now extant. His notes are mostly short and to the point, and he frequently illustrates his remarks by anecdotes from Chinese history.
4. 杜佑 Tu Yu (died 812) did not publish a separate commentary on Sun Tzŭ, his notes being taken from the T‘ung Tien, the encyclopaedic treatise on the Constitution which was his life-work. They are largely repetitions of Ts‘ao Kung and Mêng Shih, besides which it is believed that he drew on the ancient commentaries of 王凌 Wang Ling and others. Owing to the peculiar arrangement of the T‘ung Tien, he has to explain each passage on its merits, apart from the context, and sometimes his own explanation does not agree with that of Ts‘ao Kung, whom he always quotes ﬁrst. Though not strictly to be reckoned as one of the “Ten Commentators,” he was added to their number by Chi T‘ien-pao, being wrongly placed after his grandson Tu Mu.
5. 杜牧 Tu Mu (803—852) is perhaps best known as a poet — a bright star even in the glorious galaxy of the T‘ang period. We learn from Ch‘ao Kung-wu that although he had no practical experience of war, he was extremely fond of discussing the subject, and was moreover well read in the military history of the Ch‘un Ch‘iu and Chan Kuo eras. His notes, therefore, are well worth attention. They are very copious, and replete with historical parallels. The gist of Sun Tzŭ’s work is thus summarised by him: “Practise benevolence and justice, but on the other hand make full use of artiﬁce and measures of expediency.” He further declared that all the military
- Wên Hsien T‘ung K‘ao, ch. 221, f. 9: 世謂牧慨然最喜論兵欲試而不得者其學能道春秋戰國時事甚博而詳知兵者有取焉.
- Preface to his commentary (T‘u Shu, 經籍典, ch. 442): 武之所論大約用仁義使機權也.