While you're right, I think that's kind of obscured by the language that a lot of functional evangelists use. I myself prefer FP (Lisp first, now Haskell,) but

While you're right, I think that's kind of obscured by the language that a lot of functional evangelists use. I myself prefer FP (Lisp first, now Haskell,) but most people who are coming from an imperative programming languages tend to see Functional languages as uselessly pure. As a matter of fact, in LYAH, the author states that Haskell is totally 100% pure. Which of course, is true in a sense, but false in another, at least in that we still model and use mutable state. (It's just marked by the type system, as you mentioned, and it's done in a functional way and usually heavily sugared.) In Haskell, I'm disregarding the IO monad.