The fifth-century historian Pei Songzhi rebutted Cao Fang's imperial decree and argued that Guo Xiu was not a hero and his assassination of Fei Yi was not "in the service of Wei". He pointed out three reasons. First, Guo Xiu was a civilian when he was captured by the enemy so he was not exactly "serving" Wei and hence his assassination of Fei Yi should not be considered an action "in the service of Wei". Second, Wei was not threatened by Shu in the same way Yan was threatened by Qin during the late Warring States period, therefore Guo Xiu's assassination of Fei Yi should not be seen in the same light as Jing Ke's assassination attempt on the King of Qin. Third, from Pei Songzhi's point of view, Liu Shan and Fei Yi were respectively a ruler and a regent of average calibre, so their deaths would not deal significant damage to Shu. Pei Songzhi thus concluded that Guo Xiu was simply an opportunist seeking to become (in)famous by assassinating the regent of a state.