Attack where he is unprepared; sally forth when he does not expect you.

Thus the expert in battle moves the enemy, and is not moved by him.

O divine art of subtlety and secrecy!

An army may be likened to water, for just as flowing water avoids the heights and hastens to the lowlands, so an army avoids strength and strikes weakness.

Be extremely subtle, even to the point of formlessness. Be extremely mysterious, even to the point of soundlessness. Thereby you can be the director of the opponent's fate.

Hostile armies may face each other for years, striving for the victory which is decided in a single day. This being so, to remain in ignorance of the enemy's condition simply because one grudges the outlay of a hundred ounces of silver in honors and emoluments, is the height of inhumanity.

Now a soldier's spirit is keenest in the morning; by noonday it has begun to flag; and in the evening, his mind is only on returning to camp.