The author, president emeritus of Princeton Theological Seminary, acknowledges his debt to F. H. Bradley's Appearance and Reality both for the title and the point of view of these lectures, first delivered in 1952. Although revised subsequently, the argument reflects so little of contemporary theological thought or historical circumstance that thae date of delivery may be said to qualify what is said. Dr. Mackay makes the familiar accusation that many Christians today are characterized by ""religious nominalism and theological illiteracy."" This charge is expanded into four basic idolatries-an idolatry of theological ideas, of emotionalism, of ""churchism"" and of ethicism. How these are to be overcome is not clear, although the author often remonstrates against them with hortatory surgery. The content, on the whole, is characterized by a traditionalism of outlook and a reliance upon heavy assertion to advance the argument. It is difficult to assign this book to any particular audience.