Immediate interests control us more than those which are remote; interests which affect ourselves, more than those which affect our descendants. Citizens of the Southern States, to save a petty individual interest, are nursing in the bosom of society a malignant canker, which, if let alone, must one day, in the inevitable course of destiny, eat into its vitals. Heroic treatment will alone meet the demands of the case. It must be a surgical operation that will penetrate to the very roots of the invading tumor. The salvation of the South itself, as well as of the Union, hangs upon the extinction of slavery. Indeed, the South has far more interest than the North in the restoration of political health as the condition of political union; and she would see it so, if slavery had not made her blind. The elimination of slavery would, in the end, be clear gain to her, while she would reap equally with the North the advantages of union, and escape the disadvantages and calamities which, as we have seen, must inevitably follow in the wake of confirmed disunion. The writer of this article bases his opposition to slavery solely upon politico-scientific grounds; he urges the recognition of a great law of human development, that its bearings on human destiny may be fairly seen, and human endeavor more wisely directed to the achievement of the end 'so devoutly to be wished.' The discussion of American Destiny in all its ramifications would involve the discussion of the ultimate fate of the negro race on this continent; but that is not within the range of our present purpose. We have aimed only to indicate the law of development from the simple to the complex, over which a necessary unity at length prevails; to show that this law obtains in the political as in all other realms; to insist that political unity should enlarge its area as facilities for intercommunication permit, and the interrelation of industrial, commercial, and social interests demand; that the jurisdiction of the political unity should correspond to the extension of general interests, so far as may be possible in the face of physical necessities not yet overcome in the progress of civilization. We would apply the doctrine more especially to the present crisis in American affairs, to enable us to realize that all our sacrifices to maintain the Union are fully warranted by the great principle of human development which is involved in the contest.