6. Weak Points and Strong
Rouse him, and learn the principle of his activity or inactivity.
Chang Yu tells us that by noting the joy or anger shown by the enemy on being thus disturbed, we shall be able to conclude whether his policy is to lie low or the reverse. He instances the action of Cho-ku Liang, who sent the scornful present of a woman's head-dress to Ssu-ma I, in order to goad him out of his Fabian tactics.
Force him to reveal himself, so as to find out his vulnerable spots.