The similar treatment of these very different minor characters highlight's Prospero's obsession with control, as well as his own return to the human world. Consider that although Prospero mourns his exile, he even uses captivity as an enticement for Miranda and Ferdinand's courtship, forcing the young man to carry wood like he does Caliban. The young man responds cheerfully, "There be some sports are painful, and their labor/Delight in them sets off: some kinds of baseness/Are nobly undergone and most poor matters/Point to rich ends. (3.1) But the comparison as well as the contrast between the suitor and the rapist in their similar labors and different emotional responses to that labor adds further depth to the pairing of freedom and captivity themes that structure the play. Thus, all of the minor character in "The Tempest" highlight different forms of freedom and incarceration, and exist in binary oppositions only in their differing psychological and emotional responses to these themes. But even of the minor characters that are elemental in their depiction, there is some variation. Consider the freedom of language and rage that Caliban exhibits and the tyranny of Prospero's control over his body, and the similar plight of his mirror image Ariel, who also verbally bridles, then is silenced at the idea of being captive.

But Shakespeare's greatest contribution to the notion of minor or emblematic characters that represent different variations on a play's theme is that, although these characters are thematic in their significance on stage, this does not mean that Caliban does not suffer, any more than Ferdinand does not love...

Even Ferdinand's cheerful rather than angry response to his enforced labors under Prospero's control are more significant to the plot in the way that they show his fitness as a human being, as well as what they represent.
Even the archetypal Caliban's suffering is perhaps most poignantly revealed when Trinculo notes, upon seeing him, "This is some monster of the isle with four legs, who hath got, as I take it, an ague. Where the devil should he learn our language? I will give him some relief, if it be but for that. If I can recover him and keep him tame and get to Naples with him, he's a present for any emperor that ever trod on neat's leather." Like Prospero, but for a different reason, Trinculo wishes to captivate the monster for his own ends -- as Prospero extracts a price from Ariel for his own ends. But Caliban, even in his dreams as he writhes before Trinculo, raves "Do not torment me, prithee; I'll bring my wood home faster," as if Prospero has not only possessed his language but his entire mind and body with fear.

Caliban really suffers, even while he represents something beyond himself. Thus the minor character Trinculo becomes a stand-in for Prospero, highlighting the potential immoralities of the less than perfect central moral figure as a theme, and simply extracting a similar form of emotional suffering upon a fellow living being.

All of the minor characters thus exist simultaneously as living figures and as questions, questions of a linear interpretation of the figure of Prospero. Without the corresponding desire of Trinculo to capture Caliban for his own ends, Prospero's control of the spirit world would not seem as sinister as it is, and as detrimental to the lives of Caliban and Ariel. Without Ferdinand's labors for Miranda, Caliban's enforced labors for his attempted rape of Miranda would come less strikingly to the audience's attention. And because the audience can still emotionally identify with all of these complex minor characters, the emotional as well as symbolic significance of this mythical island is all the more resonant, even after the close of the play.

Works Cited

Shakespeare, William. "The Tempest." 11 Jan 2005. MIT Shakespeare Homepage. http://www-tech.mit.edu/Shakespeare/tempest/tempest.2.2.html