The superb exterior of this book, published in the best English style, leads the reader to expect something unusually excellent in the contents. Nor will he be disappointed. This work is no mere repetition of other books. It is learned, original, carefully prepared, well written, and has undergone an examination by competent theologians, not only in England, but also at Rome. The genuine doctrine of Catholic unity, as opposed to the pseudo-catholicity of Anglicans, is exposed in it, with a refutation of the objections of Bishop Forbes, Dr. Pusey, and others. The questions of the Easter controversy, the dispute between St. Cyprian and Pope St. Stephen, the dispute between Paulinus and St. Meletius of Antioch, the Celtic controversies, etc., are fully discussed. The only criticism we have to make is concerning the manner of treating the question of the divided obediences at the epoch between the pontificate of Urban VI. and that of Martin V. The author thinks that the adherents of Peter de Luna, called Benedict XIII., were really in schism, although most of them were innocent of any sin. We think otherwise, and our opinion has been derived from the most approved Catholic authors. Without doubt, the authors of the division were formal schismatics. Yet they were able to make out such a plausible case against Urban and in favor of Benedict, that for the time being Urban's right was doubtful in a large portion of Christendom. Those who refused to recognize him were not therefore guilty of rebellion against the Roman pontiff as such, any more than those would be who should refuse to obey a papal rescript of doubtful authenticity. After the election of Alexander V. there was much greater reason to doubt which of the three rival claimants, Gregory XII., Benedict XIII., or Alexander V., was the true pope. It is now perfectly certain that Gregory XII. was canonically elected, and we suppose it is by far the more probable opinion that he remained in possession of his right as legitimate pope until his voluntary resignation at the Council of Constance. Nevertheless, his claim, at the time, was a doubtful one, and the majority of the cardinals and bishops adhered, after the Council of Pisa, to Alexander V. and his successor John XXIII. Peter de Luna was a schismatic in the fullest extent of the word. But what shall we say of Alexander and John? Their names still appear on the lists of popes, and some maintain that they were true popes. They undoubtedly believed that a council could depose doubtful popes, and that therefore the Council of Pisa could deprive both Gregory and Benedict of whatever claim either of them might have to the papal throne. They believed themselves lawfully elected, and were not, therefore, schismatics, even though they were not lawful popes. If the author maintains that two of the three obediences which eventually concurred at Constance in the election of Martin V. were in a state of schism