Caliban is a famous fictional character from William Shakespeare’s play The Tempest (written around 1610–1611). Caliban is the son of the witch Sycorax and the only native inhabitant of the island where the play takes place. • When the magician Prospero and his daughter Miranda are stranded there, they take control of the island. • Prospero enslaves Caliban, forcing him to serve as a laborer and treating him as a “monster” or savage. The phrase that you mentioned is from Oscar Wilde, specifically from the preface to his 1890 novel The Picture of Dorian Gray. Wilde is making a witty, paradoxical comment about art, truth, and human hypocrisy: • Realism in art shows life as it really is — flaws, ugliness, corruption, and all. • Wilde says that people of his time “disliked realism” because it forced them to see themselves too clearly — like a mirror showing their true face (that’s Caliban seeing his reflection). So: The “rage of Caliban seeing his own face in a glass” = people’s anger at art that exposes their reality. And: The “rage of Caliban not seeing his own face” = people’s anger at art that’s too idealized, because it doesn’t reflect them at all. Basically, people get upset when art reflects them but they also get upset when art doesn’t reflect them