necessary alteration in the form of the Dedication. I cannot refrain from bearing my grateful testimony to him and his books. Ever since I first read his The Christian View of God and the World I have been very deeply his debtor, and have often enjoyed and profited by his massive scholarship, his wonderful insight into Christian principles, his powerful grasp of essential truth, his marvellous balance of judgment, his fair and pellucid presentation of his own and his opponents' positions, his intimate knowledge of current thought and his unswerving convictions. In addition to the books he published I have had the privilege for several years past of correspondence and personal fellowship with him, and I have frequently sought his guidance on points of history and theology. He was always abundantly ready to pour out his wealth of learning for the benefit of those who are unable to keep in touch with the latest and best that is being written in Germany and elsewhere, and I never asked his help in vain. In correspondence and personal intercourse the true simplicity of the man was deeply impressive and revealed the humble Christian in the great scholar To many, like myself, his books will long abide as a source of valuable instruction, and he being dead will yet speak in support of those great realities which were the strength, joy and inspiration of his own life.