Christians who have not in some measure been affected by the thought of Reinhold Niebuhr are rare, but rarer still are those who have been able to keep abreast of his prolific literary output, his magnificent lectures and his tremendous involvement in many practical ways with the world around him, where he has been a great theologian for two soore years. For the rest of us Gordon Harland has done a great favor in bringing together in this single, large volume the essence of his teachings, well systematized. Best of all, this has been done at a time when Dr. Niebuhr could react to the result. An important feature of Professor Harland's work is the presentation by contrast, so that Dr. Niebuhr's teachings are shown in sharp relief against those who disagreed with him or to whom he took strong exception. Students of economics, labor, politics and social problems will find lots of meat in this work, for the range of Dr. Niebuhr's interests is as broad as his mind is magnificent. Professional theologians and humble preachers will be stimulated by Gordon Harland's analysis, and the issues discussed are such that those in the field of philosophy cannot ignore. Professor Harland's work is not easy reading, for he is dealing with a man who has stretched the minds of Christians for four decades, The book has the grace of tracing the development of many of the great ideas, for Dr. Niebuhr is a man who has not hesitated to share fresh insights as the implications of the Gospel unfolded to him. Yet the basic unity and consistency of his teaching is never lost sight of.