If we consider the actual basis of this information [i.e., intelligence], how unreliable and transient it is, we soon realize that war is a flimsy structure that can easily collapse and bury us in its ruins. ... Many intelligence reports in war are contradictory; even more are false, and most are uncertain. This is true of all intelligence but even more so in the heat of battle, where such reports tend to contradict and cancel each other out. In short, most intelligence is false, and the effect of fear is to multiply lies and inaccuracies.

Any complex activity, if it is to be carried on with any degree of virtuosity, calls for appropriate gifts of intellect and temperament. If they are outstanding and reveal themselves in exceptional achievements, their possessor is called a 'genius'.

War is an act of violence pushed to its utmost bounds.

What do we mean by the defeat of the enemy? Simply the destruction of his forces, whether by death, injury, or any other means-either completely or enough to make him stop fighting. . . . The complete or partial destruction of the enemy must be regarded as the sole object of all engagements. . . . Direct annihilation of the enemy's forces must always be the dominant consideration.

No one starts a war--or rather, no one in his sense ought to do so--without first being clear in his mind what he intends to achieve by the war and how he intends to conduct it.

War is the domain of physical exertion and suffering.

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