Everything you need to understand or teach The Island of the Day Before by Umberto Eco.
Like Eco's other novels, The Island of the Day Before reflects his background and interests as one of the world's foremost semioticians. He pursues theoretical and practical problems of signs and signification through the labyrinths of nature and society, and through verbal mazes of his own making. The overarching theme of the novel might be expressed as follows: how perception and experience alter each other in a never-ceasing dance.
Perception is conditioned by experience, but also modified by rhetorical training, philosophical systems, and special lenses. Roberto de la Grive and his contemporaries view the world through their complex, antithetical wordplay. Roberto becomes so enmeshed in the letters he writes and the fictions he imagines that ultimately he can no longer separate external reality from the reality inherent in his words.
His fascination with the various orthodox and heterodox philosophies he encounters profoundly affects his vision of the world...