The major themes of the play The Tempest are The Pursuit of Power , The forgiveness/Reconcillaition or Regeneration, The Futility of Nurture, Usurpation, Supernaturalism etc.
The pursuit of power and the exercise of power is the primary theme of the play. The exercise and quest for power can be seen in various realms like spiritual, temporal, natural and supernatural: power over the outer world and the power over the self. The ardent love for power can be clearly seen in Antonio, Stephano, Alonso even the menial servant, Sebastian.Antonio, Sebastian and Alonso yearns for the political and worldly power , while Ariel and Prospero uses their Supernatural powers.
Forgiveness is the major theme of The Tempest. eventhough left at the mercy of the turbulent waves and wind by his own brother Antonio, who is referred to as
"the ivy which had hid my princely trunk,
And suck'd my verdure out on't" by Prospero is forgiven by him towards the close of the play. Regeneration is moreover a moral necessity in here. Alonso undergoes regeneration as the play reaches its fag end. "the rarer action is in virtue than in vengeance" reflects this thought.
The futility of nurture was manifested through the character of Caliban. "the poisonous slave got by the devil himself" . It gaves us a peep into the natures which cannot be improved by nurture.It shows the ineffectiveness of nurture in improving the inherent nature of a person. Caliban says,
" You taught me language : and my profit on't
is, i know how to curse."
Usurpation is yet another important theme. Through out the play we find various instances of ousting. Towards the onset of the play Antonio usurps the rightful duke of Milan - Prospero while as the plot progresses we see the ousting of Caliban the rightful master of the island by Prospero. The anguish in Caliban's words mirrors it,
" This island is mine , by Sycorax my mother
Which thou tak'st from me"
Supernaturalism which pervades through out the play is another theme in the play. It can be witnessed from the very beginning with the wreckage of the ship and continues through various occurances in the island. The Masque is an excellent example of Supernaturalism. The magical powers of prospero and Ariel add charm to the play.
These are some of the major themes of "The Tempest."