One of the first principles of all social happiness is, that before the law of nature, and before the face of God, all men are equal. This principle is based on the unity of the human race, the origin of all men from one common father. If we study the History of Paganism, we find that all heathen nations overturned this great principle, since we find among all heathen nations the evil of _Slavery_. Prior to the coming of Christ, the great majority of men were looked upon as a higher development of the animal, as animated instruments which might be bought and sold, given away and pawned; which might be tormented, maltreated, or murdered; as beings, in a word, for whom the idea of right, duty, pity, mercy, and law had no existence. Who can read, without a feeling of intense horror, the accounts left us of the treatment of their slaves by the Romans? There was no law that could restrain in the least the wantonness, the cruelty, the licentious excess of the master, who, as master, possessed the absolute right to do with his slaves whatsoever he pleased. To remove this stain of slavery has ever been the aim of the Catholic Church. "Since the Saviour and Creator of the world," says Pope Gregory I., in his celebrated decree, "wished to become man, in order, by grace and liberty, to break the chains of our slavery, it is right and good to bestow again upon man, whom nature has permitted to be born free, but whom the law of nations has brought under the yoke of slavery, the blessing of their original liberty." Through all the middle ages--called by Protestants the _dark ages of the world_--the echo of these words of Gregory I. is heard; and in the thirteenth century Pope Pius II. could say, "Thanks to God, and the Apostolic See, the yoke of slavery does no longer disgrace any European nation." Since then slavery was again introduced into Africa, and the newly-discovered regions of America, and again the Popes raised their voices in the interests of liberty,--from Pius II. to Pius VII., who, even at the time Napoleon had robbed him of his liberty, and held him captive in a foreign land, became the defender of the negro, to Gregory XVI., who, on the third of November, 1839, insisted in a special Bull on the abolition of the slave trade, and who spoke in a strain as if he had lived and sat side by side with Gregory I., thirteen hundred years before. But here let us observe, that not only the vindication of liberty for all, not only the abolition of slavery, but the very mode of action followed in this matter by the Popes, has gained for them immortal honor, and the esteem of all good men. When the Church abolished slavery in any country where it existed, the Popes did not compel masters, by harshness or threats, to manumit their slaves; they did not bring into action the base intrigues, the low chicanery, the canting hypocrisy of modern statesmen; they did not raise armies, and send them into the lands of their masters