To determine this, we must first look and understand that both Ledger and Phoenix are playing the character of the Joker at two very different times in his life. Phoenix plays the character of Arthur Fleck and shows how that character spiralled into madness and became the Joker. Whereas Ledger plays as he says ‘an agent of chaos’ the Joker you see in the Dark Knight is a much later version of the character seen in the movie Joker. Therefor both performances although both amazing cannot be compared as they are not portraying the same version of the Joker.
Within Ledger’s performance we see a completely crazy antagonist who as Michael Caine’s character says ‘just wants to watch the world burn’ he throughout the whole film outwits batman and destroys every ideal that he fights for. The genius of Ledgers performance is that you only see the character of the joker throughout the whole film you never see Ledger. This meaning that he became so engrossed in the character that you as the audience member only see a villain. There were stories that throughout filming while on set ledger would stay in character the entire time. This commitment to the role makes it so incredible. The random madness he portrays encapsulates the everything that Joker is meant to be, a man of pure evil that has no motive behind anything other than to bring down society.
This in comparison to Phoenix’s Joker who shows a normal man with underlying issues that is pushed to breaking point. The skill in this performance is how Phoenix shows that anyone can become crazy if they are beaten enough by life. The level and depth Phoenix goes in to for this character like Ledger is seen in the uncontrollable laughter Fleck has throughout the film making him seem crazy in front of people despite it being a medical condition he has no control over. Phoenix gradually shows the fall that Fleck has as a character and this causes the whole of the society around him to follow his lead and go insane and fall into madness. This is all brought to a climax in the final scene when he is laughing for the first time properly as he has finally realised that he enjoys being crazy. The man of Arthur Fleck slowly transitions into the agent of chaos that is the Joker.