Sun Tzu (6th–5th century B.C.), Chinese general. The Art of War, ch. 5, axiom 17 (c. 490 B.C.), ed. James Clavell (1981).
The translator of this edition, Lionel Giles, added the explanatory note: "If you wish to feign confusion in order to lure the enemy on, you must first have perfect discipline; if you wish to display timidity in order to entrap the enemy, you must have extreme courage; if you wish to parade your weakness in order to make the enemy over- confident, you must have exceeding strength."