The art of the indirect approach can only be mastered, and its full scope appreciated, by study of and reflection upon the whole history of war. But we can at least crystallize the lessons into two simple maxims- one negative, the other positive. The first is that, in face of the overwhelming evidence of history, no general is justified in launching his troops to a direct attack upon an enemy firmly in position. The second, that instead of seeking to upset the enemy's equilibrium by one's attack, it must be upset before a real attack is, or can be successfully launched

Direct experience is inherently too limited to form an adequate foundation either for theory or for application. At the best it produces an atmosphere that is of value in drying and hardening the structure of thought. The greater value of indirect experience lies in its greater variety and extent. History is universal experience, the experience not of another, but of many others under manifold conditions.

The more closely [the German army] converged on [Stalingrad], the narrower became their scope for tactical manoeuvre as a lever in loosening resistance. By contrast, the narrowing of the frontage made it easier for the defender to switch his local reserves to any threatened point on the defensive arc.

In war, the chief incalculable is the human will.

For the spread and endurance of an idea the originator is dependent on the self-development of the receivers and transmitters.

It is thus more potent, as well as more economical, to disarm the enemy than to attempt his destruction by hard fighting ... A strategist should think in terms of paralysing, not of killing.

For if we merely take what obviously appears the line of least resistance, its obviousness will appeal to the opponent also; and this line may no longer be that of least resistance. In studying the physical aspect, we must never lose sight of the psychological, and only when both are combined is the strategy truly an indirect approach, calculated to dislocate the opponent's balance.