Metaphor for Kevin’s Mortality
Kevin’s leg braces and wheelchair are more than just a metaphor for his being earthbound but it is also metaphoric of his mortality, that he is living on borrowed time and even then, not a lot of it. Initially Kevin moves around with the assistance of leg braces but as his condition continues to deteriorate he moves from braces to a wheel chair, an indication of how he is getting closer to his eventual demise.
Metaphor for Freedom
Both Max and Kevin dream of freedom; Max dreams of being free from being associated with his father, a cold-blooded killer and Kevin dreams of being free of his leg braces and later on, his wheel chair. Flight, in the form of the Ornithopter, is metaphoric for the freedom that both young men desire so much.
Metaphor for Defeat
Max regularly goes through the moments depression and confusion. Later in the novel he goes through a season of deep grief when he loses his best friend. Every time the Max goes through a gloomy phase in his life he retreats to their basement to brood and nurse his hurts. He entitles the place “The Down Under” both because it is literally located down under the house and because he goes there when he is emotionally down. The Down Under, because of the circumstances of its use, becomes symbolic of defeat, particularly for Max. Instead of rising up to meet the challenge he chooses instead to wallow in the closest thing he has to a deep, dark pit.
Metaphor for Transformation and Maturity
Kevin makes constant references to King Arthur especially when he tries to cheer up Max or inspire him to rise above the challenges he faces. Kevin looks up to the fictional king because he identifies with his humble beginnings and hopes for his eventual rise into greatness despite being aware of the fatality of his condition. The boys find inspiration in his example and as a result they try their best to emulate his example, mimicking his nobility of character and bravery. In this regard, King Arthur becomes a metaphor for maturity and transformation.
Metaphor for Hope
The blank journal is what Kevin uses to inspire Max to keep pushing and challenging himself into growing his talent as a writer, even when he passes away. The blank journal is a metaphor for hope; hope that Max, despite what he thinks of himself would grow his talent for writing--something that only Kevin managed to see. It can also be inferred that the blank journal is also symbolic of the hope that Max would be able to forgive Kevin for lying about his condition.
