The end and aim of spying in all its five varieties is knowledge of the enemy; and this knowledge can only be derived, in the first instance, from the converted spy. Hence it is essential that the converted spy be treated with the utmost liberality.
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.
Should one ask: 'how do I cope with a well-ordered enemy host about to attack me?' I reply: seize something he cherishes and he will conform to your desires.
There are not more than five musical notes, yet the combinations of these five give rise to more melodies than can ever be heard.There are not more than five primary colors, yet in combination they produce more hues than can ever been seen.There are not more than five cardinal tastes, yet combinations of them yield more flavors than can ever be tasted.
Invincibility is in oneself, and vulnerability is in the opponent. Invincibility is a matter of defense, vulnerability is a matter of attack. Therefore skillful warriors are able to be invincible, but they cannot cause opponents to be vulnerable. That is why it is said that victory is discerned and not manufactured.