What are the differences and similarities of how Prospero treats Ariel and Caliban?
At first it seems that Prospero treats Ariel and Caliban very differently; he's devoted to Ariel and seems to respect him and partners with him to concoct his various schemes and plans throughout the play. Prospero acts as a kind of puppet master with Ariel a kind of powerful magician’s assistant, working as a double act to manipulate the other characters in the play. Prospero regards Ariel as a colleague, although one that he sometimes sternly rebukes, but Caliban he hurls the worst of his abuse at, physically punishes with painful spells, and gives him only the worst and most menial tasks to perform on the island.
His treatment of them is more similar than it first appears, though, because he has them both enslaved. Although he treats one of them with a certain amount of respect and the other with total contempt, he holds them both in bondage and they both express resentment at the fact that they are not free to come and go as they please, nor can they refuse to carry out his orders. He's forcing them both to serve him, and the play comments interestingly on the dynamic and morality of slavery, suggesting that slavery is a condition that will always be resisted, and that how a slave is treated does not mitigate the resistance and resentment a slave feels toward being held against his will.