《孟子·告子章句下·第四节》
宋牼说： 我听说秦、楚两国要交战，我准备去见楚王劝说他罢兵休战；如果楚王不高兴，我就准备去见秦王劝说他罢兵休战。这两个君王中我将会遇见意见相合的。 孟子说： 我不想问你详细的情况，我只想请问你的宗旨，您打算怎么劝说呢？ 
曰： 轲也请无问其详，愿闻其指。说之将何如？ 曰： 我将言其不利也。 
Song Yang replied, I have heard that the Kings of Ch'in and Ch'u are about to engage in war, and I am going to see the king of Ch'u, and to remonstrate with him, and, if he do not listen to me, I will go to see the King of Ch'in, and remonstrate to him. I shall thereby meet with one or other of these princes who will listen to my counsels, and I will serve him: such is my object.