He who wishes to fight must first count the cost

Now an army is exposed to six several calamities, not arising from natural causes, 1 but from faults for which the general is responsible. These are: (1) Flight; (2) insubordination; (3) collapse; (4) ruin; (5) disorganisation; (6) rout.

Spies cannot be usefully employed without a certain intuitive sagacity; They cannot be properly managed without benevolence and straightforwardness; Without subtle ingenuity of mind, one cannot make certain of the truth of their reports; Be subtle! be subtle! and use your spies for every kind of warfare; If a secret piece of news is divulged by a spy before the time is ripe, he must be put to death together with the man to whom the secret was told.

Sweat more during peace: bleed less during war

Order or disorder depends on organisation and direction; courage or cowardice on circumstances; strength or weakness on tactical dispositions.

Kill one, terrify a thousand.

Act after having made assessments. The one who first knows the measure of far and near wins - this is the rule of armed struggle.