In another meaning Rule is the means used of discerning a recondite truth in a particular sign lying close at hand, in order to attach to this particular sign the law of action directed upon the whole truth. Of this kind are all the rules of games of play, all abridged processes in mathematics, &c.
Directions and instructions are determinations of action which have an influence upon a number of minor circumstances too numerous and unimportant for general laws.
Lastly, Method, mode of acting, is an always recurring proceeding selected out of several possible ones; and Methodicism (METHODISMUS) is that which is determined by methods instead of by general principles or particular prescriptions. By this the cases which are placed under such methods must necessarily be supposed alike in their essential parts. As they cannot all be this, then the point is that at least as many as possible should be; in other words, that Method should be calculated on the most probable cases. Methodicism is therefore not founded on determined particular premises, but on the average probability of cases one with another; and its ultimate tendency is to set up an average truth, the constant and uniform, application of which soon acquires something of the nature of a mechanical appliance, which in the end does that which is right almost unwittingly.
The conception of law in relation to perception is not necessary for the conduct of War, because the complex phenomena of War are not so regular, and the regular are not so complex, that we should gain anything more by this conception than by the simple truth. And where a simple conception and language is sufficient, to resort to the complex becomes affected and pedantic. The conception of law in relation to action cannot be used in the theory of the conduct of War, because owing to the variableness and diversity of the phenomena there is in it no determination of such a general nature as to deserve the name of law.