To what extent does Caliban differ from The Tempest’s human characters? What might Shakespeare be saying by giving dialogue to an inhuman beast?

At first, Caliban resembles a freak, whose greed, lust, and laziness contrast with the noble attributes of the humans around him. But as the story progresses, Caliban seems less a monster and more a kindred spirit to Antonio, Duke of Milan. As the characters reflect on what it means to be a man, they cite many of Caliban’s most prominent—and least flattering—qualities. Through Caliban, Shakespeare implies that monster and man are one and the same.

When Shakespeare introduces us to Caliban, he emphasizes Caliban’s most repugnant qualities. The son of a witch and the devil, Caliban did not have human companions until Prospero and Miranda washed up on his island. Instead of showing gratitude to his new friends for their efforts to teach him English, Caliban attempts to rape Miranda, to “people the island with Calibans.” Although he could have tried to mitigate the harsh punishment he received by showing remorse for the attempted rape, Caliban continues to insist he did nothing wrong and to curse his human captors. He conspires with a drunkard to overthrow Prospero and persists in believing that Miranda is a pawn who will gladly bear children for anyone who asks. He is a brute—idiotic, foul-tempered, and abhorrent.

Yet Shakespeare implicitly asks if Caliban is as different from his human neighbors as he seems. The character Antonio is not only human but also a powerful duke—and yet he shares many of Caliban’s nastiest tendencies. Like Caliban, he commits a form of rape (by violating and stealing Prospero’s sovereignty), and like Caliban, he conspires for yet more unearned power in the course of the play. Caliban’s attempts to incite treason within Stephano and Trinculo mirror Antonio’s attempts to put Sebastian on Alonso’s throne. Indeed, Antonio shows himself to be more monstrous than a monster, for unlike Caliban, he cannot excuse his behavior with drunkenness or genetics. (His mother was not a witch, but the same woman who gave birth to the generally moral duke, Prospero.) In fact, Shakespeare suggests that in some ways Caliban is more sympathetic than his human counterpart: Caliban gives a beautiful speech on the natural wonders of the island, whereas Antonio can only stupidly curse its “barrenness.” Though human, Antonio repeatedly acts like a beast.

By including the vile yet human character Antonio in his drama, Shakespeare reinforces the idea that people can behave just as monstrously as Caliban. This idea recurs throughout the comments characters make about their fellow humans. One would think these characters were talking about Caliban, not their own brothers and sisters. Trinculo, for example, remarks on the human tendency to ignore poverty and suffering in favor of paying money to laugh at circus freaks. Young, innocent Miranda observes that villains such as her uncle are nevertheless products of human relationships. When she sees the shipwrecked men for the first time and exclaims “O brave new world!” her father can only cynically imply that the world’s newness will soon wear off, exposing a vast network of schemers and thieves. He tells Antonio that his behavior is unnatural, but he means that his behavior should be unnatural. On Shakespeare’s troubled island, the wish to murder and steal is all too human.

By setting up a false contrast between Caliban and the human characters, Shakespeare makes The Tempests pessimism all the more devastating. At first, we are led to believe that there is nothing human about Caliban: the facts of his breeding, behavior, and personal history set him apart from the more temperate, human characters we meet. But through a sustained comparison between Caliban and Antonio, Shakespeare shows that Caliban’s brutish instincts lurk in some human beings. In fact, humans can commit acts of treason and assault even if they do not have Caliban’s many motives and grievances. In The Tempest, Shakespeare erases the line between monster and man.