"Some subtleties o’ th’ isle, that will [not] let you/ Believe things certain." (Act V, Scene 1, line 140-141)
This quote of Prospero’s reminded me of Caliban’s speech about the island (Act 3 scene 2, lines 148-156) when he talks about all the magical happenings of the island. In Caliban’s opinion all the sounds and spirits of the island and harmless and the island is wonderful. However, in Prospero’s note here we see that although the island is full of magic, this isn’t necessarily as great as Caliban sees it. The magic of the island that Caliban talked about, like the “sounds and sweet airs” cause Alonso and company to question the world around them and what is real and what isn’t. Also in this scene Prospero is having his sort of last hoorah with his magic before giving it up so in noting that the island causes people to question realities he could also be referring to the negative side of magic. This is a first for Prospero considering the entirety of the play thus far we have seen Prospero using magic to his advantage. With this view of the island readers can further see a change in Prospero from being strictly power hungry to being more forgiving and human in a sense.