11.  Interior lines.

As a reaction against this false direction, another geometrical principle, that of the so-called interior lines, was then elevated to the throne.  Although this principle rests on a sound foundation, on the truth that the combat is the only effectual means in War, still it is, just on account of its purely geometrical nature, nothing but another case of one-sided theory which can never gain ascendency in the real world.

12.  All these attempts are open to objection.

All these attempts at theory are only to be considered in their analytical part as progress in the province of truth, but in their synthetical part, in their precepts and rules, they are quite unserviceable.

They strive after determinate quantities, whilst in War all is undetermined, and the calculation has always to be made with varying quantities.

They direct the attention only upon material forces, while the whole military action is penetrated throughout by intelligent forces and their effects.

They only pay regard to activity on one side, whilst War is a constant state of reciprocal action, the effects of which are mutual.

13.  As A rule they exclude genius.

All that was not attainable by such miserable philosophy, the offspring of partial views, lay outside the precincts of science—­and was the field of genius, which raises itself above rules.

Pity the warrior who is contented to crawl about in this beggardom of rules, which are too bad for genius, over which it can set itself superior, over which it can perchance make merry!  What genius does must be the best of all rules, and theory cannot do better than to show how and why it is so.

Pity the theory which sets itself in opposition to the mind!  It cannot repair this contradiction by any humility, and the humbler it is so much the sooner will ridicule and contempt drive it out of real life.

14.  The difficulty of theory as soon as moral quantities come into consideration.

Every theory becomes infinitely more difficult from the moment that it touches on the province of moral quantities.  Architecture and painting know quite well what they are about as long as they have only to do with matter; there is no dispute about mechanical or optical construction.  But as soon as the moral activities begin their work, as soon as moral impressions and feelings are produced, the whole set of rules dissolves into vague ideas.

The science of medicine is chiefly engaged with bodily phenomena only; its business is with the animal organism, which, liable to perpetual change, is never exactly the same for two moments.  This makes its practice very difficult, and places the judgment of the physician above his science; but how much more difficult is the case if a moral effect is added, and how much higher must we place the physician of the mind?