Trying to teach them logic or the need for evidence is answered with, "That's just your opinion. You aren't respecting my opinions."
I hear that all the time... Emotion IS logic to some.
Understanding the difference between making a decision and giving a reason for that decision is something that is ellusive to a lot of folks.
"Why did you choose to do X?"
"Because that is what I decided to do."
"I know you decided to do X, but why did you decide to do X instead of Y?"
"Because I thought it through and chose to do X - it was the decision I came to."
"I realize that, but why?"
"Because it seemed like a good decision."
"OK, what made that decision seem good? What were the pros for doing X rather than Y or Z?"
"I told you - Cause that is just what I decided!"
And these are adults who are rasing children with whom I am dealing.