劉向 Liu Hsiang (B.C. 80–9) in his 新序 says: “The reason why Sun Wu at the head of 30,000 men beat Ch‘u with 200,000 is that the latter were undisciplined.”[17] 鄧名世 Têng Ming-shih in his 姓氏辨證書 (completed in 1134) informs us that the surname 孫 was bestowed on Sun Wu’s grandfather by 景公 Duke Ching of Ch‘i [547–490 B.C.]. Sun Wu’s father Sun 馮 P‘ing, rose to be a Minister of State in Ch‘i, and Sun Wu himself, whose style was 長卿 Ch‘ang-ch‘ing, fled to Wu on account of the rebellion which was being fomented by the kindred of 田鮑 T‘ien Pao. He had three sons, of whom the second, named 明 Ming, was the father of Sun Pin. According to this account, then, Pin was the grandson of Wu,[18] which, considering that Sun Pin’s victory over 魏 Wei was gained in 341 B.C., may be dismissed as chronologically impossible. Whence these data were obtained by Têng Ming-shih I do not know, but of course no reliance whatever can be placed in them. An interesting document which has survived from the close of the Han period is the short preface written by the great 曹操 Ts‘ao Ts‘ao, or 魏武帝 Wei Wu Ti, for his edition of Sun Tzŭ. I shall give it in full:— I have heard that the ancients used bows and arrows to their advantage.[19] The _Lun Yü_ says: “There must be a sufficiency of military strength.”[20] The _Shu Ching_ mentions “the army” among the “eight objects of government.”[21] The _I Ching_ says: “師 ‘army’ indicates firmness and justice; the experienced leader will have good fortune.”[22] The _Shih Ching_ says: “The King rose majestic in his wrath, and he marshalled his troops.”[23] The Yellow Emperor, T‘ang the Completer and Wu Wang all used spears and battle-axes in order to succour their generation. The _Ssŭ-ma Fa_ says: “If one man slay another of set purpose, he himself may rightfully be slain.”[24] He who relies solely on warlike measures shall be exterminated; he who relies solely on peaceful measures shall perish. Instances of this are Fu Ch‘ai[25] on the one hand and Yen Wang on the other.[26] In military matters, the Sage’s rule is normally to keep the peace, and to move his forces only when occasion requires. He will not use armed force unless driven to it by necessity.[27]