The illusionary nature of life is thematic to Macbeth's soliloquy in Act V of Macbeth. Interestingly, there is a double entendre of sorts in the soliloquy as Macbeth mentions that
Life's but a walking shadow, a poor player
That struts and frets his hour upon the stage
And then is heard no more. (5.5.26-28)
For, not only has Macbeth's "vaulting ambition" and his faith in the witches' prophesies been illusionary, but Shakespeare's play itself is but an illusion on an Elizabethan stage, "signifying nothing."
Indeed, Macbeth and his wife have created a fantastic world in their self-deception, but it is a world "of sound and fury" that truly has no meaning. In his book, Shakespeare: The Invention of the Human, renowned critic Harold Bloom writes,
Imagination (or fancy) is an equivocal matter for Shakespeare and his era, where it meant both poetic furor, as a kind of substitute for divine inspirations, and a gap torn in reality, almost a punishment for the displacement of the sacred into the secular.
Both with Shakespeare's play and within the plot of Macbeth, there is a "gap torn in reality"; Macbeth's realization of his self-deception in believing in the preternatural world's power to rule the earthly one leads to his despair. His fantasy and cupidity, he feels, makes for
... a tale
Told by an idiot, full of sound and fury,
It is a "petty" tale as well, for it has little to do with anything that is significant, Macbeth senses with great pessimism the cost of his delusions as before, in Scene 3, he has felt,
My way of life
Is fall'n into the sear, the yellow leaf,
And that which should accompany old age,
As honor, love, obedience, troops of friends,
I must not look to have (5.3.25-28)
Yet, some critics feel that there is also a "self-justifying quality to his words" that still prevails in Macbeth. For, if all "signifies nothing," then Macbeth's heinous acts are also mitigated since they, too, like all other things, "signify nothing." Therefore, while Macbeth admits to the illusionary quality of life, he holds on to his self-deception as a means of justifying his "heart of darkness." Truly, Macbeth's soliloquy thematically captures Shakespeare's visionary tragedy.