Joker's encounter with Spectre in The Spectre #51 forced him to feel remorse for his actions, showing a potential for redemption, however slim, exists within comics' most chaotic character. Spectre granted Joker moral clarity, leading to the villain being overwhelmed with regret and even going catatonic, proving he isn't inherently evil but rather that he can't differentiate between good and bad. Joker's inability to distinguish between good and evil makes him tragic; DC has suggested several times that if permanently cured, he'd never commit another crime.

The Joker is one of the most vicious, violent characters in DC Comics but even he has been given hints of a possible redemption arc over the years. As unlikely as it seems, one story in particular showed that the Joker truly does have the capacity to feel remorse for his actions, even if it is usually buried by his insanity.

The Spectre #51 written by John Ostrander,...