Batman takes the blame for Harvey Dent's murders because Gotham City's hope is entirely anchored to Dent's image as the White Knight. If the public learns that their reformist District Attorney became a murderous vigilante who executed police officers and threatened Jim Gordon's family, the legal and moral progress Gotham made would instantly collapse. Every criminal prosecuted under the Dent Act would be released back onto the streets. By taking the blame, Batman preserves Dent's legacy as an uncorrupted symbol of justice, ensuring the city's spirit remains intact. As Jim Gordon explains to his son, Batman is the hero Gotham deserves, but not the one it needs right now. The Joker's ultimate goal was to prove that even the best of humanity could be broken down to his level of nihilism. If Dent's fall became public, the Joker would have won the ideological battle for Gotham's soul. Batman's sacrifice is a tactical lie that defeats the Joker's thesis. It shifts Batman from an aspirational hero to a hunted outcast, redefining his vigilante mission not as a quest for glory, but as a burden of absolute selflessness.■