In considering a patriot army as exemplifying collective life of a relatively high level, we distinguished five principal conditions that raise it above the level of the mental life of the crowd, in addition to one which is present in some crowds. This last was a common well-defined purpose present to, and dominant in, the minds of all individuals. It is this condition mainly that renders the collective mental life of such an army so simple, so relatively easy to understand, and so extremely effective.
This condition--a clearly defined common purpose dominant in the minds of the great mass of the constituent units--is for the most part lacking in the life of nations; its absence is one of the principal reasons for the ineffectiveness and bewildering complexity of their mental life. It is, however, occasionally realised in national life, and then we see how immense is its influence. Such an occasion is a war for national existence. Consider how, when the excesses of the French Revolution excited all the monarchies of Europe to attack France, the French nation, becoming animated with the one strong purpose of asserting its right to exist and to choose its own form of government, successfully drove back all its enemies and rose to a height of power and glory greater than at any other period; and how, at the same time, its parts were welded more firmly together, so that it displayed a high degree of unity as well as of efficiency. Having achieved this high degree of unity and efficiency, the French nation, led on by the ambitions of Napoleon, became aggressive. And we are told by the historians that the attacks of Napoleon upon the various European peoples, which threatened to destroy whatever degree of national life those peoples had attained, were like the blows of a smith's hammer and resulted in welding together and hardening into nations the loosely aggregated races ruled over by the various monarchs; and that in this way these attacks initiated the modern period of Nation-States[75].
War for national existence unifies nations. So long as the nation is not utterly shattered and crushed, such war greatly develops the national mind; because it makes one common purpose dominate the minds of all the citizens.