The Baron in the Trees is a novel written by Italo Calvino. The book was published as Il barone rampante in its original Italian language in 1957. The novel tells the story of Baron Cosimo Rondo, who, at the age of 12, climbed into the trees and spent the rest of his life in the forest. Cosimo was an eccentric person who encountered many other eccentric people throughout the book.

The story of The Baron in the Trees was set during the transitory phase between the Enlightenment and the Romantic periods. In this context, Cosimo represented the characteristics of both periods. For instance, Cosimo held beliefs that were prominent during the Enlightenment, such as ideas of social and philosophical progress.

However, Cosimo was a bipolar character in that he also exemplified the characteristics of the Romantic period. For example, Cosimo showed egotistical desires and a maximalist lifestyle as a baron of the woods.

In essence, Cosimo's character was the embodiment of the contradictory schools of thought at the period the story was set in.

The Baron in the Trees is full of examples of duality. For instance, Cosimo can be seen as a nontraditional protagonist or an antihero. The reader is likely to admire some of Cosimo's qualities but detest others. Cosimo also symbolizes the psyche and contradictory behavior patterns of people. Cosimo is primitive and wild, yet he envisions "a world republic of men—equal, free, and just.”

The character of Cosimo is the embodiment of man's desire to be free, a characteristic of the Romantic period, and also man's desire to transcend his earthly limitations, which is the defining characteristic of the Enlightenment period.