An idea found in the TaoChia philosophy.
Never argue with anybody. Just go with the other's idea, because the other may be right and he may explain what he thinks if you get confused.
GoWithTheFlow is about not arguing with the other, but developing the other's idea further to see if it is right or wrong, to see how it applies; eventually the idea will be so forward that it won't even look like his original idea.
Typically, arguing against somebody just puts him on the defensive and assures that he will hate your point of view. If, however, you give his view the respect and consideration he thinks it deserves, he is more likely to treat yours likewise. (See HowToWinFriendsAndInfluencePeople, Part Three.)