PRINCIPLE is likewise such a law for action, except that it has not the formal definite meaning, but is only the spirit and sense of law in order to … - Carl von Clausewitz

War is merely the continuation of policy by other means. We see, therefore, that war is not merely an act of policy but a true political instrument, a continuation of political intercourse carried on with other means. What remains peculiar to war is simply the peculiar nature of its means.

but the disadvantages of this position must naturally not be of a transitory nature, at least in appearance, otherwise the enemy, instead of yielding, will hold out, in the prospect of a change for the better.

The moral elements are among the most important in war. They constitute the spirit that permeates war as a whole, and at an early stage they establish a close affinity with the will that moves and leads a whole mass of force, practically merging with it, since the will is itself a moral quantity. Unfortunately they will not yield to academic wisdom. They cannot be classified or counted. They have to be seen or felt. … It is paltry philosophy if in the old-fashioned way one lays down rules and principles in total disregard of moral values. As soon as these appear one regards them as exceptions, which gives them a certain scientific status, and thus makes them into rules. Or again one may appeal to genius, which is above all rules; which amounts to admitting that rules are not only made for idiots, but are idiotic in themselves.