The idea of books as a device for escape

For Tereza, books are seen as an 'imaginary escape from reality', this is similar to that of D-503, where he uses his diary to unleash his inner feelings and desires that ultimately led to his realisation of his individuality. Tereza find that books are a 'single weapon' against an unsatisfying world surrounding her whereas D-503 initially writes for the Integral, but ultimately, he  awakens to his own self.