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.

Direct pressure always tends to harden and consolidate the resistance of an opponent.

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.

While there are many causes for which a state goes to war, its fundamental object can be epitomized as that of ensuring the continuance of its policy - in face of the determination of the opposing state to pursue a contrary policy. In the human will lies the source and mainspring of conflict.

As has happened so often in history, victory had bred a complacency and fostered an orthodoxy which led to defeat in the next war.

With growing experience, all skillful commanders sought to profit by the power of the defensive, even when on the offensive.

Air Power is, above all, a psychological weapon - and only short-sighted soldiers, too battle-minded, underrate the importance of psychological factors in war.