This is the century of revolutions. Rome has in our time been besieged three times; three Popes have been driven out of it, two have been shut up in the Vatican. The city is now full of the Revolution. The whole Church has been tormented by Falck laws, Mancini laws, and Crispi laws. An unbeliever in Germany said some years ago, "The net is now drawn so tight about the Church, that if it escapes this time I will believe in it." Whether he believes, or is even alive now to believe, I cannot say. Nothing thus far has been said as proof. The visible, palpable facts, which are at this moment before the eyes of all men, speak for themselves. There is one, and only one, worldwide unity of which these things can be said. It is a fact and a phenomenon for which an intelligible account must be rendered. If it be only a human system built up by the intellect, will and energy of men, let the adversaries prove it. The burden is upon them; and they will have more to do as we go on. Thus far we have rested upon the evidence of sense and fact. We must now go on to history and reason. Every religion and every religious body known to history has varied from itself and broken up. Brahminism has given birth to Buddhism; Mahometanism is parted into the Arabian and European Khalifates; the Greek schism into the Russian, Constantinopolitan, and Bulgarian autocephalous fragment; Protestaritism into its multitudinous diversities. All have departed from their original type, and all are continually developing new and irreconcilable, intellectual and ritualistic, diversities and repulsions. How is it that, with all diversities of language, civilization, race, interest, and conditions, social and political, including persecution and warfare, the Catholic nations are at this day, even when in warfare, in unchanged unity of faith, communion, worship and spiritual sympathy with each other and with their Head? This needs a rational explanation. It may be said in answer, endless divisions have come out of the Church, from Arius to Photius, and from Photius to Luther. Yes, but they all came out. There is the difference. They did not remain in the Church, corrupting the faith. They came out, and ceased to belong to the Catholic unity, as a branch broken from a tree ceases to belong to the tree. But the identity of the tree remains the same. A branch is not a tree, nor a tree a branch. A tree may lose branches, but it rests upon its root, and renews its loss. Not so the religions, so to call them, that have broken away from unity. Not one has retained its members or its doctrines. Once separated from the sustaining unity of the Church, all separations lose their spiritual cohesion, and then their intellectual identity. _Ramus procisus arescit_.