A metaphor is a mapping from one domain to another. For example, moo is to cow as beep is to car. These mappings get so buried in our language that we don't even notice their effects.
For example, take the language used to describe a debate:
"He shot down her ideas."
"She defended her position."
"She overwhelmed his arguments."
"He had to retreat from that position."
These are all debate-as-war metaphors. It's a zero sum game. Someone wins and someone loses. The idea that both people could learn from each other just doesn't come up.
What if we used a different metaphor, perhaps debate-as-exploration? We might say:
"They covered new ground."
"During the debate, they discovered things they hadn't noticed before."
"The debate opened up new vistas."
This metaphor lets a debate be a positive sum game. Both debaters can be better off because of the debate. Further, they can abandon arguments that don't seem fruitful, because changing your mind while exploring is not a bad thing. On the other hand, changing your mind while at war might be taken as a sign of weakness.