The object of defense is preservation; and since it is easier to hold ground than to take it, defense is easier than attack. But defense has a passive purpose: preservation; and attack a positive one: conquest.... If defense is the stronger form of war, yet has a negative object, it follows that it should be used only so long as weakness compels, and be abandoned as soon as we are strong enough to pursue a positive object.

A general in time of war is constantly bombarded by reports both true and false; by errors arising from fear or negligence or hastiness; by disobedience born of right or wrong interpretations, of ill will; of a proper or mistaken sense of duty; of laziness; or of exhaustion; and by accident that nobody could have foreseen. In short, he is exposed to countless impressions, most of them disturbing, few of them encouraging. ... If a man were to yield to these pressures, he would never complete an operation.

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

War is the domain of physical exertion and suffering.

Obstinacy is a fault of temperament. Stubbornness and intolerance of contradiction result from a special kind of egotism, which elevates above everything else the pleasure of its autonomous intellect, to which others must bow.

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

The side that feels the lesser urge for peace will naturally get the better bargain.