The modern founder of political science, Machiavelli, writer as well as statesman, in his most instructive work, the Discourses on Livy, has a chapter entitled, “For a Republic to have long life, it is necessary to bring it back often to its origin”:[295] where he shows how the native virtue in which a Republic was founded becomes so far corrupted that in process of time the body-politic is destroyed,--as in the case of the natural body, where, according to the doctors of medicine, something is daily added, from time to time requiring cure. The remarkable publicist teaches under this head that Republics are brought back to their origin, and to the principles in which they were founded, by pressure from without, where prudence fails within; and he affirms that the destruction of Rome by the Gauls was necessary, in order that the Republic might have a new birth, with new life and new virtue,--all of which ensued, when the barbarians were driven back. If the illustration is fanciful, there is wisdom in the counsel; and now the time has come for its application. The Gauls are upon us, not from a distance, but domestic Gauls, flinging their swords, like Brennus, into the scales; and we, too, may profit by the occasion to secure for the Republic a new birth, with new life and new virtue. Happily, the way is easy; for there is no doubt of its baptismal vows, or the declared sentiments of its origin. There is the Declaration of Independence: let its solemn promises be redeemed. There is the Constitution: let it speak according to the promises of the Declaration. Let it speak, and the last act of the great American tragedy will be ended, while the stage is piled with corpses. From its early beginning in the hold of the Dutch ship on its way to Jamestown, as the Pilgrims in the Mayflower were on their way to Plymouth, down to this bloody Rebellion, Slavery has been a prolonged tragedy. History and Art will hereafter portray the scenes. Nor can its death be otherwise than an epoch, not only for our own country, but for mankind. Slavery in its distant origin was the substitute for death. The slave was allowed to live, but without the rights of man. Instead of death in the grave with its insensibility and decay, there was death in life with constant degradation and suffering. Hence in all ages the awakened sympathies of the good and humane,--heard sometimes in sorrow for the unhappy fate of an individual, and then in appeal for a race.