Kurt Vonnegut Junior served in World War two. His experiences there allowed him to write the novel Slaughter-House Five. In the book he serves as the narrator, observing, not only the calamities of those who held the status of prisoners of war, but the life of Billy Pilgrim in particular. Pilgrim's life is hard to keep up with, for in it are many journeys. Through these journeys he deals with issues of free-will, war, and innocence and ignorance. His life was multi-dimensional, as the insignificance of time played a major role. .
The Tralfmadorians can be correlated to this insignificance of time, for they did not recognize the past, present, or future. They, unlike man, were able to see the fourth dimension. They were able to see all at once and viewed man as being "a bug trapped in the amber." This idea serves the story in that it suggests man's lack of free will. It can be interpreted to mean that man has no way of preventing war. He can only stand helplessly by and watch. Mankind cannot stop war; man is "trapped in the amber." The Tralfmadorians imply that attempting to stop war would be useless, because man is "designed" that way. Those who work for peace do not understand human nature.
The idea of free-will is also explored through the many forces that Pilgrim finds himself unable to control. For instance, when he was a child, Pilgrim's father tossed him into the deep end of the pool. Billy decided he would prefer to just stay there, but he was rescued nonetheless. He was later drafted into the war against his will. .
Billy Pilgrim was an optometrist, which causes one to think about sight. This sight can be observed beyond the literal level, though, because of Pilgrim's experiences with the Tralfmadorians. Because of them he is able to recognize the existence of a fourth dimension. He sees the future, for according to them the past repeats itself in the present and future. .
While there are many symbolic correlations throughout the story, one of particular interest is the reverse recount of war, which we are given shortly before Billy Pilgrim is picked up by the Tralfmadorians.