Prospero is really the center of the play, since the other characters relate to one another through him and because he manipulates everyone and everything that happens. The play ends with Prospero's victory over his enemies; he has the most lines, and he speaks the epilogue. Although he has far fewer lines than several other characters, Caliban, at only 100 lines, is often the focus of student interest, as well as that of many critics, often with an importance far greater than his actual presence in the play. Much of this interest reflects the social position of critics, scholars, and students. Whether Caliban is a monster, whether he is a victim of colonialism, or whether he represents some other disadvantaged element of society depends almost entirely on the social and cultural constructs and interests of the reader or audience. An important part of Caliban's appeal is his ambiguity of character.
The audience first learns of Caliban from Prospero's description to Ariel, in which the child of the witch, Sycorax, is described as "A freckled whelp, hag-born — not honoured with / A human shape" (I.2, 285–286). The audience learns more about Caliban's physical description from Trinculo and Stefano, who describe Caliban as less than human. Trinculo asks if the form before him is "a man or a fish?" (II.2, 24), and Stefano describes Caliban as a "moon-calf" (II.2, 104), a deformed creature. But it is not his appearance that makes Caliban monstrous in Prospero's eyes, nor was Caliban treated as a slave — at least not initially. Caliban, himself, relates that Prospero treated him well, teaching him about God when the two first met (I.2, 337–338). But it was Caliban's attack on Miranda that resulted in his enslavement and the change in Caliban's social position. Caliban sees the attempted rape of Miranda as a natural behavior. Had he not been stopped, Caliban would have "peopled else / This isle with Calibans" (I.2, 353–354). Reproductive urges are a natural function of animals, but humans modify their desires with reason and through social constraints. Without reason to modify his impulses, Caliban's behavior aligns him with the animals. Yet, at the same time, he is clearly more than a beast.
