Batman's 9 Greatest Failures

It's a question that gets asked of Batman repeatedly: why do you not just kill the Joker?

Nearly everyone who has written about the Batman and Joker dynamic has presented their answer to this question; most sticking to the moral line of Batman never taking a life or the fact that he doesn't kill him is what separates him from the Joker.

No matter what atrocities Joker commits, the Caped Crusader always chooses to save his own soul instead of permanently putting down the Clown Prince of Crime. Only by telling a story about the twilight years of Bruce Wayne could writer/artist Frank Miller address the question, how much of a toll on a man's sanity could a lifetime of Jokers cruelties take?

The answer is almost enough to push Batman to do the unthinkable. After causing another massacre, the World's Greatest Detective tracks down Joker and gives in to his anger, beating his enemy within an inch of his life and leaving him paralysed. The Joker would snap his own neck as a result and the world at large would believe it was Batman who had killed him.