Learning happens in 3 ways:
The first way is learning new information; that is, for instance, learning how to operate a new computer program after never having seen it before.
The second way is integrating new information into a previously-held understanding; such as learning how a computer program can do X and Y though maybe you didn't know that before.
The third way is learning something that completely abrogates previously-understood learning. That's the toughest one to integrate, and often creates disconnects within both the learner and the teacher.
The theories of argument go directly to that third way of learning.
I experienced this for myself after taking an extended world trip a number of years ago, and discovered for myself that my predispositions to social conservatism were based on falsehoods. I came back a changed man, and it wasn't something that happened easily; it was excruciating to discover that much of what I had taken for granted for decades was based on falsehoods.
But to the point: argument is not war. Argument avoids war. That's why we have things like the House of Commons in the UK and Canada, and the Congress in the United States. Better to shout at one another than to shoot at one another.