So great indeed is the value of abstract strategical study from this point of view, that it is necessary to guard ourselves against over-valuation. So far from claiming for their so-called science more than the possibilities we have indicated, the classical strategists insist again and again on the danger of seeking from it what it cannot give. They even repudiate the very name of "Science." They prefer the older term "Art." They will permit no laws or rules. Such laws, they say, can only mislead in practice, for the friction to which they are subject from the incalculable human factors alone is such that the friction is stronger than the law. It is an old adage of lawyers that nothing is so misleading as a legal maxim, but a strategical maxim is undoubtedly and in every way less to be trusted in action.
What then, it will be asked, are the tangible results which we can hope to attain from theory? If all on which we have to build is so indeterminate, how are any practical conclusions to be reached? That the factors are infinitely varied and difficult to determine is true, but that, it must be remembered, is just what emphasises the necessity of reaching such firm standpoints as are attainable. The vaguer the problem to be solved, the more resolute must we be in seeking points of departure from which we can begin to lay a course, keeping always an eye open for the accidents that will beset us, and being always alive to their deflecting influences. And this is just what the theoretical study of strategy can do. It can at least determine the normal. By careful collation of past events it becomes clear that certain lines of conduct tend normally to produce certain effects; that wars tend to take certain forms each with a marked idiosyncrasy; that these forms are normally related to the object of the war and to its value to one or both belligerents; that a system of operations which suits one form may not be that best suited to another. We can even go further. By pursuing an historical and comparative method we can detect that even the human factor is not quite indeterminable. We can assert that certain situations will normally produce, whether in ourselves or in our adversaries, certain moral states on which we may calculate.