And that's a definition that is awfully close to both Wayne and the Joker--the Joker has just fallen, or leapt, or run flat out, farther into it than Bruce, at this point.
Oh, totally. Batman -- and I'm honestly thinking of him from the comics, not the 2 most recent (Bale et al.) movies -- is a lunatic. He dresses like a giant flying rodent and his entire life is centered on stopping crime in a major city (almost) single-handedly, without any superpowers.
When I say that, people tend to bust out the argument of "he has buckets of money, he's brilliant, trained for years with the best of the best, etc., etc." That's true. He does and did.
Again, I say that to do ALL THAT in order to train/prepare oneself to operate outside the law and beat up criminals makes him a LUNATIC.
Which is why I dig him so much. He is fucked up beyond fucked up. The difference between Batman and the Joker is, essentially, that Batman is on the side of Good and the Joker is on the side of Chaos. That's about it, when you honestly look at it.