Re: The relationship between Batman and the Joker
I guess part of why Batman doesn't kill is because he feels that deep down no-one is beyond saving. Even from themselves.
In this way, The Joker is the absolute living embodiment of one of his core beliefs.
It's not that he likes him at all -in fact, paradoxically, I think Bats despises the guy- but if he could redeem The Joker, make him see the error of his ways then that, in a way, would be his greatest triumph, no?
I mean The Killing Joke -THE Joker story- basically begins and ends with Bats trying to reason with the guy on a human level...
Just a theory.