One of the themes in "The Tempest" is that of justice and the reality or falseness of it. Characters deal with questions about what is just verses what is fair. What does justice really mean for humanity, and how do we cope with it?
A second theme is that of the monstrous nature of humanity. It is difficult at some points in the play to distinguish between men and monsters. We can see humanity in Caliban, and we can see monstrous behavior in some men. Prospero notes,
"If I should say, I saw such islanders,—
For, certes, these are people of the island,—
Who, though they are of monstrous shape, yet, note,
Their manners are more gentle-kind than of
Our human generation you shall find
Many, nay, almost any"(Act III Scene III lines 30-35).
A third theme is that of colonialism. Should one culture invade another and have authority over it? What makes one culture superior to another?
Most plays have several themes or main ideas.