Jeffrey Shallit has an excellent post on the conceptual failure of creationists to grasp even the possibility of an absence of intent. You probably know the feeling — you are trying to explain some process in biology or chemistry, and your student is struggling to fit the story into his mental picture of molecules or cells with purpose and plan, and he can’t move on to the next stage of understanding until he sheds the preconception of intelligent guidance to the reaction or interaction. Shallit compares it to a poor confused tourist to a computer lab who can’t quite figure out where the people doing the drawings on the graphic screens are.

And then he discusses an Intelligent Design blog, which makes the tourist look like a genius.