Experience has shown us that war is almost invariably preceded by revolution. These are not days in which potentates can assemble their armies, march across their frontiers without palpable cause of offence, and seize upon the territory of their neighbours. But for the spirit of innovation, restlessness, and lust of change, never more generally exhibited than now amongst the people, the world would remain at peace. It is only when, as in the case of Germany and Italy, the sceptre is wrenched from the hands of the constitutional authorities, and when the rule of demagogues and experimentalists commences, that the danger of war begins. At such a time, there are no settled principles of polity or of action. Crude theories are produced, and, for a time, perhaps, acted upon as though they were sound realities. Men adopt vague and general terms as their watchwords, and strive to shape out constitutions to be reared upon these utterly unsubstantial foundations. Laws are changed, and the executive loses its power. All is anarchy and confusion, until, by common consent of those who still retain some portion of their senses, military despotism is called in to strangle the new-born license. This is a state of matters which usually results in war. The dominant authorities feel that their hold of public opinion is most precarious, unless they can contrive to give that opinion an impulse in another direction, and, at the same time, to employ, in some way or other, those multitudes whom revolution has driven from the arts and occupations of peace, and who, unless so provided for, immediately degenerate into conspirators at home. War is sometimes resorted to as the means of avoiding revolution. The disturbed state of the north of Italy furnished Charles Albert with a pretext for marching his army on Milan, as much, we believe, on account of the revolutionary spirit rife within his own dominions, as from any decided hope of territorial aggrandisement. This was the policy of Napoleon, who perfectly understood the character of the people he had to deal with, and who acted on the thorough conviction that war was the necessary consequence of revolution. We do not say that, in the present instances, such calamitous results are inevitable--we have hope that France may this time achieve a permanent constitution without having recourse to aggression. At the same time, it would be folly to shut our eyes to the fact that, throughout a great part of Europe, the old boundaries have been grievously disturbed; and that the modern system of intervention has a decided tendency to provoke war, at periods when the popular mind is raised to a pitch of extraordinary violence, and when the passions are so keenly excited as to disregard the appeals of reason.