Within the play magic is used as a kind of illusion. Ariel is shown as a spirit throughout the play who can create music, and fly freely about the island. Ariel could form all aspects of fire, air, earth, and water; the characters could not always see Ariel but could always here him. Ariel is a very mysterious character who, when he is not serving Prospero, sometimes uses his magic to cause mischief.
One of Ariel’s key roles in The Tempest is to provide music; this is one of the main forms of magical effect within the play. His melodies/‘airs that give delight,’ are heard throughout the island and they can control the actions of the other characters. Ariel uses his magical ability to have a hold over the other characters; when he sings he can control their thoughts and decisions on their actions. This is extremely powerful; potentially Ariel has control of the island using just the magic within his voice. Ariel uses language as a form of magic. Ariel’s charms take the form of mystical songs. In Act 2, Scene 1, he awakens the counsellor Gonzalo with the words “If of life you keep a care, Shake off slumber and beware, Awake!” Gonzalo then stops Antonio and Sebastian from murdering Alonso. Ariel uses language more deliberately in Act 3, Scene 2, when he imitates the voice of Trinculo and calls Caliban a liar, causing discord among the rebels who intend to overthrow Prospero. The power of these words is enough to derail the seditious plot. In this scene, the audience also discovers that the source of Prospero’s power is his books. Later, Ariel visits Alonso and Gonzalo as a Harpy. When they draw their swords to defend themselves, he says, “Your swords are now too massy for your strengths / And will not be uplifted.”
Shakespeare draws a distinction between good magic and bad magic, by using the characters Prospero and Sycorax. Sycorax is said to have worshipped the devil and been full of "earthly and abhorred commands". She was unable to control Ariel, who was "too delicate" for such dark tasks. Prospero's rational goodness enables him to control Ariel where Sycorax can only trap him in a tree. Sycorax's magic is frequently described as destructive and terrible, where Prospero's is said to be wondrous and beautiful. Prospero seeks to set things right in his world through his magic, and once that is done, he renounces it, setting Ariel free.
Prospero is by far the most authoritative character in the play as he controls the fate of all other characters by using his magical powers, ‘If thou more murmur’st, I will rend an oak and peg thee in its knotty entrails.’ He can be seen in two different ways: as a powerful and magnanimous man, or as a cruel sorcerer. Prospero’s beloved books are said to be the source of his power as this is where he gained all magical knowledge. Prospero can be seen to use his powers for both good and evil within the play, but consequently, the end result is always respectable. He uses his powers to free Ariel from Sycorax’s undignifying spell which portrays him as a superior and compassionate character, but there is always a catch. Prospero then knows that Ariel owes him, so he uses his magic to make Ariel serve him in every way he wishes for three days.
Prospero uses his magical powers to control Miranda and Ferdinand’s relationship. He frequently tests the pair, for example when he pretends to think Ferdinand is a spy to test Miranda’s feelings and Ferdinand’s honesty. ‘The name thou ow’st not and hast put thyself upon this island as a spy, to win it from me, the lord on’t.’ This type of magic could be illustrated as selfish and unfair as Miranda and Ferdinand should be able to decide on their relationship without magical intervention; although Prospero’s intentions were always for good.
Prospero also uses language as a weapon against his slave, the monstrous Caliban. He constantly threatens to torture Caliban, but the audience does not witness these events. Instead, Prospero describes them in exact detail: “Tonight, thou shall have cramps,” he tells the man-beast in Act 1, Scene 2. In this case, Prospero holds power over other characters onstage because of his mastery over language. Only Caliban dares to challenge Prospero’s rule, but his lone voice of dissent is ineffective; as he confesses, the only benefit he has gained from learning language is that he “knows how to curse.”
In conclusion, magic is potentially the most significant and influential theme within The Tempest and the whole play centres around this idea. Without the power of magic Prospero would have been unable to create the tempest and the characters would not have even got to the island. The character of Ariel is a spirit which is essentially created by magic, and the ideas of good and evil, which is also a key theme, also centre around magical power. Without the power of magic Ariel would never have been freed from the tree, and Prospero would never have been able to bring the characters together, which consequently means that Miranda and Ferdinand would never have met and fallen in love. The Tempest is very different to Shakespeare’s other plays and the theme of magic is the foundation on which the play is based.