In answer to Serioussham's question, at least part of the reason in this specific case, I'm mocking this prediction because I'm somewhat cynical about its motives. I suspect that the Rev. Camping is saying this mostly for attention. And thus he's being a dick too, and is therefore completely mockable. Secondly, and this applies more generally, ideas don't exist in a vacuum. People believe in the things they believe in for a reason, and that may be fair, but people use those beliefs, and their beliefs lead them to sometimes less than honourable ends. I don't want to live in a world where anyone's beliefs about anything, however ill formed can do so much to shape the world around me. And ridicule is one way of affecting that process. And to answer your question of what is logical and what isn't, you can argue all you like that all viewpoints are equally valid, and one man's logic is another man's insanity, however, some ways of thinking are more likely to lead to positions and opinions which are, for want of a better term, "congruent with reality". Mr. Camping's way of looking at the world has led him to believe that the rapture will occur tomorrow. Mine has led me to believe that it will not. He believes the biblical flood happened. I do not. Now, he may be as sane and as rational as I am. But on each of these things, only one of us can be correct, either Noah's flood happened, or it didn't, either the rapture will occur tomorrow, or it will not. I suppose you could argue that we'll never know if the flood occurred, and for the sake of argument I'll concede that point. But when christians don't start floating up to heaven like a crate of blow up dolls filled with helium...some people might be left wondering what it is that some people were correct and others were not.