What is the literary function of Billy Pilgrim becoming "unstuck in time" in Slaughterhouse-Five?
I know what "unstuck in time" means but what function does it serve? I am confused on that. He travels to different periods of his life, but what does this signify as a whole to the novel? The main importance is what I am having trouble with.
There are a few ways to approach this question. Thematically, the fact that Billy is "unstuck" in time supports the idea that the past and the present are inextricably connected.
‘‘All moments, past, present, and future, always have existed, always will exist.’’
Functionally, Billy's time travel serves to express this theme and also provides a logic for the novel's structure.
Both of these facets of Billy's relationship to time work together, though we might say that the "literary function" of the time-travel is more oriented toward a discussion of its relationship to the novel's structure (plot structure and compositional structure). There is an argument to be made that the thematic side of this question has at least an equal importance for an overall discussion of the novel.
Time-travel, for Billy Pilgrim, is suggestive of a lack of control over how Billy's emotions and psychology deal with the events of his life (his past). The Dresden bombing is something that takes up a great deal of psychological room, as it were, in Billy's mind. Thus as it is set against the other events of his life, the bombing is given precedence in the narrative.
Both the centrality of this event and its radically alienating effect on the rest of Billy's life are represented by the novel's structure. (eNotes)
The use of time-travel allows for this subtle communication of the thematic idea: a person's past never leaves him/her and its continued presence will be determined by its psychological weight. Time-travel then becomes a metaphor representing the way the mind deals with the past, or we might phrase this idea inversely and say, time-travel becomes a metaphor for the way the past (memories) continually breaks into the present.