Hence the saying: One may know how to conquer without being able to do it.

In making tactical dispositions, the highest pitch you can attain is to conceal them.

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.

Attack the enemy's strategy.

Too frequent rewards indicate that the general is at the end of his resources; too frequent punishments that he is in acute distress.

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.

Maneuvering with an army is advantageous; with an undisciplined multitude, most dangerous.