Ch’en Chen-sun of the Sung dynasty has the note:—
Military writers look upon Sun Wu as the father of their art. But the fact that he does not appear in the Tso Chuan, although he is said to have served under Ho Lu King of Wu, makes it uncertain what period he really belonged to.
He also says:—
The works of Sun Wu and Wu Ch’i may be of genuine antiquity.
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;