It is noticeable that both Yeh Shui-hsin and Ch’en Chen-sun, while rejecting the personality of Sun Wu as he figures in Ssu-ma Ch’ien’s history, are inclined to accept the date traditionally assigned to the work which passes under his name. The author of the _Hsu Lu_ fails to appreciate this distinction, and consequently his bitter attack on Ch’en Chen-sun really misses its mark. He makes one of two points, however, which certainly tell in favour of the high antiquity of our "13 chapters." "Sun Tzŭ," he says, "must have lived in the age of Ching Wang [519-476], because he is frequently plagiarized in subsequent works of the Chou, Ch’in and Han dynasties." The two most shameless offenders in this respect are Wu Ch’i and Huai-nan Tzŭ, both of them important historical personages in their day. The former lived only a century after the alleged date of Sun Tzŭ, and his death is known to have taken place in 381 B.C. It was to him, according to Liu Hsiang, that Tseng Shen delivered the _Tso Chuan_, which had been entrusted to him by its author. [29] Now the fact that quotations from the _Art of War_, acknowledged or otherwise, are to be found in so many authors of different epochs, establishes a very strong anterior to them all,—in other words, that Sun Tzŭ’s treatise was already in existence towards the end of the 5th century B.C. Further proof of Sun Tzŭ’s antiquity is furnished by the archaic or wholly obsolete meanings attaching to a number of the words he uses. A list of these, which might perhaps be extended, is given in the _Hsu Lu;_ and though some of the interpretations are doubtful, the main argument is hardly affected thereby. Again, it must not be forgotten that Yeh Shui-hsin, a scholar and critic of the first rank, deliberately pronounces the style of the 13 chapters to belong to the early part of the fifth century. Seeing that he is actually engaged in an attempt to disprove the existence of Sun Wu himself, we may be sure that he would not have hesitated to assign the work to a later date had he not honestly believed the contrary. And it is precisely on such a point that the judgment of an educated Chinaman will carry most weight. Other internal evidence is not far to seek. Thus in XIII. § 1, there is an unmistakable allusion to the ancient system of land-tenure which had already passed away by the time of Mencius, who was anxious to see it revived in a modified form. [30] The only warfare Sun Tzŭ knows is that carried on between the various feudal princes, in which armored chariots play a large part. Their use seems to have entirely died out before the end of the Chou dynasty. He speaks as a man of Wu, a state which ceased to exist as early as 473 B.C. On this I shall touch presently.