But the main point is that soldiers, after fighting for some time, are apt to be like burned-out cinders. They have shot off their ammunition, their numbers have been diminished, their strength and their morale are drained, and possibly their courage has vanished as well. As an organic whole, quite apart from their loss in numbers, they are far from being what they were before the action; and thus the amount of reserves spent is an accurate measure on the loss of morale.

Self-reliance is the best defence against the pressures of the moment.

War should never be thought of as something autonomous, but always as an instrument of policy.

Friction is the only concept that more or less corresponds to the factors that distinguish real war from war on paper.

To be practical, any plan must take account of the enemy's power to frustrate it.

Four elements make up the climate of war: danger, exertion, uncertainty and chance.

Surprise becomes effective when we suddenly face the enemy at one point with far more troops than he expected. This type of numerical superiority is quite distinct from numerical superiority in general: it is the most powerful medium in the art of war.