resulted from a misunderstanding of the final words of Ts’ao King’s preface. This, as Sun Hsing-yen points out, is only a modest way of saying that he made an explanatory paraphrase, or in other words, wrote a commentary on it. On the whole, this theory has met with very little acceptance. Thus, the Ssu K’u Ch’uan Shu says: "The mention of the 13 chapters in the Shih Chi shows that they were in existence before the Han Chih , and that latter accretions are not to be considered part of the original work. Tu Mu’s assertion can certainly not be taken as proof."
There is every reason to suppose, then, that the 13 chapters existed in the time of Ssu-ma Ch’ien practically as we have them now. That the work was then well known he tells us in so many words. "Sun Tzŭ’s 13 Chapters and Wu Ch’i’s Art of War are the two books that people commonly refer to on the subject of military matters. Both of them are widely distributed, so I will not discuss them here." But as we go further back, serious difficulties begin to arise. The salient fact which has to be faced is that the Tso Chuan , the greatest contemporary record, makes no mention whatsoever of Sun Wu,