Slaughterhouse-Five's main story deals with Billy Pilgrim's memory of the war supported by such unrealistic elements as a kind of time warp, extraterrestrials and their four dimensional points of view. These science fictional elements are actually the lies Billy relies on in order to reduce, in his recollection of the air raid on Dresden, what Leon Festinger, the social-psychologist, calls “cognitive-dissonance." Though Vonnegut succeeds in driving the appalling tragedy of Dresden home to the readers in the 1960s, Billy is too weak to fight against wars or to protect any peace. This is why Vonnegut adds the other story of the writer who speaks of Billy's story, to complement Billy's story. This thesis discusses these literary and psychology techniques Vonnegut used in Slaughterhouse-Five to create “an anti-war novel" in the 1960s from his World War II experience.