The range and effect of different weapons is very important to tactics; their construction, although these effects result from it, is a matter of indifference; for the conduct of War is not making powder and cannon out of a given quantity of charcoal, sulphur, and saltpetre, of copper and tin: the given quantities for the conduct of War are arms in a finished state and their effects.

Strategy makes use of maps without troubling itself about triangulations; it does not inquire how the country is subdivided into departments and provinces, and how the people are educated and governed, in order to attain the best military results; but it takes things as it finds them in the community of European States, and observes where very different conditions have a notable influence on War.
39.

GREAT SIMPLIFICATION OF THE KNOWLEDGE REQUIRED.
That in this manner the number of subjects for theory is much simplified, and the knowledge requisite for the conduct of War much reduced, is easy to perceive.

The very great mass of knowledge and appliances of skill which minister to the action of War in general, and which are necessary before an army fully equipped can take the field, unite in a few great results before they are able to reach, in actual War, the final goal of their activity; just as the streams of a country unite themselves in rivers before they fall into the sea.

Only those activities emptying themselves directly into the sea of War have to be studied by him who is to conduct its operations.
40.