In act 1, Shakespeare introduces the conflict between Prospero and Caliban through their argument about the past and about who has the right to control the island. Prospero says he treated Caliban kindly when he first arrived. He taught him language, and tried to educate him. Prospero presents himself as a rightful ruler who brought knowledge and language to the island. On the other hand, Caliban says the island belonged to him since he was born there before Prospero came and he even showed Prospero around the island when he first arrived. Caliban believes Prospero took the island by force and made him a servant. Even though Prospero taught him language, Caliban now uses that language to challenge his authority.

This early portrayal suggests that their struggle is about who has the right to rule the island and what makes power legitimate. Prospero believes his power is justified because he educated Caliban, and controls island with knowledge. From his view, he is a rightful ruler because he is more civilized. Caliban, however, believes that island belongs to him because he lived there first and inherited it from his mother.