From "The Anxious Idiot," an excellent description of the titular deniers:
I should define “idiot” for our purposes. I don’t mean someone of low I.Q. or poor academic abilities. Intelligence as commonly conceived has nothing to do with it. By “idiot,” I mean exactly what my brother meant when he tagged me with the epithet: an impractical and unreasonable person, a person who tends to forget all the important lessons, essentially a fool, one who willfully ignores all that he has learned about how to come to his own aid. A person who is so fixated on the fact that he is in a hole that he fails to climb out of the hole. An idiot, in short, is someone who is self-defeatingly lazy.