Themes are the fundamental and often universal ideas explored in a literary work.

The Destructiveness of War

Whether we read Slaughterhouse-Five as a science-fiction novel or a quasi-autobiographical moral statement, we cannot ignore the destructive properties of war, since the catastrophic firebombing of the German town of Dresden during World War II situates all of the other seemingly random events. From his swimming lessons at the YMCA to his speeches at the Lions Club to his captivity in Tralfamadore, Billy Pilgrim shifts in and out of the meat locker in Dresden, where he very narrowly survives asphyxiation and incineration in a city where fire is raining from the sky.

However, the not-so-subtle destructiveness of the war is evoked in subtle ways. For instance, Billy is quite successful in his postwar exploits from a materialistic point of view: he is president of the Lions Club, works as a prosperous optometrist, lives in a thoroughly comfortable modern home, and has fathered two children. While Billy seems to have led a productive postwar life, these seeming markers of success speak only to its surface. He gets his job not because of any particular prowess but as a result of his father-in-law’s efforts. More important, at one point in the novel, Billy walks in on his son and realizes that they are unfamiliar with each other. Beneath the splendor of his success lies a man too war-torn to understand it. In fact, Billy’s name, a diminutive form of William, indicates that he is more an immature boy than a man.

Vonnegut, then, injects the science-fiction thread, including the Tralfamadorians, to indicate how greatly the war has disrupted Billy’s existence. It seems that Billy may be hallucinating about his experiences with the Tralfamadorians as a way to escape a world destroyed by war—a world that he cannot understand. Furthermore, the Tralfamadorian theory of the fourth dimension seems too convenient a device to be more than just a way for Billy to rationalize all the death with he has seen face-to-face. Billy, then, is a traumatized man who cannot come to terms with the destructiveness of war without invoking a far-fetched and impossible theory to which he can shape the world.

The Illusion of Free Will

In Slaughterhouse-Five, Vonnegut utilizes the Tralfamadorians, with their absurdly humorous toilet-plunger shape, to discuss the philosophical question of whether free will exists. These aliens live with the knowledge of the fourth dimension, which, they say, contains all moments of time occurring and reoccurring endlessly and simultaneously. Because they believe that all moments of time have already happened (since all moments repeat themselves endlessly), they possess an attitude of acceptance about their fates, figuring that they are powerless to change them. Only on Earth, according to the Tralfamadorians, is there talk of free will, since humans, they claim, mistakenly think of time as a linear progression.

Throughout his life, Billy runs up against forces that counter his free will. When Billy is a child, his father lets him sink into the deep end of a pool in order to teach him how to swim. Much to his father’s dismay, however, Billy prefers the bottom of the pool, but, against his free will to stay there, he is rescued. Later, Billy is drafted into the war against his will. Even as a soldier, Billy is a joke, lacking training, supplies, and proper clothing. He bobs along like a puppet in Luxembourg, his civilian shoes flapping on his feet, and marches through the streets of Dresden draped in the remains of the scenery from a production of Cinderella.

Even while Vonnegut admits the inevitability of death, with or without war, he also tells us that he has instructed his sons not to participate in massacres or in the manufacture of machinery used to carry them out. But acting as if free will exists does not mean that it actually does. As Billy learns to accept the Tralfamadorian teachings, we see how his actions indicate the futility of free will. Even if Billy were to train hard, wear the proper uniform, and be a good soldier, he might still die like the others in Dresden who are much better soldiers than he. That he survives the incident as an improperly trained joke of a soldier is a testament to the deterministic forces that render free will and human effort an illusion.

The Importance of Sight

True sight is an important concept that is difficult to define for Slaughterhouse-Five. As an optometrist in Ilium, Billy has the professional duty of correcting the vision of his patients. If we extend the idea of seeing beyond the literal scope of Billy’s profession, we can see that Vonnegut sets Billy up with several different lenses with which to correct the world’s nearsightedness. One of the ways Billy can contribute to this true sight is through his knowledge of the fourth dimension, which he gains from the aliens at Tralfamadore. He believes in the Tralfamadorians’ view of time—that all moments of time exist simultaneously and repeat themselves endlessly. He thus believes that he knows what will happen in the future (because everything has already happened and will continue to happen in the same way).

One can also argue, however, that Billy lacks sight completely. He goes to war, witnesses horrific events, and becomes mentally unstable as a result. He has a shaky grip on reality and at random moments experiences overpowering flashbacks to other parts of his life. His sense that aliens have captured him and kept him in a zoo before sending him back to Earth may be the product of an overactive imagination. Given all that Billy has been through, it is logical to believe that he has gone insane, and it makes sense to interpret these bizarre alien encounters as hallucinatory incidents triggered by mundane events that somehow create an association with past traumas. Looking at Billy this way, we can see him as someone who has lost true sight and lives in a cloud of hallucinations and self-doubt. Such a view creates the irony that one employed to correct the myopic view of others is actually himself quite blind.

The Inevitability of Death

Death pervades Slaughterhouse-Five, and Vonnegut uses a consistently matter-of-fact tone to describe each of Billy’s encounters with death, whether it be the catastrophic bombing of Dresden or the candles made from the fat of slain prisoners. After every mention of death and mortality, Vonnegut explores the mystery and inevitability of death with his “so it goes” refrain. While the repetition of this phrase comes across as cold and irreverent, it more likely reflects Billy Pilgrim’s adoption of Tralfamadorian philosophy. The Tralfamadorians teach Billy that time is not a linear event, and therefore Billy’s death has already happened and he cannot control the circumstances surrounding his death. Billy finds comfort in this idea that a corpse is simply a person “in bad condition in that particular moment,” but that same person is “just fine” in other moments. Therefore, death is nothing to spend too much time commenting on and obsessing over.

Throughout Slaughterhouse-Five, death is depicted as more of an inevitable experience than as an end to one’s life. For example, Billy “has seen his own death many times” throughout his time-travels, so when his day of death finally arrives, Billy remains serene and good-humored. After Paul Lazzaro shoots Billy, the narrator says Billy “experiences” death instead of describing him as actually dying, and then Billy “swings back into life again.” Billy’s complete acceptance of death may indicate that the Tralfamadorians are a figment of his imagination, an intricate coping mechanism to explain the prolific deaths he witnessed throughout the war. In believing that death is merely an experience, Billy can trust that everyone who died during the Dresden bombing is still alive and well somewhere.