...only a fraction of book learning will seep into practical life anyhow; and the more foolish the theory, the less of it. - Carl von Clausewitz

No one starts a war - or rather, no one in his senses ought to do so - without first being clear in his mind what he intends to achieve by that war and how he intends to conduct it.

The spirit and other moral qualities which animate an Army, a General, or Governments, public opinion in provinces in which a War is raging, the moral effect of a victory or of a defeat, are things which in themselves vary very much in their nature, and which also, according as they stand with regard to our object and our relations, may have an influence in different ways.

Although little or nothing can be said about these things in books, still they belong to the theory of the Art of War, as much as everything else which constitutes War. For I must here once more repeat that it is a miserable philosophy if, according to the old plan, we establish rules and principles wholly regardless of all moral forces, and then, as soon as these forces make their appearance, we begin to count exceptions which we thereby establish as it were theoretically, that is, make into rules; or if we resort to an appeal to genius, which is above all rules, thus giving out by implication, not only that rules were only made for fools, but also that they themselves are no better than folly.

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 leave the judgment more freedom of application when the diversity of the real world cannot be laid hold of under the definite form of a law.