However desperate the situation and circumstances, don't despair. When there is everything to fear, be unafraid. When surrounded by dangers, fear none of them. When without resources, depend on resourcefulness. When surprised, take the enemy by surprise.
There are roads which must not be followed, armies which must not be attacked, towns which must not be besieged, positions which must not be contested, commands of the sovereign which must not be obeyed.
Of all those in the army close to the commander none is more intimate than the secret agent; of all rewards none more liberal than those given to secret agents; of all matters none is more confidential than those relating to secret operations.
There are five kinds of incendiary attack: The first is called setting fire to personnel; the second, to stores; the third, to transport vehicles and equipment; the fourth, to munitions; the fifth, to supply installations...In all cases an army must understand the changes induced by the five kinds of incendiary attack, and make use of logistical calculations to address them.
Getting people to fight by letting the force of momentum work is like rolling logs and rocks. Logs and rocks are still when in a secure place, but roll on an incline; they remain stationary if square, they roll if round. Therefore, when people are skillfully led into battle, the momentum is like that of round rocks rolling down a high mountain - this is force.
We cannot enter into alliance with neighbouring princes until we are acquainted with their designs. We are not fit to lead an army on the march unless we are familiar with the face of the country - its mountains and forests, its pitfalls and precipices, its marshes and swamps. We shall be unable to turn natural advantages to account unless we make use of local guides.