(1) The King does not blench at the dumb-show for the simple reason that he does not recognise his own crime either in that or in the Gonzago play itself, which is a mere verbal repetition of it.
   (2) The information which the Ghost gives to Hamlet is, therefore, an incorrect version of what took place.
   (3) Consequently the Ghost's speech must be interpreted as nothing but a figment of Hamlet's overwrought brain.
   (4) And finally, the essential feature of the story (the poisoning through the ears of the victim) could only have taken root in Hamlet's mind through a subconscious memory of the very play which he afterwards employed "to catch the conscience of the king".   (5-6)

On the political element:

The usurpation is one of the main factors in the plot of Hamlet, and it is vital that we moderns should not lose sight of it. Hamlet, as we have seen, is not unmindful of it; still more important, Claudius is not unmindful either. In short, Hamlet's ambitious designs, or what his uncle takes so to be, form, not of course the most important, but a leading element in the relations between the two men throughout the play. During the first half Claudius is constantly trying to probe them; they explain much in the conversations between Hamlet and the two spies Rosencrantz and Guildenstem; they clarify the whole puzzling situation after the play scene; and they add surprising force and meaning to one of the most dramatic moments of the play scene itself. In a word, suppress the usurpation-motive and we miss half the meaning of what happens in acts 2 and 3.   (34)

On "sullied flesh" vs. "solid flesh":

. . . "sullied flesh" which, subject to a slight emendation, the Second Quarto reads for the "solid flesh" of the Folio, and is the first phrase that falls from Hamlet's lips when he is alone, strikes the keynote. of what follows, not only in the soliloquy, but in everything he says for the rest of the play. "Sullied-melt-thaw-dew"; the Image behind these words is not difficult to guess. Hamlet is thinking of snow begrimed with soot and dirt in time of thaw, and is wishing that his "sullied flesh" might melt as snow does. For his blood is tainted, his very flesh corrupted, by what his mother has done, since he is bone of her bone and flesh of her flesh. The restored epithet anticipates "incestuous sheets" at the end of the soliloquy, and so binds the whole soliloquy together. It does more; it gives expression, for the first time, to one of the leading themes of the play. Why are Hamlet's "imaginations . . . as foul as Vulcan's stithy"? Why does that "couch for luxury" so perpetually haunt his thoughts? What does he mean when he warns Ophelia that "virtue cannot so innoculate our old stock but we shall relish of it", or again, "I could accuse me of such things that it were better my mother had not borne me"? "Sullied flesh" is the clue to these and other passages; it is partly also the clue to his strange conduct towards Ophelia and his equally strange language about her to Polonius. Hamlet felt himself involved in his mother's lust; he was conscious of sharing her nature in all its rankness and grossness; the stock from which he sprang was rotten.   (42)

On Hamlet's "antic disposition":

In a word, Shakespeare wishes us to feel that Hamlet assumes madness because he cannot help it. The tragic burden has done its work, and he is conscious that he no longer retains perfect control over himself. What more natural than that he should conceal his nervous breakdown behind a mask which would enable him to let himself go when the fit is upon him?   (92)

On Hamlet's cruel comments about Ophelia:

Hamlet must have overheard what Polonius said to the King. The context allows no escape from this conclusion, inasmuch as what Hamlet says to Polonius is only intelligible if the conclusion be allowed. It remains to examine the text in order to discover, if possible, what Shakespeare's intentions, clearly impaired in some way by corruption, may have been. We are left, of course, to conjecture, but even so we are not entirely without clues. Says Polonius:
     You know sometimes he walks four hours together
     Here in the lobby;
and as he speaks we may imagine him jerking a thumb over his shoulder towards the inner-stage before which the three plotters, stand, their faces to the audience. Words and the action are a direct invitation to the spectators to look in that direction; and, as they do so, Hamlet enters the inner-stage from the door at the back, his eyes upon his book, quite unconscious at first that his uncle, his mother and Polonius are on the outer-stage, which stands for the audience-chamber of the castle. In short, "Here in the lobby" is equivalent to a stage-direction, and marks with practical certainty the moment at which Hamlet comes in and the place of his entry. And it is the right moment; for the entry should seem unquestionably accidental, lest the audience should suspect him of deliberate spying. It would never do, for example, to let him linger in his place of concealment. Between the King's question "How may we try it further?" and his resolve "We will try it" there lie eight lines of dialogue. They just give Hamlet time to enter the lobby, grow conscious of voices in the larger chamber beyond, pause for a moment beside the entrance thereto, compose his features, and come forward. But brief as the period is, it is long enough for him to take in the whole eavesdropping plot and to implicate Ophelia beyond possibility of doubt in his ears as one of his uncle's minions.   (106-107)

On the heart of Hamlet's mystery:

In fine, we were never intended to reach the heart. of the mystery. That it has a heart is an illusion; the mystery itself is an illusion; Hamlet is an illusion. The secret that lies behind it all is not Hamlet's, but Shakespeare's: the technical devices he employed to create this supreme illusion of a great and mysterious character, who is at once mad and the sanest of geniuses, at once a procrastinator and a vigorous man of acdon, at once a miserable failure and the most adorable of heroes. The character of Hamlet, like the appearance of his successive impersonators on the stage, is a matter of "make-up".   (229)