This is one of the best quotes I have seen in a very long time:

 

“One of the saddest lessons of history is this: If we’ve been bamboozled long enough, we tend to reject any evidence of the bamboozle. We’re no longer interested in finding out the truth. The bamboozle has captured us. It’s simply too painful to acknowledge, even to ourselves, that we’ve been taken. Once you give a charlatan power over you, you almost never get it back.”

 

 
― Carl Sagan, The Demon-Haunted World: Science as a Candle in the Dark