No apology is needed for offering to the public a translation of a work by so eminent an author as Dr. Hergenröther, and on a subject so much discussed as the relations of Church and State. The Author is already known in England by his Anti-Janus, which has been translated by Professor Robertson; and in Germany he is recognised as one of the most learned and zealous among the defenders of the Church. As such, he is singled out for especial attack by the champions of the Döllingerite heresy, and is mockingly called 'the official refuting theologian of the Vatican.' But as the English public is fortunately unacquainted with these attacks, it is needless to give that portion of the introduction to his essays in which Dr. Hergenrother repels the charges brought against himself and his fellow-labourers, and exposes the rude insolence of his opponents: showing their literary failings and contradictions, which contrast with their arrogant claim to a monopoly of historical and theological learning. It is enough to say that this work, while answering the criticisms on Anti-Janus, is far more than a mere answer. The author's intention has been not to rest on the surface, but to give so thorough and deep an account of the relations of Church and State, as to serve for more than the purposes of ephemeral controversy, and to be a work of permanent value and reference.