and harmonise the different elements thereof before pitching his camp. ["Chang Yu says: "the establishment of harmony and confidence between the higher and lower ranks before venturing into the field;" and he quotes a saying of Wu Tzŭ (chap. 1 ad init.): "Without harmony in the State, no military expedition can be undertaken; without harmony in the army, no battle array can be formed." In an historical romance Sun Tzŭ is represented as saying to Wu Yuan: "As a general rule, those who are waging war should get rid of all the domestic troubles before proceeding to attack the external foe."]