Subversion is Heller's key technique in Catch-22. He uses old tools like burlesque, irony and parody in a new way and new ones like Black Humor to drive home his entropic life vision. Heller presents the realities his generation had to confront in a comic manner. His vision is essentially nihilistic. Heller maintains the vision that attempts of rationalizing the irrational world is futile and entropic. There is no space for optimism the world as such is undergoing heat death.