“Hell is empty and all the devils are here.”
This is one of the most famous quotes in the play which has been maintained in the film as well. The quote is uttered by Prospero, who thinks about the fate of humanity in general. Before this, Prospero pointed out how everyone seems to be afraid of the future and the possibility of being sent to hell for eternity. but, as he points out, humanity is punished day by day on this earth and the devils are those who want nothing more but to further their own means and to gain as much fame and wealth as possible, even if it means that other people have to suffer.
"when I waked, I cried to dream again.”'
This quote is uttered by Caliban after he and the rest of the people on the ship ended up on the island, shipwrecked. The purpose of this quote is to transmit the idea that real life is cruel at times and hard to accept. Because of this, dreaming, or rather living in a constant state of delusion is much simpler and much more pleasant. But, as Caliban is unable to remain in the land of the dreams for an extended period of this, the normal person has to return to normal life and to face the problems everyone is faced with.
“Thought is free.”
Ferdinand and the other characters are all trapped on the island. Physically they are trapped but they all realize that while they cannot leave the island, they are free in spirit and have the possibility to express what they think and what they feel without any fear of repercussion. Thus, because of this, the characters find solace in the thought that even though they are physically captive, no one can stop them from thinking.