Mu?

In an evening talk, Dogen said:

Even if you are speaking rationally and another person says something unreasonable, it is wrong to defeat him by arguing logically. On the other hand, it is not good to give up hastily saying that you are wrong, even though you think that your opinion is reasonable.

Neither defeat him, nor withdraw saying you are wrong. It is best to just leave the matter alone and stop arguing. If you act as if you have not heard and forget about the matter, he will forget too and will not get angry. This is a very important thing to bear in mind.