Nature
Theme of nature is the underlying theme presented in the novel. The young boy climbs the trees and is able to move long distances without touching the ground. The narrator points out several times how the destruction of nature, men's love towards axe, has made it impossible to do that now, at the moment he is recalling the story of his brother. The novel portrays love towards the nature, beauty of it with its corresponding imagery. It portrays a connection of man to the nature and reliance.
Rebellion and consistency
What essentially happened, that spurred the entire story, is a boy getting angry at his father and rebelling against him. His father, the baron, mockingly says to him, after he climbed a tree in anger, that he has to come down to the ground at some point. The boy never in his life sets a foot on the ground again from that moment on. Cosimo decides to not rely on his father and family anymore, and live by his own rules. The story is about a boy who rebels, but in his rebellion re-discovers himself and his purpose in life, and never breaks his own determination for anything.
Love
Another theme explored in the novel is the theme of love. Cosimo meets his childhood love Viola, while refusing to come down from the tree as a sign of rebellion against his father. He promises her that he will never come down to the ground and is consistent until the end of his life. They meet again as adults, when Viola comes back to Ombrosa as a rich widow. Cosimo is madly in love with her, and she is one of the reason he kept off the ground. He's been waiting for her entire life, Unfortunately, the love story doesn't have a happy ending. Both of them are extremely proud and stubborn, and they lose each other because of that stubbornness.
Being in a brother's shadow
The narrator of the novel is Cosimo's younger brother. He tells Cosimo's story as well as his own, being a younger brother who always wants to have his older sibling's attention, appreciation and praise. Despite growing up and living a successful and luxurious life, the narrator always felt as if he lived in his brother's shadow. His family always shut down each sign of his own rebellion with saying that one rebellious son is enough. The narrator describes how this marked his entire life, where he had to be the complete opposite to his brother, to keep the balance in the family and to fill in his brother's place. In a way, Cosimo's determination to live completely freely, ripped his younger brother of his entire freedom.
