Bad History!

Is there such a thing as 'really bad books' - e.g. the author picks upon The Da Vinci Code as an example of bad history which is so powerful that many people think that this is 'how it is': The world is full of "bad books"; not just uninteresting, or ill-informed, or morally repugnant books, but books that set out to present or defend positions that are insupportable in logic. I speak here not of…