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.
Carl von ClausewitzA 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.
Carl von ClausewitzBeauty cannot be defined by abscissas and ordinates; neither are circles and ellipses created by their geometrical formulas.
Carl von ClausewitzOnly the element of chance is needed to make war a gamble, and that element is never absent.
Carl von ClausewitzThe more a general is accustomed to place heavy demands on his soldiers, the more he can depend on their response.
Carl von ClausewitzBut 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.
Carl von Clausewitz