In the course of defending controversial ideas and positions, I frequently come across an annoying little trend:  People disguise subtle insults as regular parts of a conversation.  Usually it goes something like this: 

Me:  I believe dragons existed thousands of years ago. 
Smart guy:  Any intelligent person can easily come to the conclusion that dragons are mythical creatures that could not have possibly ever existed. 

Or this: 

Me:  I believe the Bible is the infallibly inspired word of God. 
Smart guy:  Most logical people agree that infallibility is impossible.  Oh, and God doesn't exist. 

Or this: 

Me:  I think most people are too stupid to have an intelligent opinion about politics. 
Smart guy:  No reasonable person would ever say something like that. 

What's happening in each of these very real examples is more than just a rebuttal or a disagreement.  It's a personal attack.  I, as a fringe-dwelling Bible-believing anti-political luminary, am unintelligent, illogical, and unreasonable.  While at least 2 out of those 3 points might be true, I like to think I'm at least slightly intelligent.  But besides that, I think the attacks are misdirected.  If you're arguing about a topic, focus the criticism on the topic, not the person presenting the topic.  If you think dragons go hand in hand with stupidity, that's fine.  Just don't insult me for believing something you deem to be unintelligent.