"Our revels now are ended...."
This passage, playing as an epilogue set against the pageantry of a masque, is often interpreted as Shakespeare's self-reflective aside to his audience. It seems a perfect symmetry, after all. The story of the play is nearing its end, Prospero is preparing to give up both his magic and island realm, and The Tempest marks a closing chapter in Shakespeare's theatrical career. It is indeed tempting to hear Shakespeare's own voice lurking beneath the words Prospero speaks.
Such sentiments derive from other examples sprinkled throughout Shakespeare's works. From the chorus of Henry V asking the audience to "Gently to hear, kindly to judge, our play" to Puck's "If we shadows have offended" speech from A Midsummer Night's Dream to the inside joke of Twefth Night's "If this were played upon a stage now, I could condemn it as an improbable fiction," the canon is rife with the author's winks and nudges. Some are blatant; some are sublime. Depending upon how one wishes to read the selection, this speech ranks as both—and neither—at the same time.
On the surface, Prospero is letting Ferdinand know that the masque has been nothing more than an illusion. At the same time, he metaphorically compares the masque with the fleeting temporality of life. When viewed in the light of both Miranda's impending marriage and Prospero's story arc at this point in the play, the speech can also partly be seen as a wistful passing of the baton from one generation to another. Soon, Prospero will return to the dust; it weighs on his mind in Act V when he says, "And thence retire me to my Milan, where/Every third thought shall be my grave."
Is there another layer at work in The Tempest? Shakespeare, within a year or so of writing the play, had retired to Stratford-upon-Avon. In that same year, he drafted his last will and testament. His role as resident playwright within the King's Men had been assumed by John Fletcher, with whom Shakespeare collaborated before his death in 1616. There are some clear symbolic parallels between Shakespeare and Prospero when looking at the speech in this context. Two older gentlemen, both planning a return to their birth places to await death, both having relinquished their respective gifts, and both certainly thinking of the finite remainder of their days. And can't "the great globe itself" be construed as a pun on Shakespeare's great stage?
It's certainly romantic to believe it so. The truth is elusive, as is usually the case when attempting to superimpose the autobiographical upon the artistic expression. There is no proof, nor will there ever be, and we can choose to view the speech as purely Prospero's, purely Shakespeare's, or any range in between. The irony is that this speech of temporality is part of the enduring monument of Shakespeare's canon.
You do look, my son, in a moved sort,
As if you were dismay'd. Be cheerful, sir.
Our revels now are ended. These our actors,
As I foretold you, were all spirits and
Are melted into air, into thin air;
And, like the baseless fabric of this vision,
The cloud-capp'd towers, the gorgeous palaces,
The solemn temples, the great globe itself,
Yea, all which it inherit, shall dissolve,
And, like this insubstantial pageant faded,
Leave not a rack behind. We are such stuff
As dreams are made on, and our little life
Is rounded with a sleep.
—Act IV, sc. i