“So there are logical problems, such as building a bridge. And there are psycho-logical ones: whether to paint the lines on the road or not. The rules for solving both are different; just as I make a distinction between nonsense and non-sense, I also use a hyphen to distinguish between logical and psycho-logical thinking. The logical and the psycho-logical approaches run on different operating systems and require different software, and we need to understand both. Psycho-logic isn’t wrong, but it cares about different things and works in a different way to logic. Because logic is self-explanatory, our preference is to use it in all social and institutional settings, even where it has no place. The result is that we end up using inappropriate software for the operating system, neglecting the psycho-logical approach.”