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.

Inflict the least possible permanent injury, for the enemy of to-day is the customer of the morrow and the ally of the future

A complacent satisfaction with present knowledge is the chief bar to the pursuit of knowledge.

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.

The nearer the cutting off point lies to the main force of the enemy, the more immediate the effect; whereas the closer to the strategic base it takes place, the greater the effect.

If you wish for peace, understand war.

Natural hazards, however formidable, are inherently less dangerous and less uncertain than fighting hazards. All conditions are more calculable, all obstacles more surmountable than those of human resistance.