War is nothing but a duel on a larger scale.

The very nature of interactions is bound to make it unpredictable.

War is the realm of uncertainty; three quarters of the factors on which action is based are wrapped in a fog of greater or lesser uncertainty.

Kind-hearted people might of course think there was some ingenious way to disarm or defeat an enemy without too much bloodshed, and might imagine this is the true goal of the art of war. Pleasant as it sounds; it is a fallacy that must be exposed: War is such a dangerous business that the mistakes which come from kindness are the very worst.

In war, where imperfect intelligence, the threat of a catastrophe, and the number of accidents are incomparably greater than any other human endeavor, the amount of missed opportunities, so to speak, is therefore bound to be greater.

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.

The deduction of effect from cause is often blocked by some insuperable extrinsic obstacle: the true causes may be quite unknown. Nowhere in life is this so common as in war, where the facts are seldom fully known and the underlying motives even less so.