Reading the ancient text Guan Zhi "The Battle of Ziyu" has a feeling: In 638 BC, Chu and Song fought for hegemony, and Chu sent troops to attack Song in order to save Zheng Guo.
Song Xianggong did not adopt Sima Ziyu's advice, which eventually led to the defeat of the Song war. Reading about the wars between the vassal states of the Spring and Autumn Period, I was often attracted by the "half-crossing attack" in terms of combat tactics.
If Song Xianggong issued an attack order during the Chu army's crossing of Hongshui, it was likely that the Chu army would be defeated by a single blow;If Song Xianggong had launched an attack before the Chu army had time to arrange troops after crossing the Hongshui, perhaps the outcome of the war between Chu and Song would have been rewritten.
The reason why Song Xianggong did not take Ziyu's suggestion was: "The gentleman is not seriously injured, and he is not a bird." This means that a gentleman does not harm the wounded, and does not arrest the gray-haired. Full of benevolence and morality, but there is no need to talk about benevolence and righteousness in war, and war means bloodshed and killing.
This reminds me of Confucius, who was not treated well by the princes of the vassal states during his lifetime because his morality of benevolence, righteousness and morality was out of place, and his Confucianism could be used to govern the country, but it could not enrich the country and strengthen the army.