The general unreliability of all information presents a special problem in war: all action takes place, so to speak, in the twilight, which, like fog or moonlight, often tends to make things seem grotesque and larger than they really are. Whatever is hidden from full view in this feeble light has to be guessed at by talent, or simply left to chance. So once again for the lack of objective knowledge, one has to trust to talent or to luck.
Carl von ClausewitzFour elements make up the climate of war: danger, exertion, uncertainty and chance.
Carl von ClausewitzThe 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.
Carl von ClausewitzWhere execution is dominant, as it is in the individual events of a war whether great or small, then intellectual factors are reduced to a minimum.
Carl von Clausewitz