In Joseph Heller's novel "Catch-22," the concept of Catch-22 serves as a paradoxical rule that governs the behavior of the characters. It highlights the absurdity of war and the bureaucratic absurdities that individuals face. The rule indicates that a soldier can be deemed insane if he willingly continues to fly dangerous missions, yet if he applies to be declared insane to avoid flying those missions, it proves he is sane, thereby disqualifying him from the exemption.

This creates a no-win situation for the characters, emphasizing the struggle between the instinct for self-preservation and the irrational demands of the military system. Heller's exploration of this theme reflects a broader commentary on the contradictions of human logic when confronted with perilous circumstances, capturing the essence of how the mind rationalizes fear and danger in the pursuit of survival.