This analysis of the nature of the Church, based on the work of both past and present experts in the field of Church history, and written in the light of recent theological developments and emphasis, will be of great interest to theologians and church historians. It treats in satisfying detail every aspect of the problem and is rich as a reference source for material on the subject. It is, however, a book for the interested scholar who already has a good background for the subject. Father Hamer's discussion of such topics as the relation of the ""ekklesia tou Theou"" of the New Testament to the ""quahal Jahvah"" of the Old Testament, and of the twofold ""corporeity"" in St. Thomas concerning the state of the beatific vision are not for the average reader. But the latter will find the discussions, by the members of the First Vatican Council, of what Papal Infallibility really is, and what its extension is, as interesting historically as theologians will find it interesting theologically. A most valuable reference book for seminary and college libraries.