For the present it is enough to say that no human legislation, authority or constraint can ever create internal unity of intellect and will; and that the diversities and contradictions generated by all human systems prove the absence of Divine authority. Variations or contradictions are proof of the absence of a Divine mission to mankind. All natural causes run to disintegration. Therefore, they can render no account of the world-wide unity of the One Universal Church. Such, then, are the facts before our eyes at this day. We will seek out the origin of the body or system called the Catholic Church, and pass at once to its outset eighteen hundred years ago. I affirm, then, three things: (1) First, that no adequate account can be given of this undeniable fact from natural causes; (2) that the history of the Catholic Church demands causes above nature; and (3) that it has always claimed for itself a Divine origin and Divine authority. I. And, first, before we examine what it was and what it has done, we will recall to mind what was the world in the midst of which it arose. The most comprehensive and complete description of the old world, before Christianity came in upon it, is given in the first chapter of the Epistle to the Romans. Mankind had once the knowledge of God: that knowledge was obscured by the passions of sense; in the darkness of the human intellect, with the light of nature still before them, the nations worshiped the creature--that is, by pantheism, polytheism, idolatry; and, having lost the knowledge of God and of His perfections, they lost the knowledge of their own nature and of its laws, even of the natural and rational laws, which thenceforward ceased to guide, restrain, or govern them. They became perverted and inverted with every possible abuse, defeating the end and destroying the powers of creation. The lights of nature were put out, and the world rushed headlong into confusions, of which the beasts that perish were innocent. This is analytically the history of all nations but one. A line of light still shone from Adam to Enoch, from Enoch to Abraham, to whom the command was given, "Walk before Me and be perfect." And it ran on from Abraham to Caiaphas, who crucified the founder of Christianity. Through all anthropomorphisms of thought and language this line of light still passed inviolate and inviolable. But in the world, on either side of that radiant stream, the whole earth was dark. The intellectual and moral state of the Greek world may be measured in its highest excellence in Athens; and of the Roman world in Rome. The 'state of Athens--its private, domestic, and public morality--may be seen in Aristophanes.