止楚攻宋
Stopping Chu's Attack on Song
公輸盤為楚造雲梯之械，成，將以攻宋。子墨子聞之，起於齊，行十日十夜而至於郢，見公輸盤。公輸盤曰："夫子何命焉為？"子墨子曰："北方有侮臣，願藉子殺之。"公輸盤不說。子墨子曰："請獻十金。"公輸盤曰："吾義固不殺人。"子墨子起，再拜，曰："請說之。吾從北方聞子為梯，將以攻宋，宋何罪之有？荊國有餘於地，而不足於民，殺所不足，而爭所有餘，不可謂智。宋無罪而攻之，不可謂仁。知而不爭，不可謂忠。爭而不得，不可謂強。義不殺少而殺眾，不可謂知類。"公輸盤服。
Gongshu Ban had built cloud ladders for Chu, which were now complete, and Chu planned to use them to attack Song. When Master Mozi heard of this, he set out from Qi, walking for ten days and ten nights until he reached Ying, where he went to see Gongshu Ban.
Gongshu Ban said: 'What do you command, Master?' Master Mozi said: 'Someone in the north has insulted me. I wish to borrow your services to kill him.' Gongshu Ban was displeased. Master Mozi said: 'I will offer you ten pieces of gold.' Gongshu Ban said: 'My principles firmly prevent me from killing people.'
Master Mozi rose and bowed twice, then said: 'Allow me to explain. I heard in the north that you had built ladders to attack Song. What crime has Song committed? Chu has more land than it needs but not enough people. To kill those it lacks in order to fight over what it has in excess cannot be called wise. To attack Song when it is innocent cannot be called benevolent. To know this yet not contend against it cannot be called loyal. To contend yet not prevail cannot be called strong. To claim one's principles prevent killing a few yet kill many cannot be called understanding categories.' Gongshu Ban was persuaded.
Notes
This is perhaps the most celebrated story in the Mozi. The narrative -- Mozi walking ten days and nights to prevent a war, using rhetorical brilliance and then military expertise to stop Chu's attack on Song -- perfectly encapsulates the Mohist ideals of anti-war activism, logical argumentation, and defensive military capability.
Ying (郢) was the capital of Chu, located near modern Jingzhou, Hubei province. Song (宋) was a smaller state in modern eastern Henan/western Shandong.