"It is the mark of an educated mind to be able to entertain a thought without accepting it." - Aristotle
I have met certain people that are terribly hard to discuss things with...
...it is not for want of intellect - they are often intelligent, capable people.
...it is not passion - passion is a love for the topic which drives intense conversation (although rare conversion).
...it is not arrogance - though this is to be loathed in any argument.
...maybe it is the inability to entertain any thought but their own.
Could it be that it is not their fault? Maybe it is just that sort of education which is missing in some schools today. Maybe there is a sad sort of indoctrination going on that fails to admit of more than one idea (too textbookish?). One gets little exposure to a really good adversary. In short one is not suitably challenged enough to develop this part of oneself. Could that be?
If so then it seems that in this way mankind is MADE for challenge and cannot develop fully without it.
Of course this is all about step 1... after entertaining the idea, the next step is being able to correctly judge between the opposing thoughts. And that is a habit well worth gaining!