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

Criticism exists only to recognize the truth, not to act as judge.

The heart of France lies between Brussels and Paris.

Action in war is like movement in a resistant element. Just as the simplest and most natural of movements, walking, cannot easily be performed in water, so in war, it is difficult for normal efforts to achieve even moderate results.

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.

Be audacious and cunning in your plans, firm and persevering in their execution, determined to find a glorious end.

Everything in war is very simple, but the simplest thing is difficult. The difficulties accumulate and end by producing a kind of friction that is inconceivable unless one has experienced war. ... Countless minor incidents - the kind you can never really foresee - combine to lower the general level of performance, so that one always falls short of the intended goal.