Looking back over the past century it is hard to find justification for Gentz’s optimism. The respite that Europe had for a generation from war was due in a sense to the lesson learned in the Napoleonic struggle; but it was not a permanent lesson. We shall proceed to examine the expedients that came to be used for the end specified; but it is certain that they did not achieve permanently the end desired. Had the Congress of Vienna done all that was expected of it, the world might today be at peace. If not at peace, we might at least say that the men of the Congress did all they could to secure peace. If we ask for the fundamental cause of the failure of the Congress of Vienna to satisfy the hopes of liberal men in constructing what Gentz called “a more complete political structure,” the answer must lie in the illiberal views of the ruling classes in the European states. Self-government was less developed than in the most conservative state of today. Had the people of these states been in power, and had they been to a fair degree trained in the principles of good government, the result could hardly have been as it was. But the ignorant bureaucrats and arbitrary rulers were in power, men who in their own lives never knew the burdens of war, and to whom national egotism appeared a high virtue; and they thought only of gaining territory for their states. They placed such things above the high opportunity to reform the political structure of Europe. They turned to the future with the old principles still dominant, hoping that by a system of concert among the great states they could stave off war for an indefinitely long period. They could place self-interest against self-interest, forgetting that a time was likely to come when self-interest might lead the strongest to dare the rest of the world, hoping to move quickly in a moment of temporary advantage and thus gain ends that only the most severe sacrifices could take away. But that is a story reserved for another chapter. Before we take up the Concert of Europe we must deal with the Holy Alliance, which, though but an interlude in the play, is so frequently mentioned in the books that it cannot be omitted from this discussion. It was signed at Paris, November 20, 1815, and may be considered only one of the forms in which the tsar’s ideal was embodied. Its religious character made it the butt of ridicule for the “practical” statesmen of the day, and the historian has been prone to look at it from their standpoint. But it was then popular to express political principles in religious phrases, and the alliance is to be interpreted by the purpose that lay underneath, rather than by the mere form in which it was set forth.