What I like about discussions is that at the end both parts have the same ideas as in the beginning.
And one thinks:
"How can somebody be so stupid as to insist on this?"
While what he says is:
"I really understand your point of view, but this or that..."
Because one doesn't want to look stupid or which is even worse, antidemocratic... you have to give others the chance to say what they think, even if you already know they are wrong...
Discussing is really mostly just reorganizing one's own prejudices.
That is why Blogging is so much better.
It's like a monologue, "it saves time and prevents arguments".
And that is also why there is a button called "comment" which nobody presses.
People have since long understood the difference between a dialogue and a monologue.