Running thematically throughout Shakespeare’s The Tempest is the desire for freedom and how this desire might be incorporated into a just and stable political community. Ariel, Caliban, and even Miranda, for instance, all seek in their own ways to be free of Prospero’s government.  Prospero himself seeks to be free from the constraints of the finite order, and his “secret studies” are of the liberal arts, disciplines that we now understand as designed to free individuals from the bonds of half truths, personal biases and public opinion. For Prospero though the liberal arts provide more than just a leg up in communication or critical thinking skills.  Prospero seeks to be free of all the constraints of the natural order and his studies give him the power to seemingly manipulate the elements at will.  After all, as noted in a previous post, Prospero understands the things of this world as akin to the illusions that he (or a good poet) creates.  And Prospero has freed himself from these illusions.

And yet, as free as Prospero has become, there are some sticky bits that refuse to merely bend to his will.  Just as they each desire their freedom, Ariel, Caliban, and Miranda all, in their own way, rebel.  Caliban thus outright revolts, plotting to with Stephano and Trinculo to kill Prospero. Miranda allows her affection for Ferdinand overcome her obedience to Prospero, telling Ferdinand her name and ultimately proposing to Ferdinand with no reason to expect that her father will consent.  Finally, Ariel,  who seeks to be released from his service to Prospero earlier then has been stipulated, is circumspect in his obedience, doing nothing that might anger his master, lest he be enslaved forever.    Prospero might be able to whip up a mean storm, but he cannot overcome the independent wills of the individuals he seeks to govern. 

Initially, Prospero does not even seem to recognize the autonomy of others, assuming perhaps that everyone perceives his superior intellect and concurs with his judgements. Hence, he hands the city of Milan over to his brother, believing that Antonio will of course be content to do all the hard work of government without any of the glory. Once Antonio betrays him, Prospero realizes that he must find ways to ensure that others content themselves with his will.  Up until the moment that Ariel counsels forgiveness of his enemies, Prospero manipulates the wills of others, just as he manipulates the other elements of the natural order.  Threatening Caliban with physical torment, toying with Miranda’s affections, and persuading Ariel that there is just one more, and one more, and one more task to do, Prospero finds ways to cajole everyone to his good purposes.  Indeed, his treatment of Ariel, while seeming the most benign, is in fact, the worst.  For Ariel’s very nature, it seems is to be free; he has done Prospero no wrong; and he appears to love his master.  And yet, rather than merely liberating Ariel from the unjust confinement imposed on him by the witch Sycorax, Prospero instead demands a payment for his service – twelve years of obedience for having the good sense of disobeying the callous Sycorax.  From an absent-minded academic, Prospero becomes a tyrant, seeking freedom by means of power (Maybe some warning there for those of us who “profess.”)

His power, however, proves futile. Miranda will love Ferdinand such that she trespasses on Prospero’s rules; Caliban will seek to kill him; and Ariel, while obedient, nonetheless, desires to be free.  Prospero might be able to control some of their outward actions, but he cannot determine their desires or intents.  All of this comes to a head when Prospero, trying to convince Miranda and Ferdinand to remain chaste, recalls the plot against his life, and Ariel confesses that he was going to say something, but he feared Prospero’s anger. Prospero might seek to teach, persuade and threaten, but, in the end, the choice of others to consent to his will does not fall within his purview.

By the end of the play, Prospero, counselled by Ariel, finds another path to freedom.  When Prospero has all of his enemies “at his mercy”(4.1.263), Ariel says that were he human, he would be moved to forgive them. Ariel, human or not, has already discovered the freedom of forgiveness. For while he has justly sought to be freed by Prospero, Prospero has not complied. Ariel, however, knows that he loves his master and seeks to be loved by him in turn (4.1.49). Ariel thus consistently forgives Prospero his fault, and continues to serve him even though he might rightly seek to punish him just as Prospero wants to punish those who have betrayed him. Forgiving Prospero his faults, Ariel relinquishes any power that he might have over him, thereby freeing Prospero, but also freeing Ariel from the temptation that he might in any way be justified or capable of overturning the will of others to match his own.  Ariel recognizes the possibility of becoming Caliban.   Instead, he submits and by means of the example of his love, he is ultimately given the freedom that he wants.

  Prospero concludes the play, asking the audience for forgiveness.  

Prospero,  along with most of the enemies he has brought to the island, has recognized  the proper limits of his power and the need for love and forgiveness if he is to be free.  And love and forgiveness are empty if they are not freely bestowed.  
Importantly, of course, Prospero is able to relinquish his control only  once all of his enemies are brought to a head, and he has secured the place of his city and the well-being of his daughter through an alliance grounded in love rather than betrayal.  The work of maintaining this state cannot be merely given up the way that Prospero has given up his books.  As Ariel, however, knows a justice that is founded on love or the good will of rulers and the ruled necessarily takes up the autonomy of the beloved, and in seeking their good, achieves its own. 
PS: I once saw Patrick Stewart play the role of Prospero and my seat was so close to the stage that he spit on me❤️.