Sun Wu’s saying, that in war one cannot make certain of conquering, 122 is very different indeed from what other books tell us. 123 Wu Chʽi was a man of the same stamp as Sun Wu : they both wrote books on war, and they are linked together in popular speech as “ Sun and Wu .” But Wu Chʽi’s remarks on war are less weighty, his rules are rougher and more crudely stated, and there is not the same unity of plan as in Sun Tzǔ’s work, where the style is terse, but the meaning fully brought out. 124