Is there anything in the way of this union? Is there a morbid growth--a cause of irritation and disease tending to dissolution? Then, it must be removed. Is ambitious and reckless demagoguism to be apprehended? Then educate the people and diffuse science. But is there not still a worse devil to be cast out? Where slavery is, you cannot educate the people, you cannot diffuse science; and without enlightenment there can be no political justice, since unprincipled demagogues will sway all political destiny. Slavery cannot always exist side by side with freedom; it is the natural enemy of union, the enemy of civilization. Prominent secession leaders have admitted that slavery is the cause of this war, boasting at the same time that the confederate constitution is founded on a scientific distinction of races. Without slavery there could be no sufficient motive for the independent national existence of the South. Had there been no slavery, there had been no civil war. This is, at the present time, the political significance of the institution. There is no safety but in its extinction--so far at least as the border Slave States are concerned, in order to overthrow its power in the United States Senate, to enlarge the sympathies of freedom, and weaken and circumscribe the chances for revolutionary movements which slavery will be ready at any critical moment to precipitate against the Union. If we have not misinterpreted the law of development, slavery, as it exists in this country, is a morbid political condition, a social disease, which stands in the way of the natural course of social evolution. In this law, therefore, is written the doom of slavery. The enlightened world will not always permit it to blast the fair field of civilization by its poisonous presence. There is a law of human movement by which predominating conditions extend and perpetuate themselves, overcoming those which are weaker and on the wane. We observed this in our brief survey of the feudal system. Freedom is now in the ascendant, and slavery must go down. And since secession is the child of slavery, and both at war with the cardinal principles of progressive civilization, it is meet that both should fall together. This war may not directly extinguish slavery, and it may; we do not see the end. But if not directly, we believe the war is, nevertheless, indirectly setting those forces into action which will eventually extinguish the institution. If the 'confederacy' should be destroyed, as, if not saved by foreign intervention, it certainly will be, slavery, if not already dead, will be pent up, and, in that case, will soon die by its own hands.