Even perhaps more than their bodies, Amos, I think that people identify with their own mindset...all their old established opinions, beliefs, assumptions, habits, and prejudices. This is why most people immediately and instinctively attack and contend with any viewpoint that differs from their own. They subconsciously regard it as a direct threat to their own identity.

If they were simply to admit one thing..."I don't know for sure"...it would go a long way toward making them much more reasonable and less inclined to attack other's beliefs.