If we have rightly interpreted history and the law, these sacrifices are justified by a double consideration. The first, which is negative--to avoid the entanglements, broils, and conflicts of neighboring nations, and the consequent exhaustion of the resources of civilization, through which its progress would necessarily be retarded; the second, which is positive--to maintain a vast political organization on this continent in accordance with the demands of a higher civilization, as the only sure guarantee for the integrity of the 'Monroe doctrine,' and the accomplishment of a great political mission, by reacting upon Europe, and leading her isolated and fragmentary nationalities into a higher unity, involving order, authority, and the economy of power. It is the selfish interest of the crowned heads of the little nations of Europe to maintain things as they are, with a principality and a palace for each puppet of royalty. Hence their costly machinery for maintaining the 'balance of power.' There may have been a use for this in the ignorance of the masses, when the extension of sovereignty was often but the increase of despotism; but there is no such need in the advanced culture of the people and the progress of civilization. Formerly there was no public sentiment; but, with the rise of civilized methods, it became developed, and it has gradually enlarged its sphere, till, as a writer on dynamical physiology remarks, 'we now hear of the public opinion of Europe.' (Draper.) And we believe that, before this public sentiment, thrones are doomed to topple, and sceptres and diadems to fall, to make way for the more liberal and comprehensive political organizations of an advancing and triumphant civilization. And herein appears a glimpse of the political mission of the American Union, destined itself to become still more comprehensive in the inevitable fluctuation and change of the political elements. It is a hackneyed theme that all the natural features of our country, its mountains, rivers, valleys, lakes, are on a grand scale; it is, therefore, meet that we should lead the civilized world in the movement of political unity.